the book of Abstract for the 2016 ASFB OCS Conference

Transcription

1
Fish as proxies of ecological and environmental change
Bronwyn Gillanders1
1. University of Adelaide, Adelaide, SA, Australia
Aquatic ecosystems have shifted from prehistoric baseline states due to anthropogenic and environmental change, but we
generally lack long-term data to understand such change particularly in marine and freshwater systems. Fish are excellent, and
largely underused proxies for elucidating the degree, direction and scale of shifts in aquatic ecosystems. Much qualitative and
quantitative data can be derived from contemporary, archived and ancient sources. Archives of calcified structures along with
modern day samples provide an alternative resource whereby long-term data can be generated in a relatively cheap and costeffective manner. Such samples provide data on biological, ecological and environmental baseline shifts. Several species will be
used to show how the abundance, size and age structure, growth and environment inhabited by fish has changed over decadal
and centennial time scales. Understanding biological responses to ecosystem change is useful for developing effective
management and conservation strategies.
2
Are Sharks Smart? Using Brain Anatomy to Understand Cognitive Ability in Cartilaginous Fishes
Kara Yopak1
1. University of Western Australia, Crawley, WA, Australia
Selection for cognitive ability has been proposed as a key factor driving the evolution of larger brains and/or the brain structures
associated with problem solving, social behavior and other cognitively demanding tasks. Major brain structures are often subject
to different selection pressures, resulting in a significant degree of variation in brain size and complexity across vertebrates.
Although cartilaginous fishes were previously thought to have relatively small brains with a limited behavioral repertoire, these
fishes have brain/body ratios that are actually comparable to birds and mammals. This talk will explore major evolutionary
patterns of brain organization in cartilaginous fishes, and how the relative development of major brain structures reflect an
animal’s ecology, even in phylogenetically unrelated species that share certain lifestyle characteristics. I will elaborate on the
novel techniques we are employing, such as magnetic resonance imaging (MRI), 3D printing, and flow cytometry, to push the
boundaries of evolutionary neuroscience and digital dissection, allowing for both traditional and non-invasive exploration of
evolutionary questions. As a perfect ‘bioindicator,’ variation in brain development can allow us to make predictions about
sensory and behavioral specialization across species, highlight transitions in life-history stages within a single species, and
predict the fitness consequences of anthropogenic disturbances and environmental change. These data pave the way for
predicting cognitive function and/or more complex behavioral repertoires in fishes, with implications for how “intelligence” has
evolved across vertebrates.
3
Climate change and marine systems
Gretta Pecl1
1. Institute for Marine and Antarctic Studies, Hobart, TAS, Australia
Over the years my research has shifted focus from examining biological and ecological processes at various temporal and spatial
scales of organisation, towards seeking a more integrated socio-ecological understanding of natural systems. After an ARC post
doc, several seemingly unrelated grants, projects and short-term appointments fortuitously laid the groundwork for the largerscale collaborative and interdisciplinary projects this presentation will highlight, all with a focus on climate change impacts and
adaptation. Regional variation in the rate and magnitude of climate drivers offers considerable potential for rapidly changing
regions to serve as ‘natural laboratories’ providing knowledge and tools for efficient and effective adaptation to meet some of
the key challenges of associated with significant change. With colleagues, I examined our current capacity to use the ocean’s
rapidly warming ocean regions for assessing climate change risks to inform longer-term adaptation strategies for sustainable
natural resource use and management. Using metrics derived from across ecological, social, economic and governance domains,
we developed a global ‘Marine Adaptation Index’ of our observational capacity for detection of climate change impacts, and our
ability to act, learn, and moreover, to communicate and share advances in knowledge with to the broader community. We find
substantial disparity among regions in the potential to detect biological impacts of climate change, and where change can be
detected, in the proficiency for sharing new knowledge with the rest of the warming world. Additionally, through a global review
of the socio-ecological impacts of ‘species on the move’, one of the most pervasive climate change impacts, we found that
consideration of these effects were lacking in most global mitigation and adaptation strategies, including the United Nation’s
Sustainable Development Goals.
4
Past, present, and future: physiological performance of coral reef fishes in a changing world
Jodie Rummer1
1. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
Globally, coral reefs are more at risk to human-induced stressors – such as climate change, including ocean warming,
acidification, and altered water quality due to coastal development – now, than at any other time in recorded history. Dramatic
effects on fish performance, distribution, and overall ecosystem health are predicted. While the success of the fishes over their
long evolutionary history is thought to have hinged on key adaptations for maintaining oxygen transport and physiological
performance under challenging conditions, whether they possess the necessary plasticity and/or adaptations to keep pace with
the large-scale, rapid changes plaguing their habitats today is not known. Moreover, the coral reef fishes – in particular –
diversified more recently on the geological time scale, with most species radiating within the last 23 million years, a period
characterised by relatively stable environmental conditions. Evolving and existing under stable environmental conditions may
heighten the vulnerability of coral reef fishes to the rapidly changing conditions coral reefs are facing today. By harnessing
geographic gradients, such as the latitudinal thermal profile along the Great Barrier Reef, and local extreme environments, such
as the volcanic CO2 seeps in the reefs of Papua New Guinea, as analogues for future change and integrating physiological,
biochemical, and molecular techniques, the mechanisms that fish use to acclimate and adapt to these stressors can be
identified. Such responses may become potential targets of natural selection and will determine which species and populations
may be most at risk from climate change and other human-induced stressors and potentially priorities for conservation and
management.
5
Chasing sharks to change management
Michelle Heupel1
1. James Cook University, Townsville, QLD, Australia
Sharks have been exploited by man for centuries. They are used as a source of food and other products in most regions around
the world. In recent decades the demand for shark products, especially meat and fins has resulted in the significant decline of
many species caught by fisheries. The ability of sharks to sustain exploitation varies among species and depends on a range of
biological and ecological characteristics. One of these key characteristics is movement, and it can be used to improve
management of sharks. Acoustic telemetry has been used for decades to answer questions about where fish go and what they
are doing in specific locations. However, links between movement ecology and management are not always apparent or
explored. My research has focused on how movement ecology can be applied to conservation and management of shark
populations. In this talk I will provide a number of case studies where I have used acoustic tracking data to help inform stock
assessments, advise on marine protected area management, inform coastal water management and quantify cross-jurisdictional
movements. The outcomes of this research will demonstrate the utility of acoustic telemetry to improving the management of
sharks to help address the increasing conservation needs of many species and aid in their sustainable use.
6
Using biogeochemical tracers and sclerochronologies derived from fish otoliths to detect environmental change
Gretchen Grammer1
1. SARDI Aquatic Sciences, West Beach, SA, Australia
Biogeochemical tracers and sclerochronologies are used to answer many ecological questions that require linking organisms
with the environment. Calcified hard parts of organisms that remain chemically inert after formation are particularly
advantageous for extracting information (e.g. otoliths, shells, coral) on both the organism and the environment. My research has
focused on otoliths (fish earstones) as an environmental proxy, since they contain both biogeochemical (i.e. radiocarbon and
trace elements) and sclerochronological (i.e. growth) signals that reflect changes in aquatic systems. In my presentation, I will
describe using these otolith-based chemical and growth signals to: (1) establish a radiocarbon record for upwelled waters in the
southeastern Indian Ocean, and (2) describe physiological and environmental controls on otolith chemistry, using a novel
modelling framework paired with a strong, local upwelling signal as an extrinsic cue. Consequently, after considering life history
traits and physiological processes of a test species, otoliths carbonate records are an accessible mechanism that gives us the
capacity to examine magnitude and direction of environmental change in both a spatial and temporal context.
7
The summer super-highway: migration of oceanic fishes between New Zealand and the tropical South Pacific islands
Malcolm P Francis1, Clinton A J Duffy2, John Holdsworth3, Tim Sippel4
1. National Institute of Water and Atmospheric Research, Wellington, New Zealand
2. Department of Conservation, Auckland, New Zealand
3. Blue Water Marine Research, Northland, New Zealand
4. National Marine Fisheries Service, La Jolla, California, USA
Many large oceanic fishes migrate seasonally between New Zealand and subtropical or tropical waters of the south-west Pacific.
Commercial catch data and tagging data were used to determine the timing and routes of the migrations of some of these
species, providing new insights into their behaviour and habitats. Albacore tuna (Thunnus alalunga) and skipjack tuna
(Katsuwonus pelamis) are caught around New Zealand in summer and return to the tropics in autumn. Other large tropical
oceanic species such as whale shark (Rhincodon typus), oceanic whitetip shark (Carcharhinus longimanus), tiger shark
(Galeocerdo cuvier), giant manta ray (Manta birostris), wahoo (Acanthocybium solandri), and yellowfin tuna (T. albacares)
appear in northern North Island waters in summer, and are presumed to migrate between the tropical Pacific and New Zealand.
Electronically tagged juvenile shortfin mako sharks (Isurus oxyrinchus), spinetail devilrays (Mobula japanica), striped marlin
(Kajikia audax) and broadbill swordfish (Xiphias gladius) migrated from northern New Zealand to the tropical South Pacific and
the Kermadec Ridge. Great white sharks (Carcharodon carcharias) migrated from southern New Zealand to the tropical South
Pacific and north-eastern Australia in winter–spring. The movement of large numbers of many species of large-bodied teleosts
and chondrichthyans results in the seasonal transfer of large amounts of biomass between tropical and temperate waters.
8
Movement and behaviour of the endangered Maugean skate, Zearaja maugeana, in Macquarie Harbour, Tasmania
Justin Bell1, Jeremy Lyle1, Jayson Semmens1, David Moreno1
1. Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, TAS, Australia
Maugean skate (Zearaja maugeana) are a micro-endemic solely inhabiting two embayment’s in western Tasmania. The
population in Bathurst Harbour appears to be small and although the Macquarie Harbour is relatively large it is subject to
anthropogenic pressures including pollution from historic mining, salmonid aquaculture and gillnetting. As such, the present
study investigated the spatial utilisation of Maugean skate in Macquarie Harbour to determine how the above pressures are
likely to impact the population and formulate strategies to minimise them.
Maugean skate are highly philopatric with 50% (core range) and 95% (home range) utilisation distributions generally <3km 2 and
<10km2 respectively. The core range of only one skate overlapped with aquaculture leases, whereas the home range of most
individuals did overlap but by <2km2 in all cases. Maugean skate displayed an affinity for waters 6–12m deep, which is likely
dictated by water chemistry: shallow waters have low salinity and high temperature variability; deep waters are stable but have
low dissolved oxygen; waters 6–12m deep are relatively stable. They also displayed diurnal variation in depth utilisation,
presumably representing foraging behaviour.
Direct interactions between Maugean skate and aquaculture operations were minimal. There may, however, be indirect
interactions whereby organic wastes and reduce dissolved oxygen or increase dissolved nutrients. A number of changes were
implemented to reduce impacts of gillnetting on Maugean skate as a result of this study; spatial closures limiting gillnetting
mainly to waters <5m and the closure of areas important to the species are anticipated to greatly reduce captures.
9
Space utilisation, movement and behaviour of the spiny dogfish, Squalus acanthias, in Macquarie Harbour, Tasmania.
David Moreno1, Justin Bell1, Jeremy Lyle1, Jayson Semmens1
1. IMAS, University of Tasmania, Hobart, Tas, Australia
Movement and spatial use provide insights into the behaviour of marine organisms which, in turn, enables their effective
management. The spiny dogfish, Squalus acanthias, is a common, but vulnerable, shark inhabiting temperate continental shelves
circumglobally, yet no information exists on the spatial dynamics of the species in Australia. Twenty-three S. acanthias were
implanted with acoustic transmitters and monitored over 1.5 years using a passive acoustic array in Macquarie Harbour,
Tasmania. Markov chains and Brownian bridge models were used to analyse the distribution of the species in the harbour. Both
males and females displayed non-random site affinity, although the ranges of males changed seasonally. Social association
indicated a varying degree of sexual segregation during winter, although patterns were not as clear as reported elsewhere. This
represents the first example where the species displays phylopatric behaviour and does not undertake large scale movement.
Both sexes are likely to be vulnerable to a variety of anthropogenic impacts within the Harbour and spatial management could
be effectively implemented to nullify these impacts. The patterns of space use and behaviours observed in this study are unique
for the species. By using random walk models and social networks, it is possible to gain a better understanding of the ways in
which S. acanthias has adapted to a seemingly unfit environment.
10
State-space modelling methods for telemetry data: an application to surface-association behaviours in tropical tuna
Joe Scutt Phillips1, Graham M Pilling2, Bruno Leroy2, Karen Evans3, Thomas Usu4, Kurt M Schaefer5, Chi H Lam6, Simon Nicol7
1. Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
2. Oceanic Fisheries Programme, Secretariat of the Pacific Community, Nouméa, New Caledonia
3. Ocean and Atmosphere Flagship, Commonwealth Scientific and Industrial Research Organisation, Hobart, Tasmania, Australia
4. National Fisheries Authority, Port Moresby, Papua New Guinea
5. Inter-American Tropical Tuna Commission, La Jolla, CA, USA
6. Large Pelagics Research Center, University of Massachusetts, Amherst, MA, USA
7. Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra, NSW, Australia
Objectively classifying the behavioural time-series obtained from animal telemetry experiments requires factors such as
temporal autocorrelation, varying time-scales, high-resolution data and underlying motivation to be considered. Hidden Markov
models (HMMs), a form of state-space model, provide a useful classification tool for such data. HMMs assume that the observed
patterns in movement data are generated by an unseen Markov process, which switches between an observation model of
mixed distributions, each with different parameters.
Here, we describe the design and numerical parameter estimation of these models for time-series of telemetry data, and
present an example application examining the vertical behaviour of two species of tropical tuna. Tuna are known to reside near
the surface around drifting and anchored fish aggregating devices (FADs) over periods of time that range from days to months.
This residence makes them more vulnerable to fishers by increasing their horizontal encounter rate with vessels, and by causing
a switch in vertical movement in favour of extended association with shallow waters. Estimating HMMs on 80 time-series from
electronic tags implanted in bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna at liberty in the Western and Central
Pacific Ocean, we defined and objectively identified periods of surface-association that are typical in residence around floating
object.
The proportion of time exhibiting surface-association was generally lower than has been previously observed, although intraand inter-individual variability was high. Surface-association was clear and prolonged for many fish following release, but prior
to recapture, surface-association events were non-existent or shorter than two days for 85% of bigeye and 74% of yellowfin.
These results suggest the vertical component of floating-object association may be less important than short-term horizontal
concentration when increasing probability of capture. Controlling the number of sets made on FADs may be a more effective
management measure than the current approach of periodic closures.
11
Simulation-based evaluation of reserve network performance for a vulnerable deep-sea shark
Ross Daley1, Alistair Hobday2, Jayson Semmens3
1. University of Tasmania, West Moonah, TAS, Australia
2. CSIRO, Hobart
3. University of Tasmania, HObart
An individual-based simulation model of the movements of C. zeehaani was developed and applied to determine how long a
depleted population would take to recover from 8% of un-fished numbers to a target of 20%. Individual movements were based
on tracking results and simulated across closures and fished areas. Key uncertainties were length of the female breeding cycle,
natural mortality and spatial variation in population density. The base case (three year cycle, 2% natural mortality) predicted
recovery in 63 +- 3 years. Poor matching of closure locations to population density would delay recovery by 31.9 years.
Sensitivity testing predicted the target would be reached 19.2 years earlier with a 2-year cycle or 16.5 years later with a fouryear cycle. If natural mortality were half the base case estimate then the target would be reached 13.5 years earlier or,
significantly, if the natural mortality were doubled, recovery to the target would take 98.3 years longer. Improving handling
practices for sharks or changing fishing methods on the continental shelf would not significantly affect the time for recovery but
re-introducing trawling for orange roughy in deep waters would delay recovery by 45.9 years. Doubling or halving the size of a
closure located where C. zeehaani is abundant would change recovery by +12.6 or -9.9 years but such changes have no
significant effects where C. zeehaani are not abundant. The model can be used to evaluate the consequences of alternative
management interventions and can be applied to other species with telemetry data.
12
Spatial orientation and magnetic alignment in Port Jackson sharks
Sherrie L Chambers1, Catarina Vila Pouca1, Culum Brown1
1. Macquarie University, NSW, Australia
Many animals are able to detect magnetic fields, which can influence behaviours such as foraging, predator evasion and longdistance navigation. Some marine species including turtles, cetaceans and elasmobranchs use magnetic ridges on the sea floor
as a navigational tool for large-scale migrations, particularly in pelagic areas where there may be a lack of visual or olfactory
cues. Additionally, both aquatic and terrestrial species have been shown to align themselves on a north-south axis whilst resting,
although the purpose of this behaviour is not fully understood. Numerous shark species are known to be highly sensitive to
magnets in a variety of contexts and some have demonstrated the use of magnetic fields in long distance navigation, however
little is known about the use of a magnetic sense for spatial orientation at smaller scales. Here we investigate resting magnetic
alignment in Port Jackson sharks to better understand the use of this magnetic sense in the context of spatial ecology. Captive
juvenile sharks housed in circular tanks were photographed at intervals over a 16-day period, and resting orientation was
compared before and after the addition of rare earth magnets to the tanks. We expect this study to provide a better
understanding of the mechanisms underlying spatial orientation in Port Jackson sharks and their ability to detect and use
magnetic cues to orient themselves and navigate habitats over small spatial scales. It may also provide insight into how they
navigate over longer distances during their annual migration.
13
It works! Building a biophysical larval-fish dispersal model for the Great Barrier Reef based on empirical larval and adult
behavior data…and testing it.
Jeffrey M Leis1, Luciano B Mason2, Séverine Choukroun3, Michael Bode4, Geoffrey P Jones3, David Williamson3, Hugo Harrison3
1. University of Tasmania, Mt Nelson, TAS, Australia
2. Australian Maritime College, Launceston
3. James Cook University, Townsville
4. Melbourne University, Melbourne
Larval dispersal models increasingly include larval behavior rather than assume passive larvae. However, few include a range of
dispersal-relevant behaviors. Fewer still are tested. Many models over-generalize adult behaviors such as seasonal, lunar and
diel timing or location of propagules release. Even if empirically-based behavior is included, variation among individual
propagules is seldom included: rather, mean behavior is used, unrealistically constraining dispersal outcomes. Our model for
Great Barrier Reef (GBR) fishes uses empirical measures of larva vertical distribution, swimming and orientation, and variation in
and ontogeny of them. Only virtual larvae with sufficient swimming ability to overcome currents within ‘detection zones’ around
reefs can settle. Propagules are released at empirically-determined times and places. Egg buoyancy is included. Hydrodynamics
are a 3D development of the 2D James, et al. (2002) model. We tested three model scenario predictions (1- all empirical larval
behavior; 2 - hypothetical SE swimming; and 3 - passive larvae) for a grouper (Plectropomus maculatus) in the southern GBR
using genetic parentage techniques that matched recruits at the end of the 2011/12 spawning season with adults from spawning
aggregations (Williamson et al. in review). Observed dispersal direction and distance best fit model Scenario 1 predictions.
14
First excursions into the ‘black box’ period of the blackspot seabream Pagellus bogaraveo: a missing piece of a deep-sea life
cycle puzzle
João Teixeira1, 2, Jorge Fontes3
1. Dept. of Oceanography and Fisheries, University of the Azores, Horta, Portugal
2. School of BioSciences, University of Melbourne, Melbourne, Australia
3. IMAR - Institute of Marine Research , Dept. of Oceanography and Fisheries, University of the Azores, Horta, Portugal
The blackspot seabream, Pagellus bogaraveo, is ecologically and commercially one of the most important demersal species in
the archipelago of the Azores. Its exploitation around the islands has increased due to the collapse of the fishery in continental
waters. Despite the importance of recruitment processes in marine fisheries productivity, research has been focused primarily
on the general aspects of the species’ biology and population dynamics, and as consequence little is known about the early life
stages in the wild. My work focused on the understanding and characterization of its early life history, recruitment and postsettlement dynamics. To achieve these goals I used two methods: 1) underwater visual census, i.e., recruit counts, to investigate
the temporal dynamics of recruitment, and 2) the analysis of juvenile otolith microstructure to investigate the early life history
traits. Recruitment surveys were conducted monthly from April 2011 to May 2012 in Faial island, Azores. The results showed
clear seasonal patterns of recruitment. Recruitment peaks were observed in April and May in two consecutive years, followed by
a clear succession in the juvenile size structure over the following months culminating with the disappearance of bigger sized
recruits from inshore waters during winter months. Otolith daily increment formation was validated which allowed us to
retrospectively study the early life history of blackspot seabream. After interpreting the otolith microstructure and identifying
the settlement mark, we were able to determine age, length-at-age relationship, pelagic larval duration (37.37±0.28 d),
estimated size at settlement (13.50±0.17 mm), and average growth rates. Growth rates were significantly higher after
settlement (16.82±0.47 mm d-1) compared to the larval stage (7.11±0.08 mm d-1). After back-calculating birth dates and
grouping individuals by batch, comparison tests were used to investigate if there were significant differences in early life history
traits among batches.
15
Consequences of kelp habitat modification for the recruitment of cryptic reef fish
Victor Shelamoff1, Jeffrey T Wright1, Matthew J Cameron1, Cayne Layton1, Masayuki Tatsumi1, Craig R Johnson1
1. Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
Anthropogenic habitat alterations can have major impacts on the supply of new recruits to coastal fish populations. We aimed
to determine the impact of kelp habitat patchiness and a reduction in canopy cover of Southern Australasia’s most dominant
canopy forming kelp, Ecklonia radiata, on the recruitment of cryptic reef fish. We monitored larval recruitment across an array
of 28 artificial reefs with transplanted Ecklonia, representing seven different reef patch sizes (from 0.12m2-6.68m2) crossed with
four kelp densities (0, 4.1, 8.3 and 16.6 individuals/m 2). 95 precent of the 232 individuals recorded were either Forsterygion
gymnotum or Pictiblennius tasmanianus recruits, with both species showing a similar pattern of prevalence across the reefs.
Overall, recruitment was higher on smaller reefs than larger reefs, but there was only a weak indication of any kelp density
effects. However, canopy density was significant for Pictiblennius, where reefs with the highest kelp density and zero kelp had
higher recruitment than reefs supporting kelp at low-density. We discuss the potential role of various settlement and postsettlement processes in driving these patterns and the likelihood that reef size, at this spatial scale, will influence whether the
presence of a kelp canopy has a positive or negative influence on recruitment. In a connected reef-scape,
declining Ecklonia cover is likely to result in adverse consequences for cryptic species similar
toForsterygion and Pictiblennius. However, small isolated reefs, especially those devoid of kelp, may form havens for larval
settlers, but are unlikely to contribute meaningfully to adult populations.
16
Recruitment of Snapper, Chrysophrys auratus, in Port Phillip Bay depends on the match-mismatch of spawning period and
production of preferred planktonic prey
Gregory Jenkins1, Kerry Black1, Paul Hamer2, Andrew Longmore1
1. University of Melbourne, Parkville, VIC, Australia
2. Fisheries Victoria, Queenscliff, Victoria, Australia
Port Phillip Bay is the main spawning area for the Victorian western stock of Snapper, Chrysophrys auratus. The dynamics of the
western stock are primarily driven by the recruitment success of Snapper in Port Phillip Bay. Recruitment success for Snapper in
the bay is determined in the early larval stage. In this study we used a model of plankton dynamics in the bay to show that
production of preferred prey for larvae (copepods) was determined by flows and associated nutrient inputs, and the effects of
these on phytoplankton composition. Years of high larval survival and recruitment success occurred when production of
preferred prey was high, and coincided with the early summer spawning period of Snapper. These years were characterised by
moderate flows and nutrient inputs leading up to the spawning period that led to phytoplankton composition favouring
flagellates. Years of very low flows and nutrient inputs led to an overall lack of plankton productivity and correspondingly poor
larval survival and recruitment. Equally, years of high flows and nutrient inputs also led to poor recruitment because conditions
in the plankton favoured diatoms that are a poorer food source for copepods, reducing production of these preferred prey.
Overall, inputs of nutrients to Port Phillip Bay have a strong influence on the dynamics of the west Victorian Snapper stock, and
the management of environmental flows and associated nutrients to the bay may be key factor in the ongoing sustainability of
the fishery.
17
Early development of Eel-tailed catfish, Tandanus tandanus (Mitchell) (Teleostei: Plotosidae) from a subtropical Queensland
stream, with validation of daily otolith increment formation
Kate Burndred1, Bernie Cockayne1
1. DNRM Queensland, Bucasia, QLD, Australia
Tandanus tandanus has recently experienced widespread population declines in eastern Australia; with some southern
populations facing the risk of extinction, the management and conservation of Queensland populations should be considered a
priority. To assist in clarifying the influence of changes to the natural environment on the reproductive ecology of T. tandanus,
we investigated their early life history using naturally fertilised eggs and larvae from a wild population. Tandanus tandanus eggs
ranged in diameter from 2.6 to 4.0 mm throughout development, and preservation of eggs in ethanol caused significant
shrinkage (mean 18.9%). Hatching occurred between four to seven days (mean 5.29 days; 15.7 - 28.0°C). Larvae collected from
nests ranged in age and standard length from one day old (mean SL 5.1 mm) to 16 days old (mean SL 15.3 mm); and SL was
successfully modelled as a function of age. Larvae are likely to actively disperse from their nest at approximately 16 days old,
and reach juvenility soon thereafter. Daily otolith increment formation was validated up to 28 days post-hatch; and sagittal
otoliths were successfully used to develop an age-length relationship for larvae. These results can assist researchers in
estimating the timing of critical recruitment events, and investigating how the species early life history is influenced by
environmental conditions.
18
From the other side of the Pacific Ocean: environmental indicators and recruitment of Grenadiers in Chile and Australia
Claudio Castillo-Jordan1, Paul Hamer2, Geoff Tuck3, Stewart Frusher4, Luis Cubillos5, Sean Tracey4
1. CSIRO-UTAS PhD Program in Quantitative Marine Science, Hobart, Tasmania, Australia
2. Departament of Environment and Primary Industries , Queenscliff, Victoria, Australia
3. CSIRO Oceans and Atmosphere Flagship , Hobart, Tasmania, Australia
4. Institute for Marine and Antarctic Studies , University of Tasmania, Hobart, Tasmania, Australia
5. COPAS Sur-Austral, Universidad de Concepcion, Concepcion, BioBio, Chile
Grenadiers are an important commercial and ecosystem component of the demersal and mid water fisheries of Chile and
Australia, locally known as Patagonian grenadier (Macruronus magellanicus) and blue grenadier (Macruronus novaezelandiae)
respectively. The Chilean spawning area is located in the bifurcation of the Humboldt and Cape Horn currents, influenced by the
west wind drift. For Australia, the spawning area is located off the west coast of Tasmania. Bayesian correlations and Bayes
Factor Analysis indicate important relationships between the strength of a number of fish stocks and climate indices on both
global and regional scales (such as the Interdecadal Pacific Oscillation (IPO), Southern Annular Mode (SAM), the Southern
Oscillation Index (SOI), sea surface temperature and wind). Similarly here, recruitment of grenadier stocks on both sides of the
Pacific was found to be influenced by regional temperature and wind variables. Negative relationships with SOI were observed
for Chilean and Australian populations, and Patagonian grenadier recruitment also showed associations with the time-series of
SAM and IPO. Sea surface temperature and wind anomalies presented high correlations with recruitment for both populations.
The highest correlations between the global and regional variables were in the summer - autumn period prior to the winter
spawning season. It is possible that the global indices are producing a synchronous pattern of recruitment fluctuation for both
populations, modified locally by regional variables. We discuss potential biophysical processes that could be responsible for the
environment - recruitment correlations.
19
Should we sweat the trophodynamic details?
Beth Fulton1
1. CSIRO, Hobart, TAS, Australia
Trophodynamic ecosystem models are more than 30 years old and there is an increasing number of them, with a growing global
coverage. Such models are being used to inform policy and management decision making. With this use comes a responsibility
to make clear the implications of uncertainty. At the centre of ecosystem models is the food web. Understanding the true
sensitivity of model dynamics to the form and parameterisation of these structures is fundamental for constraining uncertainty.
Two decades of experience with such models indicates that parametric sensitivity differs from ecosystem to ecosystem, but
structural sensitivity is a universal reality. The coming challenge for trophodynamic models is to remain robust to all forms of
uncertainty while remaining flexible enough to capture large scale system shifts and biodiversity turn over under global change.
20
Using stable isotope data to advance marine food web modelling
Stacey A McCormack1, 2, Jessica Melbourne-Thomas1, 2, 3, Rowan Trebilco1, 2, Julia L Blanchard1, Andrew Constable1, 2, 3
2. Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
3. Australian Antarctic Division, Department of the Environment, Kingston, Tasmania, Australia
Marine foodweb models are important tools for guiding sustainable management decisions and for evaluating the potential
combined effects of harvesting and climate change. A key challenge is handling uncertainty in these models to ensure they
provide robust predictions and management advice. Uncertainty is arguably highest for parameters relating to mid-trophic
levels – in particular mesopelagic fish – for foodweb models in many regions, despite the fact that these groups are thought to
play a central role in trophic energy transfer. Stable isotope signatures are an important data source for both parameterising
these mid trophic levels, and for evaluating model skill. However the full potential of this data source has not been realised, and
the implications of recent theoretical advances in the analysis and interpretation of stable isotope data have not yet been
considered. We review the development and evaluation process for ecosystem models and assess the potential for
incorporating stable isotope results into the parameterisation and evaluation of these models. This review provides an
integrated framework for understanding how stable isotope data are used in both size- and species-based models, and clearly
identifies priorities for future work. We conclude by discussing an example - a foodweb model under development for Prydz Bay
and the southern Kerguelen Plateau region in the Indian Sector of the Southern Ocean- and consider the implications of our
modelling work for evaluating the effects of climate change and fishing in the region.
21
Putting adaptive dynamics into food web models
Romain Forestier1, Julia L Blanchard1, Elisabeth A Fulton2, Kirsty Nash1, Craig Johnson1
1. IMAS, Hobart, Tasmania, Australia
2. CSIRO, Hobart, Tasmania, Australia
Ecosystem models are increasingly being used to help support management and for predicting the ecosystem impacts of fishing
and climate change. Many models represent detailed trophic interactions but these interactions can depend on the traits of
individuals and species. Moreover, pressures such as fishing and climate change can affect the way in which traits are evolving in
real systems. However, evolutionary processes are often ignored in ecosystem models. As a result, the consequences of
evolutionary changes are not yet understood in an ecosystem context. To address this issue, food web models have begun to
incorporate evolutionary processes using an approach called adaptive dynamics. This poster explains how to use adaptive
dynamics within food web models, including key concepts, advantages and limitations. Future developments and applications of
this framework will also be presented.
22
The guts of ecosystem models: are they still needed and can new methods assist?
Catherine Bulman1, Andrew Revill1, Olly Berry1, Heidi Pethybridge1, Elizabeth Fulton1
1. CSIRO Ocean and Atmosphere, Hobart, Tasmania, Australia
Dietary studies on common commercial and ecologically important fishes from the 1980s & 1990s form the basis of ecosystem
models currently in use in southern Australia. These models are increasingly relied upon to provide guidance for fisheries
management, particularly as ecosystem-based management ideals are embraced. Therefore it’s vitally important that the
dietary data underpinning these models are kept current and accurate.
Oceanographic conditions off eastern Australia are highly variable but now there are indications that oceanographic regimes
might shift permanently as a result of climate change. Moreover, there is evidence that species distributions are changing, so we
asked whether the diets of several fishes from the early studies have changed to an extent that we need to re-parametrise our
models? We sampled ten commercially-caught species from the southeastern Australian shelf to determine their current diets
and compare them mid-1990s diets. We used traditional stomach content analysis (visual) but we also established base-line
data-sets for DNA meta-barcoding analyses of the stomach contents and for analyses of bulk and compound-specific amino acid
stable isotopes, and fatty acids of the fish tissue samples.
Diet compositions of some of the species had changed but for others the results were unclear, complicated by a high incidence
of un-identifiable prey or by small sample sizes. DNA analyses increased prey identification in many cases, particularly where
contents were unidentifiable, and identified new trophic links but not quantitatively. The biochemical markers provided insights
into longer-term nutritional status, trophic positions and basal food web sources but were limited by small sample sizes.
Potentially these newer techniques add greater depth of ecological understanding to ecosystem models and may eventually
help to overcome the financial constraints of long-term sampling programs but visual stomach content analyses still remain
invaluable to the trophic biologists and ecosystem modellers.
23
the role of cephalopods in ecosystems, the importance of modelling these species impact and ecology with groups of
different habitats.
Thibaut de la Chesnais1, 2, 3, Elizabeth Fulton1, Sean Tracey2, 3, Gretta Pecl2, 3
1. CSIRO, Hobart, Tasmania, Australia
2. IMAS, Hobart, Tasmania, Australia
3. UTAS, Hobart, Tasmania, Australia
The evolution of ecosystems are often driven by key components or species. Because of their interaction with numerous
elements of the food web and their high productivity, cephalopods may be a structuring component in marine ecosystems, as
they have a key role in the transfer of nutrients through trophic levels. While catches of many stocks have declined or plateaued,
the captures of cephalopods have strongly increased since the 70s. However, they are prey or predators of many other fisheries
resources. Building a clear understanding of their role in ecosystems is thus a key challenge for the future of Ecosystem-Based
tools for fisheries and marine resource management. We highlight the important lack of understanding of the impact of
cephalopods on food webs around the world and the poor implementation of the cephalopod taxa in ecosystem models. The
ecology of cephalopod, and thus their role in food webs, strongly depends on their habitat. The inclusion of cephalopod groups
from different habitats in an ecosystem model of South Eastern Australia confirms this idea. On one hand, some oceanic squid
species have a key role in the transfer of nutrients up trophic levels, acting as a link between neritic habitats and open waters,
and between pelagic and benthic habitats. On the other hand, neritic species are more locally constrained and have a variable
role in nutrient transfer. While most ecosystem models are built with one single group for ‘cephalopods’ or ‘squids’, these
results prove that there is a need for investing in greater details the different cephalopod ecological groups to properly assess
the various roles of key species with different habitats and ecology. This is a key point of improvement for ecosystem models
and management tools as cephalopods are likely to adapt relatively fast to changing conditions, including climate change and
fishing pressure.
24
Novel real-time PCR developed to assess DNA degradation in archived tiger shark (Galeocerdo cuvier) skeletal material
Einar E Nielsen1, Jess A.T. Morgan2, 3, Safia L Maher4, Janette Edson5, Maely Gauthier6, Julian G Pepperell7, Bonnie J Holmes4,
Michael B Bennett4, Jennifer R Ovenden3
1. National Institute of Aquatic Resources , Technical University of Denmark, Vejlsøvej 39, Silkeborg, Denmark
2. Queensland Government, Dutton Park, QLD, Australia
3. Molecular Fisheries Laboratory, The University of Queensland, St Lucia, QLD, Australia
4. School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
5. Queensland Brain Institute, The University of Queensland, St Lucia, Queensland, Australia
6. QFAB Bioinformatics, St Lucia, Queensland, Australia
7. Pepperell Research & Consulting Pty Ltd, Caringbah, NSW, Australia
Archived shark specimens from public and private repositories are highly valuable sources of DNA for retrospective genetic
analysis. Here the usefulness of skeletal material as a source of DNA for temporal genetic studies is assessed. For cost effective
processing, qPCR assays were developed to determine the quality of extracted DNA prior to downstream analysis. Independent
assays were developed using SYBR fluorescence detection to amplify 100 and 200 base targets. Suitable single copy sequence
targets in the tiger shark genome were found in the flanking sequences of microsatellite loci. An internal positive control (IPC)
involving the addition of a synthetic oligonucleotide was also used to assess for PCR inhibition in the DNA extractions. Jaws
yielded relatively high DNA quantity and quality, while large differences in yield were observed for vertebrae. Application of the
method to 38 museum and private angler trophy specimens dating back to 1912 yielded sufficient DNA for downstream genetic
analysis for 68% of the samples. No clear relationships between age of samples, DNA quality and quantity were observed, likely
reflecting different preparation and storage methods for the trophies. This study demonstrates that archived shark jaws and
vertebrae are potential high yield sources of DNA for genetic analysis.
25
Shark Share Global: a virtual tissue bank for collaborative elasmobranch research
Madeline E Green1, 2, Lauren C Meyer2, 3
1. University of Tasmania, Hobart, TAS, Australia
2. Shark Share Global, Collaborative Research Networks Ltd. , Hobart, TAS, Australia
3. Southern Shark Ecology Group, Flinders University, Adelaide, SA, Australia
With more than a quarter of elasmobranchs considered endangered and another 47 per cent lacking basic biological data, there
has never been a more crucial time for shark and ray scientists to work collaboratively and efficiently to understand the biology,
ecology and physiology of elasmobranchs. Although opportunistic tissue collection occurs often in the field, in many cases not all
potential samples are collected, samples are disposed of due to a lack of institutional storage, or they are left in freezers for
potential future projects, which may not materialize. Additionally, sourcing samples for research projects remains challenging
without broad global connections. Here, we propose an online database (Shark Share Global) to help overcome sampling
inefficiencies and provide a user-friendly platform for sharing elasmobranch tissues. By creating a virtual global tissue bank,
Shark Share Global is able to facilitate collaborative efforts, increasing multidisciplinary research without drastically increasing
project costs. Here, we will introduce the database, its functionality and expected outcomes for the greater elasmobranch
research
community.
26
Effects of acoustic stimuli on the behaviour of wild and captive sharks
Lucille Chapuis1, Laura A Ryan1, Kara E Yopak1, Robert D McCauley2, Nathan S Hart3, Shaun P Collin1
1. Neuroecology Group, School of Animal Biology and the Oceans Institute, The University of Western Australia, Perth, WA,
Australia
2. Centre for Marine Science and Technology, Curtin University, Perth, WA, Australia
3. Biological Sciences, Macquarie University, Sydney, NSW, Australia
The effect of sounds on the behaviour of sharks has not been investigated since the 1970s. However, in a context where
mitigation strategies are in high demand to counter fisheries pressure on sharks caught as bycatch, and negative interactions
between sharks and humans, sound offers an advantage over other sensory stimuli, as it can spread in all direction quickly and
further than any other sensory cue. We investigated the behavioural responses of wild and captive sharks to the playback of two
different sounds: killer whale calls and a custom-made artificial sound. We also presented a combination of the sound with
bright flashing (strobe) lights to explore the effect of multisensory cues. Great white sharks (Carcharodon carcharias), as well as
seven species of benthopelagic reef sharks were targeted in the wild, while Port Jackson sharks (Heterodontus portusjacksoni)
and epaulette sharks (Hemiscyllium ocellatum) were tested under controlled conditions in the laboratory. Our results show
interspecific differences in the effect of underwater sounds on shark behaviour. We also found an enhanced adverse effect
when strobe lights were used in combination with sound. We discuss our results within a neuroecological framework, in the
context of anthropogenic noise and shark mitigation technologies.
27
Sperm storage in deep-sea holocephalans
Brit Finucci1, Matthew R Dunn1, Emma Jones2, Jane Anderson3
1. Victoria University of Wellington, Wellington, New Zealand
2. National Institute of Water and Atmospheric Research (NIWA), Auckland, New Zealand
3. Department of Pathology and Molecular Medicine, University of Otago, Wellington, New Zealand
Chimaeras are a globally distributed and yet relatively unknown subclass of fish within the Chondrichthyes. Many chimaeras are
deep-sea, and are presumed to have reproductive parameters similar to other chondrichthyans that are characteristic of low
productivity. Sperm storage has been reported in many chondrichthyans. The ability to store sperm is thought to be
advantageous for deep-sea species, increasing reproductive efficiency in a resource-limited environment where sexual
segregation is often present. To date, sperm storage has only been confirmed in the inshore chimaera (Callorhinchus milli) and
based on this observation, is presumed to be widespread across the holocephalans. Specimens of longnose spookfish (Harriotta
raleighana), Pacific spookfish (Rhinochimaera pacifica), and brown chimaera (Chimaera carophila) were collected from research
trawl surveys and commercial vessels around New Zealand at depths between 400 and 1300 m. Using histological techniques
and transmission electron microscopy, sperm storage tubules (SSTs) and sperm bundles were identified in the terminal zone of
the oviducal gland of mature individuals. SSTs were identified in both macroscopically active and resting stages. A large,
gelatinous mass, consistent with a sperm plug, was also found in the accessory genital gland of mature H. raleighana and R.
pacifica. These results contribute to the ecological understanding of a relatively unknown and unique group of deep-sea
animals.
28
Seaweed-associated fish communities are shaped by meadow quality and seascape context
Joshua van Lier1, Christopher Fulton1
1. The Australian National University, Turner, Canberra, ACT, Australia
Seascape variables (e.g., patch size, isolation, distance to other habitats) can interact with the local species pool to shape the
composition of fish communities within patch habitats. Recent work on mesohabitats such as coral reefs, mangroves and
seagrass beds have found that both within-patch conditions (e.g., habitat complexity, predator abundance) and spatial context
(e.g., connectivity, isolation) can be important predictors for fish community structure. Similar understanding is needed for
seaweed meadow patch networks, which have recently been demonstrated to be key nurseries for tropical fishes. We explored
how patch quality (e.g., patch size, microhabitat structure) and seascape context (e.g., distance to next patch, distance to coral
reef) may help explain the distribution and abundance of labrid fishes within a 6 km 2 section of the World Heritage Ningaloo
Marine Park. In situ visual surveys of fish and habitat, in conjunction with on-ground GPS mapping for 31 patches revealed that
key measures of microhabitat complexity interact with the spatial context of a seaweed meadow to provide key predictors for
the diversity and abundance of fish species and functional groups. Our results suggest that spatial management and
conservation approaches need to take account of both patch habitat quality and positioning in the seascape in order to
encompass the local species pool in a given area of concern.
29
Pump Screen Technology Uptake in Inland NSW – Major Projects
David Ward1
1. NSW Department of Primary Industries, Calala, NSW, Australia
The rivers of inland New South Wales (NSW) face a range of pressures with regards to the management of aquatic habitat. Land
management issues have a crucial role in influencing the health of aquatic ecosystems. Inland NSW is currently under increasing
pressure from resource development for coal seam gas, coal and other extractive industries. These resource development
projects often involve large scale water extraction requirements from both groundwater and surface water sources. The
application of pump screening technology for State Significant Development (Major) Projects within inland NSW has presented
NSW Department of Primary Industries with a range of legislative and logistical challenges to ensure there is no negative impact
on native fish populations. Incorporation of pump screen technology has generally been limited to large town water supply
projects and major extractive resource projects. Incorporating targeted and comprehensive aquatic environmental monitoring
into these projects is a critical aspect of project development, particularly if threatened species, populations or ecological
communities are present. In addition, these monitoring programs can assist in the development of pump screen criteria for
wider application.
30
Species-specific: divergence in reef shark movement patterns
Michelle Heupel1, Mario Espinoza2, Elodie J.I. Ledee3, Andrew Tobin3, Colin Simpfendorfer3
1. Australian Institute of Marine Science, Townsville, QLD
2. Universidad de Costa Rica, San José, Costa Rica
Understanding the movement patterns of predators is crucial to defining their role in ecosystems as well as developing effective
management and conservation policies. Reef associated sharks are often considered to have similar habitat requirements and
movement patterns. Here we examined the long-term presence and movements of several species of reef-associated sharks in
the central and southern Great Barrier Reef. Long-term acoustic telemetry data collected from grey reef, blacktip reef, whitetip
reef, weasel, silvertip, tiger and bull sharks over a five year period revealed complex movement patterns that vary by size, sex,
species and habitat type. Home range and network analyses demonstrated that the amount of space used and location of home
ranges varied among species and locations. Despite their similar sizes, grey reef, blacktip reef, whitetip reef and weasel sharks
moved and used space differently. These results suggest biological needs may be key drivers of reef shark movement and
distribution. The differences observed in reef shark movement patterns are relevant to management of reef shark populations
as concerns around these species increase within and beyond the Great Barrier Reef.
31
Spatial interactions and long-term coexistence of sharks in a tropical coastal embayment
Samantha Munroe1, Michelle Heupel2, Andrew Chin3, Danielle Knip3, Colin Simpfendorfer3
1. Australian Rivers Institute, Griffith University, Brisbane, QLD, Australia
2. Australian Institute of Marine Science Townsville, Townsville, QLD, Australia
3. James Cook University, Townsville , QLD, Australia
Diverse shark assemblages have been documented in coastal areas across the globe, however few studies have investigated the
long-term spatial interactions of shark communities. This study examined the spatial interactions of six co-occurring shark
species in a tropical embayment using passive acoustic telemetry. Eighty-two sharks were tracked in Cleveland Bay, Queensland
between 2008 and 2014: The Australian sharpnose shark Rhizoprionodon taylori (8), the spottail
shark Carcharhinus sorrah (16), the creekwhaler C. fitzroyensis (8), the pigeye shark C. amboinensis (23), the blacktip reef
shark C. melanopterus (17), and the Australian blacktip shark, C. tilstoni (10). Monthly activity space size was similar between
species, however annual results showed that the smallest species, R. taylori, had the largest activity space. These results were
surprising as they indicated body size had a limited influence on the space use patterns of the collective assemblage. Spatial
overlap analysis revealed species experienced some overlap at the extent of their range; however most species exhibited low
core activity space overlap. Low core overlap suggested populations had unique resource preferences or may have avoided each
other to limit competition. The exception was C. amboinensis, C. fitzroyensis, and C. tilstoni, which had high spatial overlap.
Dietary data showed these species likely target different prey. As high spatial overlap could result in unsustainable competition,
our results suggest these species limit competition with dietary rather than spatial partitioning. Our study indicates multiple
potential mechanisms enable long-term coexistence of shark species.
32
Spatial and temporal patterns of habitat use by six shark species in inshore environment
Elodie J.I. Ledee1, Michelle R. Heupel1, 2, Andrew Chin1, 2, Samantha Munroe3, Colin Simpfendorfer1
1. Centre for Sustainable Tropical Fisheries and Aquaculture & College of Science and Engineering, James Cook University,
Townsville, Quensland, Australia
2. Australian Institute of Marine Science, Townsville, Queensland, Australia
3. Australian Rivers Institute, Griffith University, Brisbane, Queensland, Australia
Passive acoustic monitoring was used to track the movements of six shark species (Australian sharpnose, blacktip reef, common
blacktip, creek whaler, pigeye and spottail sharks) in Cleveland Bay, Queensland, from 2012 to 2015. Acoustic monitoring
allowed long-term observation of behaviour and movement via a network of moored listening stations recording the presence
of tagged animals. Network analysis is a novel and alternative approach to conventional habitat use analysis that treats habitat
types as network nodes and analyses spatial and temporal habitat use patterns based on frequency of use of a node by an
individual during a specific period. Cleveland Bay has diverse habitat types including coral reef, sand banks, intertidal mud-flats,
sea-grass beds and mangrove forest. Preliminary results show the number of habitat types used was significantly different
between species, with pigeye and spottail sharks using on average more habitats (mean ~ 3.9) than blacktip reef shark (mean ~
2.7). Furthermore, habitat segregation was found between species; for example, sea-grass beds were the most important
habitat for Australian sharpnose shark whereas blacktip reef shark predominantly used inshore reefs throughout the monitoring
period. Further spatial and temporal analyses are required to confirm that Australian sharpnose, common blacktip and creek
whaler sharks, which were predominantly using sea-grass beds, were spatially and temporally co-occurring. These results
highlight unique behaviours between co-occurring species, and enhance our understanding of animal interactions in inshore
habitats to help provide guidance for their management.
33
Empirical evidence of a large Scalloped Hammerhead Shark (Sphyrna lewini) nursery ground in the Rewa Delta, Fiji
Amandine D Marie1, Cara Miller1, Celso Cawich1, Susanna Piovano1, Ciro Rico1
1. the University of South Pacific, Suva, Fiji
At least three sharks die every second worldwide due to bycatch, targeted fishing and/or the destruction of their habitats. The
Scalloped Hammerhead Shark (SHS, Sphyrna lewini) is among the most globally threatened shark species (listed as endangered
in the IUCN Red List) and has recently being included in the Appendix II of CITES. The purpose of this study is to present
empirical evidence of the existence of a SHS nursery in the Rewa Delta, Fiji. A total of 1217 captures (including 107 recaptures)
were made from September 2014 to March 2016 by using gill nets. A total of 952 individuals (+ 102 recaptures) were captured
during the field surveys and an additional total of 163 SHS were captured by local fishermen as by-catch (five of these 163
individuals were previously tagged during our study). According to the definition of a shark nursery area proposed by Heupel et
al. (2007), our results unambiguously confirmed that the Rewa Delta is a nursery ground for scalloped hammerhead sharks
because the following conditions were met: 1) the abundance of SHS is higher in the nursery ground than its surroundings, 2)
there is site fidelity of SHS neonate and young of the year in the Rewa Delta and, 3) a long term presence of SHS in the Rewa
Delta was observed. To the best of our knowledge, this is the largest and probably the most important nursery ground for the
species ever documented in the tropical South Pacific Ocean.
34
The ups and downs of the tiger shark – an up-close view of their behaviour
Samantha Andrzejaczek1, 2, Adrian C Gleiss3, Charitha B Pattiaratchi 1, Taylor K Chapple4, Mark G Meekan2
1. School of Environmental Systems Engineering , University of Western Australia, Crawley, WA, Australia
2. Australian Institute of Marine Science , Crawley, WA, Australia
3. Centre for Fish and Fisheries, Murdoch University, Murdoch, Western Australia, Australia
4. Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
Tiger sharks (Galeocerdo cuvier) are a keystone predator in the food chains of many tropical reef systems worldwide. Recently,
cameras deployed on these sharks have provided new insights into their behaviour, including feeding on a wide variety of prey
species and continuous cycles of ascent and descent through the water column. Here, we deployed CATS camera and diary tags
on tiger sharks at Ningaloo Reef, Western Australia in order to investigate hunting strategies and the drivers of movement
patterns. These tags were clamped to the dorsal fin and recorded both physical parameters such as depth and temperature,
and, through the use of accelerometers, in situ measurements of animal trajectory and locomotion, which enabled calculation of
dive geometry and swimming energetics. These data were compared with behaviours recorded simultaneously by video
cameras. To date, our tags have recorded a number of predator-prey interactions, swimming strategies as well as recovery from
the process of tag application. Our data have demonstrated the suitability and effectiveness of these tags as a means to link the
processes of locomotion and behaviour of these animals.
35
An evaluation of long-term monitoring of larval fish in eastern Australia
James A Smith1, Iain M Suthers1, Ana Lara-Lopez2, Anthony J Richardson3, Kerrie Swadling4, Tim Ward5, Paul van Ruth5, Jason D
Everett1
1. University of New South Wales, Sydney, NSW, Australia
2. Integrated Marine Observing System, University of Tasmania, Hobart, TAS, Australia
3. CSIRO Marine and Atmospheric Research, Brisbane, QLD, Australia
5. South Australian Research and Development Institute, Adelaide, SA, Australia
Regular monitoring of larval fish began in 2014-2015 at five locations in the Integrated Marine Observing System (IMOS)
National Reference Station (NRS) network. We evaluated the value of this monitoring for detecting spatial and temporal trends
in the distribution and spawning of key taxa, and trends in the larval fish community. We focused on 3 East coast NRS (North
Stradbroke Island, Port Hacking, and Maria Island) due to the availability of comparable historical larval fish data for this region.
Historical data from 7 surveys (spanning 1983-2015) was used to provide long-term context to help evaluate the value of longterm larval fish monitoring at NRS. We found that the abundance of larval fish is high variable in time and space, which makes
trend detection difficult. A power analysis predicts that this monitoring would need to occur for at least 20 years to detect
moderate declines in the larval abundance of key taxa, and > 50 years for many taxa. There was a clear latitudinal trend in the
larval fish community, but we found evidence that this gradient has shifted recently, in part due to poleward shift in the
spawning of some temperate species. We conclude that larval fish monitoring is a valuable fishery-independent data source for
identifying changes in the marine environment, and the current NRS monitoring will likely be useful for identifying large range
shifts, changes in phenology, and trends in abundance for some taxa, if monitoring is continued over the long term.
36
Comparison of fish larvae communities in a young versus an old frontal eddy of the East Australian Current in relation to
possible source waters
Tony Miskiewicz1, Valquaria Garcia2, Hayden Schilling3, Derrick Cruz3, Steven Hawes4, Jason Everett3, Iain Suthers3
1. Wollongong City Council, Wollongong, NSW, Australia
2. School of Aquaculture, Federal University of Santa Catarina, Florianópolis, SC, Brazil
3. School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, NSW, Australia
4. School of Biological Science, University of Sydney, Sydney, NSW, Australia
Frontal eddies, which are generated by current shear along the edge of ocean boundary currents may entrain larval fish from
shelf waters and contribute to the connectivity and recruitment of coastal populations. Larval fish assemblages were sampled
from two frontal eddies of the East Australian Current and their expected source waters on the shelf. The smaller, younger eddy,
located 150 km offshore, was characterised by distinctive coastal water properties of lower temperature (<20°C) and salinity,
and higher abundances of fish larvae of coastal shelf families and estuarine taxa of commercial importance. However when the
putative, coastal source waters of this eddy were sampled, the region was found to be swept over by the East Australian
Current, and had similar water properties and a family composition, dominated by oceanic taxa, similar to a larger northern
frontal eddy that was formed 4 weeks earlier. Shelf taxa were evident in the putative coastal source waters of the older eddy,
but these were no longer evident in the older eddy. The larval fish communities caught at each location were found to only
reflect the water characteristics of the previous few weeks. Myctophidae composed 48% of the overall community, followed by
Notosudidae (10%), Labridae (3.5%) and Phosichthyidae (3.35%). Both factors, location and depth, were showed significant
variation in the larval fish community composition. Myctophidae and Labridae were distributed across all sites. The younger
eddy was characterized by higher abundances of coastal families such as Acropomatidae, Carangidae, Serranidae and
Gonorhynchidae. The younger eddy source water site and the older northern eddy locations were dominated byoceanic families
(Notosudidae, Phosicthyidae, Howellidae and Gonostomatidae). Clupeidae and Engraulidae larvae were more common at the
older northern eddy source water location. In relation to depth distribution, Myctophidae, Notosudidae and Labridae were
found across all depths. Acropomatidae were more representative of the deeper strata and Gonorhynchidae and
Scomberesocidae dominant in the surface layer. Clupeidae and Engraulidae were more abundant in the surface and the upper
mixed layer (5-50m) than the 50-100m strata. Our study revealed the difficulties due to ocean dynamics of determining the
potential significance of frontal eddies as offshore nursery areas.
37
Freshwater fish spawning linked to both wet and dry season flows in the wet-dry tropics of northern Australia
Alison King1, Catherine Doidge1, Duncan Buckle1
1. Research Institute for Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia
The rivers of the wet-dry tropics in northern Australia support a high diversity and abundance of freshwater fish. Previous
studies, both in Australia and throughout the world, have highlighted the importance of the wet season as a significant period
for fish spawning and recruitment in tropical rivers. But few studies have examined larval abundance across seasons. We
conducted a pilot study to determine the spatial and temporal variability of spawning across one hydrological cycle (1 year) in
the Daly River, Northern Territory, Australia. Fish spawning occurred throughout the year, with the composition of the larval
assemblage varying considerably. The highest larval species diversity occurred in the wet season high-flow period, but 10 species
were also collected during the low-flow dry season. Some species spawned throughout the entire year, while others
preferentially spawned in either the wet or dry seasons. Spatial variability between sites was also evident in the dry season. This
preliminary study highlights that the dry season, low-flow period may have been underestimated as an important spawning and
recruitment period for freshwater fishes in tropical rivers. This finding has important implications for predicting the effects of
increasing dry season water extraction on freshwater fishes of the wet-dry tropics.
38
Landscape-scale life-history gradients in New Zealand freshwater Galaxias spp.
Gerry Closs1, Jason Augspurger1, Peter Jones1
1. Department of Zoology, University of Otago, DUNEDIN, New Zealand
Intra- and inter-specific variation can reveal ecological mechanisms and evolutionary steps leading to the evolution of new
species. We tested the hypothesis that egg size and fecundity would vary across an altitude gradient (i) within the widely
distributed Galaxias vulgaris and (ii) between G. vulgaris and two other closely related species.
In Galaxias vulgaris, egg size increased and fecundity decreased with increasing altitude. Inter-specific egg size and fecundity of
the three species also varied across an altitude gradient, with egg size increasing and fecundity decreasing as altitude
increased. Galaxias paucispondylus, a high altitude species compared to the other two species, had the largest mean egg size
and lowest fecundity. In contrast, mean egg size and fecundity of lower altitude G. brevipinnis was an order of magnitude higher
and lower respectively than G. paucispondylus. Mean egg size and fecundity of G. vulgaris was intermediate relative to the other
species, reflecting a distribution that broadly spans the altitudinal gap between the G. paucispondylus and G. brevipinnis.
Our results suggest that egg/ fecundity trait variation is driven by differences in the productivity of larval rearing habitat. High
altitude (low productivity) environments require large larvae (and therefore eggs), but at the cost of maternal fecundity. At
lower altitudes (higher productivity), maternal fitness is maximised by increasing fecundity by reducing egg size to the detriment
of larval fitness. Our results highlight how egg size-fecundity trade-offs could facilitate the evolution of species at either end of
the egg size-fecundity life history spectrum.
39
Spawning and recruitment of fish in response to environmental watering in the lower Lachlan River system.
Rhian Clear1, Ben Broadhurst1, Fiona Dyer1
1. Institute for Applied Ecology, University of Canberra, Bruce, ACT
A Long Term Intervention Monitoring (LTIM) program has been established to monitor and evaluate the ecological responses to
Commonwealth environmental watering in seven river systems across the Murray Darling Basin. One of the selected areas for
the program was the lower Lachlan River system. To determine the effect of environmental flows on fish spawning and
recruitment, larval fish were sampled fortnightly from mid-October to mid-December in 2014 and 2015, using drift nets and light
traps at three sites on the Lachlan River in the Hillston area, NSW. Flow and environmental conditions were markedly different
over the two years of monitoring. In August 2014 a flow of 5 GL of tributary inflows were protected within the river channel to
provide cues for native fish to migrate and spawn as well as contribute to habitat access, fish condition, spawning and larval
survival. In August – December 2015 a large translucent event (72 GL) was combined with releases of 25 GL to improve
ecological conditions and a subsequent 9.4 GL which specifically targeted golden perch movement and spawning. A total of 536
and 1141 larval fish were captured in 2014 and 2015, respectively, across the five sampling events. Five native species (Murray
cod, Flat-headed gudgeon, Carp gudgeon, Australian smelt, Eel-tailed catfish) and two alien fish species (Eastern gambusia and
Carp) were captured. Spawning of equilibrium and opportunistic species were observed in both years, however there was no
evidence of spawning of periodic species. Opportunities for initiating spawning in periodic species are being explored and may
be related to a combination of the condition and structure of the population, the timing of flow releases, and the prevailing
environmental conditions.
40
An environmental DNA based method for monitoring spawning activity: A case study using the endangered Macquarie Perch
(Macquaria Australasica)
Jonas Bylemans1, Elise Furlan1, Christopher M Hardy2, Prudence McGuffie3, 1, Mark Lintermans1, Dianne Gleeson1
1. Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
2. CSIRO Land and Water, CSIRO, Canberra, ACT, Australia
3. Department of Primary Industries, NSW Government, Batemansbay, NSW, Australia
Determining the time and location of reproduction for threatened species is critical to design and evaluate management actions.
The current available methods for monitoring reproduction in aquatic species are often biased, costly, time intensive and
sometimes require lethal sampling. Here we present an environmental DNA (eDNA) based methodology for monitoring
spawning activity, which can overcome these constraints. During spawning the mass release of spermatozoa, which contain few
mitochondria and highly protected nuclear DNA, forms a major source of eDNA. Thus, we hypothesized that the relative
abundance of mitochondrial and nuclear eDNA will change during reproductive events. Through an experimental and field-based
study, focusing on the endangered Macquarie perch, we were able to show that both target fragments are equally abundant
outside of the reproductive period. However, after the release of spermatozoa a strong increase in nuclear eDNA was observed
while mitochondrial eDNA concentration only increased moderately. Hence, the changes in the ratio between nuclear and
mitochondrial eDNA can be indicative of recent spawning activity and can be used to monitor reproductive activity in species
relying on external fertilization.
41
Gravid spot: A surrogate for predicting progress of embryonic development and reproductive output in a live bearing fish
(Gambusia holbrooki)
Lokman Norazmi1, John Purser1, Jawahar Patil2, 3
1. Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies,, University of Tasmania, Launceston, Tasmania,
Australia
2. Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies,, University of Tasmania, Hobart, Tasmania,
Australia
3. Inland Fisheries Service, New Norfolk, Tasmania, Australia
Brooding females of livebearing fish can be identified by the presence of the gravid spot; a dark pigmented spot located at a
lateral and cranial position to the anal/genital pore. However, its use to predict embryonic development and clutch size remains
unexplored. This study quantified visual attributes (intensity and size) of the gravid spot in relation to key features of internal
embryonic development and clutch size in Gambusia holbrooki, a pest fish of concern to Australia. Observations show that the
colour of the gravid spot arises from progressive melanisation on the surface of the ovarian sac. As predicted, the intensity and
size of the gravid spot were closely linked with both developmental stage and clutch size, suggesting their reliable use as
external surrogates. This reliability was harnessed to design and document downstream experiments on gestation, parturition
and hormonal sex reversal. The gestation period was very sensitive to a small change in temperature—significantly longer
(F=364.58; df=1,48; P<0.05) when reared at 23°C (897±43.93 degree days) compared to 25 °C (715±48.5 degree days). However,
temperature did not have significant impact (P>0.05) on clutch size or diel timing of parturition which occurs predominantly in
the morning (0900-1100h under 16:8h light: dark photoperiod, time on 0600h). The first-ever description on the birth posture
of G. holbrooki fry (progenies) during parturition where the tail of the fry emerged first with a few exceptions of head-first, twin
and premature births, was also documented. The reproducibility and utility of the relationships imply that they are also relevant
to management of wild populations such as for stock assessment, monitoring environmental impacts, and control of pest
populations among others. The observed embryonic superfetation and its relevance to reproductive adaptation and
management will also be discussed.
42
The importance of habitat structural complexity in the assessment of marine reserve performance
Matt Rees1, Andy Davis1, Alan Jordan2, Michelle Linklater3, Nathan Knott4
1. Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
2. NSW Department of Primary Industries, Nelson Bay, NSW
3. School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW
4. NSW Department of Primary Industries, Huskisson, NSW
The importance of habitat structural complexity in the assessment and understanding of Marine Protected Area (MPA)
performance remains unresolved. Habitat structural complexity is known be an important driver of the abundance and diversity
of fishes so therefore may confound spatial comparisons between reserves and non-reserves. This is specially the case when
assessments of MPA effectiveness involve non-random allocation of treatments or low replication. Here we present an
assessment of the performance of marine reserves in the Lord Howe Marine Park (LHIMP), NSW, Australia while accounting for
underlying variation in habitat structural complexity. The LHIMP comprises of two marine reserves where fishing is prohibited,
surrounded by habitat protection zones that allow recreational fishing and charter boat fishing operations. High resolution
multi-beam surveys in the LHIMP have revealed substantial variation in habitat structural complexity across all zones. As a
result, the LHIMP provides an ideal opportunity to investigate the importance of how habitat structural complexity influences
the assessment of MPAs. In this study we tested the performance of LHIMP by comparing the abundance of Seriola
lalandi (Yellowtail Kingfish) and Carcharhinus galapagensis (Galapagos Whalers) between reserves and non-reserves while
accounting for habitat structural complexity. We found that Seriola lalandi abundance was significantly greater in reserves
compared to non-reserves but only at sites with high structural complexity. In contrast, the abundance of Carcharhinus
galapagensis did not differ between reserves and non-reserves nor with habitat structural complexity. We propose that the
disparity in results is due to differences in fishing pressure and habitat preferences between the two taxa. Carcharhinus
galapagensis is a pelagic species displaying little affinity to seafloor habitats and is not intentionally targeted by fishers. In
comparison, Seriola lalandi displays a stronger tie to benthic habitats and is heavily exploited by fishers. Our findings
demonstrate that habitat structural complexity is important to consider when testing MPA performance. We suggest that future
studies assessing MPA performance to incorporate measures of habitat variability if the data is available.
43
Acute climate-mediated disturbances – the defining role in structuring coral reef futures?
Anna Cresswell1, Mick Haywood2, Damian Thomson2, Tim Langlois3, Gary Kendrick3
1. CSIRO/ University of Western Australia, City Beach, WA, Australia
2. CSIRO, Perth, Western Australia, Australia
3. Plant Biology, University of Western Australia, Perth, WA, Australia
Key theories in ecology surround the concepts of equilibrium in ecosystems and the role of disturbances in driving ecosystem
function and diversity. Climate change brings not only chronic stressors to reef ecosystems, such as temperature rise and ocean
acidification, it is also associated with predictions of increased acute disturbance events: cyclones/severe storms, heat waves,
and flooding. This is all overlain with ever increasing human impacts. The degree to which acute natural disturbances will shape
ecosystems compared, or in synergy with, chronic anthropogenic and environmental stressors is unknown.
Corals are among the greatest marine ecosystem engineers: providing habitat, protection and food and altering physio-chemical
conditions for associated reef fauna. Understanding of the reliance of key fauna on the health and composition of the benthos is
necessary if we are to develop targeted conservation strategies to promote ecosystem resilience. Changes in the benthos are
arguably the most evident and quantifiable. Impacts to reef fishes are more difficult to measure, having higher short term
variability and may be a direct result of disturbances or an indirect result facilitated through ecosystem processes and
associations.
Ningaloo Reef, Western Australia, has been subject to multiple acute disturbances over the last decade, including cyclones, a
heatwave and a flood. Due to a relative lack of local anthropogenic pressures in the global coral reef context, studies of the role
of acute disturbances at Ningaloo Reef are comparatively free of confounding drivers.
Here I report on documented changes in benthic and fishes assemblages over a decade and report on how trophic and
functional associations may drive indirect impacts following disturbances. With improved understanding of the processes driving
indirect disturbance impacts to reef associated fauna – juvenile fishes, obligate corallivores, key herbivorous groups and
important commercial fishes – management strategies may target specific ecosystem functions to promote resilience of whole
ecosystems.
44
Ecoregionalization of coral reef fish in New Caledonia using gradient forest modeling.
Jessica Garcia1, Thomas Bockel1, Liliane Caprentier1, Dominique Pelletier1
1. IFREMER, IFREMER - French Research Institute for Exploitation of the Sea, NOUMEA, FRANCE
Beta diversity is a key concept for our understanding of ecosystem dynamics. It is broadly used to describe turnover in species
composition thought environmental gradient at different spatial and temporal scales. In this study, we propose to define
spatially homogeneous geographical units of beta diversity at the New Caledonia (17-24° S, 158-172° W) scale as well as the
relative importance of spatial environmental factors (physical, chemical and habitat) on fish species turnover. By determining
three hierarchical spatial scales, we evaluate the impact of the choice of spatial scales on the order of importance of these
factors. Fish abundance and habitat data were collected with unbaited rotative underwater video (STAVIRO). We used a gradient
forest modeling and clustering method (ssi) to predict the turnover in fish assemblages across environmental gradients. We
delimited 8 distinct ecoregions in the New Caledonia. The factors that better explained fish beta-diversity were phosphate,
salinity, temperature, nitrates and silicates. We showed that the order of importance of each environmental factor changed
according to the spatial scale. At the local scale, living coral cover differed between sampling locations and reflected the human
pressure on the local ecosystem. Physical and chemical factors influenced the turnover of fish assemblage for healthy local
ecosystem. For degraded ecosystem, habitat was the most important factor to explain fish beta diversity. For healthy and
isolated ecosystems where human pressure remains weak, phosphates and nitrates are the main drivers of fish diversity. We
hypothesize that the natural eutrophication provided by the nutrient enrichments from the avifauna may have positive effect on
the marine ecosystem. However, the hierarchical importance of environmental factors (physical, chemical and local habitat)
differed according to the local degree of health for the ecosystem considered. Contrary to common believes, our study
demonstrate that moderate eutrophication can have benefit effects on fish diversity for healthy ecosystems due to a more
efficient absorption process.
45
Microhabitat specialisation underpins coral-seaweed niche segregation in tropical reef fishes
Lucy N Wenger1, Joshua van Lier1, Christopher J Fulton1
1. The Australian National University, Canberra, ACT
Seaweed meadows are a significant feature of tropical coastlines, yet these habitats are only just beginning to be recognised as
key parts of tropical marine ecosystems. While recent research has revealed that numerous reef-associated fishes may be
dependent on seaweed meadows at some stages of their life history, we are yet to understand the extent to which these fishes
specialise towards a seaweed existence, and the traits that may be associated with this type of habitat specialisation. For my
Honours research, I studied the Macropharyngodon-Xenojulis phylogroup of wrasses to explore the extent to which closely-
related reef fishes may specialise, and therefore, depend upon coral and/or seaweed habitats. Using a combination of published
and new data, I found that this related group of species had a distinct affiliation with either seaweed or corals. Although there
was some overlap apparent at the mesohabitat scale, microhabitat preferences revealed strong ecological segregation via the
association of each species with either hard corals (Macropharyngodon) or canopy-forming seaweeds (Xenojulis). Moreover,
foraging and dietary preferences also differed according to microhabitat, with Macropharyngodon generally consuming more
foraminifera from sand-pavement microhabitats, while Xenojulis gleaned their diverse epibiont prey from canopy-forming
seaweeds. Our findings suggest the potential for strong microhabitat specialisation and dependency on both seaweed and coral
habitats, which means these should be conserved and managed as equally important components of tropical marine
ecosystems.
46
Grey reef shark dependence to habitat characteristics and community composition in the central GBR
Stacy L Bierwagen1, Colin Simpfendorfer1, Michelle Heupel
1. James Cook University, Townsville City, QLD, Australia
Sharks play a vital role in the functioning of marine ecosystems and, in coral reef habitats, have come under increasing pressure
from human activity. Management of coral reefs often uses zoning and protected areas to boost productivity to sites subject to
disturbance. These measures are often complex and devoid of long-term data crucial in determining success of marine reserve
design. Studies investigating efficacy of a protected area are often species-specific and vary based on habitat composition and
influencing physical factors. While animal movement is a significant aspect in defining boundaries of a reserve, simplistic
mechanisms of predator-prey interactions are often overlooked. Prey selection can be a pertinent component in outlining
habitat and space use of a species and presently little data are available linking abundance of predators to abundance of prey.
Reef sharks that tend to be site-attached carry energetic capacities with potential to span larger distances than other siteattached reef fish. With changing climate conditions and persistent resource exploitation, it is necessary to determine factors
that influence residency of mobile species and whether degraded reefs can support an abundance of predators. Using an
ecosystem-based approach, sources of productivity in reef communities were examined from 2006-2014 using long-term fish,
benthic, and environmental monitoring data from the Australian Institute of Marine Science for four reefs in the central Great
Barrier Reef. This data was modeled against residency data collected from telemetry studies of grey reef sharks from 2011-2013.
Preliminary results indicate fine-scale variabilty in abundance and species-richness by site where specific habitats may be more
resilient to changing conditions. Sources of productivity for grey reef sharks such as piscivores are severely depleted since 2006
surveys and require further analysis to determine whether lower prey abundance has an effect on residency to reefs in the
central GBR.
47
Fish fuction as a sensitive indicator of coral reef degradation
Christopher Goatley1, David Bellwood1, Roberta Bonaldo2, Rebecca Fox3
2. Universidade de São Paulo, Sao Paulo, Brazil
3. UTS, Sydney
Fishes play important roles in maintaining the resilience and recovery potential of coral reefs, yet our monitoring techniques
rarely extend beyond counting the number of fishes in an ecosystem. The presence of fishes, however, does not mean that they
are performing their functions in that location. The development of more sensitive tools, which complement traditional
methods of monitoring coral reef fishes, may therefore reveal earlier signs of ecosystem changes, and provide an opportunity
for pre-emptive responses. In this presentation I will reveal new, sensitive metrics of the ecosystem functions performed by
fishes that allowed us to quantify subtle, yet destabilising, changes to the ecosystem on an inshore coral reef on the Great
Barrier Reef. The findings clearly highlight that fish abundance does not equate to function on coral reefs, and that to fully
understand the role played by fishes we should attempt to make direct process-based measurements. With herbivory proving to
be among the most important functions performed by fishes on coral reefs, estimates of grazing and/or browsing rates appear
to act as sensitive tools which can be used to detect subtle ecosystem degradation and may be critical in identifying the effects
of disturbances prior to wide scale loss of fish species.
48
Functional distinctions among browsing herbivorous fishes: reduced redundancy and the importance of large individuals
Robert P Streit1, David R Bellwood1, Andrew S Hoey1
Publish consent withheld
49
Age, growth and maturity of oceanic whitetip shark (Carcharhinus longimanus) from Papua New Guinea
Brooke M D'Alberto1, Andrew Chin1, Jonathan J Smart1, Leontine Baje2, 1, William T White3, 4, Colin A Simpfendorfer1
Townsville, QLD, Australia
3. CSIRO Oceans & Atmosphere, Hobart, TAS, Australia
4. Australian National Fish Collection, CSIRO National Research Collections Australia, Hobart, TAS, Australia
Oceanic whitetip sharks (Carcharhinus longimanus) in the Western Central Pacific Ocean have been overfished and require
improved assessment and management to enable planning recovery actions. Samples from 103 individuals, 70 males (76.0 – 240
cm TL) and 33 females (128 – 235 cm TL) were used to estimate age, growth and maturity parameters from sharks retained by
longline fisheries in Papua New Guinea (PNG). Back calculation was used to account for the low number of juveniles and a multimodel framework with AICC used to estimate growth parameters. The von Bertalanffy growth model (VBGF) provided the best
fitting growth model for both sexes. Parameter estimates for males were L∞ = 314 cm TL, k = 0.059 yr-1, L0 = 75.1 cm TL, and L∞ =
317 cm TL, k = 0.057 yr-1, L0 = 74.7 cm TL for females. Maximum age was estimated to be 18 years for males and 17 years for
females, with a calculated longevity of 24.6 years and 24.9 years, respectively. Males matured at 10.8 years and 193 cm TL, while
females matured at 15.8 years and 224 cm TL. These are the first estimates of life history parameters for C. longimanus from
PNG.Carcharhinus longimanus is a slow growing, late maturity species, with regional variation in life history parameters
highlighting increased vulnerability to fishing pressure in this region.
50
Age and growth of the silky shark Carcharhinus Falciformis from Papua New Guinea
Michael I Grant, Jonathan Smart, Colin Simpfendorfer, Andrew Chin, William White
Carcharhinus falciformis is listed as near threatened on the IUCN red list. They are one of most heavily fished tropical shark
species and are incidentally caught in significant numbers by long-line and purse seine fishing operations. Serious sustainability
concerns from overfishing have emerged in recent years throughout their distribution, particularly within the Central West
Pacific. Despite dominating local catch, life history information is not available for silky sharks in this region, impeding sound
fisheries management. Age and growth estimates from length-at-age data (n= 527) were produced for the silky
shark Carcharhinus falciformis from Papua New Guinea. Age estimates were produced from vertebral analysis conducted on
samples collected by an on-board observer program operating in the Papua New Guinea long line fishery. A multi-model
approach incorporating AIC was used to estimate growth rates which included the von Bertalanffy, logistic and Gompertz growth
functions as candidate growth models. Estimates of length and age-at- maturity were also produced.
51
Age and growth of teraglin, Atractoscion aequidens (Family: Sciaenidae) in New South Wales and their implications for
fisheries management
Anne-Marie Hegarty1, John Stewart1, William Gladstone2
1. Fisheries NSW, Sydney, NSW, Australia
2. University of Technology, Sydney, NSW, Australia
Teraglin (Atractoscion aequidens, family Sciaenidae) are found in eastern Australian waters from southern Queensland to
Montague Island. In NSW, teraglin are targeted by the NSW Ocean Trap and Line commercial fishery and by recreational fishers.
This is the first study of the life-history characteristics of A. aequidens in NSW and describes the geographical and temporal
variation in age, growth, and reproductive characteristics of this species and compares life history parameters with populations
in southern Queensland and South Africa. A. aequidens is fast growing reaching approximately 40 - 45 cm FL in the first year of
life and can live to 14 years. Preliminary analysis indicates the age at which 50% of the population matures is approximately 1
year old, this is similar to results found in QLD. In South Africa, the same species matures at 90 cm FL and 5 years of age. The
commercial fishery in NSW is predominantly based on young fish < 3 years and there are concerns that this species may be
subject to unacceptable levels of fishing mortality.
52
Long term trends in juvenile blue grenadier Macruronus novaezelandiae otolith increment growth variability and fishing zone
sex ratio on the west coast of Tasmania.
Philip Sweetman, James Haddy
Growth is a fundamental biological process in the dynamics of fish populations and is the basic parameter underlying
characteristics such as stock biomass and size frequencies. Investigators of inter-annual variability in fish growth often use hard
body part analysis, such as variability in otolith increment widths as a proxy for somatic growth. This study presents inter-annual
variability of otolith growth in blue grenadier Macruronus novaezelandiae off the west coast of Tasmania from 1991 to 2011.
Capture size at age data highlighted that M. novaezelandiae females grow larger than males with mean size at age statistically
diverging by 3 years of age and remaining separated thereafter. In contrast, statistical differences in mean otolith increment
widths at age between sexes were detected at earlier ages but these differences were lost after the age of 7. Inter-annual
variation in mean otolith increment widths for the first four increment zones (juvenile zones) all showed a similar trend with
declining increment widths from 2006 to 2010. Inter-annual cohort sex ratios across year-of-birth also varied (χ2 = 366.11, df40,
p << 0.0001) and displayed a similar trend to the first year otolith increment growth profiles of both male and females.
Correlation of birth year sex ratio with mean otolith increment widths indicated a highly statistically significant negative
correlation with first year growth declining in both genders with increasing numbers of male offspring (Male: r(19) = 0.71, p <
0.001; Female: r(19) = 0.66, p = 0.001).
53
Deepwater sharks and rays of the Great Barrier Reef: how vulnerable are they?
Cassandra L Rigby1, William T White2, Colin A Simpfendorfer1
Townsville, Qld, Australia
2. Australian National Fish Collection, CSIRO, Hobart, Tasmania, Australia
The deepwater sharks and rays of the Great Barrier Reef are poorly known and life history information is required to enable
their effective management. The shark and ray bycatch from the deepwater eastern king prawn fishery at the Swain Reefs in the
southern Great Barrier Reef was examined to determine the species present and provide information on their life histories. In
all, 1533 individuals were collected from 11 deepwater shark and ray species, with the Argus skate Dipturus polyommata, piked
spurdog Squalus megalops and pale spotted catshark Asymbolus pallidusthe most commonly caught. All but one species is
endemic to Australia with five species restricted to waters offshore from Queensland. This high level of endemism and
geographically restricted distribution is common among deepwater sharks and rays and potentially reduces their resilience to
fishing pressure. The life history traits across all species were characteristic of deep water sharks and rays with relatively large
length at maturity, small litters and low ovarian fecundity; all indicative of low biological productivity. However, variability
among these traits and spatial and bathymetric distributions of the species suggests differing degrees of resilience to fishing
pressure. This highlights the need to monitor the bycatch of these species in fisheries within the Great Barrier Reef.
54
Running out of stream. Drivers of occurrence and abundance in a thermally restricted headwater fish.
Mischa Turschwell1, 2, Stephen Balcombe 1, Erin Peterson3, Ashley Steel4, Fran Sheldon1
1. Australian Rivers Institute, Griffith University, Nathan, Queensland , Australia
2. Data61, CSIRO, Brisbane, Queensland , Australia
3. Australian Centre for Mathematical and Statistical Frontiers and the Institute for Future Environments, Queensland University
of Technology, Brisbane , Queensland , Australia
4. Pacific Northwest Research Station, USDA Forest Service, Seattle , Washington, USA
For many freshwater fish there is often little known about the spatio-temporal drivers of their distribution, particularly among
different life stages, making their conservation challenging. We used two-stage hurdle models to investigate drivers of
occurrence and abundance for locally threatened adult and juvenile northern river blackfish in the upper Condamine River,
Queensland, Australia. Our results demonstrate that there are different processes driving occurrence versus abundance
between the two life-history stages. Both adult and juvenile occurrence were negatively associated with high magnitude,
extended warming events, suggesting blackfish are thermally restricted to cooler headwaters. Furthermore, juvenile fish
demonstrated increased sensitivity to high stream temperatures as compared to adults. In contrast, drivers of abundance
differed between life-history stages. Adult fish were negatively associated with increased fine sediment loads, while juveniles
were negatively associated with a hydrologically-active inverse-distance-weighted grazing metric that accounted for the greater
influence of grazed land close to stream or in areas of high overland flow. By teasing out environmental drivers affecting
multiple life-history stages of a locally threatened headwater species, our approach allows us to provide direct management
recommendations for best conserving this species, as well as ecologically similar headwater fishes and their associated habitats.
55
Variation in size-structure, diet and habitat use in the Darling hardyhead, Craterocephalus amniculus Crowley & Ivantsoff
1990, in the upper Macintyre River, northern Murray-Darling Basin
Karl G Moy, Glenn WIlson1
1. University of New England, Armidale, New South Wales, Australia
The Darling hardyhead, Craterocephalus amniculus (Atherinidae), is a threatened fish species inhabiting upstream reaches of a
number of northern Murray-Darling Basin catchments. We examined patterns of seasonal size structure, interannual and spatial
variation in diet, and habitat selection in this species across three sites and four seasons in the upper Macintyre River, northern
New South Wales. Size structure data suggested a single annual spawning season in late September or early October, with only a
single cohort apparent in the population in three of the four seasons. Dietary diversity increased with distance downstream. At
the two upstream sites, aquatic invertebrates made up most of the diet while over half the gut contents at the downstream site
was unidentified detritus. Diets varied significantly, both between seasons at the downstream site and among the three sites.
Preference was shown for pool habitats with a sand or cobble substrate, increased channel depth and width and distance from
the bank, and reduced flow velocity, while in-stream woody debris cover, and exotic riparian vegetation cover were avoided.
Darling hardyhead may be vulnerable to further population decline in light of its narrow spawning season and habitat
preferences. However, comparable data from nearby catchments will be necessary to ascertain the species’ conservation status
across its broader distribution.
56
Piecing together a living puzzle: biogeographic patterns in some shallow water sharks and rays in New Guinea
William White1, Gerry Allen, Mark Erdmann
Understanding the biogeography of organisms provides us with a better understanding of the evolutionary patterns and
processes which have led to their present day distributions. Biogeographic information can be crucial for understanding how
species react to changes in their environment. New Guinea has a very complicated geological history and is one of the most
mobile zones in the earth’s crust. Combined with its location in the Coral Triangle, this has resulted in New Guinea having one of
the most diverse and unique floral and faunal assemblages in the world. While there have been many studies on the
biogeographic patterns of many invertebrate, terrestrial vertebrates and plants in New Guinea, there have been far fewer
marine organism-focused studies and no detailed shark and ray specific studies. In this study, the biogeographic patterns of
three shallow-water, reef associated elasmobranch species are considered. The epaulette sharks (genus Hemiscyllium) contains
9 species, with 7 restricted to the New Guinea region and the other two found only in northern Australia. While morphologically
very similar, they can be readily separated based on their coloration. The bluespotted fantail rays (genus Taeniura) were
previously considered to consist of a single Indo-West Pacific species, but taxonomic studies have revealed that the Pacific Island
populations represent a distinct species. In New Guinea, both species occur but do not overlap in their distributions. Recent
taxonomic studies on the maskrays (genus Neotrygon) suggest that their distribution in the New Guinea region is more
complicated than it was previously considered to be. The results of this study highlight the importance of both detailed regional
studies and biological collections in order to obtain detailed biogeographic information for various organisms.
57
The role of fishes in the evolution and ecology of coral reefs
David Bellwood1
1. College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
Fishes have driven the evolution and ecology of reef ecosystems for over 200 million years and today, fishes are the strongest
link between humans and coral reefs. This presentation will (i) explore the importance of fishes in shaping the evolution of
marine ecosystems, especially coral reefs, (ii) examine the critical roles of fishes in maintaining ecosystem processes, and (iii)
discuss how fishes reveal the nature and impacts of human activity on coral reefs and in other ecosystems. The overarching goal
of my research has been to develop a picture of coral reefs as functional ecosystems. The approach has enabled us to examine
changes over evolutionary timescales, looking at how reefs operated rather than simply documenting changes in diversity
through time. More importantly, this functional approach also provides insights into the critical importance of fishes in
maintaining key processes on modern coral reefs. By recognising these processes, we are able to understand how human
activity is shaping the future of coral reefs and other aquatic ecosystems. Our capacity to modify fish populations, for example,
can profoundly alter marine ecosystems. Yet if these changes are detected early and if appropriate measures are taken, our
interactions with fishes may enable us to plan for positive outcomes in an increasingly uncertain future. Our ability to
understand the importance of fishes, not only for humans, but also for marine ecosystems, will be critical for our future welfare.
Once simply targets for the dinner plate, fishes may become one of our best allies when coping with environmental change.
58
Fine-scale population structure and sex-biased dispersal of a highly philopatric coastal shark species
Jo Day1, Jennalee Clark2, Culum Brown2
1. Taronga Conservation Society Australia, Mosman, NSW, Australia
2. Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
Understanding population connectivity of marine species is becoming increasingly important for conservation planning,
especially for species inhabiting coastal environments where anthropogenic threats are escalating. A recent acoustic tracking
study on Port Jackson sharks (PJs) breeding in Jervis Bay, NSW, has discovered that PJs undertake yearly long-distance
migrations as far south as Tasmania. There is also early evidence of PJs breeding in Sydney waters migrating south at similar
times. However, not all sharks from Jervis Bay appear to follow the same the migration pattern and the reasons for these
migrations are generally not well understood. Given the overlap of migration pathways between Jervis Bay and Sydney
aggregations, we investigated the genetic structure and dispersal patterns of PJs from these two regions. We analysed 89 PJs
samples using ten highly polymorphic microsatellites that were developed for this study as well the mitochondrial DNA (mtDNA)
control region. Despite the breeding sites being separated by only 200km, significant population structure was detected using
mtDNA. This result was not observed with microsatellites and further analysis based on assignment indices confirmed malebiased dispersal for this species. However, observations of fine-scale movement patterns in Jervis Bay over multiple breeding
seasons have shown that adult males are generally more philopatric than females, returning to the same breeding site year after
year. Taken together, these results suggest that juvenile male PJs may be dispersing from their natal area, thereby facilitating
gene flow among these NSW coastal populations. This study emphasizes the need for multi-disciplinary approach to
understanding population connectivity, especially when developing conservation management strategies for threatened or
ecologically important marine species.
59
Integrative approach to elucidating the population structure of coastal reef fish in northern Australia (Part I: Otolith
chemistry)
Jonathan A Taylor, Di P Barton1, 2, Laura Taillebois2, David Crook2, Thor Saunders1, Alan Grieg1, Mark Hearnden1, David J Welch3,
Stephen J Newman4
1. Fisheries Research, Northern Territory Government Department of Primary Industry and Fisheries, Darwin, Northern Territory,
Australia
2. Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
3. C2O Fisheries, Cairns, Queensland, Australia
4. Western Australian Fisheries and Marine Research Laboratories, Department of Fisheries, Government of Western Australia,
Perth, Western Australia, Australia
Information on the structure of exploited fish populations is critical to their sustainable harvest, allowing appropriate
management regimes to be implemented at spatial scales that reflect the population dynamics of a species across it range. This
project utilised microsatellite DNA, parasitology and otolith microchemistry techniques to examine population structure among
populations of three coastal reef fish species across northern Australia (Protonibea diacanthus, Lutjanus johnii and Lethrinus
laticaudis).
Part I of the project involved using otolith microchemistry to examine population structuring of these three species of coastal
reef fish. By analysing variation in multi-elemental otolith chemical signatures, it is possible to estimate the levels of connectivity
and population structure between fish sampled from different areas. Additionally, the persistence of these patterns was
investigated by sampling three specific areas of each otolith that represented a different life history stage of the fish: the core,
or “primordium”, reflecting the larval phase; the near-core, representing the early juvenile phase; and the otolith margin to
represent the sub adult/adult phase. Analysis of the multi-elemental otolith chemistry signatures using linear discriminant
function analysis (LDFA) and multi-variate analysis of variance (MANOVA) showed that variability in otolith chemistry was
sufficient to discriminate fish collected from sites separated by distances of 50-1200km.
Population structure is influenced by behavioural and physical processes that act over a range of temporal scales. Therefore, the
use of multiple and potentially complementary techniques that integrate information over different scales is likely to provide
the best inference on population structure of fish. Incorporating the results from the otolith microchemistry research with the
genetic and parasitology results, which have different spatial and temporal resolution, allows more precise estimation of both
the spatial and temporal scale of stock structuring that exists for these three commercial and recreationally important fish
species across northern Australia.
60
Integrative approach to elucidating the population structure of coastal reef fish in northern Australia (Part II: Parasite
assemblages).
Di Barton1, Laura Taillebois2, Jonathan Taylor1, David Crook2, Thor Saunders1, David Welch3, Mark Hearnden1, Steve Newman4,
MichaelTravers Travers4, Richard Saunders5, Safia Maher6, Christine Dudgeon6, Jenny Ovenden6
1. NT DPIF, Berrimah, NT, Australia
2. Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia
3. C2O Fisheries, Cairns, Qld, Australia
4. Western Australian Fisheries and Marine Research Laboratories, Department of Fisheries, Government of Western Australia,
Perth, WA, Australia
5. Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Qld, Australia
6. Molecular Fisheries Laboratory, The University of Queensland, Brisbane, Qld, Australia
The integrated use of a number of techniques that cover multiple aspects of a fish species' life history have been shown to
provide the best basis for potential management of that species. Parasites provide information on aspects of short- to long-term
aspects of a fish's biology, depending on the parasite species in question. In this study, the parasite fauna of three commercial
and recreationally important fish species across northern Australia (Protonibea diacanthus, Lutjanus johnii and Lethrinus
laticaudis) were examined in combination with microsatellite genetics and otolith microchemistry to determine potential stock
structure for future management scenarios. A diverse range of parasites was found to infect all fish across the collection range
from the Pilbara region in Western Australia to Moreton Bay in South-East Queensland. For all three fish species their parasite
fauna provided high levels of reclassification success, usually 2-3x that calculated by chance alone, providing fine-scale spatial
structuring of their fish hosts. Protonibea diacanthus had the highest level of reclassification success, with 67% overall, followed
by Le. laticaudis with 56% and L. johnii with 44%. Once subdivided into jurisdictional management units, reclassification success
increased with up to 90% of fish successfully reclassified in some regions. Between the three fish species, different groups of
parasites were found to be better overall predictors of their host stock structure: encysted larval stages for P. diacanthus and L.
johnii and external parasites for Le. laticaudis.
61
Integrative approach to elucidating the population structure of coastal reef fish in northern Australia (Part III: Genetics and
summary)
Laura Taillebois1, Di P Barton2, 1, Jonathan Taylor2, David A Crook1, Thor Saunders2, Alan Grieg2, Mark Hearnden2, David J Welch3,
Stephen J Newman4, Michael J Travers4, Richard J Saunders5, 6, Christine Dudgeon7, Safia Maher7, Jennifer Ovenden7
1. Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
2. Department of Primary Industry and Fisheries, Northern Territory Government, Berrimah, Northern Territory, Australia
3. C2O Fisheries, Cairns, Queensland, Australia
4. Western Australian Fisheries and Marine Research Laboratories, Government of Western Australia, North Beach, Western
Australia, Australia
5. Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Douglas, Queensland, Australia
6. Animal Science, Queensland Department of Agriculture and Fisheries, Brisbane, Queensland, Australia
7. Molecular Fisheries Laboratory, School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
Modeling fisheries populations is one of the many components of management aimed at achieving sustainable exploitation.
Definition of the spatial extent of stocks, in particular, is a founding principle of this assessment process. The concept of stocks
as natural management units is based on demographically cohesive groups of individuals of a species and is commonly defined
in genetic terms. The status of coastal reef fisheries in northern Australia remains undefined for many exploited species. In this
study, we aimed to identify the stock structure of three commercial and recreationally important fish species across northern
Australia (Protonibea diacanthus, Lutjanus johnii and Lethrinus laticaudis) using a combination of ecological, geochemical and
genetic techniques for uptake into fisheries management. All three species were sampled across their Australian distributional
range and between 10-13 genetic microsatellite DNA markers were specifically developed for each species. The distribution of
the genetic diversity was characterized and tested using F-statistics and Bayesian model-based approaches, and revealed
contrasting results between the three species. Protonibea diacanthus and Le. laticaudis presented low but significant FST and the
Bayesian clustering revealed distinct populations and major genetic breaks, whereas no pattern of genetic structure was
revealed for Lutjanus johnii. Our holistic approach to stock discrimination combines and integrates parasites abundances, otolith
microchemistry and population genetics. The different levels at which these three techniques operate - from the individual life
history to multi-generational levels of population connectivity - ensures that if stock structure exists, it has more chance to be
revealed and elucidated than using a single technique.
62
Could capture stress affect future reproductive outcomes in elasmobranch species? A case study: the southern fiddler
ray, Trygonorrhina dumerilii.
Leonardo Guida1, Terence I Walker1, Richard D Reina1, Cynthia A Awruch3, 2
1. School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
2. School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
3. Grupo de Ecofisiología Aplicada al Manejo y Conservación de la Fauna Silvestre. CESIMAR (Centro Para el Estudio de Sistemas
Marinos) , CENPAT (Centro Nacional Patagonico)-CONICET, Puerto Madryn, Chubut, Argentina
Assessing fisheries impacts on elasmobranch populations has focused on quantifying immediate and delayed mortality rates.
However, little is known about the sub-lethal effects of capture stress, particularly in pregnant females. The southern fiddler ray
(Trygonorrhina dumerilii) was used as a case study to investigate the consequences of capture on a pregnant elasmobranch
species. Nineteen pregnant females were collected, 10 were kept for control and nine were subjected to trawl capture (8 hr)
followed immediately by air exposure (30 min). Immediately prior to, and for up to 28 days post trawling, all females were
routinely sampled to monitor changes in total body mass (TBM), sex-steroid levels (estrogen, progesterone, testosterone) and
granulocyte to lymphocyte ratio (G:L). At parturition, neonates were measured for total length (TL), TBM and where possible,
G:L was also calculated. Trawling reduced maternal TBM and elevated the G:L for up to 28 days post trawling. Trawling did not
significantly affect any sex-steroid titters, however females reported lower than expected concentrations in sex-steroids at 28
days post trawling. Neonates who experienced pre-natal stress were lower in TBM and TL, and had an elevated G:L. Our results
suggest that depending on the magnitude of environmental stress experienced by a pregnant female, a single capture event is
sufficient to influence current and future reproductive efforts. Although more studies will be necessary to evaluate whether
these results could be generalised to the entire elasmobranch group, the outcomes of this study suggest that stress related
reproductive effects may have management implications.
63
Are sightings of fish outside their usual ranges early indications of climate-driven range shifts or false alarms?
Hannah E Fogarty1, Michael T Burrows2, Gretta T Pecl1, Lucy M Robinson3, Elvira S Poloczanska4
2. Scottish Association for Marine Science, Oban
3. Commission for the Conservation of Marine Antarctic Living Resources, Hobart
4. CSIRO Oceans and Atmosphere, St Lucia, Queensland
Shifts in species ranges are a global phenomenon, well known to occur in response to a changing climate. New species arriving in
an area may become pest species, modify ecosystem structure, or represent challenges or opportunities for fisheries and
recreation. Early detection of range shifts and prompt implementation of any appropriate management strategies is therefore
crucial. This study investigates whether “first sightings” marine of species outside their normal ranges could provide an early
warning of impending climate-driven range shifts. We examine the relationships between first sightings and marine regions
defined by patterns of local climate velocities (calculated on a 50-year time scale). as lacking connections to warmer areas
(climate ‘source’), where moving isotherms converge (‘corridors’), and places were isotherms locally disappear (‘sink’ areas),
while also considering the distribution of observational effort (i.e. number of sampling days recorded for biological observations
in global databases). Additionally, we investigate the latitudinal band first sightings were recorded in, and species’ thermal
affiliations. We found that first sightings in climate sink and divergent regions occur independently of sampling effort and ocean
area, indicating that climate velocity has influenced the distribution of first sightings in sink regions. The majority of our first
sightings appear to be tropical and sub-tropical species moving towards high latitudes, as would be expected in climate
warming. Our results indicate that first sightings are likely related to longer-term climatic processes, and could therefore have
potential use to indicate likely climate-driven range shifts. The development of an approach to detect impending range shifts at
an early stage will allow resource managers and researchers to better manage opportunities resulting from range-shifting
species before they potentially colonise.
64
Interactions between cleaners and client fishes
Kate S Hutson1, Alexandra S Grutter2, Thane A Militz1, David B Vaughan1
1. James Cook University, Douglas, QLD, Australia
2. School of Biological Sciences, University of Queensland, Brisbane, QLD, Australia
Fishes are constantly subjected to parasitic attack, pathogenic infections and associated injury. How fishes respond to these
challenges often influences their survival. Infected and/or injured fishes may engage in behaviours that mitigate parasite loads
and promote wound healing. Behaviours range from attempts to dislodge parasites against hard substrates, migrations to
actively alter the osmotic environment, or complex cleaning interactions with specialist ‘cleaners’. We estimated that global
cleaner diversity comprises 207 cleaner fish (from 106 genera representing 36 families) and 51 cleaner shrimp (from 11 genera
representing six families). Experiments in aquaria showed that cleaner shrimp clean during the day and night, whereas cleaner
fish are strictly diurnal in their cleaning, which permits a resurgence of parasite abundance on ‘cleaned’ host fishes the following
night. Cleaner shrimp also reduced the infection pressure of a parasitic monogenean flatworm by eating the parasite’s benthic
eggs and free-swimming infective larvae, implying that scavenging behaviour by shrimp has the potential to remove parasite life
stages on substrates and in the water column. Moreover, cleaner shrimp masticate parasite eggs, larvae and adults and render
them non-viable whereas parasite eggs can pass through the intestinal tracts of cleaner fish unabated in their capacity to hatch.
Although cleaner fish are believed to support wound healing on injured fish clients in the wild, cleaner shrimp may aggravate
injuries opportunistically on fish in aquaria, indicating that client fish may actively regulate these interactions. The diversity of
species that engage in cleaning symbiosis and the varied regulatory behaviours offered by cleaner fish and shrimp offer
substantial value to the fitness of client fishes and may be vital to temperate and tropical reef diversity.
65
How does metabolic phenotype and social interaction effect growth disparity of Spiny Lobster?
Audrey Daning Tuzan1, Quinn P. Fitzgibbon1, Chris Carter1, Stephen Battaglene1
Spiny lobsters can display large difference in growth rate which is thought to be associated with agonistic behaviour of dominant
individuals controlling a disproportional share of food resources. Recently it become clear that variability in the metabolic
physiology of individuals can an important factor influencing behaviour and growth of marine organisms and thus is an
important consideration for understanding intraspecific diversity of performance. However, the relationship between metabolic
phenotype and growth has not been previously examined in any spiny lobster species. We investigated the possible effect of
individual variation in metabolic rate and growth performance of juvenile Eastern spiny lobster (Sagmariasus verreauxi). In a
laboratory experiment, juvenile lobsters were randomly distributed into two rearing conditions; individual (n=17) and communal
(n=20). Growth performance, survival and feed intake was greater for juveniles were cultured communally demonstrating that
social interaction is important for promoting growth of lobsters. The relationship between growth and standard metabolic rate
showed positive correlation in individual cultured juveniles indicating a direct link between metabolic phenotype of individuals
and growth. In communal culture, the influence of social interaction outweighed the direct relationship between metabolic rate
and lobster growth. The results demonstrated that growth performance of spiny lobsters is affected by individual variation in
metabolic status but social behaviour plays a more dominant role in determining the growth of individuals.
66
Trophic ecology of a whale shark aggreagtion at Ningaloo Reef (Western Australia), from stable isotope anlaysis
Lara Marcus1, Patti Virtue1, 2, Peter Nichols2, Mark Meekan3, Heidi Pethybridge1, 2
1. Institute for Marine and Antarctic Studies, Hobart
2. CSIRO Ocean &Atmosphere, Hobart
3. Australian Institute of Marine Science, Perth
We investigated the trophic ecology of whale sharks using carbon and nitrogen-stable isotope analysis from both whale shark
sub-dermal tissue and an extensive set of potential prey including zooplankton and other pelagic organisms from Ningaloo Reef,
Western Australia, in two consecutive years (2013 and 2014). Results showed that the composition of stable isotopes of whale
shark sub-dermal tissue was not significantly different between years or sex. A positive relationship was however found
between δ13C and δ15N and shark total length suggesting ontogenetic shift with size. When comparing whale shark sub-dermal
tissue with potential prey isotopic signatures, δ15N values situated whale sharks as a secondary consumer similar to other
zooplanktivores organisms. An enrichment in δ13C values in whale shark sub-dermal tissue resulted in no match in isotopic
signatures between predator and potential prey. These results indicated that whale sharks might obtain part of their diet from
other sources than merely pelagic. Overall, stable isotope analysis combined with non-lethal sampling techniques have
demonstrated to be a good tool to examine trophic intravariability in large predators as well as to infer food web relationships.
67
Mucus in elasmobranch dietary studies using stable isotope analysis: preliminary findings from the giant manta ray
Katherine Burgess1, Andrea D Marshall 2, Michael B Bennett1
1. The University of Queensland, St Lucia, QLD, Australia
2. Marine Megafauna Foundation , Truckee, California , USA
Stable isotope analysis provides an insight into feeding ecology and trophic interactions and is fast becoming a preferred, nonlethal tool in elasmobranch research. Slow turnover tissues, such as muscle, are representative of a long-term average
(integrated) isotopic signal and do not represent recently ingested prey items. In comparison, tissues with fast turnover rates
can be used to provide insight into seasonal dietary shifts that coincide with changes in foraging grounds. Validated fast turnover
tissues in elasmobranchs include blood and liver, but these are difficult or impossible to sample in large free-swimming species.
In bony fishes, mucus has been shown to be a rapid turnover tissue of value in dietary studies using stable isotope analysis,
however, its utility in elasmobranch feeding studies is unknown. Here, we report the first attempt at processing mucus for use in
stable isotope analysis for any elasmobranch species. Mucus and muscle tissue were collected from giant manta rays Manta
birostris while on SCUBA. In comparison to muscle tissue the average mucus δ 13C was depleted, and was similar to surface
zooplankton δ13C values. No significant differences were found between muscle and mucus δ15N, indicating that M.
birostris feeds at the same trophic level irrespective of a change in the source of dietary carbon. Results suggest that M.
birostris mucus may be representative of a recent resource switch from a δ 13C-enriched food web to surface zooplankton. The
time period represented by isotopic values in different tissues is poorly understood for migratory elasmobranch species. Analysis
of mucus may provide insight into aggregation site use by elusive and threatened elasmobranch species, however, controlled
feeding studies are recommended to examine test the reliability of this approach.
68
Determining the functional limitations of using fatty acid profiles for diet determination with punch biopsies and degraded
tissue samples
Lauren Meyer1, Heidi Pethybridge2, Peter D Nichols2, Crystal Beckman3, Barry Bruce2, Charlie Huveneers1
1. Flinders University, Adelaide, South Australia
2. CSIRO, Hobart, Tasmania
3. South Australian Research and Development Institute, Adelaide, South Australia
Biochemical markers are used to investigate food web structure of many ecosystems and to describe the trophic ecology of an
increasing number of marine taxa. Fatty acids (FA) profiles are a valuable tool to study trophic interactions between marine
organisms. However, functional limitations and capabilities of these biomarkers must be assessed within the context of speciesspecific collection methods. We analysed FA in muscle tissue biopsies through non-lethal sampling of white shark (Carcharodon
carcharias) and investigated the minimum sample size needed to provide reliable measurements of FA profiles and the effects of
sample degradation over time. Muscle samples as small as 12 mg DW provided reliable and consistent FA profiles, while
connective tissue less than 40 mg DW yielded inconsistent profiles. Both amounts validate the suitability of FA analysis for use
with punch biopsies, and suggest the methods could be used with scalpel biopsies of smaller elasmobranchs. The integrity of FA
profiles in muscle and connective tissue samples were retained for the first three days, with differences in FA profiles appearing
over the following two days, including relative decreases in key FAs, making these degraded samples unreliable for accurate
determination of dietary sources. Together, these investigations determined the functional limitations of FA analysis within the
context of tissue collection methods available for a protected species from which tissue samples are logistically difficult to
obtain. This study provided key information to ensure reliable FA profiles can be obtained to assess the feeding ecology of highorder predators, including the white shark.
69
Examining diet variation in euryhaline and coastal elasmobranchs using fatty acid and stable isotope biomarkers
Sharon L Every2, 3, 1, Heidi R Pethybridge4, Christopher J Fulton3, Peter M Kyne2, David A Crook2
1. North Australia Marine Research Alliance, Darwin, NT, Australia
2. RIEL, CDU, Darwin, NT , Australia
3. Research School of Biology, ANU, Canberra, ACT, Australia
4. CSIRO, Hobart, Tas, Australia
Euryhaline and coastal elasmobranchs are high-order predators that play important roles in ecosystem function and assemblage
structure. Unfortunately, many of these species have declined in recent decades and are of increasing conversation concern.
Understanding the trophic ecology of elasmobranchs in estuaries and coastal waters is important to develop our understanding
of the ecological implications of these species and to inform conservation policy and management. Analyses of fatty acids (FA)
and stable isotopes (SI) of δ13C and δ15N in body tissues are increasingly utilized, non-fatal approaches for obtaining integrated
information on the dietary composition of animals (e.g., by collecting muscle biopsies or fin clips). In this study, we examined the
dietary composition of four species of elasmobranchs (Carcharhinus leucas, Glyphis garricki, G. glyphis andRhizoprionodon
taylori), and compared them with putative prey species via analysis of muscle biopsies. By correlating muscle FA and SI within
prey and sharks, we found significant seasonal differences in FA and SI profiles of prey species, but that such a pattern did not
occur in elasmobranches. Both Glyphis spp. had similar FA and SI profiles that indicate the use of fresh and estuarine prey. In
contrast, local prey species made only a minor contribution to the diet of C. leucas, suggesting that this species relies on
alternative food sources. There was little evidence of intra-specific dietary specialization in these species, which may be due to
the changes in sites and seasons of prey species. Our study shows that these sharks feed across multiple ecosystems,
congregating in productive sections of the river.
70
Developing robust and cost-effective methods for estimating the national recreational catch of southern bluefin tuna in
Australia
Andy Moore1, Kylie Hall2, Khageswor Giri2, Sean Tracey3, Lindsay Penrose1, Scott Hansen1, Peter Ward1, Ilona Stobutzki1, James
Andrews2, Simon Nicol1, Paul Brown2
1. Department of Agriculture and Water Resources, Canberra, ACT, Australia
3. IMAS, Taroona, Tasmania, Australia
Southern Bluefin Tuna (SBT) is an iconic species both domestically and internationally. The most recent stock assessment
estimated the spawning stock biomass at 9 per cent of unfished levels. SBT is listed as conservation dependent under the
Environment Protection and Biodiversity Conservation Act, endangered in New South Wales and threatened in Victoria. The
stock is subject to an international rebuilding plan under the Convention for the Conservation of Southern Bluefin Tuna.
Recreational fishing for SBT spans over 6,500 kilometres of Australia’s coastline and recreational fishing activity can be dispersed
and episodic. Dedicated surveys for estimating SBT catch have occurred in Victoria and Tasmania with catch statistics for the
other states coming from general angler surveys. SBT fishing is a low frequency activity and this characteristic has restricted the
inference on total catch of SBT from general angler surveys. Hence, the total national recreational catch has never been
quantified with the reliability needed for fisheries management.
A project to develop methods for estimating the national recreational catch of SBT has been completed. The project reviewed
survey options and trialled an on-site stratified random access point survey in South Australia. Data from this trial, expert angler
interviews, and commercial catch was used to model and test various sampling strategies. The methods used to develop an
optimal survey design for estimating SBT catch in Australia have application more generally for designing recreational angler
surveys when disparate sampling frames and episodic fishing activity are present.
71
Using ramp cameras to assess recreational fishing effort
Michael D. Smith1, 2, Paul W. Hamer3
1. Mezo Research, Melbourne, Victoria
2. University of Melbourne, Parkville, Victoria
3. Fisheries Victoria, Queenscliff, Victoria
Many coastal and estuarine fisheries around Australia are now dominated by recreational fishing. This poses a problem for
assessment and sustainable fisheries management because recreational catch and effort are difficult to track. While creel
surveys and diary angler-type approaches can provide information on catch composition and catch rates, critical information on
fishing effort is generally missing. This project has trialled the use of boat ramp cameras to obtain data on overall recreational
boat fishing effort in Port Phillip Bay and the adjacent Western Port Bay in Victoria.
Seven cameras have been installed since spring 2014. Each camera takes a photograph every 2 minutes, which results in well
over 20,000 images per camera each month. Due to the time-intensive nature of the image analysis (viewing), we have explored
sub-sampling approaches to provide an acceptable estimate of overall effort while requiring fewer images to be viewed.
We performed sub-sampling estimates of the total catch using 20 – 50 percent of the total available images, and tested
randomization routines using whole days or in hourly blocks, and also a routine which focussed more effort on times of
expected activity (pre-dawn and pre-dusk). Sampling in hourly blocks randomized across all days of the study produced
estimates with greater than 80 percent accuracy using less than 30 percent of total images, although the error rate increased as
the total effort in the underlying data decreased.
An alternative approach to reducing the total number of images is to use activity sensor software that is programmed so that
the cameras take photographs only when a specific type of motion is detected in a set field of view. We present preliminary
results on the performance of the activity sensor software, and prospects of this approach.
72
Improving the accuracy of recreational catch estimates with complementary surveys and auxiliary data on human dimensions
Fabian I Trinnie1, Karina L Ryan, Brent S Wise, Norm G Hall
1. Department of Fisheries, WA Government, Hillarys, WA, Australia
The accuracy of estimates of recreational catch and predictions of future catches can be improved by employing data from
complementary surveys and adjusting for human dimensions and spatial factors. Data on the recreational component of the
Western Australian fishery for western rock lobster (Panulirus cygnus) have been collected annually for 28 consecutive years
using a mail survey of randomly-selected licence holders. During the 2000s, the mail survey was complemented by phone-diary
surveys of licence holders selected from the same database using probability-based sampling. Research has focused on
expanding the recreational catch data collected in these surveys to a whole-of-fishery level. The auxiliary data relating to human
dimensions and spatial aspects of fishing, which were also collected in the surveys, have also provided a valuable time series on
fishers’ avidity, experience, age, residence, fishing method (e.g. potting, diving), fishing gear and technology, depth and location
of fishing. The extent of which these characteristics of both fishers and fishing activity can improve the estimates and predictions
of recreational catch for this fishery is now being explored. The use of complementary surveys, in combination with continued
collection, refinement, and application of human dimensions data, are strongly recommended for this and other recreational
fisheries.
73
Managing for change: the Tasmanian recreational fishery for rock lobster
Jeremy M Lyle1, Sean R Tracey1, Klaas Hartmann1
1. University of Tasmania, .Hobart, TAS, Australia
Recreational fishers are highly responsive to changes in fish availability, either increasing or decreasing targeted effort and/or by
switching between species. In Tasmania rock lobster support major commercial and recreational fisheries but over the past two
decades stocks have undergone dramatic changes in abundance. Legal size biomass doubled between 1995 and 2005 and then
almost halved over the following five years, influenced by poor recruitment. Catch rates for both sectors have declined and, for
the recreational sector, levels of catch and effort have fallen as the number of active fishers and average days fished per fisher
have declined.
The recreational fishery is concentrated off the east coast, a region where the stock is in poorest condition. Modelling indicates
that catches need to be reduced to facilitate stock recovery and a stock rebuilding strategy has been implemented. The strategy
includes a 200 tonne catch cap that is based on a notional resource sharing arrangement of 21% for the recreational sector (42
tonnes) and 79% for the commercial sector (158 tonnes). In an attempt to constrain recreational catches, east coast bag limits
have been reduced and recreational season length reduced by four months. However, modelling suggests that these measures
are unlikely to constrain recreational catches to the catch share. As stocks recover, recreational fishing pressure is expected to
increase with the potential to impact the rate of stock rebuilding, imposing significant challenges for resource management. In
this presentation we examine relationships between stock size, fisher behaviour and management of the fishery.
74
Crossing lines: a multidisciplinary framework for assessing migratory hammerhead sharks across jurisdictional boundaries
Andrew Chin1, Michelle Heupel2, Colin Simpfendorfer1, William White3
1. James Cook University, Douglas, QLD, Australia
2. Australian Institute of Marine Science, Townsville, QLD, Australia
The conservation and management of migratory species is complex and challenging. International agreements such as CITES and
CMS provide frameworks to manage highly migratory species, but management can be compromised by lack of data and
tractable mechanisms to integrate disparate datasets. Hammerhead sharks (Sphyrna spp.) are highly migratory species taken in
coastal and oceanic fisheries around the world and are listed in CITES and CMS. A large scale assessment of scalloped
hammerhead (S. lewini) and great hammerhead (S. mokarran) populations across northern Australia, Indonesia and Papua New
Guinea was conducted to inform management responses to CITES and CMS. A simple Integrative Assessment Framework (IAF)
was devised to systematically incorporate disparate data types across jurisdictions and create a regional synopsis. The IAF
amalgamated data from fisheries catch records, fishery independent research, shark control programs, market surveys, BRUVS
and citizen science data. Hammerhead populations are segregated by sex and size across the assessment area, with Australian
populations dominated by juveniles and small sized adult males, while Indonesian and Papua New Guinean populations
contained large adult females. The final IAF assessment stage introduced genetic and tagging data to produce conceptual
models of regional hammerhead movement and stock structure. Several viable hypotheses for regional stock structure and
movement patterns were produced, but more data are needed to identify the most plausible hypothesis. This work
demonstrates a simple conceptual framework for assessing migratory species, and highlights priority areas for management and
research of hammerheads in the Australasian region.
75
Genetics: a vital tool for understanding connectivity and the ability of a threatened marine species (Maugean skate (Zearaja
maugeana)) to withstand future challenges.
Kay Weltz, Jennifer Ovenden1, Jeremy Lyle2, Jess AT Morgan1, David A Moreno2, Dean C Blower1, Jayson M Semmens2
1. University of Queensland, Brisbane
2. IMAS, UTAS, Hobart, Tasmania, Australia
The Maugean skate (Zearaja maugeana) has been classified as Endangered by the IUCN and the Australian EPBC Act, based on
its low estimated population size and restricted range in one estuarine embayment in western Tasmania, Macquarie Harbour
(MH). Given Z.maugeana’s highly restricted distribution, this species is vulnerable to environmental changes caused by natural
and anthropogenic forces present in MH. With no knowledge existing on population characteristics of Z.maugeana, population
genetics was used to investigate habitat use, population connectivity, population structure, genetic diversity and effective
population size (Ne) of Z.maugeana in MH. Mitochondrial DNA (mtDNA) results showed no significant variation for 16
individuals for four gene regions, with a haplotype diversity (h) and nucleotide diversity (π) of zero within each region.
Genotyping results of 195 individuals using 8 microsatellites suggest the population in MH is one large, interbreeding population
with very low genetic diversity (Fst=0.35±0.2). Low genetic diversity in mtDNA and microsatellites could indicate a genome wide
lack of genetic diversity, which may reduce the ability of Z.maugeana to withstand future environmental changes.
Environmental DNA (eDNA) was investigated as an additional genetic tool for determining habitat use and connectivity of
endangered elasmobranchs in the wild. Zearaja maugeana eDNA was successfully amplified from as little as 1L of marine water
collected at depth in MH. Exponential decay models revealed that Z.maugeana eDNA persists 6.4 days in MH water, before
dropping below detectable limits of the assay. These results may be incorporated into the development of future eDNA assays
for the detection and management of threatened elasmobranchs. Overall, genetics is an important tool for investigating habitat
use and connectivity of populations of threatened marine species, providing vital information for conservation and management
at appropriate scales. With recent molecular technological advances, genetics can be incorporated into all population studies on
threatened marine species, without requiring extensive genetic expertise.
76
Inferring contemporary and long-term genetic connectivity from juveniles.
Pierre Feutry1, Oliver Berry2, Peter M Kyne3, Richard D Pillans4, Richard Hillary1, Peter M Grewe1, James R Marthick5, Grant
Johnson6, Rasanthi Gunasekera1, Nic Bax1, 5, Mark Bravington1
2. CSIRO, Perth, WA, Australia
3. Charles Darwin University, Casuarina, NT, Australia
4. CSIRO, Brisbane, QLD, Australia
6. Department of Primary Industry and Fisheries, NT Government, Darwin, NT, Australia
Understanding population connectivity using molecular markers has broad application in natural resource management. The
most popular approach has been indirect estimates of connectivity derived from allele frequencies. More recently, the spatial
distribution of parent-offspring and full-sibling (FS) pairs has been used to provide direct estimates of larval or juvenile
movements. In combination, these approaches potentially provide contemporary and long-term connectivity estimates. Here we
combine indirect estimates from whole mitogenome sequences and nuclear SNPs with direct estimates of adult and juvenile
movements from FS and half-sibling (HS) data for the Critically Endangered Speartooth Shark Glyphis glyphis. Over 350 juveniles
were captured from the three river systems in tropical northern Australia where this species is found. None of the 72 FS and 24
same-cohort HS pairs of juvenile sharks were captured in different rivers, suggesting strong river fidelity in juveniles. In contrast,
18 of the 121 cross-cohort HS pairs identified were captured between the two closest river systems (c. 150 km apart)
demonstrating recent male breeding movements between these rivers, but not more widely. Mitogenomic analyses revealed
river specific long-term female reproductive philopatry. Allele frequency differences in the nuclear SNP data were observed
between the river systems. However, between the two closest river systems, this only reflected the restricted movements of
juveniles since it was not evident when FS and HS pairs were discarded. Accounting for juvenile river fidelity, female philopatry
and the presence of two distinct gene pools is important for the management of this threatened species.
77
Genome wide SNPs reveal fine-scale population substructure in School Sharks (Galeorhinus galeus)
Floriaan Devloo-Delva1, Gregory E. Maes2, 3, 4, Sebastián I Hernández5, 6, Jaime S Mcallister7, Peter M. Grewe1, Robin B. Thomson1,
Pierre Feutry1
1. Oceans and Atmosphere, CSIRO, Hobart, Tasmania, Australia
2. Centre for Sustainable Tropical Fisheries and Aquaculture, Comparative Genomics Centre, James Cook University, Townsville,
Queensland, Australia
3. Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Leuven, Belgium
4. Center for Human Genetics, UZ Leuven- Genomics Core, KU Leuven, Leuven, Belgium
5. School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
6. Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Casilla 117, Coquimbo, Chile
7. Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, , University of Tasmania, Hobart, Tasmania,
Australia
School Shark (Galeorhinus galeus) is a semi-pelagic, highly migratory species with a widespread distribution in temperate waters.
Formerly an important component of the Australian shark fishery, Australian School Shark stocks have been depleted to below
20% of their virgin biomass. The recovery management plan for this species has impacted other shark fisheries where School
Sharks represent a significant bycatch, for example, in the Gummy Shark (Mustelus antarcticus) fishery. This has prompted
renewed efforts to develop management strategies through better understanding of stock structure and connectivity of School
Shark populations in Australian and New Zealand waters. To date, molecular based studies on Australasian School Shark
population structure yielded contrasting results and have suggested Australian and New Zealand individuals could be clustered
and managed as either one or multiple populations. Management practices in Australasian water reflect this uncertainty where
current management considers two separate Australian and New Zealand stocks. However, more recently there has been
discussion of managing them as a single stock for assessment purposes. Accurate determination of stock structure and
population connectivity is crucial to inform this decision. In this study, we assess of the genetic composition and population
connectivity between Australian and New Zealand School Sharks using genome-wide single nucleotide polymorphisms (SNP).
Between 2009 and 2015, 188 neonate and adult individuals originating from Australia (South Australia, West Tasmania and
South Tasmania) and New Zealand were collected and genotyped. Both neutral and outlier loci were analysed to detect finescale signals of connectivity and local adaptation. Our results indicate there may be a lower level of genetic connectivity than
previously assumed with outlier loci potentially indicating locally adapted groups at the regional level. Further investigations of
population structure among Australian and New Zealand sampling locations could help to guide management strategies
developed for the School Shark and Gummy Shark fisheries.
78
Microsatellites of megafauna: what does genetics tell us about Australian manta rays?
Amelia J Armstrong1, Christine L Dudgeon1, Michael B Bennett1, Kathy A Townsend1, Anthony J Richardson2, 3, Jennifer R
Ovenden1, 4
1. School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
2. School of Mathematics and Physics, University of Queensland, Brisbane, QLD, Australia
3. Oceans and Atmosphere, CSIRO, Brisbane, QLD, Australia
4. Molecular Fisheries Laboratory, University of Queensland, Brisbane, QLD, Australia
Reef manta rays (Manta alfredi) are a valuable ecotourism commodity in many areas of the world. Despite their value and
threatened species listing, much remains unknown with regards to local population sizes and movements. Reef manta rays
predictably aggregate at known sites seasonally, allowing for photographic mark-recapture, biopsy and tagging. Currently,
estimation of reef manta ray population size and movement relies largely on long term mark-recapture photographic databases.
Molecular genetic approaches provide a unique conservation tool for the study of threatened marine species. Not only can they
provide estimates of genetic effective population size (Ne), they can offer additional insight into critical parameters for
threatened species management, such as population structure and connectivity. In this study, we are using 10 microsatellite loci
to investigate the population genetic structure of reef manta rays from three locations of ecotourism value around Australia.
Small tissue biopsies were obtained from manta rays at Lady Elliot Island and Stradbroke Island in Queensland, and from Coral
Bay in Western Australia. Hypotheses of connectivity between locations were derived from the known photographic movement
history for each individual. Preliminary results will be presented testing for significant differences in populations of manta rays
on the East and West coasts of Australia and between two photo ID-connected populations on the East coast. Although this
study is ongoing, preliminary results emphasise the importance and value of molecular genetic approaches.
79
The Genetic Status of the Tiger Shark (Galeocerdo cuvier) in Australian Waters
Safia Maher2, 1, Mike Bennett1, Einar Nielsen3, Bonnie Holmes1, Julian Pepperell4, Jennifer Ovenden2
1. School of Biomedical Sciences, University of Queensland, Australia, Brisbane
2. Molecular Fisheries Laboratory, Brisbane
3. DTU AQUA National Institute of Aquatic Resources, Technical University of Denmark , Denmark
4. Pepperell Research and Consulting Pty Ltd, PO Box 1475, Noosaville BC, Australia
The tiger shark (Galeocerdo cuvier) occupies tropical and warm-temperate coastal and shelf waters throughout the world, and
like many large elasmobranch species, faces various anthropogenic threats, particularly fishing-related mortality.The population
structure and genetic diversity of G. cuvier is unknown and data allowing evaluation of the effect of current levels of exploitation
of the species is lacking. Mitochondrial DNA sequence data obtained from two molecular markers (control region and NADH
dehydrogenase subunit 2) was used to investigate the genetic population structure of the tiger shark across its range in Australia
as well past and present genetic diversity. Historical DNA extracted from old tiger shark jaws enabled analysis of temporal
changes in genetic diversity. Contemporary tiger shark samples were obtained from within the Coral and Tasman Seas on the
east coast, the Indian Ocean on the west coast and the Timor and Arafura Seas in the north. Concatenated sequence data from
86 contemporary G. cuvier samples revealed 12 haplotypes to use for population structure analysis. Analysis of molecular
variance identified significant population structure between East and West (Φ ST = 0.07879, P <0.05) and between West and
North (ΦST = 0.07989, P <0.05). Genetic diversity at the control region was higher in the West than the East in both modern and
historical samples; however, a temporal decline in diversity on the east (Historic; h=0.262, p=0.00403 and Modern; h=0.152,
p=0.00027) was identified using invaluable information from historical DNA. Overall genetic diversity was low compared to other
shark species.This study is among the first to provide crucial baseline data concerning the genetic status of tiger sharks in
Australian waters. The presented findings may have significant implications for fisheries management and conservation of G.
cuvier given the evidence of low and declining genetic diversity in eastern Australian waters.
80
Climate impacts and adaptation options for Australian fisheries – 25 years of progress
Alistair Hobday1
1. CSIRO Marine and Atmospheric Research, Hobart, TAS, Australia
Interest and research on the effects of climate change on Australian fish and fisheries has at least a 25 years history. Here I
review the progress over that time, focusing on a set of recommendations made at one of the first government-sponsored
workshops addressing climate concerns. The major issues were identified very early in the research history, and relatively, few
additional issues have been identified since that time. Progress in some areas has been as expected, while in others, we are still
grappling with the same ones. Recent research in Australia is leading the way internationally, and overall, the prospects for
adaptation are founded on sound science, with a range of options that mean radical transformation in Australian fisheries is not
likely for the next 25 years.
81
Key principles for undertaking marine research that enables knowledge exchange and evidence-based decision-making
Christopher Cvitanovic1, Jan McDonald1, Alistair Hobday2, Kelly Waples3, Peter Barnes4
2. CSIRO, Hobart
3. Department of Parks and Wildlife, Perth
4. Department of Parks and Wildlife, Exmouth
The conservation and sustainable management of the marine environment requires knowledge exchange among scientists and
decision-makers to enable learning and support evidence-based decision-making. Efforts to improve knowledge exchange have
often been hindered by a paucity of empirically-grounded guidance to help scientists and practitioners implement research
programs that actively facilitate knowledge exchange. To address this, we evaluated the Ningaloo Research Program (NRP),
which was designed to generate new scientific knowledge to support evidence-based decisions about the management of the
Ningaloo Marine Park in north-western Australia. Specifically, we evaluated (1) program outcomes, including the extent to which
new knowledge informed management decisions; (2) the barriers that prevented knowledge exchange among scientists and
managers; (3) the key requirements for improving knowledge exchange processes in the future; and (4) the core capacities that
are required to support knowledge exchange processes. We found that while the NRP generated expansive and diverse science
outputs directly relevant to the management of the Ningaloo Marine Park, very little has been integrated into decision-making
processes. Based on our findings we identify a set of principles that should be implemented as part of any applied research
program, including; (i) stakeholder mapping prior to the commencement of research programs to identify all stakeholders, (ii)
research questions to be co-developed by all stakeholders, (iii) implementation of participatory research approaches, (iv) use of
a knowledge broker, and (v) tailored knowledge management systems. We also identify the key individual, institutional and
financial capacities that must be developed to underpin successful knowledge exchange strategies.
82
Evaluating how the Murray-Darling Basin Plan is helping native fish
Katie Ryan1
1. Murray-Darling Basin Authority, Canberra, ACT, Australia
In 2017 five years will have swum by since implementation of one of Australia’s most significant and controversial water reform
policies, the Murray-Darling Basin Plan. This milestone brings expectation of an evaluation, which if done robustly will ease
anxieties and demonstrate the value of the policy as well as identify knowledge gaps and adaptive management opportunities.
However, evaluating how the Basin Plan is contributing to sustainable outcomes for native fish populations on a Basin wide scale
involves numerous complexities and requires much more than just analysis of monitoring data against Basin Plan targets for fish.
Life history requirements, factors external to water reform, ecological time lags and spatial variability are all being considered
when teasing out how the Basin Plan is making a difference. Understanding the level of confidence in the relationship between
flow and life history requirements and the likelihood and potential impact of external factors is critical, as is an understanding of
the management actions that have taken place as a direct result of implementation of the Plan. Thus, this evaluation is a
challenging yet exciting space where an understanding of science and management actions must intersect to ensure that the
evaluation is robust and meaningful to a public audience.
83
Using anglers to survey Murray cod: What’s the catch?
Patrick Ross-Magee1
1. University of Canberra, Canberra, ACT, Australia
Murray cod (Maccullochella peelii) are a nationally listed threatened species, as well as the most sought-after recreational
freshwater angling species in south-eastern Australia. Murray cod are well studied in the lowlands of the MDB, however little
research is conducted in upland environments. This is in part because of the difficulty in using traditional survey methods
(electrofishing) in the rocky, high gradient and narrow gorge country of upland rivers. With growing confidence in citizen
science, and increasing interest from recreational anglers to be involved in the management of their fishery, there is an
opportunity to develop novel cost-effective volunteer sampling techniques. This study used 24 volunteer anglers across 6 longterm monitoring sites in the upper Murrumbidgee River in the ACT, to capture and tag Murray cod during 3 events in 2015/16.
Immediately following the angling surveys, researchers conducted boat electrofishing surveys allowing a capture efficiency
comparison of the two sampling techniques. The mark-recapture data was also used to estimate site population. Across all 3
sampling events, 48 Murray cod were captured by anglers in 724 hours, while 149 Murray cod were captured by electrofishing in
37 hours. Angled fish length ranged from 295mm to 1140mm (median = 632.5mm), while electrofishing captured fish ranging
from 82mm to 1075mm (median = 349mm). 51 fish (34.2%) captured by electrofishing were juvenile Murray cod under the
minimum length of all angled fish. Although angling is a less efficient capture method, when used in conjunction with traditional
survey techniques it could provide the basis for increasing the scope and frequency of future monitoring programs, particularly
in upland rivers.
84
What's the future for the small, threatened wetland fish Nannoperca australis (southern pygmy perch)?
Charles R Todd1, John D Koehn1, Luke Pearce2, John R Morrongiello3, Lauren Dodd1, Paul Humphries4
1. Arthur Rylah Institute, Department of Environment Land Water and Planning, Heidelberg, Victoria, Australia
2. NSW Fisheries, Albury, NSW, Australia
3. School of BioSciences, Melbourne University, Parkville, Victoria, Australia
4. School of Environmental Sciences, Charles Sturt University, Thurgoona, NSW, Australia
Small fish species that have no commercial value are often overlooked in conservation management, despite serious concerns
about their long-term future. The Nannoperca australis (southern pygmy perch) of temperate south eastern Australia is
representative of many small freshwater fishes. We develop a structured population model for this species to assess risk of
localised extinction and assist in the decision making for their conservation management in NSW, Australia. The objectives of
this study were threefold: to develop a stochastic population model for Nannoperca australis; to determine what constitutes a
viable population for the species; and to use the model to provide guidance for the establishment of new populations, assess
the impacts on donor populations, and consider other conservation management actions. The model was sensitive to the
estimation of early life history survival for which there are no estimates from field data. Given uncertainty in some vital rates,
the modelling indicates that a population in stable habitat that would be expected to support 2000 female adults would be likely
to be viable and able to withstand some disturbance and possibly be used as a source population for reintroductions, however it
was found that with multiple disturbances and being used as a source population generates an 7.9% risk or extinction. A larger
stable habitat expected to support 8000 females with multiple disturbances and being used as a source population generates a
2.4% risk of extinction. A stable habitat expect to support 500 female adults may not be viable as multiple disturbances together
with being used as a source population generates a substantial risk of extinction of 24% and a very high probability of being
small, Pr(minimum population size ≤ 25) = 71%. If suitable habitat can be found or established, releasing 1000 female adults over
5 years would likely result in the establishment of a viable population. The model allows for a variety of reintroduction strategies
to be tested as well as other management options. This type of approach can be used to improve the conservation management
of many similar species worldwide.
85
Elevation and waterfalls structure fish assemblages in short-steep-coastal-streams
Brendan C Ebner1, James A Donaldson2, Helen Murphy3, Paul Thuesen4, Andrew Ford3, Jason Schaffer5
1. CSIRO and TropWATER, JCU, Atherton, QLD, Australia
2. TropWATER, James Cook University, Atherton, QLD, Australia
3. CSIRO, Land & Water, Atherton, QLD, Australia
4. Formerly: James Cook University, Cairns, QLD, Australia
5. TropWATER, James Cook University, Townsville, QLD, Australia
Elevation gradients including abrupt barriers such as cascades and waterfalls, are known to shape the composition of
amphidromous fish assemblages in tropical Pacific streams. We aimed to describe the structuring of fish assemblages in shortsteep-coastal-streams (SSCS) of the Australian Wet Tropics by snorkeling continuous lengths of three streams from the upper
tidal limit to the source. Greatest species richness consistently occurred in the lower course of streams, and while elevational
generalists were observed (Sicyopterus lagocephalus, Anguilla spp.) a number of elevational specialists, primarily sicydiine
gobies, were exclusively found in the mid to upper course. Subsequently, species assemblages were identified and used to
disentangle elevation and barrier effects on faunal distribution based on natural differences in stream profile. We also provide
preliminary evidence that the stream profile dictates the upstream limits of keystone diurnal predators capable of ascending
cascades and a subset of waterfalls, and that in turn this has implications for top-down effects on prawns and shrimps. We
conclude that the detection and mapping of sicydiine gobies poses a challenge for comprehensive conservation planning and
protection of regional fish diversity in SSCS of the Australian Wet Tropics.
86
At the junction where predators, temperate reefs and marine resource management interact
Natasha A Hardy1, Brendan P Kelaher2, Renata Ferrari1, Melinda Coleman3, Tina E Berry4, Michael Bunce4, Georgina Wood1,
Gwenael Cadiou5, Simon D Goldsworthy6, Bronwyn Gillanders7, Sean D Connell7, Will F Figueira1
1. School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
2. Centre for Coastal Biogeochemistry Research, National Marine Science Centre, Southern Cross University, Coffs Harbour, New
South Wales, Australia
3. Department of Primary Industries, National Marine Science Centre,, NSW Fisheries, Coffs Harbour, New South Wales, Australia
4. Trace and Environmental DNA (TrEnD) Laboratory, Department of Environment & Agriculture, Curtin University, Perth,
Western Australia, Australia
5. School of Environment, University of Technology, Sydney, New South Wales, Australia
6. South Australian Research and Development Institute, Henley Beach, South Australia, Australia
7. School of Earth & Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia
Recovering populations of large predators are indicative of productive ecosystems, and also bring with them crucial ecosystem
services and oft cascading trophic effects to biological communities. Understanding the role of predators in shaping ecosystem
processes is critical for effective marine resource management and therefore ecosystem conservation, a critical issue on highly
populated and human-impacted coastal areas. We investigated the trophic dynamics of two sympatric predators, Australian and
long-nosed fur seals, using DNA metabarcoding techniques to analyse their diets across multiple locations of recolonisation on
the south coast of NSW. To evaluate the potential for localised effects of predator aggregation sites on fish and temperate reef
communities, we also undertook surveys at fur seal haul-out sites and sites of relatively low fur seal activity. We found
considerable overlap of key prey groups in the diets of both seal species across sampling time at the most peripheral haul-out
site (Jervis Bay) and strong trophic linkages with coastal ecosystems due to the high prevalence of benthic, demersal and reefassociated prey. In contrast, diet composition of both seal species from the breeding colony (Montague Island) were more
consistent with foraging patterns for both species from more central parts of their geographic range. These results suggest there
may be different trophic interactions at newly recolonised sites compared to established colonies, with different outcomes for
marine communities and which may impact the way that we manage dynamic species and communities. We detected some
localised effects of fur seal haul-out sites on temperate reef communities, however, effects were not as strong as expected,
indicating that local initiatives for marine resource management are not necessarily severely compromised by recovering
populations of predators. Finally, there was considerable overlap in predator diets with important fisheries on the east coast of
Australia, highlighting a need to better evaluate this overlap and complex trophic interactions between multiple key players in
ecosystem processes.
87
Trophic ecology of coral trout: Is one sampling approach enough?
Jordan K Matley1, Colin A Simpfendorfer1, Aaron T Fisk2, Andrew J Tobin1, Floriaan Devloo-Delva1, Gregory Maes1, Michelle R
Heupel1, 3
1. Centre for Sustainable Tropical Fisheries and Aquaculture , James Cook University, Townsville, QLD, Australia
2. Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada
Understanding the ecological role and associated behaviours of aquatic animals is often difficult because sampling techniques
have inherent limitations. The goal of this study was to explore how different sampling approaches (passive acoustic telemetry
and dietary proxies) can be used in conjunction to provide a more refined account of fish behaviour. Fifty-eight acoustic
receivers were deployed at three reefs to monitor the movements of an economically significant species group – coral trout
(Plectropomus spp.; n≈150 individuals). Additionally, gut content identification (visual - n≈200 and genetic - n≈100) and stable
isotope analysis (n≈120 x three tissues) were completed over a two-year period to assess species-specific differences in feeding
ecology. By using multiple approaches, we found that broad resource and habitat selection trends differ between sympatric
species, but interestingly, the way they differ is unique to each species pairing. For example, at offshore reefs the space use of P.
laevis overlapped with P. leopardus, and they consumed distinct prey; while at inshore reefs, the space use of P. maculatus had
little overlap with P. leopardus, and they consumed similar prey. These findings demonstrate the value of using complimentary
sampling approaches to explore fish behaviour.
88
Extreme inverted trophic pyramid of reef sharks supported by spawning groupers
Johann Mourier1, Jeffrey A. Maynard2, Valeriano Parravicini2, Laurent Ballesta3, Eric Clua2, Michael Domeier4, Serge Planes2
1. Macquarie University, Marsfield, NSW, Australia
2. EPHE, PSL Research University, UPVD, CNRS, USR 3278 CRIOBE, Perpignan, France
3. Andromede Oceanology, Carson, France
4. Marine Conservation Science Institute, St Waikoloa, Hawaii
The extent of the global human footprint limits our understanding of what is natural in the marine environment. Remote nearpristine areas provide some baseline expectations for biomass and suggest that predators dominate, producing an ‘inverted
biomass pyramid’. The southern pass of Fakarava atoll – a Biosphere Reserve in French Polynesia – hosts an average of 600 reef
sharks, 2-3 times the biomass/ha documented for any other reef shark aggregations. This huge biomass of predators makes the
trophic pyramid inverted. Bioenergetics models indicate the sharks require ~ 90 tons of fish/year while the total fish production
in the pass is ~ 17 tons/year. Energetic theory shows that such trophic structure is maintained through subsidies and empirical
evidence suggests sharks must engage in wide ranging foraging excursions to meet energy needs. We used underwater surveys
and acoustic telemetry to assess shark residency in the pass and feeding behavior, and bioenergetics models to understand
energy flow. Contrary to previous findings, our results highlight that sharks may overcome low local energy availability by
feeding on fish spawning aggregations which concentrate energy from other local trophic pyramids. Fish spawning aggregations
are known to be targeted by sharks, but were previously believed to play a minor role representing occasional opportunistic
supplements. This research demonstrates fish spawning aggregations can play a significant role in the maintenance of local
inverted pyramids in pristine marine areas. Conserving fish spawning aggregations can help conserve shark populations,
especially if combined with shark fishing bans.
89
The trophic impact of an estuarine pelagic fish: a bioenergetics approach
Christopher Lawson1, 2, Stephanie Brodie1, 2, Iain Suthers1, 2, Hayden Schilling1, 2
1. School of Biological, Earth and Environmental Sciences, UNSW, Sydney, NSW, Australia
2. Sydney Institute of Marine Science, Sydney, NSW, Australia
Consumption rates are central to understanding the trophic dynamics of an ecosystem. The consumption rates of many pelagic
predators are unknown, despite their importance as ecosystem regulators and fisheries resources. We present a bioenergetics
model that estimates the consumption rates of a juvenile pelagic predator, tailor (Pomatomus saltatrix), during its obligate
estuarine phase. Using metabolic rate to parameterise the bioenergetics model, we determined the effect of body size and
temperature on the metabolic rate of tailor. Laboratory respirometry trials were used to measure the routine metabolic rate
(RMR; mgO2 kg-1 hr-1) of varying-sized tailor at 18, 21, 24, 27 and 30°C. The mass-specific RMR of tailor ranged from 135.9
mgO2 kg-1 hr-1 at 18 °C, to 395.9 mgO2 kg-1 hr-1 at 30 °C (mean body size of 80g). RMR increased exponentially with temperature,
with the Q10 estimated at 2.43. A linear regression between body mass and RMR was similar to previous generalised models of
metabolic theory, with a scaling exponent of -0.24.
The bioenergetics model estimated the energetic costs of metabolic and growth rates in relation to body mass, water
temperature, and prey type. A juvenile tailor during its ontogenetic estuarine phase needs to consume at least 3% of its body
weight daily. The bioenergetics model uses estimates of tailor biomass and mortality rates to scale to population size, thereby
quantifying the trophic impact of tailor in the estuarine system. Altering model parameters such as temperature, biomass, and
prey, integrates the seasonal and latitudinal variation of estuaries along eastern Australia. The results of these model
perturbations will be discussed. This bioenergetics model can be used to inform fisheries management of coastal resources, as
well as gain insight into the trophic dynamics of estuarine ecosystems.
90
Trout in a New Zealand river: Disturbers of the trophic peace or not?
Adam Canning1, Russell Death1
1. Institute of Agriculture and Environment - Ecology, Massey University, Palmerston North, New Zealand
Brown Trout (Salmo trutta) are a game fish that have been introduced all over the world, including New Zealand, to the joy of
many freshwater anglers. However, they are not loved by all camps with many arguing that they cause trophic cascades that
reduce ecosystem health and make rivers very green. This study investigates the relationship between brown trout and the food
web within a popular river in New Zealand’s capital city. We make use of a long term monitoring dataset to assess trophic
patterns over time and assess whether changes are driven environmental or biological factors. We then assemble and use a
quantitative food web model to simulate the effects of trout density on food web structure.
91
Physical and biological changes during the filling of a temperate upland reservoir following its enlargement
Sally Hatton1, Fiona Dyer1, Mark Lintermans1
Human population growth in a changing climate and subsequent increase in water demands have resulted in proposals for many
dams to be built, enlarged or refurbished. Recently, the value of reservoirs as refuges for threatened fish species has been
highlighted, but the trophic and biotic interactions that occur in reservoirs need to be understood if they are going to be
successfully managed as fish refuges. Recently Cotter Dam, in south-eastern Australia, was enlarged to twenty times its previous
capacity. This offered a unique opportunity to investigate changes in water quality, invertebrates, fish diet and food web as the
reservoir was in its initial filling stage. Sampling occurred in the early to mid-stage of the reservoir filling. Water quality data, in
particular nitrogen and phosphorus, were collected in autumn and spring, with supplementary data supplied by the water
owner. Micro- and macroinvertebrates were sampled in autumn and spring, along with Macquarie perch (Macquaria
australasica) and rainbow trout diet (Oncorhynchus mykiss) and stable isotope sampling (δ13C and δ15N). We found that, during
the early filling stage, nutrients in the reservoir increased, as did microinvertebrates. Macroinvertebrates remained stable in the
initial filling stages. Initially, fish diet changed from aquatic invertebrates to terrestrial items, particularly terrestrial oligochaetes.
By mid-filling there was a shift back to aquatic invertebrates and an increase in piscivory in trout. Stable isotope analysis showed
how the importance of terrestrial inputs changed throughout the filling stage. Understanding the impact that enlargement of
reservoirs has on fish diet and prey availability is important, as changes in food availability may affect fish condition, and
potentially their reproductive output. Knowledge gained from this project may be used to enhance future management
decisions surrounding reservoir filling and its implications for native freshwater fish species.
92
An alternative explanation for global trends in thermal tolerance
Nicholas L Payne1, James A Smith2
1. National Institute of Polar Research, Tokyo, Japan
2. University of New South Wales, Sydney, NSW, Australia
Ectotherms from higher latitudes can generally perform over broader temperature ranges than tropical ectotherms. This pattern
is thought to reflect trends in temperature variability: tropical ectotherms evolve to be ‘thermal specialists’ because their
environment is thermally stable. However, the tropics are also hotter, and most physiological rates increase exponentially with
temperature. Using a dataset spanning diverse ectotherms, we show that the temperature ranges marine and terrestrial
ectotherms tolerate (the difference between lower and upper critical temperatures, and between optimum and upper critical
temperatures) generally represents the same range of equivalent biological rates (e.g. metabolism) for cool and warm adapted
species, and regardless of latitude. This suggests latitudinal trends in temperature variability may not be the ultimate
mechanism underlying latitudinal trends in thermal tolerance. Rather, we propose that the reason tropical ectotherms can
perform over a narrower range of temperatures than species from higher latitudes is because the tropics are hotter.
93
Hypoxia tolerance in fish: assessing phenotypic diversity and temporal repeatability among populations
Geoffrey M Collins1, Alexander G Carton1, Timothy D Clark2
1. School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
94
Efficiency and versatility underpin the global ecological success of a single fish genus in extreme coral reef habitats
Christopher Fulton1, Peter Wainwright2, Andrew Hoey3, David Bellwood3
1. Research School of Biology, The Australian National University, Canberra, ACT, Australia
2. Evolution & Ecology, University of California, Davis, CA, USA
3. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
Phenotypic innovations can allow organisms to relax abiotic selection and facilitate their ecological success in challenging
habitats, yet we have relatively little evidence for this phenomenon at macroecological scales. We examined the relative
abundance of coral reef wrasses and parrotfishes (f. Labridae) across three ocean basins and the Red Sea to reveal the
consistent global dominance of extreme wave-swept habitats by a single fish genus - Thalassoma - which had abundances up to
15 times higher than any other sympatric labrid. Winged pectoral fins were a key part of this global success, since numerical
dominance by Thalassoma was contingent upon the presence of high intensity wave energy where winged fins allow for efficient
locomotion. Notably, the extent of ecological success varied with species richness and the presence of congeneric competitors.
While many fish taxa have evolved winged pectoral fins, Thalassoma appears to have combined efficient high-speed swimming
(to relax abiotic selection) with trophic versatility (to maximise exploitation of rich resources) to exploit and dominate extreme
coral reef habitats around the world.
95
Mechanistic understanding of climate driven range shifts: using thermal tolerances of rock lobster to predict future range
shifts
Samantha Twiname1, Quinn Fitzgibbon1, Alistair Hobday2, Chris Carter1, Gretta Pecl1
1. Institute for Marine and Antarctic Studies, Private Bag 49, Hobart, Tasmania
2. CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, Tasmania
Ocean warming is affecting marine species worldwide, with one of the most observed changes being alterations to species
geographical distributions. Understanding what drives these range shifts is key to predicting what may happen with future
warming. This study takes a mechanistic approach to understanding climate-driven range shifts, looking at the metabolic and
escape responses of spiny rock lobster and how they may change under different temperature scenarios. We examined the
metabolic physiology and escape response of the puerulus and juvenile stages of Jasus edwardsii, a common Tasmanian species
of spiny rock lobster, and Sagmariasus verreauxi, a species of spiny rock lobster extending its range into and further south in
Tasmania. The puerulus stage of the spiny rock lobster life cycle is an important transitional stage between the larval and
juvenile stages and understanding how ocean warming may affect their aerobic and swimming capacity allows us to better
predict future scenarios of population dynamics. Jasus edwardsii individuals of both life stages were tested at 16, 18, 20, 22, 24
and 26°C, and S. verreauxi individuals were tested at 22, 24, 26, 28 and 30°C. Intermittent flow respirometry was used to
determine aerobic scope (AS), excess post-exercise oxygen consumption (EPOC) and recovery times. Escape velocities were
determined from high speed stereo-video footage. The comparison between the physiologies of the two species indicates that S.
verreauxi have higher thermal tolerances than J. edwardsii, and this may facilitate further expansion of this range-shifting
species into Tasmanian waters with future ocean warming.
96
Is acclimation achievable? Long-term effects of combined hypoxia and temperature exposure on three freshwater fish.
Kayla L Gilmore1, Zoe A Doubleday, Bronwyn M Gillanders
1. Southern Seas Ecology Laboratories, School of Biological Sciences and Environment Institute, University of Adelaide, Adelaide,
SA, Australia
Research on the physiological thresholds of fish to hypoxia and temperature have focussed on short-term tolerances (<96
hours), with few researchers testing longer term exposures. Furthermore, fish exposed to persistent low levels of dissolved
oxygen may be able to acclimate over time. Juvenile golden perch (Macquaria ambigua ambigua), silver perch (Bidyanus
bidyanus) and Murray cod (Maccullochella peelii), key native freshwater species in the Murray Darling Basin, were acclimated for
a longer time than generally used (30+ days) to different temperatures (20, 24 and 28°C) crossed with normal (6-8mg L-1) and
hypoxic conditions (3-4mg L-1). Acclimation ability of Murray cod was also tested after 7 and 14 days of hypoxia exposure.
Responses to hypoxia and thermal stress were measured for behaviour, mortality during the acclimation period and aerobic
capacity (using resting respirometry). Murray cod and golden perch exhibited high tolerances to hypoxia during behavioural
tests, while, silver perch did not survive more than 3 weeks exposure during the initial acclimation period. Longer term exposure
to hypoxia improved the tolerances of golden perch during behavioural tests, however, Murray cod typically exhibited poorer
tolerances the longer they were acclimated. Murray cod were most tolerant to hypoxia at the lowest temperature (20°C) and
shortest exposure time. While prior exposure to hypoxia may allow fish to cope with hypoxic conditions better in the long-term,
a short acclimation time resulted in the greatest tolerances for this study, suggesting resilience to hypoxia might decrease as a
function of exposure time. Observed species-specific responses illustrate the need to consider tolerances and acclimation
abilities of known sensitive species within a system to prevent mass mortalities of fish through better management of
waterways.
97
Adaptive divergence in swimming performance and body shape of river and isolated reservoir populations of Australian smelt
(Retropinna semoni)
Daniel P Svozil1
1. Charles Sturt University, Lavington, NSW, Australia
Modification of river systems through reservoir construction has given rise to altered ecosystems, characterised as slow flowing
or still-water habitats. Fish populations isolated in reservoirs can exhibit adaptive divergence from the source population and
flow velocity may be an important driver of this divergence, leading over time to functional and morphological trait changes.
Several studies have demonstrated that fish from populations living in still and flowing habitats are substantially different in
average body shape. It is widely assumed that selection favours body shapes that confer optimum swimming ability in a
particular environment, thereby enhancing a population’s fitness and persistence.
The aim of this study was to test the hypothesis that variation in body shape predicts divergence in swimming performance
between river and isolated reservoir populations of Australian smelt (Retropinna semoni). Fish were sampled from 6 rivers and 6
reservoirs across South Eastern Australia.
Geometric morphometric analysis of 16 homologous landmarks was used to compare average body shape among these
populations, while swimming performance was assessed using the critical swimming speed (U-crit) test to determine if body
shape was a predictor of swimming performance.
River and reservoir populations of Australian smelt had significant differences in swimming performance. However, geometric
morphometric analysis revealed that body shape of fish did not consistently differ between river and reservoir populations.
These results indicate that morphology does not necessarily predict swimming performance and other physiological factors may
be involved in determining swimming performance.
This study provides insights into the relationship between morphology and swimming performance of Australian smelt living
under different extremes of flow velocity. The role of swimming performance in life-sustaining activities and the potential microevolutionary consequences of human-induced habitat modification are discussed.
98
Love between my brothers and my sisters, all over this river.
Alan Couch1, Fiona Dyer1, Mark Lintermans1
1. Institute for Applied Ecology, University Of Canberra, ACT, Australia
Analysis of many single nucleotide polymorphisms (SNPS) identified using a genome reduction technique and next generation
sequencing (NGS) can provide good quality cost effective estimates of a pair of individuals being a full sibling, half sibling, or a
parent-offspring dyad in a sufficiently large group of conspecifics. If that set is temporally constrained to a set that cannot
include parents or offspring, we can infer, with a high degree of certainty, full sibling or half sibling status. If this is combined
with appropriate meta-data a novel and useful way of studying movement, population and mating strategies inter alia, becomes
available.
In this study we calculate sibling status of 243 Murray Cod larvae from a 60 km reach of the upper Murrumbidgee River, from
years 2011-2013, and use associated meta-data to infer details about mating strategy, dispersal, and the correlation of
biogeochemical signatures in larval otolith cores with relatedness.
99
How low do we go- the challenge of passing juvenile fish upstream in sub-tropical/tropical Australia.
Tim Marsden1, Andrew Berghuis2, Claire Peterken
1. AFPS, Shoal Point, QLD, Australia
2. Aquatic Biopassage Services, Bundaberg, QLd, Australia
The provision of fish passage in Australia has traditionally focussed on adult and sub-adult fish of a number of iconic species such
as murray cod, golden perch, barramundi and mullet. However, there are a wide range of other species whose post lavae
juveniles are undertaking upstream migrations from estuarine habitats into lowland freshwater habitats in Queensland. Species
such as empire gudgeons, long-finned eels, bony bream, anchovies, mangrove jack, striped mullet and barramundi have
juveniles that are very small when entering freshwater. These fish are often encountering barriers when they are as small as
8mm long, with their successful passage crucial to reducing predation rates and maximising productivity of the species. In
extreme cases barriers can completely block these life stages and lead to a collapse in the species populations within a
catchment. Providing passage for these extremely small fish has required a rethink of traditional fish passage options, with a
focus on very low turbulence and roughened fishways that cater for the micro habitats that these fish use to move upstream.
We outline the options available for provision of fish passage for these fish and how they have successfully have been used at
sites throughout Queensland.
100
Cue but no follow- through: the challenge of movement opportunity in the northern Murray-Darling Basin
Kate Hodges1, Ryan Woods1
1. Department of Science, Information Technology and Innovation, Brisbane, QLD, Australia
In dryland river systems fish are isolated in waterholes and can only undertake longitudinal movement during flow events and
subsequent reconnection. These events may provide cues for fish to move, but flow regime modification and artificial barriers
severely reduce movement opportunities. We are investigating what flow attributes both cue fish movement, and provide
opportunity for that movement to be realised in the lower Balonne system of the northern Murray-Darling Basin. We use an
acoustic telemetry array to track movements of 240 individuals of carp, yellowbelly (Macquaria ambigua), spangled perch
(Leiopotherapon unicolor), and Hyrtl’s tandan (Neosilurus hyrtlii). During no-flow conditions local-scale (2-10 km) movement
was significant, with some individuals continuously moving throughout the length of a waterhole. Recruitment of yellowbelly
and spangled perch was also recorded. A late summer flow provided opportunity for larger-scale movement, but the majority of
tagged fish remained in their starting waterhole during the event. Hyrtl’s tandan however migrated up to 40 km upstream on
the flow, and returned to their original location in the same week the flow subsided. There was no clear upstream or
downstream preference for carp or spangled perch, but some carp moved large distances downstream (>100km). We discuss
the implications of these results for population connectivity and recolonization of habitats in intermittently flowing rivers, and
examine the question of how flows for fish movement can provide both cue and opportunity in a modified system. Results will
inform water resource planning in the lower Balonne floodplain.
101
Designing fishways for floodplain species of the Lower Mekong Basin
Lee Baumgartner1, Douangkham Singhanouvong2, Garry Thorncraft3, Tim Marsden4, Oudom Phonekhampheng3
1. Charles Sturt University, Thurgoona, NSW, Australia
2. Living Aquatic Resources Research Centre, Vientiane, Lao PDR
3. National University of Laos, Vientiane, Lao PDR
4. Australasian Fish Passage Services, Mackay, Queensland, Australia
River development in Lao P.D.R. has led to construction of numerous water regulation devices (over 10,000) which limit
migratory fish movement. Movements of fish (and other aquatic animals) between rivers and floodplains is subsequently
restricted, or may be entirely prevented, and this has led to severe declines in fish production in many areas. Fish-passage
technology has the potential to enable movement of migratory fish past these low-level (less than 6 m) barriers. Consequently,
fisheries agencies are interested in increasing capacity to design, manage and operate fish passage facilities on new and existing
low-level water control structures. The first fishway in Lao P.D.R. was constructed and assessed at a wetland regulator between
2011 and 2014. Over 170 species, from a range of size classes, were captured within the fishway. Many species successfully
recolonised a wetland which had been previously disconnected by regulator construction. But not all species were able to
ascend, and local hydrology substantially impacted fishway effectiveness. These observations suggests that fishways may be an
important tool for increasing fisheries productivity in the Lower Mekong Basin. But capturing a high number of migratory
species, with a range of different swimming abilities, indicates that strategies to suit all fish will require diverse and flexible
solutions.
102
Migration phenology and biomass estimation of upstream migrating prawn (Macrobrachium spinipes) in a tropical north
Australian river
Peter A Novak1, Michael M Douglas2, Bradley Pusey2, Erica A Garcia 1, Peter Bayliss3, David Crook1
1. Charles Darwin University, DARWIN, NT, Australia
2. University of Western Australia , Perth, WA
3. Commonwealth Scientific and Industrial Research Organisation, Brisbane
The amphidromous river prawn, Macrobrachium spinipes (known locally as cherabin) is a large bodied and abundant tropical
prawn species occuring throughout northern Australia. The species supports a significant recreational fishery and is a critical
prey species for predators a such as Lates calcarifer. We investigated the upstream migration of Macrobrachium spinipes in the
Daly River, Northern Territory, to determine migration phenology, estimate migration biomass and if the migrating shrimps were
transporting marine derived carbon upstream.
Monthly observations and sweep net sampling over two years revealed that the migration of juvenile M. spinipes occurred
during extended periods of declining discharge during the wet season and specifically, occurred en-mass after the wet season,
when stream discharge was returning to base flow. The en-mass migration occurred over a period of 4-6 weeks between MarchMay. This period was targeted for fine scale sampling using fyke nets. Analysis of environmental descriptors and migration
biomass consistently found discharge as the strongest predictor of biomass, while moon illumination and cloud cover were also
found to be significant predictors. An estimated 15-20 million shrimp migrated upstream during the period, transporting
approximately 100 kg of carbon and 28 kg of nitrogen. Two different methods were trialled to determine if marine carbon was
transported upstream; sulphur stable isotopes and strontium isotope ratios. No evidence of marine carbon was found through
either method employed.
While we found little evidence the migration of the amphidromous prawns was transporting marine derived energy and
nutrients upstream, the migration was providing millions of individuals that likely constitute an important process subsidy to the
river system.
103
Rehabilitating passage for migrating Galaxias (family: Galaxiidae) through a 70 m pipe-culvert
Frank Amtstaetter1, Justin O'Connor1, Dan Borg, Ivor Stuart1, Paul Moloney1
1. Arthur Rylah Institute for Environmental Research, Heidelberg, VIC, Australia
Movement through streams is critical for the maintenance of diadromous fish populations. Numerous fish passage improvement
techniques exist and managers require knowledge of their effectiveness to conserve diadromous species. The passage success of
young-of-year (YOY) Galaxias sp. through a pipe-culvert was monitored using a mark-recapture technique, before and following
the creation of a pool within the culvert, to investigate whether fish passage improved compared to a control site. A lateral ridge
rock-ramp fishway was installed downstream of the culvert to decrease water velocity within the culvert and baffles were
installed in the upstream portion of the culvert to provide refuge from higher water velocity at this location. The passage success
of YOY Galaxias sp. increased following these treatments to similar levels observed at a control site. Field evaluation and
demonstration of the effectiveness of the fishway and baffles on a 70 m culvert provides managers with an important case-study
to further adopt this technique to improve fish passage on a broader scale and fills a knowledge gap in the primary literature
relating to the success of this technique.
104
Science informs restoration of a fragmented ecosystem: a fish passage case study from an estuarine barrage
Chris Bice1, BrentonBrenton Zampatti1, Martin Mallen-Cooper2
1. SARDI Aquatic Sciences, West Beach, SA, Australia
2. Fishway Consulting Services, NSW
Dams, weirs, barrages and a multitude of other regulating structures fragment riverine and estuarine ecosystems, and obstruct
the movement of fish. Fishways are used worldwide to facilitate fish movement and partially mitigate the impact of barriers.
Implementing effective fish passage is reliant on knowledge of migratory fish, including spatio-temporal patterns of movement,
behaviour and physiology. The early history of fishway construction in Australia provides numerous examples of fishways that
were designed in the absence of such scientific knowledge, and consequently, resulted in ineffective structures.
The Murray Barrages, at the terminus of the Murray-Darling Basin, are long (7.6 km collectively), low-level (~1 m) structures that
separate the freshwater Lower Lakes from the Coorong Estuary and Southern Ocean, and represent significant barriers to fish
movement. From 2003 to the present, the barrages have been the subject of substantial investment in fish passage, with a total
of 11 fishways either completed or under construction. Throughout this period, monitoring and research have greatly improved
knowledge of migratory fishes and fishway function at the site, leading to refinements in models of fish movement and fishway
hydraulics. Ultimately, this has led to improved fishway design, as well as more environmentally sensitive operation of the
barrages.
Whilst the collection of scientific data was fundamental in achieving this outcome, the dissemination of this information and
collaboration between scientists, natural resource managers, engineers and river operators was equally important. We provide a
summary of the science used to inform fish passage at the Murray Barrages with a focus on the importance of collaborative
relationships and lessons learned throughout.
105
Fish need water: Developing and delivering flows for fish
Anthony Townsend1, Katherine Cheshire2, Iain Ellis3, Craig Copeland4, Liz Webb2
1. NSW Department of Primary Industries, Fisheries NSW, Tamworth, NSW, Australia
2. NSW Department of Primary Industries, Fisheries NSW, Queanbeyan, NSW, Australia
3. NSW Department of Primary Industries, Fisheries NSW, Buronga, NSW, Australia
4. NSW Department of Primary Industries, Fisheries NSW, Wollongbar, NSW, Australia
The majority of native fish populations in the Murray-Darling Basin are in a poor condition. Planning processes currently being
developed as part of Basin Plan implementation provide the opportunity to improve flow regimes and contribute to the
restoration of native fish populations. To effectively manage water for native fish, we need to understand the flow drivers that
support healthy fish populations. The Fish and Flows projects completed by NSW DPI-Fisheries used the latest management and
scientific information to develop an understanding of the relationships between hydrology, life history requirements and
population dynamics for native fish. As part of this process, native fish were classified into flow related functional groups based
on the biological, hydrological and hydraulic requirements needed for spawning, recruitment, movement and maintenance
outcomes. Using this information, a management framework was developed, defining the ecologically significant components of
the flow regime and the life history outcomes they supported for different fish groups. The use of this framework at regional
scales, in combination with site specific information, will guide water management decisions that support the recovery of native
fish in a healthy working Basin.
106
Sometimes fish need more than water: Supporting flow management with complementary actions to enhance fish outcomes
Iain Ellis1, Katherine Cheshire2, Anthony Townsend3, Craig Copeland4, Liz Webb5
1. DPI Fisheries NSW, Buronga, NSW, Australia
2. DPI Fisheries NSW, Queanbeyan, NSW, Australia
3. DPI Fisheries NSW, Tamworth, NSW, Australia
4. DPI Fisheries NSW, Wollongbar, NSW, Australia
5. DPI Fisheries NSW, Queanbeyan, NSW, Australia
Water is the most fundamental requirement for fish; however fish won’t survive unless their habitat, food, and life-cycle
requirements are also met. Environmental flows can contribute to restoring more natural flow regimes and variability within
aquatic habitats. They can also increase connectivity, enhance productivity and improve water quality. The potential to achieve
more sustainable long-term ecological outcomes through improved water management may be further enhanced by
undertaking parallel complementary actions that address additional threats to native fish. These additional activities include
(amongst others) habitat restoration and enhancement (e.g. re-snagging, instream and riparian zone management); mitigating
cold water pollution or hypoxic black water impacts; improving fish passage and connectivity; screening diversions to minimise
fish entrainment; pest species control, and; conservation stocking or translocations in cases where native species are unlikely or
unable to recolonise rehabilitated habitats.
As part of recent water management activities, NSW DPI Fisheries staff are trialing a range of associated complementary actions
including manipulation of wetland hydrology, inlet screening (to exclude colonisation by adult carp, and thus improve water
quality and promote macrophyte health) and stocking or translocation of native fish. These complementary actions aim to
support native fish outcomes from improved environmental water management in the lower Murray River reaches of NSW.
Some outcomes of these activities will be explored, demonstrating how native fish benefits can be enhanced by water
managers, land managers and fish ecologists working together to return native fish to the Murray-Darling Basin.
107
Bush Blitz fish surveys across remote northern Australia: scientific discovery, management outcomes and community
engagement
Michael Hammer1, Glenn Moore2, Jeff Johnson3, Jo Harding4
1. Museum & Art Gallery of the Northern Territory, Darwin, NT, Australia
2. Department of Aquatic Zoology, Western Australian Museum, Welshpool, WA, Australia
3. Ichthyology, Queensland Museum, South Brisbane, Qld, Australia
4. Bush Blitz, Australian Biological Resources Study, Director of National Parks, Canberra, ACT, Australia
Bush Blitz is a pioneering biodiversity discovery and knowledge program based on a cross-sector partnership of government,
non-government organisations, industry and science (major partners are the Australian Government, BHP Billiton's Sustainable
Communicates and Earthwatch). It involves a continent-wide multi-disciplinary survey program and a range of follow up
taxonomic and educational programs aimed at better management, conservation and awareness of Australian fauna and flora.
Some 29 Bush Blitz expeditions have been undertaken, including six across northern Australia which have included fish as a
target group (2012–2015). These surveys occurred on large, remote and often very rugged areas of the central deserts (Henbury
Station), Top End (Fish River Station, Wongalara Sanctuary, Judbarra-Gregory National Park), East Kimberley (Karunjie and
Durack River stations) and Cape York (Olkola Country), across a combined area of some 3.7 million hectares! Freshwater fish
diversity in Australia increases dramatically in the tropical north, and results to date indicate that there is still much to be
documented in terms of the species baseline. The surveys recorded areas of significant fish biodiversity, identified several
unique forms that may represent new species, uncovered important information on narrow range endemic species, collected
high quality morphological and DNA material to contribute to broad systematic reviews of the Australian fish fauna, and
developed imagery to help promote fishes and aquatic habitats. Indigenous rangers work alongside researchers in the field
sharing knowledge and expertise. Information from surveys is provided back to land managers and traditional owners to assist
with property management and feeds into public data portals such as the Atlas of Living Australia. School teachers also work
alongside researchers teaching live back to their classrooms via Skype and online blogs as part of the Bush Blitz TeachLive
program. Partnerships and engagement are a key part of the success of Bush Blitz.
108
Harnessing ecological knowledge to inform fish-flow management
John Koehn1, Charles Todd1, Scott Raymond1, Stephen Balcombe2, Brenton Zampatti3, Ivor Stuart1
1. Arthur Rylah Institute, Heidelberg, VIC, Australia
2. Australian Rivers Institute, Griffith university, Brisbane
3. SARDI, Adelaide, SA, Australia
There is always a need for the ‘best available science’ to inform environmental management. Getting it there, however, is
another issue, and outdated data, knowledge, and ecological concepts can compromise the potential success of management
actions. Within the Murray-Darling Basin (MDB), the Basin Plan and its watering strategy are being deployed for the
rehabilitation of aquatic ecosystems. This is occurring at a speed rarely previously seen and is testing researchers and managers;
especially in developing flow objectives and monitoring response. Rehabilitation of native fish populations is considered a
primary goal of the Basin plan. To aid in the management of flow regimes for fish outcomes, contemporary and historical data
have been collated, and conceptual and population models developed, to enable prediction and test outcomes within an
Adaptive Management framework. This has occurred through literature searches, expert workshops (14 so far), talking, talking,
talking (over 70 fish scientists and managers to date) to collect data, knowledge and experience to assist with model
development. This process is being undertaken for nine native fish species of the MDB (Golden perch, Silver perch, Murray cod,
Trout cod, Macquarie perch, Freshwater catfish, Southern pygmy perch, Olive perchlet, Murray hardyhead). In addition, we have
also queried managers to determine what they want from researchers in relation to fish and flows. This can be summarised as:
provision of robust, evidence-based information (research and monitoring) and timely, relevant advice in simple terms;; be
prepared to ‘give things a go’; and have a proactive, collaborative approach to determining water management. Key knowledge
gaps for research were also identified. Stronger concluding sentence?
109
Dams, rainfall, fires and fish: the links and opportunities for building resilience.
Stephen Beatty1, Mark Allen2, David Morgan1, Alan Lymbery1
1. Murdoch University, Murdoch, WA, Australia
2. Western Australian Museum , Perth, Western Australia, Australia
Most dams have major ecological impacts and their removal would greatly benefit riverine ecosystems. While in global terms
we are still beavering away, in some parts of the world, dam removal now outpaces their construction and the diminishing cost
efficiency of dams (and increasing recognition of their impacts) in drying regions may increase the rate of removals. However,
while often hotspots for alien species and unfavourable to native species, artificial lentic habitats created by dams and other
artificial lentic habitats can also act as refuges for aquatic fauna. Using the severely drying south-western Australia as a case
region, we highlight that artificial refuges can be very important to native fishes, and contend their value may actually increase
in the future due to the influence of climate change. Examples highlighted include fire-fighting waterpoints that offer critical
dry-season refuge for threatened species, and large water supply dams that are free from alien piscivores (by eradication or
luck). We argue that in regions where the major impact of climate change will be to reduce streamflow and where fishes can
readily utilise lentic habitats for refuge or recruitment, there is potential to harness artificial waterbodies to achieve
conservation outcomes while not jeopardising other values.
110
Sawfish in Papua New Guinea: what we know and where to next
William White1, Sharon Appleyard1, Leontine Baje2, Benthly Sabub2
During a large-scale project on the shark and ray fisheries of Papua New Guinea which commenced in 2014, records of sawfish
catches were collated and anecdotal information from fishers collected. Tissue samples, photographs and morphometric
measurements from dried rostra and/or fins were taken from any sawfish observed during artisanal surveys. Also, an observer
program on prawn trawlers in the Gulf of Papua collected data and samples from any sawfish captures. All four species known to
occur in the area (Anoxypristis cuspidata, Pristis clavata, P. pristis and P. zijsron) were recorded in the fishery
catches. Anoxypristis cuspidata was by far the most abundant species caught. Most records were from the Gulf of Papua but
records also taken from Manus, Rabaul and Bougainville. The difficulties in collecting such data in Papua New Guinea and the
best way to continue acquiring good data and providing capacity building tools are discussed.
111
Come find me: Defining habitats and habitat use for Chondrichthyans
Melissa C Marquez
Over the last few decades, a key part of risk assessment is evaluating the distributional overlap of fish with the commercial
fisheries, where fish distribution is influenced by habitat use. We synthesise published observations of habitat use for different
life history stages of Chondrichthyans and hypothesise the associated catch composition in terms of sex, size, and maturity. We
then searched for these catch compositions and locations using New Zealand research vessel catch data. Results show that some
life history stages and habitats can be identified, whereas others cannot. More results will be presented at the conference.
112
Reproductive cycle of Urolophus cruciatus in south-eastern Australia.
Fabian I Trinnie1, Terence I Walker, Paul L Jones, Laurie J Laurenson
1. Department of Fisheries, WA Government, Hillarys, WA, Australia
Observations of synchronous rapid growth of embryos and ovarian follicles in pregnant females during the half-year December‒
May leading to parturition, ovulation, mating and fertilization suggests Urolophus cruciatus has the capacity for an annual
reproductive cycle. Conversely, the higher proportion of the pregnant females in the population carrying eggs than carrying
embryos in utero during December‒May and all pregnant females in the population only carrying eggs in utero during June‒
November indicate a longer reproductive cycle. Analysis based on the usual assumptions implies that the species most likely
exhibits a biennial cycle with ~18-month period of diapause following ovulation prior to ~6-month period of rapid
embryogenesis. However, it is feasible that the period of the cycle is triennial with ~30-month period of diapause or alternatively
diapause varies among individuals and varies from year to year. Rather than exhibiting a fixed-term reproductive cycle where
obligatory diapause leads to parturition timed every year to provide favourable conditions for neonates, as suggested for several
other chondrichthyan species, U. cruciatus may exhibit facultative diapause where the period of diapause and hence the
reproductive cycle varies depending on the prevailing environmental conditions or density-dependent factors as described for
many terrestrial species. Urolophus cruciatus is highly matrotrophic (>4000% wet mass gain from ovum to full-term embryo),
litter size (1‒4) increases with maternal length, sex ratio among embryos is 1:1, and male breeding condition varies seasonally
with peak sperm production coinciding with female ovulation.
113
How do Port Jackson sharks find their home?
Catarina Vila Pouca1, Culum Brown1
Benthic shark species have long been understudied, especially concerning their movement ecology. While it was generally
assumed they have small scale movements and limited ranges, recent studies have rendered this idea erroneous. In eastern
Australia, Port Jackson sharks undertake seasonal migrations of hundreds of kilometres in a few weeks, and aggregate yearly in
shallow rocky reefs off the NSW coast during the austral winter–spring season to breed. Interestingly, in the Jervis Bay Marine
Park, NSW, both males and females have small home ranges and show over 90% site fidelity during the breeding season and
from year to year. To better understand their fine scale movements and homing abilities, we displaced eight Port Jackson sharks
3-7 km from their home reef in Jervis Bay and used active acoustic telemetry to track their movements following release. Some
sharks were displaced to different reefs in the bay, while others were released in deep sandy areas in the middle of the bay, and
displacements were done in the morning or at dusk. Tagged sharks alternated between stationary and travelling states upon
release, with most activity observed after sunset. Most sharks stopped moving once they reached a rocky area, but all returned
to their capture location, even those released on reefs with habitat very similar to their home reef. This is the first study to
experimentally test a benthic shark species’ ability to return home, and our preliminary results show Port Jackson sharks did not
have a preferred compass bearing towards their home reef during the initial hours after displacement. This finding suggests they
might not have a cognitive map of the whole bay and need to reach a familiar area to orient and navigate home.
114
Contextually-specific variations in white shark activity measured by 3D-acceleration logger
Charlie Huveneers1, Yuuki Watanabe2, Nicholas L Payne2, Jayson Semmens3
1. School of Biological Sciences, Flinders University, Bedford Park, SA, Australia
3. Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, Hobart, Tasmania, Australia
Wildlife tourism is one of the fastest growing sectors of the tourism industry. White sharks, Carcharodon carcharias, have
become a key attraction to wildlife tourism, which often occurs at important shark aggregation areas. In South Australia, the
intensity of cage-diving activities more than doubled around 2007 from about 120 days of operations per annum to 265 days.
Recent studies assessing the effects of such expansion showed that cage-diving operations can affect the behaviour and
residency of white sharks. It is, however, unknown whether such changes are detrimental to sharks. We deployed activity
packages encompassing high frequency acceleration and swim speed loggers, depth and temperature recorder, and animalborne camera to describe the fine-scale behaviour of white sharks at the Neptune Islands and assess whether cage-diving
tourism changes the energy expenditure of white sharks due to increased activity. Ten sharks were fitted with activity packages
for deployment periods ranging from 30 minutes to ~40 hrs (mean 22 hrs). A range of behavioural modes were recorded and
varied between and within individuals. Strong accelerations were observed throughout the day and night. Bait chasing and a
natural predation were recorded by the loggers and camera allowing to allocate accelerations and swimming speed to
behaviours and compare the energetic cost of activities between these behaviours.
115
Morphology of the electrosensory system of three sympatric dasyatids from Moreton Bay.
Arnault Gauthier1, Darryl Whitehead1, Bronwen Cribb2, Shaun Walter1, Ian Tibbets2, Michael Bennett1
1. School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
2. School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
Electroreception is the sense that allows organisms to detect weak electrical fields in the environment to detect prey or
predators, orientate themselves through the Earth’s geomagnetic field, and communicate with conspecifics. Several decades of
research on the electroreceptive ampullae of Lorenzini of elasmobranchs have shown that their morphology and distribution
vary among species, and this has been attributed to be a function of differences in environment and lifestyle. The estuary
stingray, Dasyatis fluviorum, the blue-spotted maskray, Neotrygon kuhlii, and the brown whipray, Himantura toshi, are three
dasyatids common in Moreton Bay, Queensland, Australia. Despite foraging sympatrically for benthic prey over intertidal sand
flats their diets differ; N. kuhlii feeds primarily on polychaetes, D. fluviorum on brachyurans and H. toshi on caridean shrimp. We
used light, confocal, scanning electron and transmission electron microscopy to assess whether morphological differences in
their electrosensory system might explain their seeming ability to differentiate among buried prey. The electrosensory systems
of these species were generally of similar morphology; however, previously undocumented features such as the peculiar shape
of the ampullary canals and of their supportive cells in the ampulla proper were identified.
116
Future ocean conditions and the development, physiology, and behaviour of shallow sharks
Jodie Rummer1, Connor Gervias1, 2, Dennis D.U. Heinrich2, 3, Martijn S. Johnson2, Daniel W Kraver2, Tiffany J. Nay2, Gillian M.C.
Renshaw4
2. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
3. Southern Shark Ecology Group, School of Biological Sciences, Faculty of Science & Engineering, Flinders University, Bedford
Park, South Australia, Australia
4. Hypoxia and Ischemia Research Unit, School of Allied Health Science, Griffith University, Gold Coast, Queensland, Australia
Increasing atmospheric CO2 (43% since the Industrial Revolution) is warming the oceans (2.0-4.8°C by 2100), increasing the
frequency and extent of hypoxia (low oxygen), and decreasing ocean pH (0.3-0.4 units by 2100; ocean acidification) at a rate
100-times faster than over the past million years. Tropical sharks may be some of the most negatively affected by climate
change. Warmer, narrow temperature ranges and their life history – slow growing, late sexual maturity, and low reproductive
output – could mean they are unable to adapt fast enough to keep pace with climate change. The epaulette shark (Hemiscyllium
ocellatum) may be different. This species lives on shallow coral reef flats and in lagoons where they may frequently encounter
short-term periods of challenging environmental conditions (e.g. hypoxia, elevated CO2, and temperature fluctuations)
especially during low tides. Indeed, epaulette sharks are remarkably tolerant to short periods (hours) of hypoxia, and we have
been recently investigating this species after prolonged exposure to elevated CO2 and temperatures – as would be relevant
under climate change – in ovo, upon hatching, as neonates, and into adulthood. Overall, adults are both behaviourally and
physiologically tolerant to elevated CO 2, and our results from embryos reared under end-of-century CO2 conditions suggest that
tolerance may start very early in life, just post-fertilization. Yet, we are only just beginning to understand the consequences of
elevated temperatures and the importance of acclimation and movement to this species. Epaulette sharks may already possess
adaptations that allow them to survive and thrive under the challenging environmental conditions they are already experiencing
in their shallow reef habitats – adaptations that may also confer tolerance to conditions projected for the oceans by the end of
this century. Projects are underway to determine whether other elasmobranchs, especially pelagic species that may not
experience such fluctuations in their environment, will be equally as tolerant.
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Too hot to handle? The use of movement by a benthic elasmobranch species, Hemiscyllium ocellatum, to aleviate effects of
elevated temperature.
Connor Gervais2, 1, Tiffany Nay1, 3, Gillian Renshaw4, John Steffensen5, Jacob Johansen6, Jodie Rummer1, 3
1. ARC Center of Excellence, James Cook University, Townsville, QLD, Australia
2. Macquarie University, Sydney, NSW, Australia
3. College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, Australia
4. Griffith University, Nathan, QLD, Australia
5. University of Copenhagen, Helsingor, Denmark
6. Department of Marine Science, University of Texas, Port Aransas, Texas, United States
Epaulette sharks, Hemiscyllium ocellatum, occupy shallow reef flats that can experience relatively large variations in daily and
seasonal temperatures. For example, some coral reef flats can experience temperatures that are 3-4°C warmer than surrounding
habitats on a daily basis. However, epaulette sharks may have evolved behavioural and/or physiological strategies to mitigate
the effects of elevated temperatures, which will be important to their survival with climate change projections. We used a
shuttle-box system to examine whether juvenile sharks that are exposed to current day summer and winter temperatures as
well as predicted end-of-century temperatures use movement to maintain their body temperatures. We also examined the
influence of temperature on growth and food consumption. We found that juvenile epaulette sharks showed a seasonallydependent tendency to thermoregulate. During winter, when maximal habitat temperatures are far below lethal limits,
individuals showed no thermoregulatory behaviour. However, during summer, when maximum temperatures may approach
lethal limits, juveniles actively sought to limit thermal exposure to 30.7± 1.04°C during the day and 28.54± 0.75°C at night.
Similarly, individuals acclimated to predicted end-of-century conditions (32°C), actively sought out 32.94± 0.46°C during the day
and 30.74± 0.68°C at night. Regardless of acclimation temperature, juveniles maintained the same food consumption rates (5%
of their body mass), but this resulted in decreased growth rates (mass and total length) in sharks living at 32°C. Although
behavioural thermoregulation may be a trait with some capacity for acclimation, overall, this species experienced a clear
reduction in growth and eventual mortality at temperatures just +3°C above summer averages. Within one generation,
physiological and biochemical acclimation may be more costly than movement, and therefore the latter may be a valid strategy
for this species to avoid extreme temperatures during summer months. As water temperatures continue to rise, it is important
to consider that the distribution and abundance patterns for epaulette sharks and many other coral reef species may change.
118
Animal-borne video and accelerometers reveal high energy requirements of white shark breaching behaviour
Jayson M Semmens1, Alison A Kock2, Yuuki Y Watanabe3, Charles M Shepard4, Eric Berkenpas4, Kilian M Stehfest1, Adam
Barnett5, Nicholas L payne6
1. Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, Tasmania,
Australia
2. Shark Spotters, Fish Hoek, South Africa
4. The National Geographic Society, Washington, DC, USA
5. Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Cairns, Queensland, Australia
6. University of Roehampton , London, UK
Large predators expend large amounts of energy foraging for prey based on expected high return. Documenting how they
manage costs and benefits of feeding is difficult, particularly for marine predators. Here we combined animal-borne video,
accelerometry, depth sensors, and biomechanical principles to examine behaviour and estimate energetic cost, during white
shark (Carcharodon carcharias) breaching – a behaviour where sharks launch from the water while attacking Cape fur seals
(Arctocephalus pusillus pusillus). We show that breaching begins at depths up to 20 m, is characterised by a brief (~ 7-16 s)
ascent to the surface during which pitch angle increases by ~30 °, and tail-beat frequency increases by a maximum of 6.5-fold
(0.39 to 2.50 Hz). This increase in tail-beat frequency equates to an estimated 7-fold increase in energetic costs during a breach.
Sharks also demonstrated the ability to rapidly adjust their approach to the seal during ascent. Tail-beat frequency during
breaching was ~2-4 times higher (0.83-1.67 Hz) than during non-predatory ascents (0.4 Hz). Biomechanical considerations
suggest that breaching attacks require 1.8-3.3 times more energy than non-predatory ascents. This highly energetic tactic leads
to high rates of predation success, exemplifying the high cost/high return foraging strategy of top predators.
119
Caudal fin aspect ratio as a predictor of maximum swimming speed
Darcie E Hunt1, John G Purser1, Giles A Thomas2, Jennifer M Cobcroft3, Nicholas J. F. Rawlinson1
1. Fisheries and Aquaculture Center, Institute for Marine and Antarctic Studies, Launceston, TAS, Australia
2. Mechanical Engineering, University College London, London, UK
3. Fisheries and Aquaculture Center, Institute for Marine and Antarctic Studies, Hobart, TAS, Australia
The speed at which a fish can swim is determined by a combination of the movement of the muscle structure, the shape of the
fish and the fins. There are three different types of swimming speeds identified in fish; sustained swimming, prolonged
swimming, and burst swimming. It is generally recognised that maximum swimming speeds are the most difficult to accurately
estimate. The aim of this study was to predict the maximum swimming speed using morphometrics from historical data. The
maximum speeds of various teleost species were collected from a range of sources dating back to 1952. Each species was
classified into a swimming mode based on Lindsay (1978) and only caudal fin swimmers were used. The documented maximum
speeds were plotted against caudal fin aspect ratio and an exponential trendline was fitted. A total of 255 individual swimming
speed measurements of fish species were gathered from 31 different literature sources. Anguilliform had the lowest aspect ratio
with values ranging from 0 to 1.61 and thunniform had the greatest with values ranging from 5.5 to 7.9. The relationship
between caudal fin aspect ratio (AR) and maximum swimming speed of 74 species from the literature was best described by an
exponential equation. (y = 0.59e0.42x, R2= 0.85). This allows us to make general predictions as to the maximum swimming speed
of a fish given the aspect ratio of the caudal fin. This study’s finding can be applied beyond these species, for example, the
maximum swimming speeds of fish could be utilised for the design of bycatch reduction devices or refinement of existing
gears/modifications.
120
Bioelectrical impedance analysis, not your granddaddy’s condition factor
Joe Margraf1
1. University of Alaska Fairbanks, Alaska, United States
Bioelectrical impedance analysis (BIA) is commonly used in human health and nutrition fields but has only recently been
considered as a potential tool for assessing fish condition. Once BIA is calibrated, it estimates fat/moisture levels and energy
content without the need to kill fish. Despite the promise held by BIA, published studies have been divided on whether BIA can
provide accurate estimates of body composition in fish. In cases where BIA was not successful, the models lacked the range of
fat levels or sample sizes we determined were needed for model success (range of dry fat levels of 29%, n = 60, yielding an R2 of
0.8). Reduced range of fat levels requires an increased sample size to achieve that benchmark; therefore, standardization of
methods is needed. Here we discuss standardized methods based on a decade of research, identify sources of error, discuss
where BIA is headed, and suggest areas for future research.
121
The intersection between fish physiology and behavior in regulating microhabitat use
Tiffany Nay1, Jacob Johansen2, Connor Gervais1, Adam Habary1, 3, John Steffensen3, Jodie Rummer1
2. Marine Science, University of Texas, Port Aransas, Texas, USA
3. Marine Biological Section, University of Copenhagen, Helsingør, Denmark
As global temperatures increase, fish populations at low latitudes are thought to be at risk as they are adapted to narrow
temperature ranges and live at temperatures close to their thermal tolerance limits. Numerous studies have documented
poleward shifts in the geographic ranges of many tropical fishes in response to increasing temperatures, but few have
considered movements among microhabitats. Movements among microhabitats with different temperatures (or temperature
profiles) may provide a strategy to cope with changing conditions, and allow fish to behaviourally regulate their thermal
environment. Here, we investigated the thermal preferences of a temperature-sensitive coral reef cardinalfish (Cheilodipterus
quinquelineatus) and a temperature-tolerant intertidal mudskipper (Periophthalmus argentilineatus). Fishes were exposed to
28°C (average at collection site) or 32°C (predicted end-of century) for 5 weeks prior to experiments. The thermal preference
(Tpref) was determined using a shuttlebox system, which allowed fish to behaviourally select their thermal environment.
Regardless of treatment temperature, cardinalfish preferred 29.5 ± 0.25°C, approximating the average summer temperatures
they experience in the wild. However, 32°C fish moved more frequently to correct their thermal environment than 28°C fish, and
daytime movements were more frequent than night-time movements. Mudskippers preferred 26.7 ± 2.1°C regardless of
treatment temperature, with fishes exposed to 28°C exhibiting more frequent movements than fishes exposed to 32°C during
night-time hours. Understanding temperature-mediated movements is imperative for predicting how ocean warming will
influence coral reef species and distribution patterns.
122
Global analyses of tuna diet and isotopes: moving from regional to macro-scale understanding of oceanic food webs
Heidi Pethybridge1, CLIOTOP Task Team 2016-01
1. CSIRO Oceans And Atmosphere Flagship, Hobart, TAS, Australia
Examining broad-scale patterns in marine food-webs and ecosystems is essential for understanding macro-scale patterns and
processes and could support a greater adoption of general ecosystem-based management practices. This talk will present recent
work undertaken by a team of scientist connected through the international GLOBEC program CLIOTOP - Climate Impacts on
Oceanic Top Predators. Focusing on three species of oceanic tuna (yellowfin, bigeye, albacore), two global databases were
compiled: (i) >20,000 stomach samples including more than 300 prey taxa from tunas collected 1969-2014; and (ii) >6,000 bulk
nitrogen and carbon stable isotope records, 2000-2015. These datasets were used to undertake the first inter-oceanic
comparisons of top predator diets and isotopes ever conducted at a global scale. Broad, macro-scale trophic patterns in pelagic
ecosystems were quantitatively assessed using a modified classification tree approach for stomach contents data and
generalised additive mixed models for isotope data. Interpolated results were relayed on oceanographic contour maps that
characterise the global distribution patterns of tuna prey, diet diversity and trophic positions. Global and ocean basin differences
within and between each of the three tuna species studied were detected. Results from these analyses provide valuable
depictions of the trophic pathways that underlie the production of tunas and other pelagic predators in the open ocean.
Modelling efforts also allowed hypotheses to be posed about future food web interactions in a warming ocean.
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Modeling of oceanic mid and high trophic levels with SEAPODYM
Patrick Lehodey2, 1, Inna Senina1, Beatriz Calmettes1, Olivier Titaud1, Anna Conchon1
1. Space Oceanography Division, CLS, Collecte Localisation Satellites
2. CLS, Canal Technology Park, RAMONVILLE SAINT-AGNE, France
In the pelagic foodweb, micronekton at the mid-trophic level (MTL) are one of the lesser known components of the ocean
ecosystem despite being a major driver of the spatial dynamics of their predators, of which many are exploited species (e.g.
tunas). The Spatial Ecosystem and Population Dynamics Model (SEAPODYM) is a modelling framework that includes a
representation of the spatial dynamics of several epi- and mesopelagic MTL functional groups. The dynamics of these groups are
driven by physical (temperature and currents) and biogeochemical (primary production, euphotic depth) variables. A key issue
to address is its parameterization for which we present a method using in situ acoustic data to estimate the parameters with a
maximum likelihood estimation approach. The modeling of these components is central in the development of spatial
population dynamics of larger predators, either protected species or exploited fish populations. A series of applications illustrate
the recent advances in the continuous development of SEAPODYM, including the modeling of past history of tuna populations
under the combined effect of climate variability and fishing exploitation, the projection of climate change and the progress in
operational real time systems of monitoring.
124
Fish Phylogenetics: Swimming into the 21st Century
Peter F Cowman, Thomas Near
Ray-finned fishes represent over half of the total vertebrate diversity of the planet. Yet, at the beginning of this decade, the
most successful branch in the vertebrate tree of life was ranked the lowest in terms of taxonomic sampling and phylogenetic
resolution. In recent years, a focused phylogenetic effort across the ichthyological community has resulted in three large fish
‘Trees of Life’. Although incomplete at various scales, these trees have provided an unprecedented opportunity to explore
numerous dynamics underpinning the diversification of fishes across the globe. On the eve of the genomic revolution for fish
phylogenetics, the systematic implications of these trees, comparisons with their predecessors and their topographic
concordance with fossil and morphological evidence is needed to gauge current and future progress. We examine the
acceleration these new phylogenies represent to the phylogenetic resolution of the ray-finned fishes, their ability to provide a
taxonomic consensus to fish classification, and whether there is significant agreement or disagreement with morphological
classification.
125
Population genomics & taxonomy in Australasian fishes: the five Ws and one H (what, why, when, where, who and how)
Sharon Appleyard1, John Pogonoski1, Daniel Gledhill1, Alastair Graham1
1. CSIRO National Research Collections Australia, Hobart, TAS, Australia
The Australian National Fish Collection (ANFC) holds over 150 000 specimens representing approximately 3 400 species mostly
collected from the Indo-Pacific. Its strengths are sharks, rays and deep-water fishes. Alongside taxonomy, genetic/genomic
research in the ANFC focusses on species identifications, phylogenetics, biogeography, population connectivity and inputs into
sustainable fish management and conservation. These research activities have been improved due to our involvement as an
integral partner in several domestic and international barcoding and next generation sequencing consortia. As part of these
consortia, genetics/genomics in the ANFC is divided into two equally important components – a. taxonomic validation and
uptake of mtDNA barcoding for reference databases to enable rapid species identifications, informed phylogenetic analyses and
increased species discovery; b. detection of new nuclear genomic regions of interest for species of commercial and biodiversity
importance using next generation sequencing. This presentation is a reflective synopsis of our experiences with genomic
investigations in fish. Extensive data sets and numerous case studies ranging from the application of alternate sequencing
approaches and the manipulations of large data sets in "the cloud" to the judicious choice of molecular tools to address the
question in hand will be presented. These data sets act as references for discovery and understanding of Australian fishes,
including improved resolution of taxonomic structure, distributional ranges and habitat preferences.
126
Australia’s diverse eel fauna: a preliminary overview of their taxonomy and biogeography
John J Pogonoski1
The order Anguilliformes (true eels) consists of around 1000 species worldwide in 16 different families, numbers that are
comparable to other highly diverse groups such as sharks and rays. In Australia, over 200 eel species in 13 families are
represented from freshwater, estuarine and shelf waters to the edge of the continental slope and abyssal plain beyond 3000 m
depth. As adults, species occupy a variety of habitats from within benthic sediments and caves to benthopelagic and
mesopelagic zones in tropical to polar waters. Although freshwater eels (Anguillidae) have received considerable attention
worldwide due to their commercial importance, most marine eels are poorly studied despite their ecological importance and
sometimes high abundances, as evident from trawl catches and underwater video. The poorly-sampled cryptic habitats often
occupied by eels have confounded the understanding of their taxonomy and biology as many species are only known from a
handful of specimens. On occasions, species were described based on their leptocephalus larval stage, their corresponding adult
forms yet to be determined. Opportunistic data collection during regional faunal surveys, examination of museum fish
collections over a 15 year period and molecular techniques (DNA barcoding) have all helped revise alpha-taxonomy to reveal
numerous cryptic and previously unrecognised species. Structure of the Australian marine eel fauna is discussed within different
taxonomic groupings, habitats and bioregions. Comparisons to other regional faunas in the Indo-Pacific show varying levels of
endemicity, and is highest in the Congridae and Ophichthidae. Families covered in most detail include the Congridae (conger
eels), Muraenidae (moray eels) and Synaphobranchidae (basketwork eels).
127
Long-term observing systems: what is on offer in Australia and can it improve my science?
Ana Lara-Lopez1, Tim Moltmann1
Accurate information about how our environment is changing needs reliable long-term observations in order to assess these
changes. Australia’s Integrated Marine Observing System (IMOS) was established under an Australian Government research
infrastructure program, to deliver ocean observations to the marine and climate scientists to undertake research of national and
international significance. IMOS is integrated across spatial and temporal scales, supporting open- ocean and climate science as
well as science at continental shelf scale and marine coastal science. It has observing assets in Australia’s tropical north,
temperate regions, and the Southern Ocean down to the Antarctic shelf. It is also integrated across disciplines ranging from
physics and chemistry to marine biology and ecosystems. Making all of the data openly available ensures that this collective
observational power is used by many stakeholders to generate a wide range of scientific outputs, from PhDs’ and peer-reviewed
publications to operational ocean forecasts and satellite products.
Some of the IMOS observing platforms include:
 Ships of opportunity: underway physical and biogeochemical data, including fCO2, continuous plankton recorder (CPR)
and bioacoustics.
 Autonomous Underwater Vehicle: georeferenced benthic stereo imagery
 Animal tagging: acoustic tags on a wide range of fish, sharks and mammals collecting behavioural data.
 National Mooring Network: physical and biogeochemical data including PAR, nutrients, fluorescence, plankton, pCO2
and passive acoustics.
 Ocean Gliders: Chla, CDOM, backscatter, O2, irradiance and physical variables.
 ARGO: floats deployed collecting physical variables with some collecting O2 data
The Australian Ocean Data Network is also IMOS key Facility with a long-term goal of building an open-access, standards-based,
scalable, national information infrastructure providing not only IMOS data but also data from other agencies. The sustained
physical, chemical and biological observations collected by IMOS provide a wealth of data for potential applications to fish and
fisheries research.
128
IMOS OceanCurrent web site
Madeleine Cahill1, Rich Little1
1. CSIRO, Battery Point, TAS, Australia
Bringing ocean observations to users is almost as important as actually making those observations. That's why Australia's
Integrated Marine Observing System (IMOS) includes a comprehensive data management system as well as multiple avenues for
delivering the data to a variety of users, including those with a need for the latest-available ocean observations from satellites,
HF radars and gliders.
One of these avenues is the OceanCurrent website, where a wide range of graphical representations (including animations) of
the many types of IMOS data are just a few mouse clicks away. The site also has a News section, which 1) informs readers about
ocean events such as extreme currents or water temperatures, and 2) shows people how to interpret the available graphics, to
empower them to notice such features themselves.
The site serves as a preview facility, showing the space-time coverage of the various data sets, both individually and in relation
to each other. By overlaying point measurements made by current meters, gliders etc., on maps of sea surface temperature,
ocean colour and geostrophic velocity from altimetry satellite imagery, users can quickly see the broader context of the in-situ
data, helping them to correctly interpret the point data. The imagery is updated several times a day, attracting users from
outside the research community while also allowing members of the research community to locate and study particular ocean
phenomena.
129
Physics to fisheries: IMOS data enables.
John F Middleton1, John Luick1, Charles James1, Mark Doubell1, Paul van Ruth1, Ana Redondo1, Paul Malthouse1, Nicole Patten1
1. SARDI Aquatic Sciences, Henley Beach, SA, Australia
Since 2006, SARDI has developed a significant field capability through the implementation of the Southern Australian Integrated
Marine Observing System (SAIMOS). Coupled hydrodynamic, wave, biogeochemical and larval transport models have also been
developed to address research, industry and government needs for the sustainable development of fisheries and aquaculture,
and the health of the marine ecosystems of Southern Australia. Central to these efforts is the on-going development of the (< 3
km grid) Southern Australian Regional Ocean Model (SAROM) for the shelves and Gulfs. SAROM has been validated against the
IMOS data streams of currents, temperature and salinity, and provides information along the seaward boundaries of finer scale
models for Spencer Gulf and Coffin Bay. Indeed, a PIRSA/FRDC funded project delivered a high resolution (< 1 km) coupled and
validated hydrodynamic/wave/biogeochemical model of Spencer Gulf: information along the Gulf mouth was obtained from the
SAROM and SAIMOS biogeochemical data. The model was used to evaluate the ecological carrying capacity of the Gulf based on
natural and anthropogenic nutrient sources (finfish aquaculture and waste water). The studies were presented to government
as a GUI tool (“CarCap”) to assist in the regulation of finfish aquaculture in the gulf (where, how much?). The models developed
were also used to simulate prawn larval dispersal in upper Spencer Gulf to demonstrate the optimal areas for prawn fishing
efforts so as to maintain sustainability. In collaboration with the BoM, the predictive OceanMAPS global model is being coupled
with the suite of models (validated against SAIMOS) to provide a now-cast/forecast model to assist in addressing fishing industry
needs: where do the harmful algal blooms go, how do we respond to them, what are the optimal fishing vessel routes to
minimise fuel consumption? Other applications including sardine habitat prediction will be outlined (based on water
temperature, salinity, chlorophyll-a, depth), as well as planned applications to seagrass habitat and oyster aquaculture.
130
Refining a Nordmøre-grid for the Spencer Gulf prawn-trawl fishery
Craig Noell1, Matt Broadhurst2, Steve Kennelly3, Owen Burnell1, Graham Hooper1
2. Fisheries Conservation Technology Unit, NSW Department of Primary Industries, Coffs Harbour, NSW, Australia
3. IC Independent Consulting, Cronulla, NSW, Australia
Incremental technical refinements were made to a generic Nordmøre-grid to minimise bycatches of the giant cuttlefish (Sepia
apama), blue swimmer crabs (Portunus armatus) and various teleosts, while maintaining catches of western king prawns
(Melicertus latisulcatus) in an Australian prawn-trawl fishery with Marine Stewardship Council accreditation. The Nordmøre-grid
changes involved varying bar spaces, escape-exit areas and guiding-panel lengths. Compared to a control, catches of unwanted
teleosts and the targeted prawns largely remained unaffected by any of the technical changes—although the quality of the
latter was improved. Maximum reductions in unwanted catches of giant cuttlefish and blue swimmer crabs (both ~90%) were
achieved by a Nordmøre-grid with 38-mm bar spaces, a large escape exit (>0.8 m2) and a 2.7-m guiding panel. While the fate of
escaping cuttlefish and crabs remains unknown, it is likely their survival would exceed that for discards. Through this study we
have identified a potential management tool for reducing unwanted bycatches that could be considered in the context of other
existing strategies for this fishery involving spatial/temporal closures and on-board handling.
131
Inter-annual and regional variation of fish in prawn trawl by-catch: The importance of temporal replication for identifying
potential trawl related impacts
Owen Burnell1
Prawn trawling is known to have deleterious localised effects on benthic ecosystems, particularly slow growing and sessile
organisms, although long-term impacts are varied and less certain for relatively motile bycatch, such as fish. This study examined
changes in the community structure and biomass of fish bycatch in trawl surveys from Spencer Gulf, which has supported a
prawn fishery since 1967. With the view of augmenting ecosystem-based management in the future, two fishery-independent
by-catch surveys were undertaken throughout the gulf six years apart, enabling a long-term temporal comparison of trawl bycatch. Differences in the community structure and biomass of fish were found to be driven primarily by regional (i.e. latitude)
and/or inter-survey differences, while trawl intensity (i.e. hours trawled per km2) had no consistent influence across the two
surveys. The absence of a consistent trawl-related distribution in fish biomass between the two surveys suggests our ability to
detect any localised effects of trawling is potentially limited to discrete time periods. Temporal declines in fish biomass were
evident across multiple species and size classes; however, they were most prominent in the southern half of the gulf, where
trawl effort is historically low. While variable recruitment and/or migration within southern Spencer Gulf might explain these
temporal decreases in the biomass, it is important to maintain similar ecosystem-focused studies to increase our understanding
of potential trawl-related impacts. Enhancing this understanding will require (1) in-depth biological and ecological information
about potential indicator species from the bycatch and (2) where possible, greater temporal resolution (i.e. intra-annual) and
replication (i.e. inter-annual) to develop accurate biological reference points.
132
Methods for determining in situ target strength
Ben Scoulding1, Paul G Fernandes2, Sven Gastauer3, Sascha Fassler4, David N MacLennan2, Eric Armstrong5, Stephane Gauthier6
1. Echoview, Hobart, TAS, Australia
2. Institute of Biological and Environmental Sciences, University, Aberdeen, Scotland
4. IMARES, IJmuiden, Netherlands
5. Marine Scotland Science, Aberdeen, Scotland
6. Fisheries and Oceans , Sidney, Canada
Acoustic surveys are effective methods to quantify the distribution and abundance of many aquatic fauna, and are particularly
useful for the assessment of pelagic fishes. To convert data gathered from an acoustic survey of living resources into estimates
of abundance, it is essential to know the target strength (TS, in dB) for the species and size of interest. TS is a logarithmic
description of the quantity of acoustic backscattered energy from an individual and can be measured in situ using split-beam
echosounders. Whereas in ideal conditions these may be the most representative estimates available, there is no
comprehensive approach on how to account for the potential problem of multiple target detections and other potential sources
of error. This paper describes the current state of the art and best methods to obtain standardized in situ TS measurements. We
present recommendations on: equipment settings; selection of appropriate data; single-target detection criteria; removal of
dense-echo regions to reduce the acceptance of multiple targets; post-processing; and validation methods. Most methods
tested here were implemented using Echoview post-processing software. This is the first systematic and comprehensive
description of ways to deal with the multitude of issues associated with multiple target errors. The methods described here are
therefore recommended to improve single-target detection in order to deliver the most representative measures of TS for use in
acoustic surveys.
133
Variability in Atlantic mackerel target strength and its effects on acoustic abundance estimates
Ben Scoulding1, Paul G Fernandes2, Sven Gastauer3, Sascha M.M Fassler4, Phillip Copland5, David N MacLennan2
1. Echoview, Hobart, TAS, Australia
2. Institute of Biological and Environmental Sciences, University, Aberdeen, Scotland
4. IMARES, IJmuiden, Netherlands
5. Marine Scotland Science, Aberdeen, Scotland
Atlantic mackerel Scomber scombrus is a small pelagic, migratory fish which supports valuable commercial fisheries. Fisheryindependent mackerel abundance estimates in the Northeast Atlantic are currently based on egg-production surveys every third
year, and do not yet consider acoustic data. Echo-integration surveys could provide annual estimates of abundance, with
additional scope for studying mackerel distributions throughout the year. However, this requires good knowledge of the
mackerel target strength (TS), which is not yet adequate. The present study provides in situTS values for mackerel from
measurements made at sea with split-beam echosounders operating concurrently at 18, 38, 120 and 200 kHz. Acoustic data was
analysed using Echoview post-processing software. Empirical results suggest mean TS of -51.22 dB at 18 kHz, -59.83 dB at 38
kHz, -55.51 dB at 120 kHz and -53.43 dB at 200 kHz, for a mean fish length of 33.3 cm. This differs significantly from the values
currently assumed in acoustic surveying, which advocates a TS of -53.07 dB for a 33cm fish at 38 kHz. The sensitivity of mackerel
abundance estimates to variations in TS estimates was also investigated using data from a dedicated mackerel acoustic survey
around the Shetland Islands, Scotland. Confidence limits for the biomass estimates (400,000 to 4,500,000 tonnes) at each
frequency were obtained using geostatistical techniques. Total stock biomass estimates at 38 and 200 kHz were in very good
agreement with each other (to within 2.2 %) and were in range of values from an independent (i.e. non-acoustic) mackerel stock
assessment (5,137,104 tonnes).
134
Transitioning to a brave new world: the need for, and challenge of, interdisciplinary research.
Stewart Frusher1, Marcus Haward1, Alistair Hobday2
The world rapidly needs to respond to global challenges such as food security, population growth and climate change amongst
an ever increasing rate of globalisation that is also reshaping trade and markets.
The world’s oceans cover 71% of the earth’s surface and, like many of the terrestrial deserts, are underutilised for food
production. However, unlike deserts, virtually all regions of the oceans support commercial fisheries from krill and toothfish in
Polar Regions to tunas in tropical regions. Modern commercial fisheries are still based around a “hunter-gather” genre whereas
agriculture replaced the “hunter-gather” sector thousands of years ago. The equivalent change is commencing in marine
production systems where aquaculture has been the fastest growing production system globally over the last three decades.
However, marine aquaculture is largely contained within the coastal zone – a region coming under increased stress through
population growth, recreational use and concerns for the conservation of biodiversity. This coastal zone represents only 8% of
the earth’s surface.
A brave new world will see the development of offshore marine production systems and these are likely to be multi-sector (e.g.
food production, conservation, energy production, tourism). In Australia, a country with the third largest marine jurisdiction
globally, this journey is still in its conceptual phase although interest is increasing. At the global scale there is increasing interest
in the oceans and given the rapid pace of technological change, development needs to be controlled so that sufficient research
can underpin the development of policy if we do not want to repeat some of the disasters associated with the green revolution.
Such research will require strong inter- and trans-disciplinary teams and greater global cooperation.
135
Feedbacks as a bridging concept for advancing transdisciplinary sustainability research
Jessica Blythe1, Kirsty L Nash2, Julian Yates3, Graeme Cumming1
2. Centre for Marine Socioecology, Hobart, TAS, Australia
3. Institute for Resource, Environment and Sustainability (IRES), University of British Columbia, Vancouver, Canada
Recognition of the need for marine research that spans the social-ecological divide has opened an exciting space for
transdisciplinary research. Yet, attempts at working across disciplines often leads to epistemological debates and
methodological rifts between natural and social sciences, presenting significant challenges for transdisciplinary teams. Using
fisheries research within the context of a coral reef social-ecological system as a case study, we explore how these points of
tension may be addressed using a three stage process: 1) promoting epistemological transparency, where differing perspectives
are made explicit; 2) employing feedbacks as a bridging concept to effectively engage with complex system dynamics from
multiple perspectives; and 3) encouraging plurality, rather than the unification of perspectives, to foster innovative research
along sustainable and desirable pathways.
136
Developing knowledge and tools to inform integrated marine management: Spencer Gulf as an Australian case study
Bronwyn Gillanders1, Zoe Doubleday1, Alice Jones1, Phill Cassey1, Thomas Prowse1, Sally Scrivens1, Tim Ward2
1. School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
2. South Australian Research and Development Institute of Aquatic Sciences, Adelaide, SA
Coastal and marine waters are becoming increasingly crowded. Besides fishing and aquaculture ventures there is also significant
shipping and port development associated with new mineral and processing ventures, and potential for biosecurity risks. Other
human activities operating in and around the sea also have potential to cause stress to marine and coastal habitats and the
species they support. Understanding cumulative impacts of multiple activities remains a critical gap in marine management. Our
aims were to generate a spatially explicit assessment of cumulative risk; examine current shipping traffic and determine how
shipping pathways and number of ships are likely to change given proposed mining expansion and investigate potential changes
to cumulative risk, as well as interactions with key fisheries and aquaculture activities, associated with changes in shipping. We
mapped the spatial footprint and intensity of human activities occurring throughout Spencer Gulf, a large inverse estuary. We
combined information from an ecological risk assessment using an expert elicitation process with the spatial intensity of threats
to generate a spatially explicit assessment of cumulative risk. This map shows that the most-at-risk habitats occur in northern
Spencer Gulf, near major industrial activities. Current shipping activities show that ships use clear pathways associated with
bathymetry and future scenarios for shipping and port development suggest an increase in shipping traffic of 91-249% over
current levels. Visualisation of shipping scenarios with the existing prawn and sardine fisheries suggest potential overlap of
activities. Management solutions are required to avoid congestion in the narrow shipping paths of northern Spencer Gulf and to
minimise the potential impacts and risks of increased disturbance on the Gulf environment and other industries supported by
the Gulf.
137
In the water with white sharks
Kirin Apps1, Charlie Huveneers2, Kay Dimmock1, David Lloyd1
1. Southern Cross University, East Lismore, NSW, Australia
2. Flinders University, Adelaide, SA, Australia
Interactions with marine megafauna, including shark-based tourism, has experienced exponential growth since the 1990’s
bringing with it intense management and academic scrutiny. To date, much of the research into wildlife tourism has focused on
potential negative biophysical impacts to species and habitat. However, the proponents of wildlife tourism suggest that
conservation benefits, resulting from education and interpretation, may mitigate potential impacts. Despite these discussions,
the social dimensions of marine-based tourism remain largely unexplored. Based on this gap, the current research applied a
mixed methods (qualitative and quantitative) approach to investigate the human dimensions of shark-based tourism using a
case study of white shark (Carcharodon carcharias) cage-diving at the Neptune Islands, South Australia. This study investigated a
number of features of the tourism activity including, participant’s beliefs and attitudes towards sharks, and on-tour education.
Surveys gathered responses from a sample (n=86) of participants with responses revealing the decision to cage-dive with white
sharks is driven by factors including education and the perceived naturalness of the experience. A second survey (n=655) was
conducted to investigate participant satisfaction with on-board education content and to determine what (if any) specific
information they hope to receive. While the majority of participants agreed the cage-dive tour was an educational experience,
the results support the demand for additional information about the biology, habits and threats to white sharks. The potential
for shark cage-dive tourism to facilitate and support shark conservation issues via education and interpretation initiatives are
further discussed.
138
A review of the Ocean Sunfishes (Family Molidae) in Australia and New Zealand, using genetics and fisheries by-catch data
Marianne Nyegaard1, Neil Loneragan1
1. Murdoch University, Murdoch, Western Australia, Australia
Despite an astounding paucity of information on population levels anywhere, Ocean Sunfish (Mola mola) was recently listed as
vulnerable by the IUCN. The concerns are high levels of by-catch in various fisheries across the globe, and a very limited
understanding of population dynamics. Details of sunfish interactions in the Australian and New Zealand longline fisheries have
been recorded by fisheries observers for over 15 years, and could hold valuable information on recent population trends in
these areas. But which species are caught? Over 200 years of taxonomic confusion has rendered Molidae species identification
no easy feat. To determine which sunfish species are caught in the longline fisheries across Australia and New Zealand,
Australian Fisheries Management Authority and the New Zealand Ministry for Primary Industries provided us with tissue
samples through their longline observer programs. We also used social media to locate stranded sunfish and secure tissue
samples. The surprising genetic results have provided an excellent opportunity to review the zoogeography of Australian and
New Zealand sunfish, and comment on the uncertainty associated with assessing their population trends and vulnerability to
fishing pressure, based on by-catch data.
139
Who’s your mama? Riverine hybridization of threatened freshwater trout cod and Murray cod.
Alan Couch1, Peter J Unmack1, Fiona Dyer1, Mark Lintermans1
1. Institute for Applied Ecology, University Of Canberra, ACT, Australia
Rates of hybridization and introgression are increasing dramatically worldwide because of translocations, restocking of
organisms and habitat modifications thus determining whether hybridization is beneficial or detrimental for the species involved
is commensurately important for conservation. Restocking programs are sometimes criticized because of the genetic
consequences of hatchery-bred fish breeding with wild populations. These concerns are important to conservation restocking
programs, including Percichthyidae.
Two of the better known Australian Percichthyidae are the Murray Cod (Maccullochella peelii) and Trout Cod (Maccullochella
macquariensis) which were formerly widespread over the Murray Darling Basin. In much of the Murrumbidgee River Trout Cod
and Murray Cod were sympatric until the late 1970s when Trout Cod were extirpated. Here we use genetic SNP data to examine
hybridization and introgression between Murray Cod and Trout Cod in the upper Murrumbidgee River and consider implications
for restocking programs.
For the first time we have confirmed restocked riverine Trout Cod as reproducing in the wild. We detected hybrid Trout CodMurray Cod in the Upper Murrumbidgee, recording the first hybrid larvae in the wild. Although hybrid larvae, juveniles and
adults have been recorded in hatcheries and impoundments, and hybrid adults have been recorded in rivers previously, this is
the first time fertile F1 have been recorded in the wild. The F1 backcrosses with Murray cod have also been found to be fertile.
All backcrosses were with pure Murray Cod. Such introgression hasn't been recorded previously in these species, and the
imbalance in hybridization direction may have important implications for restocking programs.
140
Lates calcarifer immune transcriptome reveals the Mincle C-Type Lectin Receptor as a partial replacement for TLR4 in LPS
recognition in fish
Emmanuelle Zoccola1, Stuart Kellie2, Andrew C Barnes1
1. School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
2. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
Fish represent the most diverse and abundant vertebrate infraclass and one of the earliest divergent phyla with adaptive
immunity. The adaptive immune system of fish has been successfully exploited through mass vaccination programs in the
aquaculture industry. However, vaccination is problematic against highly diverse antigens, such as capsular polysaccharides and
lipopolysaccharide (LPS). Fish have a subdued innate response to LPS, but adaptive response is generally high and type-specific.
To better understand the link between initial innate response and early onset of adaptive immunity to carbohydrate antigens in
the perciform barramundi (Lates calcarifer), an immune transcriptome was prepared from pronephros and spleen following
vaccination with LPS and peptidoglycan. From 163,661 transcripts derived by Illumina mRNA-Seq, most grouped in neuronal,
endocrine or immune system categories, suggesting a close relationship between the three systems. Most of the known TLRs
were transcribed in the barramundi spleen and HK transcriptome, with the notable exception of TLR4, which is primarily
responsible for LPS recognition in mammals. Several C-type lectin receptors were also identified, including CLEC4E (Mincle). As
Mincle has been shown to bind LPS and is abundant on dendritic cells, its role in response to LPS in barramundi was further
investigated. A high dose of LPS induced TNF-alpha expression via Mincle. However, IL-6 regulation, whilst still regulated in
response to LPS, did not depend upon the Mincle pathway, suggesting other routes of activation. This study thus suggests that
Mincle may act as a partial substitute for TLR4 in barramundi in the processing of LPS.
141
Asexual reproduction in elasmobranchs: who needs claspers anyway?
Christine L Dudgeon1, Laura Coulton2, Emily Bone2, Severine Thomas2
1. The University of Queensland, Brisbane, QLD, Australia
2. Reef HQ Aquarium, Townsville, QLD, Australia
Facultative parthenogenesis, asexual reproduction in otherwise sexually reproducing species, has been described from most
vertebrate classes, excepting mammals, including seven species of elasmobranchs. Here we present a case study on leopard
sharks, Stegostoma fasciatum, from the Reef HQ aquarium and discuss these findings with respect to the evolutionary
implications for reproductive flexibility in elasmobranchs.
142
Variability in multiple paternity rates for grey reef sharks (Carcharhinus amblyrhynchos) and scalloped hammerhead sharks
(Sphyrna lewini) in Papua New Guinea
Madeline E Green1, 2, Sharon A Appleyard2, William White2, Sean R Tracey1, Jennifer Ovenden3
2. Australian National Fish Collection, CSIRO National Research Collections Australia, Hobart, Tasmania, Australia
3. School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
The present study assessed the presence and prevalence of multiple paternity (MP) in litters of grey reef (Carcharhinus
amblyrhynchos) and scalloped hammerhead (Sphyrna lewini) sharks caught in Papua New Guinea. Litter size between species
significantly differed with an average of 3.3 pups for grey reef sharks and 17.2 pups for scalloped hammerhead. Using 15
microsatellite loci, we identified multiple paternity in 66% of grey reek sharks (4 out of 6 litters) and 100% multiple paternity in
scalloped hammerhead sharks (5 litters) using 10 microsatellite loci. We reported high paternal skew and a positive correlation
between adult size and litter size in scalloped hammerheads, but not in grey reef sharks. Differences in the frequency of MP
between species and the identification of paternal skew is thought to be affiliated with mating strategies and post-copulatory
mechanisms. The presence of MP is thought to benefit populations by enhancing the variation of genetic diversity therefore
increasing the population’s genetic resilience to pressures including heavy fishing. Given both species are commonly impacted in
local PNG fisheries, results from this study provide useful information for local management in the region.
143
Population structure and phylogeography of the Galápagos shark (Carcharhinus galapagensis) across the Pacific.
Diana A Pazmino1, Colin A Simpfendorfer1, Gregory E Maes2, Lynne van Herwerden1
2. Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Leuven, Belgium
Galápagos shark (Carcharhinus galapagensis) is a circum-tropical distributed species that commonly occur at isolated oceanic
islands (Compagno 1984). The species is currently listed by the IUCN as "near threatened" (2003 assessment; Bennett et al.
2013). A previous population genetic study of the species in the west Pacific tentatively identified two Management Units
(MUs): 1) Kermadec Islands and Elizabeth-Middleton Reef, and 2) Lord Howe Island; while Norfolk Island was suggested as a
stepping-stone between both MUs. Our project attempted to assess connectivity and gene flow of C. galapagensis at a bigger
scale across the Pacific region using genomic approaches.
We examined the population genomic structure of Galápagos sharks using genome wide Single Nucleotide Polymorphism
markers from DArTSeq. After rigorous steps of data filtering and quality control, a total of 8,218 SNPs were used for the
analyses. To identify potential historical gene flow and/or sex-biased dispersal, we also sequenced the mitochondrial control
region (997bp). After discarding outlier markers under potential selection, cluster analyses of neutral SNPs including STRUCTURE
and NETVIEW revealed two highly distinct genetic groups, one comprising individuals from the East (Galápagos Islands, Ecuador
and Revillagigedo, Mexico), the other from the Western Pacific (Hawaii, Australia and New Zealand). Phylogenetic analyses
under Bayesian and Maximum Likelihood criteria using SNPs were congruent with such pattern indicating the presence of the
same two major clades with high support. The sister species Carcharhinus obscurus was used as out-group. Advanced
population genomics analyses will lead to detect footprints of selection and local adaptation, as well as understanding
evolutionary connectivity, patterns and levels of gene flow and demographic history.
Keywords: DArTSeq, SNPs, Phylogenetics, connectivity.
144
Using fishing vessels for basin-scale ecological monitoring using bio-acoustics and the continuous plankton recorder
Rudy J Kloser1, Anthony J Richardson2
2. Oceans and Atmosphere, CSIRO, Brisbane, Queensland, Australia
As part of Australia’s Integrated Marine Observing System (IMOS), basin-scale ecosystem monitoring is using fishing vessels as
ships of opportunity. Bio-acoustic data are collected from the vessel’s calibrated acoustic systems and a Continuous Plankton
Recorder (CPR) is towed on basin-scale transits. These data can provide metrics for the behaviour, distribution and abundance of
phytoplankton, zooplankton and micronekton to describe annual and multi-annual trends. The context for these data is
strengthened when combined with other associated remotely-sensed or directly-sampled physical, chemical and biological
information. We review a decade of data collected from the Tasman Sea region that is predicted to be a climate change hot
spot, due in part to the strengthening and extension of the East Australian Current (EAC). The monitoring is placed in the context
of associated remotely-sensed data and ad-hoc physical net sampling of the macro-zooplankton and micronekton of ~2 to 20 cm
length (small crustaceans, gelatinous, squid and fish) that dominate the mesopelagic open ocean basins in this region. We use a
suite of ecological metrics (e.g. size, density, diversity, trophic linkages and energetic transfer) to describe and interpret interannual changes. We show that there is strong congruence in behaviour between multiple trophic levels, with synchronous diel
vertical migration. We show marked differences in the productivity of plankton and micronekton across the Tasman Sea. Our
ability to detect changes in these ecological units and the potential uptake of the data to ecological models is discussed.
145
Coastal ocean observations for fisheries
Charitha Pattiaratchi1
1. The University of Western Australia, Nedlands, WA, Australia
Integrated coastal observations provide information on the ocean in near-real time and help to understand oceanic processes
and place them in a climatological context. This presentation is based on data collected in Western Australia using IMO
infrastructure. The coastal observation system includes a number of platforms including ocean gliders, ocean Radar, mooring
arrays supplemented by satellite imagery. Integration of the oceanographic data sets from these observation platforms reveal a
number of important processes and phenomena related to fisheries. The main area of interest is located in the south-west of
Australian continental shelf and slope regions offshore Fremantle extending northwards to Jurien Bay. Within this region there
important topographic features such as the Rottnest Island and Perth Canyon and the circulation is dominated by the southward
flowing Leeuwin Current (LC) with the northward flowing Leeuwin Undercurrent (LU) beneath the (LC) and the wind driven
Capes Current (CC) located on the shelf, particularly during the summer months. The interaction between the LC and CC
generate eddies which are generate high primary production. Data collected over the past few years from the observation array
indicate year to year changes in the Capes Current an important conduit for Australian salmon migration. For example, during
early 2016 high numbers of salmon were found in the Perth metropolitan region which could be related to the strong southerly
winds experienced during the El Nino year resulting in a strong Capes Current and associated upwelling. Similarly, frontal
system between the Ningaloo Current and coastal regions between North-west Cape and Dampier is an area of numbers of fish
species.
146
Physical oceanographic influences on tropical reef and continental shelf fish from IMOS observations.
Craig Steinberg1, Jessica Benthuysen1, Karen Wild-Allen2, David K Williams1, Hemerson Tonin1, Richard Brinkman1
2. Marine and Atmospheric Research, CSIRO, Hobart, Tasmania, Australia
Australia’s Tropical Northern Seas encompass a region of rich oceanographic complexity and ecological diversity. IMOS
observations extend from Ningaloo Reef in the west, the resource rich North West Shelf to Darwin and along Queensland’s
Great Barrier Reef (GBR).
One of the primary objectives of the Australian Government NCRIS funded IMOS arrays is to monitor boundary currents
comprising of the Leeuwin, Holloway, Gulf of Papua and the East Australian Currents and their associated eddies. In addition
cross-shelf exhanges are also observed through processes such as internal waves and subsurface cold water intrusions.
Observations from satellite observations to in situ fixed and roving platforms reveal a rich amount of detail of the boundary
currents which have a strong seasonal variation. Shelf waters exhibit a transition from well-mixed in winter to a strongly
thermally stratified water column from spring-time warming through summer. Internal tides can then are able propagate into
the shallower shelf water. Along the GBR there are periods of sustained cold and nutrient rich intrusions across the shelf
through the reef matrix. In this paper a number of examples are provided across the tropical north showing how the
environmental conditions can influence fish behaviour and feeding grounds.
147
A biogeography of the mesopelagic zone based on estimated myctophid biomass within Deep Scattering Layers
Roland Proud1, Martin J Cox2, Andrew Brierley1
1. Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory,, University of St Andrews, UK
2. Australian Antarctic Division, Kingston, Tasmania, Australia
The mesopelagic zone (200 – 1000 m) may contain over 10 billion tonnes of fish, which is a potentially important future fishery
resource. The major constituents of the mesopelagic fish community are myctophids (c. 250 species): although not fit for human
consumption, they could be used as food for farmed animals and fish, and also as fertiliser for crops. During the daytime,
myctophids form deep (300 – 1000 m), horizontally extensive (1000s of km) layers that are readily detectable with
echosounders. The layers are known as Deep Scattering Layers (DSLs) because they scatter sound. At night, a proportion of fish
in DSLs migrate upwards to access their prey (including zooplankton), and feed nearer the surface. The fish migrate to depth at
dawn, and this 2-way vertical migration is an important process for vertical transport of nutrients and carbon in to the ocean
interior. The depth and biomass of the mesopelagic community is influenced by environmental factors, giving rise to
geographical variation. Akin to the surface biogeography described by A. Longhurst, which was based on primary production and
regional oceanography, here we describe a mesopelagic biogeography, based on regional estimates of myctophid biomass and
DSL depth, from a global dataset of echosounder observations. We estimate regional values of trophic efficiency and predict,
using output from a coupled climate-ecosystem model (NEMO-MEDUSA-2.0), how these values may change by 2100. Ultimately,
we provide a method for partitioning the ocean, across a range of scales, into distinct compartments/habitats, which are useful
for mesopelagic study. In doing so, we highlight the differences in structure between the surface and mid-water communities
and provide an informative map for both conservation and fisheries management.
148
New data and models to resolve ecosystem status and trends on the Kerguelen Axis in the Southern Indian Ocean
Rowan Trebilco1, Andrea Walters2, Jessica Melbourne-Thomas1, 3, Martin Cox1, 3, Michael Sumner1, 3, Andrew Constable1, 3
1. ACE CRC, Hobart, TAS, Australia
2. IMAS, Hobart, TAS, Australia
3. Australian Antarctic Division, Kingston, TAS, Australia
The Southern Ocean is rapidly changing, with future environmental changes likely to have wide- reaching consequences for the
structure and function of marine ecosystems. Along with well-designed sampling and observation programs, ecosystem models
are the central means by which we can gain insight into how these changes affect ecosystems. Developing ecosystem models
that can provide robust predictions and management advice depends on knowledge of environmental drivers and trophic
linkages for constituent species. In the Southern Ocean, this information is largely lacking for the the mid- trophic level fish and
squid groups that comprise major energy pathways making primary producers accessible to higher-order predators including
whales, seals, penguins, flying seabirds. Knowledge of mid- trophic levels has also been identified as a key uncertainty for
understanding top predator trophodynamics globally and this knowledge gap represents a major impediment to the
development of conservation and management strategies.
The Kerguelen Axis is the most important area for primary production in the Southern Indian Ocean, and a key area of interest
for Australia. However, ecosystem structure and drivers in this region are poorly understood. In January to March 2016, the
Antarctic Climate and Ecosystems CRC led an integrated ecosystem survey program along a 8850 km path comprising 9
transects. The voyage track was designed to encompass major environmental transitions in the region including frontal
features, the maximum extent of winter sea-ice coverage, and gradients of sea surface temperature and surface primary
production, with extensive biological and oceanographic sampling. The goal of this voyage was to characterize pelagic foodweb
structure and trophic linkages in this region and to pilot methodologies for future ecosystem observation and monitoring in the
region. Here, we present a summary of the fish and squid sampling conducted on this voyage and show how empirical data are
being coupled with modelling to better understand ecosystem status and trends in this region.
149
Looking into the future: seasonal to multi-year forecasts for fish and fisheries
Alistair Hobday1
1. CSIRO Marine and Atmospheric Research, Hobart, TAS, Australia
Climate influences marine ecosystems on a range of time scales, from weather-scale (days) through to climate-scale (hundreds
of years). While operational seasonal forecasts are now available for several Australian fisheries, understanding of interannual to
decadal climate variability and impacts has received less attention. Predictability up to 10 years ahead may come from largescale climate modes in the ocean that can persist over these time scales. In Australia the key drivers of climate variability
affecting the marine environment are the Southern Annular Mode, the Indian Ocean Dipole, the El Niño/Southern Oscillation,
and the Interdecadal Pacific Oscillation, each has phases that are associated with different ocean circulation patterns and
regional environmental variables. Statistical and dynamical approaches are described to generate forecasts of climate drivers
that can subsequently be translated to useful information for marine end users making decisions at these time scales.
Considerable investment is still needed to support decadal forecasting including improvement of ocean-atmosphere models,
enhancement of observing systems on all scales to support initiation of forecasting models, collection of important biological
data, and integration of forecasts into decision support tools for fishers and managers. Collaboration between forecast
developers and fishery users is needed to support forecast-based tactical and strategic decisions over seasonal to decadal time
scales.
150
Mulloway anglers or citizen scientists?
Lauren J Veale1, Nick Whiterod1
1. Nature Glenelg Trust, Warrnambool, Victoria, Australia
Despite occurring across much of our coastline, there are still significant knowledge gaps in the life history, movement patterns
and population structures of mulloway. With anglers dedicating their lives to catching a silver ghost, citizen science provides a
cost effective and efficient way of advancing our knowledge of this species. In addition, the direct involvement of anglers has
encouraged environmental stewardship and increased awareness on the importance of sustainable fisheries management. The
research program, funded by Victorian Recreational Fishing License Fees, began in late 2014 and has seen over 300 frames
donated by more than 60 anglers across Victoria. Donated samples, together with a small number of scientifically collected
mulloway, range in total length from 51 to 150 cm and have been aged between 3 and 22 years. Preliminary investigation has
identified a dominant 3+ age cohort in 2014, suggesting a strong recruitment event occurred in 2011. Majority of mulloway (90
%) have been caught from estuaries where individuals have predominantly been ≤ 85 cm and ≤ 6+ years, corresponding to the
approximate estimate of 50 % maturity. The high abundance of juveniles in Victorian estuaries therefore highlights the
importance of these systems as nursery areas. Preliminary growth curves indicate Victorian mulloway exhibit fast but highly
varied growth rates, particularly in their early years. The partnership with recreational fishers continues to enable insight into
the age structures, growth rates and reproductive characteristics of the species. Donations have also provided the necessary
genetic information to clarify the current uncertainty surrounding stock structures of mulloway throughout Victoria and their
connectivity with interstate subpopulations.
151
Aspects of the age, growth and reproductive cycle of tailor (Pomatomus saltatrix) in eastern Australia
Hayden T Schilling1, 2, Julian M Hughes2, 3, John Stewart2, 3, Iain Suthers1, 2
1. Fisheries and Marine Environmental Research Laboratory, UNSW Australia, UNSW, NSW, Australia
2. Sydney Institute of Marine Science, Chowder Bay, NSW, Australia
3. New South Wales Department of Primary Industries, Chowder Bay, NSW, Australia
Tailor (Pomatomus saltatrix) is a globally distributed pelagic predator which is targeted by both recreational and commercial
fisheries. Despite being the target of heavy recreational fishing in Eastern Australia, knowledge of the growth and reproductive
cycles in this region is limited to mostly anecdotal stories. Regular samples from the commercial and recreational fisheries in
NSW have provided insights into the population structure and dynamics of the tailor population. Ageing based upon otoliths
shows comparable growth rates to other global stocks such as that off the east coast of America, although the age structure
appears to be truncated in NSW, with fish older than 5 years old extremely rare. Using macroscopic staging of gonads and a
gonadosomadic index, a previously unknown spawning period and location has been identified in Northern NSW in late summer.
These findings reveal that the tailor population in eastern Australia is more complex than previously thought and has
implications for the management of this ecologically and economically important pelagic species.
152
A cracking new improvement in the daily egg production method: Using in situ hybridisation for discerning Chrysophrys
Auratus eggs and larvae.
Mike Steer1, Gretchen Grammer, Melissa L Wos-Oxley , Emma Westlake, Sarah R Catalano, Andrew PA Oxley
1. SARDI (Aquatic Sciences), West Beach, SA, Australia
Estimating biomass through quantifying egg production has become integral in the assessment and management of key fish
stocks throughout the world. The Daily Egg Production Method (DEPM) is most widely used and despite its simplicity, its
capability has generally been confined to species that produce eggs with distinct and identifiable morphologies. Relying on
morphological criteria alone can present problems and there are examples where spawning biomass has been overestimated as
a result of incorrect egg identification. Molecular validation of fish eggs and larvae is rapidly becoming an essential component
of existing DEPM programs and provides a clear extension of the method to species where egg identification has been
problematic. Validation methods have, so far, relied on destructive sampling, where eggs and larvae are initially identified,
ascribed a developmental stage, and their DNA or RNA is chemically extracted for analysis. This process is applied to a sub-set of
samples to determine a ‘correction factor’ and improve the confidence of the biomass estimate. In situ hybridisation (ISH)
approaches may provide a more streamlined and non-destructive validation alternative. This involves the development of a
species-specific oligonucleotide probe that targets ribosomal RNA to produce a colour reaction. Coloured eggs and larvae can
then be identified under a standard stereo microscope, separated from mixed species samples, staged and archived. This study
aims to investigate the feasibility of using ISH to validate snapper (Chrysophrys auratus) eggs and whole larvae from South
Australian waters and subsequently extend the results to estimate the spawning biomass of this commercially important species
using the DEPM.
153
Stochastic demographic analyses of the silvertip shark (Carcharhinus albimarginatus) and the common blacktip shark
(Carcharhinus limbatus) from the Eastern Indo-Pacific
Jonathan Smart, Andrew Chin1, Andrew Tobin1, William White2, Colin Simpfendorfer1
2. CSIRO, Hobart
Information on how shark populations respond to increases in fishing mortality (F) is critical to developing successful
management and conservation strategies. However, data on catch, effort and abundance are often lacking for shark populations
– preventing stock assessments from being conducted. Static demographic models circumvent this issue as they only require life
history parameters. Age-structured Leslie Matrix models were developed and applied for silvertip shark Carcharhinus
albimarginatus and common blacktip shark Carcharhinus limbatus populations from the Indo-Pacific region. Stochasticity was
introduced to these models by varying vital rates though Monte Carlo Simulations. Varying levels of F were introduced to the
analyses to determine how both species respond to fishing pressure. Management scenarios were further developed to
determine strategies that could facilitate sustainable harvesting. The demographic estimates demonstrated that both species
would have increasing populations when unfished (C. albimarginatus λ = 1.02 and C. limbatus λ = 1.04). However, both
populations would decline when low levels of F (<0.05) were applied to all age-classes. The matrix elasticities revealed that
changes to fertility elements had little effect on λ, while changes in juvenile survival produced the largest changes. However,
age-at-first-capture analysis revealed protecting the juvenile life stage of both species would be an ineffective management
strategy as both species mature at old ages. An age-at-last-capture analysis revealed that these species could be harvested while
maintaining increasing populations through a gauntlet fishery. This required F to be restrained to individuals <100cm TL while
protecting the older age-classes to preserve the breeding stock. This strategy would allow up to 20% of this length class to be
harvested for both species before population declines would occur. However, this strategy is dependent on the ability to
successfully protect all other age-classes from fishing – a strategy which may not be pragmatic in developing nations where little
regulation occurs.
154
Catch composition of a traditional Indonesian shark fishery operating off north-western Australia
Lindsay Marshall 1, Jenny Giles2, Grant J Johnson3
1. Stick Figure Fish Illustration, Sydney, NSW, Australia
2. Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
3. Department of Primary Industry and Fisheries, Darwin, NT, Australia
For centuries Indonesian fishers have harvested marine organisms from waters off north Australia. This has continued under an
Australian and Indonesian Memorandum of Understanding (MOU), signed in 1974, that allows traditional Indonesian fishers
access to 48,000 km2 off north-western Australia. In this area, known as the MOU Box, Indonesian fishers fish for sedentary
organisms, finfish, and sharks which are believed to have come under greater fishing pressure over the past decade. Despite
concern, and in contrast to other Australian shark fisheries, little work has been done quantifying catch composition, a prerequisite for effective fisheries management. Establishing the catch composition in this fishery is challenging because the catch
can only be inspected post capture and is retained as parts, such as fins. In this project novel techniques were used to identify all
sharks on nine traditional Indonesian vessels operating in the MOU Box. Photos and tissue samples were collected from 152
dorsal fins and were identified to species using expert visual identification and DNA methods. Sixteen different species belonging
to the families Carcharhinidae (Whalers) and Sphyrnidae (Hammerheads) were identified. The most abundant species were
Sandbar Shark Carcharhinus plumbeus and Tiger Shark Galeocerdo cuvier, representing 43.4% and 29.6% of the total catch,
respectively (from a catch with an estimated weight of 10.5 tonnes). Furthermore, we tested two semi-automated fin
identification methods, developed for field use by non-fin experts. These methods varied in success, with the morphometric
identification technique achieving 69% accuracy and the FAO iSharkFin program only 29% accuracy. This project provides
fundamental catch information for the management of northwest Australian shark fisheries, both in and outside the MOU Box.
Our study demonstrates the value of validating semi-automated methods using diagnostic expertise and also highlights the
difficulties associated with applying these methods to varying assemblages. If adopted more widely, the techniques used in this
study can be used to improve the accuracy of global elasmobranch fisheries data.
155
Arthurs Lake – estimating the trout population size of a large impoundment fishery.
Tim Farrell1, Rob Freeman1
1. Inland Fisheries Service, New Norfolk, TAS, Australia
Arthurs Lake is a wild brown trout recreational fishery that has not been stocked for 70 years. The inflowing streams provide
large of areas suitable for spawning and thus the lake gets ample recruitment when conditions are favourable. Between 2009
and 2014 good rainfall events enabled successful recruitment to the lake for five consecutive years. The population of brown
trout since this period has been large and resulted in a reduced potential for growth and consequently a small average sized fish,
less than 400 grams.
The Inland Fisheries Service as managers of the brown trout fisheries in Tasmania have sought to improve the average size of
trout at Arthurs Lake with the aim of achieving an average weight of one kilogram. The installation of barriers to upstream
migration on three of the lakes spawning creeks together with trapping facilities was completed in 2014 in order to achieve that
aim. The quantum of fish to be removed from the fishery to achieve the aim has not been determined, neither has the current
size of the brown trout population in the lake.
Determining the size of the population of brown trout at Arthurs Lake is problematic due it is a large storage of 65km2 and
511,550Ml at full supply level. Further to this, the actual number of fish in the lake has never been quantified thus the upper
limits are unknown.
A mark and recapture study is proposed for 2017 utilising spawning trout as the marked population. An in-lake recapture phase
will occur post spawning period after sufficient mixing with the non-spawning population of fish. Using the 2016 spawning run a
pilot study has commenced to examine tag loss, mixing time and other factors that may influence the estimate.
156
Bridging the Land-Sea divide for future food security.
Richard S. Cottrell1, Aysha Fleming1, 2, Elizabeth A. Fulton1, 2, Kirsty L. Nash1, Reg Watson 1, Julia L. Blanchard 1
1. Centre for Marine Socioecology, University of Tasmania, Hobart, Tasmania
2. CSIRO Oceans and Atmosphere , Hobart, Tasmania
Meeting food demands for the 10 billion people expected by 2050 presents a paradox. Globally, consumers are becoming more
urbanised and wealthier, increasing per capita demands on natural resources. Meanwhile, over 1 in 7 people still have
insufficient access to safe and nutritious food to allow them a healthy and active life. Thus, the food security challenge is twofold; sustainably meeting consumption demands from a burgeoning population; and feeding the world’s under-nourished
communities. Advances in terrestrial and aquatic production efficiencies have been proposed to solve the issue but largely in
isolation. We argue that production systems on land and sea are fundamentally linked through economic markets and the
Earth’s biosphere and therefore cannot be considered independently. This presentation reviews published interactions between
terrestrial and aquatic elements of the food system and suggests a more integrated approach to addressing the food security
challenge. Further the role of sectoral connectivity in social and environmental sustainability is discussed.
157
Environmental and socio-political shocks to the seafood sector: what does this mean for resilience? Lessons from two case
studies, Atlantic mackerel and Atlantic salmon
Marcello Graziano1, Clive J Fox2, Karen A Alexander3, Cristina Pita4, Sheila JJ Heymans2, Margaret Crumlish5, Adam Hughes2, Joly
Ghanawi5, Lorenzo Cannella6
1. Department of Geography, Central Michigan University, Mount Pleasant, Michigan, United States
2. Department of Ecology, Scottish Association for Marine Science, Oban, Argyll, United Kingdom
3. Centre for Marine Socioecology, University of Tasmania, Hobart, Tasmania, Australia
4. Department of Environment and Planning & Centre for Environmental and Marine Studies, University of Aveiro, Aveiro,
Portugal
5. Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
6. Dipartimento di Scienze della Terra, University of Genova, Genoa, Italy
Farmed and capture fisheries products have become important globally traded commodities. This can lead to social and
economic dependency in the regions where production occurs. Major shocks (environmental or socio-political) to demand and
supply may affect the resilience of the seafood sector and the associated dependent producing regions. Here, we describe the
results of a collaborative and interdisciplinary expert workshop on how two particular seafood industries, farmed Atlantic
salmon (Salmo salar) and North-east mackerel (Scomber scombrus), have responded to such shocks and what this means for
sectoral and regional resilience.
We identified several key findings. Firstly, we established that a reliance on healthy natural ecosystems, the existence of outside
drivers for production and certain employment patterns were elements of low resilience. Secondly, we pinpointed industry
consolidation and the central role of government in assisting the seafood sector as elements of high resilience. Moreover, we
found that the farmed salmon and wild mackerel industries share characteristics which have enabled them to be resilient to
many of the shocks which have affected them in recent years.
Our approach aimed to expand the seafood production debate from purely ‘food security’ based themes to an interdisciplinary
paradigm which incorporates social and ecological sustainability. The approach taken in this study seemed particularly effective
in analysing a sector which cuts across ecological, economic, social and political spheres and may be well placed to contribute
towards emerging approaches in ecosystem based management.
158
Relationships between Maori freshwater values and flow: developing tools for incorporating cultural fisheries values into
flow management decisions.
Shannan K Crow1, Gail Tipa2, Doug J Booker1
1. NIWA, Christchurch, New Zealand
2. Tipa and Associates Ltd, Dunedin, New Zealand
Sustainable use of freshwater resources requires managers to understand the relationships between flow and instream values.
While these relationships are available for most freshwater biota, limited tools are available that quantify the relationships
between flow and cultural values. The present study aimed to develop quantitative relationships between Maori freshwater
values and flow magnitude.
A score card was developed that quantified how observed flows supported fisheries and cultural values. Cultural health scores
were recorded across a variety of flow magnitudes for each of five Rivers in the South Island of New Zealand. Mixed-effects
models were then fitted to see: 1) if relationships were present between flow magnitude and cultural health; 2) if these
relationships differed between streams and participants.
There was a positive relationship between flow and cultural health scores after differences between sites and observers were
standardised. If differences between sites and observers were ignored, there was a positive relationship between flow and
cultural health that only explained 5% of the variation in cultural health scores. If differences between sites and observers were
accounted for in the analysis, there was a positive relationship between flow and cultural health that explained 61% of the
variation in cultural health scores.
The present study provides a framework for quantifying relationships between cultural health and flows at different sites.
Results suggest that these relationships could be developed into quantitative tools that could be used improve flow
management decisions.
159
Creating outcomes for Maori communities and taonga freshwater fisheries through collaborative research partnerships
Erica K Williams1, Jacques AT Boubée1
1. National Institute of Water & Atmospheric Research, Wellington, New Zealand
The wellbeing of many Maori (indigenous peoples of New Zealand) communities has long relied on the sustainable use of
freshwater resources, where species like tuna (freshwater eels), koura (freshwater crayfish) and kakahi (freshwater mussels)
once supported local and regional economies with significant food and resources. The Treaty of Waitangi forms the underlying
foundation of the Crown-Māori relationship with regard to freshwater resources in New Zealand. In recent times, Treaty
settlements have resulted in assets of strategic importance being returned to Māori. Many of these settlements are concerned
with the co-management, protection and restoration of values, uses and services that have not previously been a priority for
environmental research, restoration and monitoring by government and research agencies.
New Zealand’s evolving co-management context is an opportunity to co-develop research methods, tools and products that
inform new and innovative approaches for the protection, restoration and economic development of taonga (treasured)
freshwater species. This requires: (1) A focus on Maori values/uses/opportunities and research priorities; (2) Development of
Maori capacity in freshwater research, management and policy; (3) The flexibility to respond to the strategic needs of resource
managers as the co-management landscape evolves; and (4) Interdisciplinary collaborations to develop credible cross-cultural
approaches that engage our communities, and empower both matauranga Maori (Maori knowledge) and science-based
knowledge systems.
In 2001 the National Institute of Water & Atmospheric Research (NIWA) established Te Kuwaha, the National Centre of Maori
Environmental Research. Over the last 15 years NIWA has been co-delivering freshwater fisheries research of benefit to Maori,
and helping to develop Maori research capability and capacity. Using freshwater eel research as one example, in this
presentation we provide insights into some of the successful collaborative partnerships we have been privileged to be part of.
160
Development of a Harvest control rule (HCR) for Australia’s Torres Strait tropical rock lobster (TRL) fishery
Roy Deng1, Eva Plagányi1, Darren Dennis1, Trevor Hutton1, Robert Campbell2
1. CSIRO, St Lucia, QLD, Australia
2. CSIRO, Aspendale, VIC, Australia
ABSTRACT
The Torres Strait tropical rock lobster Panulirus ornatus fishery, provides employment for greater than 400 indigenous fishers as
well as a small non-indigenous sector. The fishery is transitioning from input controls to a quota managed system, necessitating
the development of an effective harvest strategy and TAC setting process. This is to take into account changes in the methods
used, as well as the survey frequency and timing, to achieve defined biological, economic and socio-cultural objectives of the
lobster fishery.
This presentation provides a brief summary of the testing and development of a new empirical Harvest Control Rule (HCR), a
description of the current TAC setting process and some alternative options for future implementation. We highlight the
performance of alternative candidate empirical HCRs using stakeholder input and demonstrate the advantages for the future
TAC setting process. For each HCR, there are a large number of performance statistics output, based on the reference points
developed for the fishery, for consideration by stakeholders. A smaller set of the key outcomes of the HCR testing are presented
here.
161
Hangin in ya PJs: Social networks in Port Jackson sharks
Johann Mourier1, Nathan C Bass1, Jo Day2, Nathan Knott3, Culum Brown1
1. Macquarie University, NSW, Australia
2. Taronga Zoo, Mossman, NSW, Australia
3. Fisheries NSW , DPI, Huskisson, NSW, Australia
An increasing number of shark species have been reported to show some site-specific reproductive philopatry in which males
and/or females return to the same location for mating and/or parturition. These patterns have mainly been found in tropical
species. Here we used acoustic telemetry to demonstrate that both sexes of Port-Jackson sharks, a temperate endemics of
Australia, return to the exact same reef in Jervis Bay to mate and reproduce after foraging in Southern Australia over summer.
We used this mating aggregation ground to investigate the social interactions between individuals using a telemetry approach
combined with genetic analysis to improve our understanding of the mating strategies of this iconic species. Our results
demonstrate that males and females have complex dyadic interactions which can persist over multiple years, despite
undertaking long distance annual migrations to foraging grounds following mating. While there are high levels of relatedness at
each breeding location, genetic relatedness did not drastically influence association patterns. These findings revealed that these
mating grounds represent social arenas in which interactions are far more complex than previously expected. This preliminary
results provide additional information on improving our understanding of evolution of reproduction and social behavior in
elasmobranchs which has profound implications for conservation management.
162
Crossing paths and time budgets: pelagic sharks and human activities in Spencer Gulf and the Great Australian Bight
Paul J Rogers1, Micheal Drew1
Functional co-existence between humans and large marine predators invloves complex social and practical challenges for the
community, industries, and managers of marine resources, threatened and protected species. In 2015, we investigated the time
budgets of individual white sharks (Carcharodon carcharias) and bronze whalers (Carcharhinus brachyurus) in gulf and
continental shelf areas used by commercial fisheries, fin-fish aquaculture, cage-dive tourism, and the community during
recreational activities. Satellite (10, C. carcharias) and acoustic telemetry (134, both spp.) were used at finfish aquaculture
leases, in areas used by commercial fisheries, at long-nosed fur seal and Australian sea lion colonies and haul-outs, and
hypothesised migration paths and bathymetric features linking these areas and habitats. Bronze whalers and white sharks
exhibited dissimilar seasonal patterns of visitation and short-term residency at offshore islands and reefs along isobaths
adjacent to fur seal and Australian sea lion colonies, and areas frequented by teleost prey. New data describing the fine- and
large-scale movements of white sharks will be presented, which will assist with the ongoing resolution of multi-jurisdictional,
regional, and industry-specific management processes.
163
Using an individual-based simulation of kinesis, advection and movement behaviours in Pacific skipjack tuna to examine
assumptions in stock assessment
Joe Scutt Phillips1, Alex Sen Gupta1, Erik van Sebille2, Michael Lange2, Inna N Senina3, Patrick Lehodey3, Simon Nicol4
1. Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
2. Grantham Institute, Imperial College London, London, United Kingdom
3. Division Oceanographie Spatiale, Collecte Localisation Satellite, Ramonville St Agnes, France
4. Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra, NSW, Australia
The western and central Pacific Ocean supports the world’s largest tuna fishery, with skipjack tuna (Katsuwonus pelamis)
constituting over 60% of the catch from this region. Stock assessment models that provide scientific advice for the management
of skipjack and other pelagic species are typically Eulerian in nature. As such, they rely on assumptions of stock transfer rates
between regions, mixing of individuals within a population, and homogeneity at fixed spatial scales. Altering these assumptions
can have profound effects on the estimated abundance and spatial distribution of this heavily exploited species. Using Eulerian
models, it is also non-trivial to represent the changes in mesoscale distribution due to ocean dynamics, range contraction due to
population depletion, and interactions between tuna conspecifics or prey.
A Lagrangian, or individual-based, approach to modelling fish distribution allows many of these assumptions to be tested in a
framework that is structured on the fundamental unit of ecology: the individual. Here, we detail such an approach using Pacific
skipjack as an application. The model extends a newly developed Lagrangian ocean particle-tracking simulator by incorporating
directed movement, non-directional kinesis, and random-walk behaviours. First replicating the spatial density evolution of a
current advection-diffusion distribution model of skipjack tuna populations, we then discuss the effect on meso- and large-scale
distribution of alternate behavioural scenarios at the individual level.
Individual-based models provide a valuable tool to analyse the assumptions behind our understanding of free-roaming animals
that are difficult to observe. In the case of skipjack and other species of Pacific tuna, anticipated uses of this tool are the
simulation of tagging experiments to aid design, the effect of changing habitat on mixing rates, and interaction with drifting fish
aggregating devices.
164
Determining demographic processes responsible for dramatic changes in South Australia's snapper fisheries
Anthony Fowler1, Paul Hamer2, Jodie Kemp2
1. SARDI, West Beach, SA, Australia
The relative significance of fish movement and local reproduction and recruitment as input demographic processes for fish
populations can be challenging to differentiate. Nevertheless, it is significant to do so, from the perspective of understanding
stock structure and appropriate spatial scales for management. Snapper is the most significant coastal, marine finfish fishery
species of South Australia. During the 2000s, its component regional fisheries underwent unprecedented changes in spatial
structure: an episodic fishery developed in the south east (SE) region; annual catches in Northern Gulf St. Vincent (NGSV)
increased exponentially to record levels; whilst catches from Northern (NSG) and Southern Spencer Gulf (SSG) declined to their
lowest levels. The demographic and fishery-related processes that underpinned these changes were unclear, which hampered
developing appropriate management responses. This study used the analysis of otolith chemistry to assess the relative
significance of inter-regional movement and local recruitment as input processes to the different regional populations.
Transverse sections of otoliths from four year classes collected from six different regional fisheries were analysed using laser
ablation – inductively coupled plasma mass spectrometry. These provided age-related estimates of elemental concentrations for
Ba, Sr, Mn and Mg that were compared amongst regions. The data were interpreted to indicate the regions of origin and
subsequent migration patterns of fish. The episodic fishery in the SE was related to variable recruitment into Port Phillip Bay,
Victoria and subsequent mass emigration out of the bay and then westward over a distance of approximately 600 km, indicating
that the Western Victorian Stock extended well into South Australian waters. Alternatively, the snapper populations in NGSV
and NSG were considered separate stocks that were not connected by adult fish movement, whose contrasting trends in
fishable biomass related to different recruitment patterns since the late 1990s.
165
Partial migration of grey mullet (Mugil cephalus) on Australia’s east coast revealed by otolith chemistry
Ash Fowler1, Shannen Smith2, David Booth2, John Stewart1
1. NSW DPI Fisheries, Sydney
2. UTS, Sydney
Partial migration affects the ecology and evolution of animal populations, and is an important consideration for the
management of harvested species, yet the phenomenon is understudied in fish. We provide the first insights into partially
diadromous migration of grey mullet (Mugil cephalus) in Australia by examining the otolith chemistry of old individuals (aged 710 years) from two regions on the east coast. Strontium and Barium concentrations were measured across the otolith using laser
ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and indicated considerable diversity in migratory histories
among individuals. Only 15% of individuals made repeated movements from estuaries to the marine environment, consistent
with the annual spawning run in the region. The remainder either made irregular movements between salinity environments
(70%), or resided in estuaries or fresh water for their entire life following the early juvenile stage (15%). The patterns are
consistent with ‘skipped spawning’ partial migration, where a proportion of the mature population forgoes spawning each year.
If confirmed, the behaviour may afford the east coast population of M. cephalus some resilience to fishing pressure on the
annual spawning run.
166
Temporal and spatial variation in strontium in a tropical river: implications for otolith chemistry analyses of fish migration
David Crook1, Katherine Lacksen1, Alison King1, Duncan Buckle1, Steven Tickell2, Jonathon Woodhead3, Roland Maas3, Simon
Townsend2, Michael Douglas1, 4
1. Charles Darwin University, Darwin, NT, Australia
2. Northern Territory Department of Land Resource Management, NT Government, Darwin, NT, Australia
3. School of Earth Sciences, The University of Melbourne, Parkville, Victoria, Australia
4. School of Earth and Environment, The University of Western Australia, Crawley, WA, Australia
Analysis of otolith strontium isotope ratios 87Sr/86Sr is an increasingly utilised approach for studying fish migration within
freshwater and across salinity gradients. A premise of this approach is that freshwater 87Sr/86Sr ratios are temporally stable
within a location, allowing variation in otolith87Sr/86Sr to be interpreted as movement by fish. We analysed surface and
groundwater from the Daly River catchment in the wet-dry tropics of Northern Australia over two years. Analyses of
otolith 87Sr/86Sr ratios were also conducted for freshwater Sooty grunter (Hephaestus fuliginosus) and the putatively diadromous
Ord River mullet (Liza ordensis). Spatial variation in freshwater 87Sr/86Sr ratios was high (range: 0.71612-0.78059) and there was
strong seasonality in water 87Sr/86Sr ratios, with highest values in the wet season. Temporal variation in water 87Sr/86Sr ratios is
attributed to seasonal patterns in surface run-off from headwaters of ancient geologic origin versus input from groundwater
aquifers interacting with younger geological formations. Temporal variation in water 87Sr/86Sr ratios precluded robust inference
on movement within freshwater for both species, although movement across salinity gradients by Ord River mullet was clearly
identified. We conclude that temporally and spatially replicated water Sr data should be a general requisite for studies that use
analyses of otolith Sr (87Sr/86Sr, Sr/Ca, Sr/Ba) to make inferences about fish movement and migration.
167
Seasonal forecasting of dolphinfish distribution in eastern Australia to aid recreational fishers and managers
Stephanie Brodie1, Alistair J Hobday2, James A Smith1, Claire M Spillman3, Jason R Hartog2, Jason D Everett1, Matt D Taylor4,
Charles A Gray5, Iain M Suthers1
1. School of BEES, University of New South Wales, Sydney, New South Wales, Australia
2. Oceans and Atmosphere, Commonwealth Scientific and Industrial Research Organisation, Hobart, Tasmania, Australia
3. Bureau of Meteorology, Melbourne, Victoria, Australia
4. Port Stephens Fisheries Institute, New South Wales Department of Primary Industries, Nelson Bay, New South Wales, Australia
5. WildFish Research, Sydney, New South Wales, Australia
Seasonal forecasting of environmental conditions and marine species distribution has been used as a decision support tool in
commercial and aquaculture fisheries. These tools may also be applicable to species targeted by the recreational fisheries
sector, a sector that is increasing its use of marine resources, and making important economic and social contributions to coastal
communities around the world. Here, a seasonal forecast of the habitat and relative abundance of dolphinfish (Coryphaena
hippurus), based on sea surface temperatures, was developed for the east coast of New South Wales (NSW), Australia. Two
prototype forecast products were created; geographic spatial forecasts of dolphinfish habitat and a latitudinal summary
identifying the location of fish abundance peaks. The less detailed latitudinal summary was created to limit the resolution of
habitat information to prevent potential resource over-exploitation by fishers in the absence of total catch controls. The forecast
dolphinfish habitat model was most accurate at the start of the annual dolphinfish migration in NSW (November and
December). Habitat forecasts for December were useful up to 5 months ahead, but other months showed variable performance
as the lead time for the habitat forecasts increased. The continued development and application of seasonal forecasts will help
fishery industries cope with future uncertainty and promote dynamic marine resource management.
168
Creating win-win scenarios for longer term monitoring of the marine domain?
Stewart Frusher1, Gretta Pecl1
Monitoring the marine world is becoming increasingly important as greater attention is being placed on the marine domain for
ecosystem services such as food, recreation, transport, and energy. These services are also being impacted by changes in
environmental parameters associated with climate change that are altering ecosystems through the change in abundance,
phenology and distribution and interactions of the species that comprise ecosystems. Major biological monitoring programs that
rely on continued scientific collection are becoming harder to fund as funding diminishes and funding bodies look for short term
outputs (e.g. 3 year cycles). The challenge that marine biological monitoring currently faces is the need to collect samples
frequently and across greater spatial scales than previously undertaken but in a cost efficient manner. Using recreational and
commercial users of the marine domain may provide the opportunity to gather data at greater spatial scales including from
regions difficult to sample, and at a frequency that could never be achieved using scientific sampling teams. In this presentation
we will demonstrate two examples. The first will show the potential of the fishing industry using a recently developed project
that provides win-win outcomes for fishers and scientific monitoring. The second example will focus on the use of citizen
scientists using the example of REDMAP, an innovative range extension database that engages divers, fishers and boaters in
reporting unusual sightings, and how this information is greatly extending available information on the changing distributions of
marine species.
169
Baited Underwater Video for an integrated monitoring network: Developing indicators and an appropriate national
framework.
Neville S Barrett1, Euan Harvey2, Nicole Hill1
1. IMAS, UTas, -South Hobart, TAS, Australia
2. Departmend of Environment and Agriculture, Curtin University, Perth, Western Australia, Australia
One of the key priority areas identified by the national science plan is the development of a national integrated monitoring
pprogram, particularly one that provides for the monitoring needs of the new CMR network in shelf waters. For coral and rocky
reef fish assemblages, baited underwater video is now a mature sampling thechnique that is both ffective in water below typical
dive sensus depths, and is non-intrusive, so fits methods appropriate for sampling in areas such as state MPA’s and CMR’s where
intrusive methods may be limited. Currently most BUV research is state-based, and while some states such as WA and NSW have
extensive BUV programs that are integrated within the State (e.g. the NSW MPA monitoring program) there is no national coordination of surveys or agreed standardisation of methods (although methods are usually similar). The new CMR network and
associated monitoring needs may act as a catalyst for this, and this talk explores the potential for establishing a working
partnership between state/commonwealth agencies and universities to further the vision of the Marine Science Plan in this
space. One essential component of a monitoring program is the development of appropriate indicators in this space for regional
and national SOE reporting and the Marine Biodiversity Hub has been exploring these during field programs in several CMRs.
Preliminary findings will be discussed here.
170
Look out behind! Are additional cameras in baited video worthwhile?
Sasha K Whitmarsh1, Peter G Fairweather1, Charlie Huveneers1
1. School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia
The increasing popularity of baited cameras to assess fish assemblages offers the opportunity to improve the design and thus
information that can be obtained from using such devices. In all currently published Baited Remote Underwater Video Station
(BRUVS) studies, cameras are oriented forward, towards the bait bag. We hypothesised that using cameras oriented in all
directions to provide a 360° view of the habitat and associated fish assemblages will increase species richness and abundance
estimates. We used single BRUVS set-ups with 4 GoPro cameras per frame, facing forward, behind, and to both sides of the unit
to test this. We conducted our study in a range of habitats (seagrass, reef, wreck, and soft sediment) to determine whether the
benefits of using this 360° set-up were consistent across habitats and fish communities. We analysed each video and compared
them individually and cumulatively and found that some species and individuals were not visible on the forward-facing camera.
A cost-benefit analysis of whether the increased field and processing time is justified by the increased species numbers and
abundance was also performed. This study quantifies the benefits of using additional cameras and provides an example of
modifications that can be applied to BRUVS to collect further information on the fish assemblages observed.
171
Converging new technologies allow improved methods for tracking sharks and acquiring contemporaneous environmental
data.
Kim Holland1, Carl Meyer1, Tiphaine du Dot2
1. Hawaii Institute of Marine Biology, Kaneohe, Hawaii
2. University of British Columbia, Vancouver
Innovations in both hardware and software technology are converging to allow improved precision in tracking sharks while
simultaneously acquiring information regarding ambient ocean conditions in near-real time. These technologies include fast
acquisition GPS, on-board analysis of ocean temperature and oxygen profiles and deployment of land-based receivers to
augment throughput of data that has previously been soley reliant on satellite coverage. In particular, the use of land based
receivers has significantly increased the amount of data that can be acquired from increasingly sophisticated tags and these data
are available in near-real time. Here we present examples of the integration of these technologies by presenting initial results
of tracks acquired from hammerhead and tiger sharks tagged in Hawaiian waters.
172
Use of baited remote underwater video systems (BRUVs) to estimate presence and size of juvenile white sharks Carcharodon
carcharias
David Harasti1, Kate A Lee1, Roger Laird1, Russ Bradford2, Barry Bruce2
1. NSW DPI, Taylors Beach, NSW, Australia
Baited remote underwater video systems (BRUVs) are commonly used to assess fish assemblages and, more recently, to record
the localised abundance and size of sharks. This study investigated the occurrence and size of white sharks (Carcharodon
carcharias) in the near-shore environment off Bennett’s Beach, part of a known nursery area for the species in central New
South Wales, Australia. Six stereo-BRUV units were deployed approximately fortnightly between August and December 2015 for
periods of five hours in depths of 7 to 14 m. BRUVs successfully recorded 34 separate sightings of 22 individual white sharks. The
highest number of individuals detected during a single day survey was eight (1.6 sharks/ per hour of BRUVs sampling). All C.
carcharias observed on BRUVs were juveniles ranging in size from 1.50 m to 2.46 m total length (mean size of 1.91 m ± 0.05
S.E, n=22). The time to first appearance ranged from 15 to 299 mins (mean 148 mins ± 15 mins). This study demonstrates that
the use of stereo-BRUVs is a viable non-destructive method to obtain estimates of size and presence of white sharks, and may
be useful to estimate relative abundance in near-shore environments where they are known to frequent.
173
The evolution and influence of Commonwealth fishery and stock status reporting
Lee Georgeson1, Ilona Stobutzki1, Simon Nicol1
1. Department of Agriculture and Water Resources, Canberra, ACT, Australia
The ABARES Fishery status reports have played a key role in the evolution of Commonwealth fisheries policy and management in
Australia since first produced in 1992. Nearly 25 years later, it is timely to reflect on this contribution and consider how these
reports might continue to influence Australian fisheries in the years to come. Over time, the classification framework has
changed slightly but has been based on biomass—that is, the weight or number of fish in a stock, and fishing mortality—that is,
the rate at which the stocks are being fished. In line with United Nations guidelines, the reports consider these biological
indicators in the context of limit reference points. The reports also consider progress towards target reference points, including
maximum sustainable yield and/or maximum economic yield. Despite the Fisheries Management Act 1991 being in place, a
worsening trend in fish stock status coupled with poor economic performance through the 1990s and early 2000s led to a
Ministerial Direction in 2005 to cease overfishing and recover overfished stocks. Key elements of this Direction were
the Securing our Fishing Future structural adjustment package and the development of a best-practice harvest strategy policy.
These, along with a number of other initiatives, have led to a stark turnaround in the biological and economic performance of a
number of Commonwealth fisheries. Since the 2005 Ministerial Direction, the percentage of stocks classified as not overfished
and not subject to overfishing has increased markedly, while the percentage of stocks classified as uncertain, or overfished and
subject to overfishing, has decreased. The Fishery status reports have provided a benchmark and a legacy for fisheries science
and management in Australia. Future opportunities include strengthening links with other jurisdictional fisheries management
and reporting frameworks and consideration of more comprehensive reporting against target reference points.
174
The status of Australia's fish stocks in relation to the total catch and economic value
Fay Helidoniotis1
1. Australia Bureau of Agricultural Resource Economics and Sciences, Canberra ACT, ACT, Australia
Australia’s Commonwealth government has the responsibility of managing fish stocks between 3-200nm. To assist in the
sustainability of fish stocks a classification system has been developed where the status of stocks are broadly categorised as
overfished or not overfished.
Two broad jurisdictions exist: Commonwealth sole-managed fisheries and Commonwealth jointly-managed fisheries. Focussing
on the former, the status of 65 stocks of the Commonwealth sole - managed jurisdiction were evaluated in 2014, and 7 stocks
were reported to be overfished. Total catch, gross value of production (GVP) and stock status are typically presented separately
and therefore it is not immediately clear what the stock status is in the context of the total catch and GVP. Specifically, it is not
known whether the catch of the overfished stocks contribute to a large proportion or small proportion of the total catch of the
Commonwealth sole managed fisheries.
The Australian Bureau of Resources Economic and Sciences (ABARES) collects a large array of data on the total catch and GVP of
over 100 fish stocks. Stock status is mainly determined by the current level of fishing mortality and the current level of biomass
relative to its unfished state.
While it is a concerning issue to management and policy that 11% of stocks are classified as overfished, results indicate that that
this only represents a small proportion (approx. 5%) of the total catch and economic value of those fisheries solely managed by
the Commonwealth.
Quantifying the proportion overfished in the context of total catch will enable a better understanding of the level of risk that
overfished stocks present to the total biomass and economic value of Commonwealth fisheries. Furthermore, overfishing of
these stocks may misrepresent and overinflate the economic value of fisheries and may subsequently lead to false long term
economic and social expectations.
175
Twenty-Five Years of Quota Management of Australia’s South-East Fishery – Success or Failure?
Kevin Rowling
It is now 25 years since the Australian Government announced a major policy initiative concerning the future management of
Commonwealth fisheries. The “New Directions” policy commenced in 1990 and mandated the use of Individual Transferable
Catch Quotas (ITQs) under a biologically determined Total Allowable Catch (TAC) as the preferred management control. In 1992
ITQs were allocated across sixteen of the main species in the trawl sector of the South East Fishery (SEF). The new policy had
three simple objectives: to ensure the conservation of fisheries resourcesand the environment which sustains
them; to maximise the economic efficiency of the industry; and to collect an appropriate charge from fishers who were
exploiting a community resource for private gain.
A review of developments in the SEF since the implementation of quota management suggests that none of the three objectives
have been successfully achieved. In 2014/15 fishers in the SEF landed only 40% (7,718 t) of the total TAC (18,965 t) for the
sixteen main species. For seven of these species the TAC was very significantly under-caught (<25% of TAC landed). The TAC
was more than 50% caught for only five species out of the sixteen. The status of many stocks in the SEF can be described as
‘concerning’ - i.e. the stock has declined, or appears to be declining, to a very low level.
The actual economic status of the SEF is difficult to determine, but there is strong evidence that real net economic returns in the
trawl sector declined by more than 50% between 1995 and 2011. This was despite two rounds of Government funded structural
adjustments in 1997 and 2007 which removed significant numbers of vessel permits (and some quota) from the
fishery. Resistance by fishers to the introduction of quotas, and the overfished status of some of the main stocks, appears to
have prevented the collection of any ‘resource rent’ from fishers for the use of publicly owned resources.
176
Using MSC certification of a commercial and recreational crab fishery in Western Australia to achieve social licence
Emily A Fisher1
1. Department of Fisheries, Perth, WA, Australia
Western Australian estuaries have been fished for as long as humans have inhabited the surrounding areas, with the first
commercial estuarine fisheries established in the early 1800s. Over time, population growth and an increasing number of
recreational fishers has led to greater competition for the estuarine resources and buy-outs of commercial fishers have been
implemented in some estuaries to reduce conflict between user groups. In the Peel-Harvey Estuary near Mandurah, a recent
Government initiative has supported the commercial and recreational fishing sectors to work together to promote their
sustainability and ensure future access to the resources. In a world first, the commercial and recreational fisheries for PeelHarvey Estuary blue swimmer crabs have been jointly assessed against the Marine Stewardship Council (MSC) standard for
sustainable fishing. Although certification is expected to provide both sectors with a social licence to continue fishing the
estuary, the process has also presented a number of challenges that will need to be addressed over the next five years. This talk
will focus on the gaps identified as part of the MSC assessment and outlines the strategies and research plans proposed to deal
with the conditions placed on these fisheries.
177
Management Strategy Evaluation for a Multi-Sector Highly Variable Fishery: the South-East Australian ‘Western’ Snapper
Stock
Athol Whitten1, Paul Hamer2
1. Mezo Research, Sydney, NSW, Australia
2. Fisheries Victoria, Queenscliff, Victoria
Two of the biggest challenges facing fisheries managers and policy makers are how to effectively manage multi-sector fisheries
and how to design harvest strategies for fisheries with highly variable productivity. The ‘western’ snapper (Chrysophrys auratus)
stock is Victoria’s most important finfish fishery, and harvesting occurs by both recreational and licensed commercial fishers. To
add complexity, the stock’s productivity is highly variable, owing to the influence of biotic and abiotic features of the stock’s
primary breeding grounds. These effects lead to large fluctuations in annual recruitment, and years later, to corresponding
changes in the productivity of the fishery.
Here we describe the development of a Management Strategy Evaluation (MSE) framework built upon Stock Synthesis (SS3) and
the ss3sim package in R, allowing for the exploration of multiple alternative harvest strategies. Tested strategies aim to balance
total yield from the fishery, sustain the spawning biomass above some target reference point, and also deal with changes in
productivity owing to highly variable recruitment success.
The MSE framework is an objective quantitative tool to help managers, policy makers, and other stakeholders understand the
performance, implications, and trade-offs associated with alternative management strategies. This in turn aids the decision
making process with regard to management controls that affect both the recreational and commercial aspects of the fishery,
while still meeting the overall requirements of resource sustainability.
178
Effects of climate change on coral trout and associated fisheries
Morgan Pratchett1, Vanessa Messmer1
Sustainably managing coastal fisheries in the face of increasing fisheries demands and widespread degradation of critical coastal
habitats is now being made even more challenging due to effects of global climate change. Effects of climate change compound
upon direct anthropogenic disturbances to coastal habitats and have particularly pronounced effect on coral reef habitats. Coral
reef fisheries are therefore, extremely vulnerable to ongoing climate change, not only due to ongoing degration of critical
habitats, but there is also evidence that current environmental regimes are already pushing the physiological limits of heavily
targeted reef fishes, such as coral trout. This talk will summarise recent research into direct and indirect effects of climate
change on coral trout (Plectropomus spp) on Australia's Great Barrier Reef (GBR), as well presenting a brief overview of potential
adaptation options necessary to ensure viable commercial and recreational fisheries. Of significant note, is that the thermal
sensitivity of coral trout is largely invariant along the length of the GBR, such that northern populations are already being
exposed to summertime temperatures that exceed their performance optima. Accordingly, catches of coral trout in the northern
GBR are very low during summer, potentially due energy conservation strategies and/ or movement of fishes to cooler, deepwater habitats. Biological and socio-economic research is ongoing, but it is clear that increasing climatic impacts necessitate a
review of current management arrangements for commercial and recreational fisheries on the GBR.
179
Establishment risk models highlight biosurveillance priorities for New Zealand lakes
Nicholas Ling1, John Leathwick2, Kevin Collier1, Brendan Hicks1, Glen Stitchbury1, Mary de Winton3
1. The University of Waikato, .Hamilton, ., New Zealand
2. Conservation Planning & Management, Hamilton, New Zealand
3. National Institute of Water and Atmospheric Research, Hamilton, New Zealand
The ability to predict invasive species spread is essential for effective biosecurity management and the allocation of monitoring
effort. Prevention of invasive fish incursions poses a significant challenge because of the wide physiological tolerances of many
species, their mobility, and the role of humans in their spread. In New Zealand, seven introduced fish species are distributed to
varying extents across the two main islands. We used field data from 470 New Zealand lakes to fit models of the current
distributions of these species; the resulting models were then used to predict risks of future establishment in all New Zealand
lakes >1 ha.
Models using lake- and catchment-scale environmental predictors identified summer temperature amongst the two most
influential variables with lake density and size also important for some species. Models for some species were improved by the
addition of variables describing human population densities and lake accessibility. All seven species occurred most frequently in
lakes close to human population centres implicating the importance of human-mediated dispersal.
Addition of a spatial variable, indicating the presence or absence of the modelled species within the broader catchment within
which each lake is located, improved the predictive performance of models for three species. This indicates that the current
distributions of these species include clusters of lakes within ‘occupied’ catchments, resulting in geographic patchiness that is
independent of the available environmental and human population predictors. This distribution has most likely resulted from
spread into accessible and suitable lakes from one or more initial liberations, either by natural dispersal along waterways or
human-assistance.
Predictions to a broader set of 3595 New Zealand lakes indicate (i) the potential for future spread is greatest for catfish, perch
and rudd, and (ii) high vulnerability to invasion for lakes along the east coast of both islands and in inland montane regions of
the South Island. Our results allow for improved identification of lakes likely to be suitable for invasive fish species which should
be accorded priority for surveillance, and highlight in particular the potential for perch and catfish to establish in higher
elevation lakes distant from human population centres.
180
Characterisation and aetiology of Jelly-like gonad condition (JGC) in the common carp, Cyprinus carpio (L)
Raihan Mahmud1, John Purser2, Jawahar G Patil1, 3
1. Fisheries and Aquaculture Centre, IMAS–Taroona, Hobart, Tasmania, Australia
2. Fisheries and Aquaculture Centre, IMAS–Launceston, Launceston, Tasmania, Australia
3. Inland Fisheries Service Tasmania, New Norfolk, Tasmania, Australia
Occurrence of gonad abnormalities in wild caught fish although rare have been reported in multiple species. Presented here is a
jelly-like testis condition routinely encountered from wild caught carp in Tasmania. To delineate the cause/s of the condition,
the prevalence, onset and progression was examined and correlated with select biotic and abiotic factors in a single cohort of
wild carp over four breeding seasons. Observations this far indicate that the prevalence increased (0 to 17.3% of the male
cohort) over four consecutive breeding seasons with progressive severity which could be sub-categorised as low, mild, severe
and complete. Statistical analysis revealed a significant positive relationship of the condition to fork-length and body weight,
with no significant influence from the abiotic factors tested. Growth of the affected fish was on average 9.22, 12.39, 14.24 and
19.78 % higher than that of female, pooled, male and immature sub-populations. Histopathological examination indicates
absence of bacteria, fungal hyphae or viral inclusion bodies. Instead the testes were characterised by enhanced proliferation of
sertoli cells in the initial stages followed by substantial apoptosis in the later stages leading to formation of fluid filled lumen that
impart the jelly-like appearance. Parallel examinations in the golden galaxiid and brown trout that inhabit the same lacustrine
system indicate that the condition is absent in both species. Elucidating the causes and mechanisms underpinning such naturally
occurring abnormalities could assist in developing powerful pest fish control methods that disrupt reproductive capability of the
target species in a species specific manner.
181
The eradication and management of European carp from two large freshwater lakes in Tasmania
Chris Boon1
Previously deemed absent from Tasmania, European carp (Cyprinus carpio) were first discovered in Lakes Crescent and Sorell in
January 1995. As a result, the Carp Management Program was established to contain, control, and ultimately eradicate carp
from the lakes. Through the development of various techniques over 12 years (1995-2007), a complete eradication of carp from
Lake Crescent was achieved using an integrated approach. By using these strategies in Lake Sorell, the carp population was
estimated to have been reduced to less than 50 fish by 2009. However, a spawning event which occurred in spring that year
resulted in the introduction of approximately 50 000 carp. The techniques used to target these fish varied with life stage.
Juvenile carp were initially targeted using rotenone poison, as they were concentrated in marsh environments. As they
developed further, intensive netting, electro-fishing, barriers, and traps were used to target these fish as they became more
mobile. Biotelemetry techniques were also used to gather knowledge of seasonable habitat preference.
A significant increase in netting effort has been implemented in response to declining catch rates as the carp population is
continually depleted. Alongside intensive netting, radio transmitter implanted carp will be utilised in order to prevent spawning
and to remove the remaining individuals from the lake. The most current population estimate calculated in March 2016 suggests
that there are now less than 1200 fish remaining, with over 95% of the original population removed.
182
Assessing maturity of Common Carp (Cyprinus carpio) in Lake Sorell to determine spawning capability and susceptibility to
varied fishing techniques.
Christopher D Bowen1
1. Inland Fisheries Service, New Norfolk, Tasmania, Australia
This study looks at the progression of maturity of a single cohort of carp in Lake Sorell Tasmania. The ability of these fish to
reproduce is an important consideration for the Carp Management Program (CMP) with the goal of eradication of this contained
population. All fish captured are assessed on maturity with macroscopic gonad staging. The most undeveloped gonads were
classified stage one through to the most developed being stage four. Fish of the same age have shown considerable difference in
the development of the gonads with only 2.22% stage four running males and 0.42% stage four running females in the
2015/2016 season. The 2015/16 season represents carp in their sixth year of growth. Historically, females in Lake Sorell reached
stage four at a minimum fork length of 353mm. Seventy five percent of stage three females are less than 350mm as of the
2015/16 season. It is this limited number of large fish that is restricting maturation in Lake Sorell. Low water temperatures along
with selecting for fast growing fish using larger mesh gill net throughout the CMP has limited the numbers of fish capable of
maturing to stage four. The small percentage (estimated <3%) of remaining carp are also the slowest growers of the cohort. This
has created a population with limited numbers of mature carp. It assists with reducing spawning risk though makes targeted
fishing using spawning aggregations difficult.
183
The shift in behaviour of European carp in Lake Sorell, Tasmania
Jonah L Yick1
Since the discovery of European carp (Cyprinus carpio) in Lakes Crescent and Sorell in 1995, intense, physical removal techniques
were implemented. As a result, carp were successfully eradicated from Lake Crescent, while approximately 3% of the carp
population in Lake Sorell remains. A key factor to the success of both lakes has been the use of radio transmitter implanted carp;
“Judas fish”. This technique was first incorporated into the Carp Management Program (CMP) in 1997, where mature male carp
were initially used as the hosts for transmitters. The data collected gave the CMP an insight into seasonal habitat preference,
which resulted in the detection of spawning aggregations. Aggregations were targeted using an integrated approach, with the
combined use of gill nets and electrofishing. After almost eradicating carp (<50) from Lake Sorell, a spawning event occurred in
2009 leading to the unfortunate recruitment of approximately 50 000 carp. Consequently, juvenile carp were implanted with
radio-transmitters to detect any aggregations, which were mainly associated with feeding. These juvenile 1 to 2 year old carp
were found to frequent warm shallows, and were thus vulnerable to effective targeting. However once reaching 3 years of age,
they moved out into deeper water. The maturity of these fish was slower than any other cohort of fish observed since the start
of the CMP. Thus over the next few years, the delayed maturity resulted in the carp avoiding the shallows for the majority of
time, and subsequently led to significantly lower catch per unit effort (CPUE) due to fewer opportunities to target aggregations.
If these fish reach maturity this coming season in conjunction with ideal environmental cues (rising lake levels and warm settled
weather in spring), it is likely that they will push back inshore and become susceptible to targeted effort.
184
Sustained Exclusion of Koi Carp (Cyprinus carpio) from Lake Ohinewai, New Zealand
Grant Tempero1, Nicholas Ling1, Adam Daniel2, Dai Morgan3
1. University of Waikato, Hamilton, New Zealand
2. Fish and Game New Zealand, Hamilton, New Zealand
3. North Tec, Whangarei, New Zealand
Lake Ohinewai is a shallow (4.5 m depth), 16 ha lake in the Waikato region on the North Island of New Zealand that has
experienced eutrophication and total loss of submerged aquatic macrophytes since 1983. Invasive fish species such as koi carp
(Cyprinus carpio) have been identified as contributing to ecosystem degradation and loss of biodiversity in many North Island
lakes. Effective tools for control of invasive fish species has become a priority for governmental agencies. Telemetry tracking of
koi carp in the Waikato region has suggested that up to 75% of koi carp undertake migratory movements at some point in their
life history. In order to exploit this behaviour, a permanent one-way barrier based on the SARDI push trap was installed on the
single outlet to Lake Ohinewai. The barrier was designed to allow passage of adult fish from the lake while preventing their
return. When coupled with biomass removals this resulted in a reduction in koi carp biomass from 373 (234 – 513 95% CI) kg/ha
in March 2011 to 36.1 (15.3 – 56.9 95% CI) kg/ha in December 2011, 42% of this reduction could be attributed to emigration by
adult koi carp. Further surveys in 2013 and 2014 found continued reductions in the koi carp population to 10.4 (3.1 – 17.7 95%
CI) kg/ha in December 2014. Analysis of length frequency data showed no significant shifts in koi carp population structure or
changes in abundance of other invasive species such as goldfish (Carassius auratus) and brown bullhead catfish (Ameiurus
nebulosus) in 2014. Water quality (Secchi disk transparency and total suspended solids) of Lake Ohinewai showed early signs of
improvement but submerged macrophytes have not yet recovered. Further surveys will be conducted during the coming 201617 summer to determine if changes in population structure or abundance of invasive species has altered since the previous
survey in 2014.
185
Application of an acoustic positioning array to investigate 3-dimensional habitat utilisation by an air breathing fish
(Neoceratodus forsteri) in a seasonally stratified riverine impoundment.
David T Roberts1, Vinay Udyawer2, Craig Franklin3, Ross Dwyer3, Hamish Campbell4
1. Seqwater, Ipswich, Qld, Australia
2. James Cook University, Townsville, Qld, Australia
3. University of Queensland, Brisbane, Qld, Australia
4. School for the Environment, Charles Darwin University, Darwin, Ql, Australia
Facultative air-breathing fish can survive extended periods in hypoxic water due to their capacity for aerial respiration. The
majority of studies on air breathing fish response to hypoxia have been experimental under forced hypoxia. How air-breathing
fish respond to hypoxic conditions in-situ has received little attention. Using high frequency acoustic tracking of the facultative
air-breathing Australian lungfish, Neoceratodus forsteri, we investigated how lungfish respond to hypoxic zones and periods of
holomixus. Lungfish were tracked within a river impoundment using depth sensitive transmitters and 26 acoustic receivers, to
locate fish positions in 3-dimensions. Three-dimensional kernel utilisation distribution models (3D-KUD) were developed to
investigate lungfish space utilisation in the presence and absence of an oxycline. During stratified conditions, lungfish
maintained a 3D-KUD above the oxycline, rarely venturing into hypoxic waters. During holomixis, lungfish 3D-KUD expanded to
utilising a wider range of depths. Despite N. forsteri having physiological adaptations to cope with anoxic conditions, the
presence of hypoxic zones and the species narrow depth preferences, reduced the total space utilised to < 8 % of the study area
substratum. With increasing demand for new impoundments in many tropical regions, our study provides insight into how airbreathing fish species might respond to altered environmental conditions.
186
Understanding eel behaviour to aid the development of downstream migration options for short-finned eels
David N Ikedife1
1. Hydro Tasmania, Hobart, Tasmania, Australia
There is a significant body of evidence that global stocks of freshwater eel (family Anguillidae) are in decline. Of the 22 known
species or subspecies of freshwater eel, eight have been listed as threatened or near threatened on the IUCN Redlist. It is likely
that the often arduous catadromous migration requirement of anguillid eels contributes to the vulnerability of this family to
anthropogenic disturbances.
Short-finned eels (Anguilla australis) are an important component of Tasmania’s freshwater fish fauna. While they are adept at
negotiating a wide range of natural barriers, large dams and weirs impact upon both upstream and downstream migration.
Trevallyn dam is located in the downstream reaches of Tasmania’s largest water catchment, and blocks the migratory path of
eels between the Tamar estuary and the South Esk River. The dam spills infrequently and downstream migrating eels have little
option but to pass through Trevallyn power station to reach the estuary.
Hydro Tasmania deployed an adaptive resolution imaging sonar (ARIS) on the intake of Trevallyn power station and implanted
migrating eels with Juvenile Salmon Acoustic Telemetry System (JSATS) tags to obtain information on migrating eel behaviour
around the dam, power station intake, and tailrace. The study showed a high level of eel activity around the intake during the
migration season, the majority of this activity was nocturnal, migration peaks were related to catchment hydrology, and the
majority of tagged eels eventually passed through the power station.
The study showed that there is significant potential to facilitate downstream migration at Trevallyn, as eels showed aversion to
entering the power station intake, and did not necessarily enter it upon their initial encounter. Hydro Tasmania is currently
designing a downstream bypass system to safely pass eels downstream by capitalising on the results of the migration study.
187
Will they stay or will they go? The occupancy and population dynamics of Murray cod in a cold-water impacted River
Zeb Tonkin1, John Koehn1, Jarod Lyon1, Graeme Hackett1, Justin O'Mahony1, Sarah Commens2
1. Department of Environment, Land, Water and Planning, Arthur Rylah Institute, Heidelberg, Victoria
2. River Management, Murray Darling Basin Authority, Canberra
The construction of large water storages and subsequent alteration of flow regimes and thermal pollution have had devastating
impacts on native freshwater fish populations globally. Native fish populations in the lower reaches of the Mitta Mitta River
have declined substantially since the construction (in the 1970’s) and operation of Dartmouth Dam. Self-sustaining populations
of Trout cod and Murray cod were reported to have substantially declined or become locally extinct in the river by the early
1990’s, attributed largely to the largely annual release of cold water during spring and summer. In more recent times,
recreational fishing reports and fish surveys have detected Murray cod again occupying this reach of river. This prompted
managers to reconsider the general view that the reach is unsuitable for native fish populations. Here we present outcomes of a
research project aimed at improving the knowledge of the Murray cod population in the lower Mitta Mitta River with the aim of
guiding improved river operations and management. We investigate patterns of population structure and hydrological records
to generate a conceptual understanding of the role of water operations in influencing the current occupancy of Murray cod in
the Mitta Mitta River and any interactions that may occur with Lake Hume downstream. We also present the preliminary results
of an acoustic telemetry program aimed at testing our hypotheses that the altered flow and temperature regimes in the Mitta
Mitta River may be influencing migratory patterns of the species.
188
Did the fish cross the road, and if so, why?
John R Morrongiello1, David D Crook2, Wayne M Koster3, Robin Hale1
1. University of Melbourne, Parkville, VIC, Australia
2. Charles Darwin University, Darwin, NT
3. Arthur Rylah Institute, Department of Environment, Land, Water and Planning, Heidelberg, VIC
The advent of modern telemetry methods have resulted in a vast increase in the volume of movement data being collected.
What do we do with all this data, and how can we use it to answer actual questions of ecological and evolutionary interest? I
argue that some studies still just ask the question: ‘did the fish cross the road?’ when in actual fact the key question is ‘why did
the fish cross the road?’. The application of not-too-complex analytical techniques to telemetry data can greatly increase our
understanding of the drivers and relevance of fish movement. Here, I present a series of mixed models, illustrated with
examples, to show how greater biological insight can be garnered from the vast data archives at hand. These include analysis of
time-to-event data, binary and continuous movement data, and cyclical environmental predictors. I will then discuss the
importance of animal personality, its relevance to animal movement, and introduce models that allow for the quantification of
this phenotypic diversity. Properly harnessing the potential of data collected in telemetry studies will greatly increase our
ecological and evolutionary understanding of the causes and consequences of animal movement.
189
More sharks in the north: Shark diversity and abundance along the Great Barrier Reef
Leanne M Currey2, 1, Michelle R Heupel2, 1
Elasmobranchs inhabiting coral reef environments experience a number of environmental and anthropogenic threats. Yet, how
species-specific distributions and habitat associations are driven by geographical and environmental factors is not well
understood. Baited Remote Underwater Video Systems (BRUVS) are a non-extractive and non-destructive technique used by the
Global FinPrint Project to assess relative abundance and diversity of sharks and rays worldwide. Existing BRUVS data 1 collected
along the Great Barrier Reef (GBR) revealed that shark abundance and species richness were most influenced by relative
distance along and across the reef shelf and hard coral cover. Evidence suggests shark occurrence and species richness was
higher in the Northern and Southern regions of the GBR compared to the Central GBR, while non-fished reefs supported higher
shark abundance. While this dataset spanned the GBR, fewer deployments were conducted in the North (11-15°S), which is
more remote, sustains comparably less fishing pressure and has been relatively unstudied. Recent FinPrint BRUVS sampling
focused on 2 locations (4 reefs, n = 154) in this region to specifically investigate shark and ray occurrence. Elasmobranchs were
observed on 85% of deployments and 14 species of sharks and 7 species of rays were identified, with 3 additional species not
observed in the previous study. The most abundant species observed were grey reefC. amblyrhynchos, blacktip reef C.
melanopterus, whitetip reef T. obesus, lemon N. acutidens and tiger G. cuvier sharks. Patterns in relative abundance and species
richness will be revealed with comparisons among locations, no-take and fished reefs, water temperature, depth, reef
orientation, benthos, and distance along and across the shelf. This research highlights the exceptional diversity and abundance
of species in remote areas of the GBR, and contributes to our understanding of their distribution patterns and marine reserve
use, which is essential for effective shark conservation.
1. Espinoza M, Cappo M, Heupel M, Tobin A, Simpfendorfer C (2014). Quantifying Shark Distribution Patterns and SpeciesHabitat Associations: Implications of Marine Park Zoning, PLOS One 9: e106885.
190
Opening the floodgates to fish and prawn recovery in a temperate coastal wetland.
Craig A Boys1, Bruce Pease2
1. NSW Department of Primary Industries, Taylors Beach, NSW, Australia
2. Consultant, Sydney, NSW, Australia
Tidally-active wetlands are important nursery grounds for juvenile fish and decapod crustacean species, but urban development
has significantly reduced their availability. Structural flood mitigation works, such as installing culverts and floodgates, have
been responsible for a lot of this decline. These works fragment habitat, restrict tidal flushing and degrade nursery habitat of
estuarine fish and decapod crustaceans (collectively referred to as nekton). Such losses cannot occur without associated losses
in the productivity of fisheries. The findings of the current study provide evidence that at least some of these declines may be
reversible if rehabilitation projects are adaptively managed over sufficiently long time periods. The incremental opening of eight
floodgates at Hexham Swamp adjacent to the Hunter River in New South Wales, afforded the rare opportunity to monitor water
quality and nekton assemblages in a tidal creek over an extensive (eleven year) period encompassing pre-floodgate opening, the
opening of one gate, three gates and finally all eight gates. Floodgate opening enhanced both water quality and nektonic
assemblages relative to a control creek whose barrier remained in place. However, recovery to a state similar to unrestricted
reference creeks was not immediate and did not occur until after all eight gates were opened. This case study serves to stress
the importance of reinstating tidal flushing to nursery habitats in order to enhance populations of economically valuable coastal
fish and decapod species, and moreover, that increasing levels of tidal flushing may need to be incrementally applied in some
systems before a threshold response in recovery is achieved.
191
Native fish use of engineered habitats
Matthew Beitzel1, Lisa Evans1, Mark Jekabsons1, Travis Howson2
1. ACT Government, Canberra, ACT, Australia
2. Australian Private Fisheries Resources, St Marys, South Australia
Two recent projects have been implemented to trial improvements to fish habitat in ACT rivers. Each project tackles different
environmental problems and conditions. The first was using concrete reef balls tm and ‘Cod Caves’ to provide habitat in a reach
highly constrained by anthropogenic influences on the Molonglo River. The second was Engineered Log Jams (ELJs) to create
habitat and mitigate the impacts of a sand slug in a section of the Murrumbidgee River. The aim of both projects was to improve
habitat for native fish in the reach particularly large bodied native fish. The reaches that had Cod Caves were compared with
nearby reaches congested with willows and reaches cleared of willows and flood debris. Monitoring of the Cod Caves over four
years found significantly fewer carp in the improved reaches than either the uncleared or cleared reaches, and that both Golden
Perch and Murray Cod were more common in the improved reaches. Monitoring of the ELJs has found high numbers of Murray
Cod juveniles and adults in the immediate vicinity of the structures compared to other habitats available nearby. Results
suggest that when applied to relevant riverine conditions the habitat improvement techniques trialled were highly successful at
improving conditions for native fish.
192
Fish community condition in the Koondrook-Perricoota Forest, a large lowland river floodplain forest.
David Hohnberg1, Meaghan Duncan2, Peter Graham2, Martin Asmus2, Wayne Robinson3
1. NSW Department of Industry, DPI Fisheries, Port Stephens Fisheries Institute, Taylors Beach, NSW, Australia
2. NSW Department of Industry, DPI Fisheries, Narrandera Fisheries Centre, Narrandera, NSW, Australia
3. Charles Sturt University, Albury, NSW, Australia
The Koondrook-Perricoota Forest (KPF) is a large floodplain forest with wetland and creek ecosystems adjacent to the River
Murray in southern New South Wales and is one of The Living Murray (TLM) icon sites. The objective for fish at KPF is to protect
and enhance viable native fish communities including improved recruitment. To determine progress toward the objectives, the
KPF Fish Condition Monitoring project was established in 2011 after drought-breaking floods in 2010. The KPF Fish Condition
Monitoring project has two major monitoring objectives: annual assessment of the condition of the KPF fish community; and
assessment of change in the condition over time. The sampling methods and analysis approach follow the Sustainable Rivers
Audit with specific adaptation for small-bodied species to improve suitability to KPF. This presentation summarises the results of
the KPF condition monitoring and the changes in the fish community since 2011. The main findings include: exotic fish species
(goldfish and common carp) dominated the fish community with native fish biomass averaging only 17% of total fish biomass.
Only 30% of native fish species on the historical species list for KPF were recorded. A relatively high abundance of native species
(carp gudgeon and Australian smelt), but low native biomass, highlights the prominence of small-bodied native species and an
almost total absence of large-bodied natives. Four small bodied native fish species had recruits present, however there were
fewer recruits than in previous years. One observed improvement in 2015 was the collection for the second year of dwarf
flathead gudgeon, a cryptic species that is very patchily distributed, having only been recorded in a few locations in Australia. To
improve the fish community in the KPF the objectives for native fish must be an ongoing priority in the development of the
water management regime for the forest.
193
Stairway to heaven or highway to hell: the pathway to recovering threatened freshwater fish in Australia.
Mark Lintermans1
1. University of Canberra, CANBERRA, ACT, Australia
Globally, freshwater fish are going down the tubes as competition for water use intensifies (domestic, industrial, agricultural,
environmental). It has recently been identified that there are at least 3,700 additional large hydropower dam planned or under
construction worldwide, and in 2013 in Australia the Abbot Federal Government came to power with an election promise of the
construction of an additional 100 large dams. There are currently 37 freshwater fish species listed as threatened under the EPBC
Act, but 60 are listed by ASFB, a sign of the trend of future EPBC listings . As new species are described, many go straight onto
threatened species lists (e.g. 9 of 14 recently described Galaxias spp.). What does the recent Commonwealth Threatened
Species Strategy mean for freshwater fish? Is the newly appointed Threatened Species Commissioner interested in fish? How
are Australia’s threatened freshwater fish faring, and what is their prognosis for the future? This presentation outlines the
history of threatened fish declarations in Australia, what we are doing to recover them, and what we need to do better.
194
Genetic structure and effective population size of the river blackfish in their most northern catchment suggests their longterm population viability is threatened
Stephen Balcombe1, Joel Huey2, 3, 4, 1, Kathryn Real1, David Sternberg1, 5, Jane Hughes1
1. Australian Rivers Institute, Griffith University, Nathan, Qld, Australia
2. Department of Terrestrial Zoology, Western Australian Museum, Welshpool, Western Australia, Australia
3. School of Animal Biology, University of Western Australia, Crawley, Western Australia, Australia
4. School of Natural Sciences , Edith Cowan University, Joondalup , Western Australia, Australia
5. Water Services Group, Central Region, Department of Natural Resources and Mines, Mackay, Qld, Australia
Fish populations in upland freshwater streams tend to be highly susceptible to anthropogenic impacts such as land degradation
and their isolation from other potentially suitable habitats, combined with the fragmented, dendritic structure of headwaters
renders their dispersal to more suitable habitats an unlikely response to recover from such impacts. The most northern
population of river blackfish (Gadopsis marmoratus) is isolated to a tiny area in the headwaters of the Condamine River in the
northern Murray Darling Basin. Local knowledge reveals they were once widespread and abundant in all headwaters, and
relatively common in lowland reaches. Their massive range contraction coincided with widespread land-clearing in the
catchment for agriculture leading to highly degraded riparian and in-stream habitat. To gain an understanding of the remnant
population of this fish we sampled them across 15 sites for an understanding of their current range then undertook an analysis
of their genetic structure and variation across the sampling area. Strong genetic structure was detected among subpopulations,
using microsatellites (0.173, p<0.0001) and mtDNA (0.369, p<0.05). Effective population size was low, ranging between 18.8 and
48.2, depending on the estimation method used. Bayesian clustering revealed three clusters, however these were not congruent
with drainage patterns, suggesting a complex history of dispersal among headwaters that are isolated by waterfalls. Overall,
these results suggest that G. marmoratus is unlikely to disperse into new habitats if their remaining habitat become unsuitable.
Low effective population size and genetic diversity also suggests that local adaptation to future impacts such as altered
temperature regimes under climate change is unlikely. It is likely that significant investment in restoration of the degraded lands
will be required to ensure the persistence of river blackfish in the Condamine River catchment.
195
Emergency efforts to conserve Running River Rainbowfish from extinction
Peter Unmack1, Michael Hammer2, Steve Brooks3, Keith Martin, Steve Hume3, Jason Schaffer4, Damien Burrows4, Luciano
Beheregaray5, Catherine Attard5, Jonathan Sandoval-Castillo5, Gerald Allen6, Culum Brown7, Mark Lintermans1
1. Institute for Applied Ecology, University of Canberra, Canberra, ACT, Australia
2. Curator of Fishes, Museum & Art Gallery of the Northern Territory, Darwin, NT, Australia
3. Qld Fisheries, Brisbane, Qld
4. TropWATER, James Cook Uni, Townsville, Qld, Australia
5. Flinders University, Adelaide, SA
6. WA Museum, Perth, WA
7. Macquarie University, Sydney, NSW
With golden to green bodies, bright red fins and distinctive black zig-zag lines on their flanks, aquarists have long recognized the
rainbowfish from Running River in the Burdekin catchment of northern Queensland as unique. As part of our groups research
into this and other enigmatic rainbowfish populations PU and MH discovered that another rainbowfish had been introduced
upstream of where the native Running River Rainbowfish lives and was invading downstream! This would almost certainly result
in extinction of this population through hybridisation. Live fish were brought into captivity for conservation purposes while we
conducted detailed genetic work on various rainbowfish populations from northern Queensland. This work demonstrated that
Running River Rainbowfish is different and efforts to compare these populations morphologically are moving forward with MH
and GA.
PU established a crowd funding effort in conjunction with the Australia New Guinea Fishes Association to raise money for
genetic testing of wild fish to ensure that all broodstock were pure fish. With help from LB, CA and JS breeders were matched to
maximise genetic variability. Fish are being bred at University of Canberra, then shipped up to JS and DB at James Cook
University to be grown out prior to release in spring 2016. PU, ML and JS conducted additional fieldwork to examine two
tributaries to Running River which had the best potential as translocation sites and to bring back additional wild
fish. Rainbowfish were not present in either creek and large waterfalls are present which would keep these populations isolated
from the introduced rainbowfish.
This talk provides an overview of the efforts so far to save the Running River Rainbowfish and to inform ASFB members of where
this collaborative conservation effort is heading next.
196
Are specific populations of key threatened MDB fishes native or introduced?
Peter Unmack1, Mark Adams2, Dean Gilligan3
2. Evolutionary Biology Unit, South Australian Museum, Adelaide, SA, USA
3. NSW DPI Fisheries, Batemans Bay, NSW
Many Murray-Darling Basin (MDB) freshwater fishes have experienced extreme declines, with around a quarter of the
freshwater fishes threatened with extinction. Here we target three native fishes that were once widespread across the MDB, but
today have all had significant declines (Purple Spotted Gudgeon, Olive Perchlet and Darling Hardyhead). Remnant populations
are extremely geographically limited, with some recently discovered populations occurring outside of the perceived natural
range of the species. Existing genetic data have been unable to clarify whether these populations are endemic or translocated.
Recovery actions for remnant populations are consequently very difficult to prioritise. We are now applying genetic data from
thousands of loci from next generation double digest RAD sequencing, coupled with comprehensive sampling from all potential
source populations. Together this should unequivocally distinguish the native status of each population. It will also provide key
information regarding each populations genetic diversity, divergence between populations and whether any loci appear to be
related to potential local adaptations. These results can then be used to guide reintroduction efforts and conservation
strategies.
197
Trojan Y genetic control of the invasive fish Gambusia holbrooki: rationale, progress, challenges and management realities.
Jawahar G Patil2, 1, Peter Cui1, Lokman Norazmi3, John Diggle2, Frank Grutzner4, John Purser3
1. Fisheries and Aquaculture Centre, IMAS–Taroona, Hobart, Tasmania, Australia
2. Inland Fisheries Service Tasmania, New Norfolk, Tasmania, Australia
3. Fisheries and Aquaculture Centre, IMAS–Launceston, Launceston, Tasmania, Australia
4. Environment Institute, School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
The history of trying to deal with destructive pest-fish species on large spatial scales has to date been ineffective with the
problem likely to grow more severe around the world in the future. Genetic approaches could revolutionize the management of
such pests but are subject to a range of technical, behavioural and ecological limitations and may face the challenge of public
acceptability. Our work on Gambusia holbrooki a pest fish of concern to Australia, takes a systematic approach of evaluating
feasibility, assessing public acceptance and making technical advances on Trojan Y as a suitable genetic control option. Using a
prototype generic model that incorporates both genetic and population dynamic determinants for the control of gonochoristic,
bisexual vertebrate pests we show that the Trojan Y is not only the most effective—about 10 and 20 times more effective
compared to a closest gender distorting recombinant approach in terms of time to eradication and cost for total eradication
respectively—but also one that remains environmentally benign and socially more acceptable. Evaluation of behavioural
tradeoffs, parametrisation of a model that is specific to a field site in Tasmania, design of a management strategy for evaluation,
and generation of population and genetic tools for assessing the progress of introgression and eradication are underway and will
be discussed.
198
Understanding and managing Common Carp (Cyprinus carpio L.) in the Glenelg River, Victoria, Australia.
Leigh Thwaites1, Josh Fredberg1, Stephen Ryan2
2. Glenelg Hopkins Catchment Management Authority, Hamilton, Victoria, Australia
Common carp (Cyprinus carpio L.) are a relatively recent invader of the Glenelg River system (circa 2001). The Glenelg Hopkins
Catchment Management Authority (CMA) is currently developing a strategy to slow their spread through the system and
manage sites where carp are present to reduce their impact on native fish and overall river health. Key to the development of a
cost effective carp control strategy is knowledge of the movement patterns and habitat preferences of carp which may be
exploited for control purposes, as well as an understanding of the carp population dynamics and the efficiency of potential carp
control techniques within targeted systems. This talk will present the results of a four year study that: 1) utilised acoustic
telemetry and geospatial modelling to investigate carp movement patterns, 2) investigated the influence of environmental
factors (i.e. temperature and flow) on movement, 3) evaluated feasible options for harvesting carp within the Glenelg River, 4)
estimated the total numbers and density of carp within the system and, 5) integrated these data and provided strategies for a
cost effective carp control program for the Glenelg River.
199
Response of size and abundance of redfin perch to successive removals
Brendan J Hicks1, Nicholas Ling1, Ian Duggan1, Susie Wood2, Stephane Gauthier3
1. School of Science, University of Waikato, Hamilton, New Zealand
2. Cawthron Institute, Nelson, New Zealand
3. Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, Canada
The 2.3-ha lower Karori Reservoir is a warm, monomictic lake with a mean depth of 8.2 m, a maximum depth of over 20 m. Its
252-ha catchment consists of mixed regenerating shrub-hardwood forest The lake is formed by an earth dam that as completed
in 1874 to provide a water supply for the city of Wellington, New Zealand. Redfin perch (Perca fluviatilis) were introduced into
the reservoir in 1878 and have formed a more or less monospecific population ever since. The lower reservoir ceased to function
as a water supply in 1992. When this happened, water through-flow also ceased and the water retention time increased from 5
days to about 300 days. As a consequence, the reservoir has been dominated by blooms of cyanobacteria. We speculated that
the trophic cascade induced by juvenile perch predation on zooplankton was exacerbating the cyanobacterial blooms so we set
about reducing the perch abundance by fishing over 5 successive years to test this hypothesis.
The response of age-0 perch (N caught = 690) to the first year (2007) of removal of all sizes of perch was a 3-fold increase in age0 abundance (N caught = 2,071) and an increase of 21 mm in age-0 mean fork length in 2008 (67.5 mm) compared to the original
mean in 2007 (46.8 mm). Perch removal in 2008 increased the number of age-0 perch in 2009 to 6 times the original abundance
(N caught = 4,281) and the mean fork length a further 3 mm to 70.9 mm. A hydro-acoustic survey before and after perch
removal in 2009 suggested that 54% of the perch population was removed. No fishing occurred in 2010, but further fishing in
2011 revealed that the number of age-0 perch had returned to close to the pre-fishing abundance (N caught = 885). The mean
fork length of age-0 perch, however, was 67.6 mm, still 21 mm greater than the original mean length in 2007.
Our results suggest that partial removal of perch is unlikely to achieve the desired top-down restoration of a healthy
zooplankton population capable of controlling algal blooms.
200
Alien fish response to enlargement of a temperate reservoir
Ben Broadhurst1, Mark Lintermans1, Rhian Clear1, Chris Fulton2
1. Institute for Applied Ecology, University of Canberra, Canberra
2. Research School of Biology, Australian National University, Canberra
The millennium drought strained water resources in south-eastern Australia. To increase domestic water security in the
Australian Capital Territory, Cotter Dam was enlarged 20-fold. Alien fish populations in the Cotter Reservoir were monitored
before and during filling, largely to determine if changes in their population size and structure due to reservoir enlargement had
resulted in detrimental impacts on populations of threatened Macquarie perch and two-spined blackfish. Since filling,
populations of goldfish have increased, likely in response to a surge in available resources as the reservoir fills. The increase in
goldfish is likely to be a driver in the establishment of a breeding colony of cormorants (never before observed in the Cotter
Catchment). Size and abundance of rainbow trout has not changed since filling began, though there has been a marked increase
in brown trout abundance. This is of some concern as a steep increase in an apex predator such as brown trout could increase
trout predation upon the Macquarie perch population. Eastern gambusia and oriental weatherloach remain rare captures with
current capture techniques; however, ad hoc observations of both of these species suggest they are common throughout the
reservoir. Since filling began in 2013, there has not been any link between alien fish population change due to reservoir filling
and increase in detrimental impacts to threatened fish populations in the Cotter catchment.
201
Prey density threshold and tidal influence on reef manta ray foraging at an aggregation site on the Great Barrier Reef
Asia O Armstrong
Large tropical and sub-tropical marine animals must meet their energetic requirements in a largely oligotrophic environment.
Many planktivorous elasmobranchs, whose thermal ecologies prevent foraging in nutrient-rich polar waters, aggregate
seasonally at predictable locations throughout tropical oceans where they are observed feeding. Here we investigate the
foraging and oceanographic environment around Lady Elliot Island, a known aggregation site for reef manta rays Manta
alfredi in the southern Great Barrier Reef. The foraging behaviour of reef manta rays was analysed in relation to zooplankton
populations and local oceanography, and compared to long-term sighting records of reef manta rays from the dive operator on
the island. Reef manta rays fed at Lady Elliot Island when zooplankton biomass and abundance were significantly higher than
other times. The critical prey density threshold that triggered feeding was 11.2 mg m-3 while zooplankton size had no significant
effect on feeding. The community composition and size structure of the zooplankton remained relatively unchanged irrespective
of reef manta ray behaviour. Higher zooplankton biomass was observed prior to low tide, and long-term sighting data confirmed
that more reef manta rays are also observed feeding during this tidal phase than other times. This is the first study to examine
prey availability at an aggregation site for reef manta rays and it indicates that they feed in locations and at times of higher
zooplankton biomass.
1. Armstrong AO, Armstrong AJ, Jaine FRA, Couturier LIE, Fiora K, Uribe-Palomino J, Weeks SJ, Townsend KA, Bennett MB
and Richardson AJ. Prey Density Threshold and Tidal Influence on Reef Manta Ray Foraging at an Aggregation Site on
the Great Barrier Reef. PLoS one. 2016; 11(5): e0153393.
202
Ecology of marine cleaning stations used by Manta alfredi in Ningaloo Reef, Western Australia
Hannah Ashe1, Mike van Keulen1, 2, Frazer McGregor2
1. Murdoch University, Perth, Western Australia, Australia
2. Coral Bay Research Station, Coral Bay, Western Australia, Australia
Marine cleaning stations are important habitats for a vast array of species. Specialized cleaners provide an essential service,
feeding on ectoparasites, dead tissue, mucus or scales from visiting clients. Cleaning stations are common aggregation sites
for Manta alfredi and often relied upon for both scientific research and the ecotourism industry. Studies of movement patterns
of Manta alfredi within Ningaloo Marine Park have shown seasonal patterns in the use of particular cleaning stations. GoPro
cameras were deployed to study the ecology of three key cleaning stations in Bateman Bay, Ningaloo Reef, during periods of low
manta visitations; the cameras were used to monitor what species visited the cleaning stations over a period of four months.
Although species composition varied between cleaning stations, similarities were also observed. Each cleaning station had
visitations from assorted clientele which provided a food source for the cleaners; M. alfredi were also seen visiting the cleaning
stations in their ‘off-season’, but infrequently. By improving our understanding of these key habitats that are repeatedly used
by M. alfredi, we can better protect these habitats and therefore this iconic species.
203
Physiological and ecological responses of an estuarine fish to fluctuating temperature and oxygen concentration
Nathan Beerkens1, Adrian Gleiss1, Stephen Beatty1, Jake Watsham1, Timothy Clark2, Steeg Hoeksma3, Alex Hams3, Gavin
Partridge4
1. Freshwater Fish Group and Fish Health Unit, Murdoch University, Perth, Western Australia, Australia
2. University of Tasmania, Hobart, Tasmania, Australia
3. Department of Parks and Wildlife, Perth, Western Australia, Australia
4. Australian Centre for Applied Aquaculture Research, South Metropolitan TAFE, Fremantle, Western Australia, Australia
Understanding how environmental conditions mediate the performance of individuals represents an important step towards
predicting how environmental perturbations may impact populations. Rainfall reductions, along with increased development,
are changing environmental conditions in south-west Australia’s iconic Swan-Canning Estuary. Of particular concern are
protracted periods of hypoxia that may impact recreational and commercial fish stocks. Here, we quantified the metabolic
physiology, via respirometry, and the voluntary activity, via animal-attached accelerometers, of Black Bream (Acanthopagrus
butcheri), a southern Australian estuarine specialist, across a range of ecologically-relevant temperatures and dissolved-oxygen
saturations. Our results show that Black Bream display temperature-dependent metabolic physiology, sensitive to changes in
oxygen saturation, that translate into changes in voluntary activity under field conditions. Overall, our data will be useful
in quantifying how past and future changes in environmental conditions impact this iconic estuarine species.
204
Climate-driven range shifts in fishes and the impacts on temperate marine ecosystems
Curtis Champion1, Sean Tracey1, Gretta Pecl1, Alistair Hobday2
1. Institute for Marine and Antarctic Studies, Hobart
2. Commonwealth Scientific and Industrial Research Organisation, Hobart
The redistribution of fish in the ocean has emerged as one of the most significant biological impacts of anthropogenic climate
change on the marine environment. These 'range shifts' are already affecting the structure and function of established
ecosystems and fisheries, with further changes likely as ocean warming continues. This research is addressing how and why
different marine fishes shift their distributions in response to climate change, and what the ecological impacts are. Two iconic
species, the yellowtail kingfish Seriola lalandi and the pink snapper Chrysophrys auratus, are being studied within the context of
a prominent marine warming hotspot that is located off south-east Australia, where ocean warming is occurring at a rate
approximately four times the global average. Both of these species from south-east Australia are thought to be extending their
ranges poleward and are likely becoming important components of Tasmanian marine ecosystems. This study aims to: 1)
quantify changes in the distributions of yellowtail kingfish and pink snapper from south-east Australia, 2) assess the connectivity
of fish found in Tasmania with populations from south-east Australia, 3) compare the condition of fish found in Tasmania with
those from populations from lower latitudes, and 4) assess the trophic interactions of these species within Tasmanian
ecosystems through stomach content analyses. Data to achieve aim 1 will be extracted from the full complement of available
sources, including Reef Life Survey, Atlas of Living Australia, Redmap, recreational game fish tagging surveys and commercial
fisheries catch records, and analysed from 1970 - present to align with confidence surrounding 'virtually certain' ocean warming
having occurred. Information for aims 2, 3 and 4 will be gathered through a combination of field sampling and fish frames
donated by recreational and commercial fishers. This research will provide an understanding of the ecology underpinning range
shifts in marine fishes, which is necessary to understand how climate change is presently impacting the marine environment.
205
Using Commonwealth environmental water to benefit native fish in the Murray-Darling Basin
Ebony A Coote1
1. Department of the Environment, Canberra, ACT, Australia
The Commonwealth Environmental Water Office (CEWO) supports the Commonwealth Environmental Water Holder (CEWH) to
plan, manage and monitor a portfolio of water for the benefit of the environment. The Commonwealth’s holdings must be
managed for the purpose of protecting or restoring the environmental assets of the Murray-Darling Basin. The CEWH's decisions
on water use, carryover and trade have been made in the context of, and consistent with, the Murray-Darling Basin Authority’s
Basin-wide Environmental Watering Strategy 2014, and annual priorities.
Fish are responsive to environmental flows, and managing water specifically for ecological benefits is one element in restoring
populations of native fish that have declined across the Basin. Commonwealth environmental watering actions focus on
providing environmental flows aimed at improving water quality, supporting native fish habitat, and migration, spawning and
recruitment opportunities for native fish within and across catchment boundaries. These actions support native fish through all
stages of their lifecycle, as well as contributing to a healthy and resilient Basin environment.
Long-term Intervention Monitoring (LTIM) commenced in 2014 and will monitor and evaluate the contribution of
Commonwealth environmental water in the Murray-Darling Basin to June 2019. An important component of each LTIM project
was the establishment of effective partnerships in environmental water delivery, including with environmental water managers,
land and catchment managers, local environmental water management groups, State agencies, academic institutions and
community members. A comprehensive data set from monitoring and evaluation activities will emerge over the five year
lifespan of the LTIM program, however monitoring undertaken to date supports the CEWO by evaluating adult and larval fish
responses to environmental water delivery, along with other indicators of river and wetland health. Examples of environmental
water delivery have been provided where methods have been refined and developed in line with adaptive management
principles and developing knowledge.
206
Trophic niches of euryhaline and coastal elasmobranchs in northern Australia
Sharon L Every1, 2, 3, Heidi R Pethybridge4, Christopher J Fulton2, Peter M Kyne1, David A Crook1
1. RIEL, CDU, Darwin, NT , Australia
2. Research School of Biology, ANU, Canberra, ACT, Australia
3. North Australia Marine Research Alliance, Darwin, NT, Australia
4. CSIRO, Hobart, Tas, Australia
By measuring the trophic niche (the diversity of dietary resources used by a species), we can understand how species use and
depend on dietary resources. This is especially important in elasmobranchs, given their steep declines and important roles as
predators that shape communities and the flow of biomass through ecosystems. Using the niche concept, we aimed to compare
an assemblage of euryhaline and coastal elasmobranchs in the South Alligator River (Carcharhinus leucas, C. amboinensis,
Himantura dalyensis, Glyphis garricki, G. glyphis, P. pristis and Rhizoprionodontaylori) using stable isotopes (SI) and fatty acids
(FA) extracted from muscle tissue samples. We used SI Bayesian ellipses to calculate niche space and overlap among species,
with sufficient sample numbers and a modified version of this to calculate FA niche metrics. We compared species δ 13C values
and found two guilds of species: one with a marine signature, and the other with an estuarine/freshwater base. Fatty acids
largely corroborated these results. However, there were slight differences, particularly for C. leucas, which may have been
caused by temporal differences in the uptake of biomarkers. Carcharhinus leucas had the largest SI niche space and was
overlapped by R. taylori. Overall, we found that these species provide important connections across riverine, estuarine and
coastal ecosystems.
207
Specialized diet of the deep-sea elasmobranch, the prickly dogfish (Oxynotus bruniensis)
Brit Finucci1, Carlos Bustamante2, Emma Jones3, Matthew R Dunn1
1. Victoria University of Wellington, Wellington, New Zealand
2. Shark and Ray Research Group, University of Queensland, Brisbane, Australia
3. National Institute of Water and Atmospheric Research (NIWA), Auckland, New Zealand
Specialist diets have been identified amongst elasmobranch, although the degree of specialization can be subjected to individual
specialists, competition, and fluctuations in spatial and temporal prey abundance and availability. Several examples of
chondrichthyans playing a large role in diet of other chondrichthyans have been previously documented, although few are
known from the deep-sea, and have included large bodied species. The prickly dogfish, Oxynotus bruniensis, is a small (< 75 cm),
little known deep-sea elasmobranch distributed on the outer continental and upper slope of southern Australia and New
Zealand. Specimens (n = 53) were collected from research trawls surveys and fisheries observers from around New Zealand at
depths from 400 to 1300 m. Stomach contents were dissected and prey items were identified to the lowest possible taxon.
Findings included Harriotta raleighana embryos and vitellus from unknown origin. 15 stomach samples were analysed with DNA
methods, revealing that O. bruniensis preys exclusively on the egg capsules of oviparous chondrichthyans,
including Rhinochimaera pacifica and Chimaera carophila. These are the first results of a wild elasmobranch sample relying
solely on other chondrichthyans as a food source. In addition to its low reproductive output and high distribution overlap with
fishing efforts, the reliance on a specialized diet may make O. bruniensis a particular vulnerable species to overfishing.
208
Sharks, culture and conservation: recognizing the value of Indigenous knowledge and cultural dimensions of sharks and rays
Karin Gerhardt1, Amy Diedrich1, Colin Simpfendorfer1, Erin Bohensky2
2. CSIRO, Townsville
In shark research and management, as in many natural resource management fields, there remains an opportunity to better
understand and appreciate Indigenous knowledge systems to enhance the completeness, value and relevance of available
knowledge. Despite the extensive evidence of the cultural significance of sharks and rays for many countries and communities
around the world, there is very little research that examines the application or collection of Indigenous knowledge to improve
the scientific understanding, conservation and/or management of sharks. This talk will provide an overview of Indigenous
knowledge systems and the cultural values attributed to sharks and rays, and will introduce a newly established, collaborative
project that involves a number of Traditional Owner groups within the Great Barrier Reef World Heritage Area. The project aims
to recognize and record the Indigenous knowledge regarding sharks and rays that exists for each group. As well as mapping and
recording Indigenous knowledge, the project will provide a better understanding of how Traditional Owners want their
knowledge to be recognised and applied in science and management.
The intricacies of developing a culturally appropriate, collaborative project (such as two-way sharing, Intellectual Property
protection in data sharing agreements and community investment and ownership of project outcomes) will also be presented.
209
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86
Evaluating the use of strontium isotopes ( Sr/ Sr) to unravel habitat use and life history movements of estuarine and
freshwater fish in South Australian estuaries
Patrick Reis-Santos2, 1, Christopher Izzo1, Justin L. Payne3, Juraj Farkaš4, Bronwyn Gillanders2, Yuexiao Shao4
1. Southern Seas Ecology Laboratories, School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
2. MARE – Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
3. School of Natural and Built Environments, University of South Australia, Adelaide, SA, Australia
4. School of Earth Sciences, The University of Adelaide, Adelaide, SA, Australia
Understanding habitat use patterns and life history movements of estuarine and freshwater fish are key to the conservation of
native fish populations, particularly migratory (e.g. diadromous, potadromous) species or those that use estuaries as nursery
areas. Here, we aimed to evaluate the use of otolith 87Sr/86Sr isotopic ratios to reconstruct estuarine and freshwater habitat use
patterns of both native and invasive fish species in several South Australian estuaries. Specifically, we analysed the variation in
water 87Sr/86Sr isotopic composition throughout estuarine habitats and freshwater stream end-members in the Onkaparinga,
Hindmarsh, and Inman estuaries, as well as the Coorong, Lower Lakes and Murray Mouth; and compared it to the corresponding
values in the edge of the otoliths of fish collected at the same sites. In addition, profile analyses of otolith 87Sr/86Sr covering
entire fish life histories were performed to characterise potential migratory and habitat use patterns. Overall, 87Sr/86Sr mixing
curves varied among estuaries, and the potential to effectively use these natural tags to examine habitat use and individual fish
movements is discussed, with results linked to the geological landscape and physical features of these estuarine systems.
Ultimately, mapping natural 87Sr/86Sr variations and developing baseline isoscapes for otolith geochemical studies will provide an
enhanced framework to unravel fish habitat use and connectivity patterns.
210
Shark cognition and its implication towards wildlife tourism
Dennis Heinrich1, 2, Culum Brown4, 3, Charlie Huveneers1, 2
1. School of Biological Sciences, Flinders University, Adelaide, SA, Australia
2. Southern Shark Ecology Group , Adelaide, SA, Australia
3. Behaviour, Ecology and Evolution of Fishes Laboratory, Sydney, NSW, Australia
Although the cognitive abilities of bony fishes have been intensely studied, until recently virtually nothing was known about the
learning capacity of sharks. Sharks diverged from other groups over 400 million years ago, yet share critical aspects of brain
organisation with all vertebrates. This early divergence of sharks from other vertebrates makes sharks an ideal model system to
explore the evolution of cognition in vertebrates. The study of cognitive abilities and associative conditioning in elasmobranchs
is also crucial given the growing global interest in the behavioural changes and learnt behaviours resulting from interactions with
wildlife tourism. This study aims to investigate the cognitive abilities of sharks in relation to behavioural changes linked to
wildlife tourism and shark feeding operations. This study will consist of four experimental set-ups. The laboratory-based
experiments will first assess the time required for a shark to habituate to a single stimulus using attractants (olfaction, sound,
electric field) and deterrents (magnetic and electric field). Secondly, the effects of reward size and training frequency on the
time required to associate two distinct events will be investigated using an operant condition design. In the field, sharks will be
trained to a feeding schedule to test whether they are able to associate time and place with food and the effects of such feeding
regimes on their metabolic requirements. Finally, we will assess shark ability to categorise objects according to their relative
position in the water. Understanding the cognitive capabilities of sharks will provide an insight into the mechanisms
underpinning shark behaviour, and allow comparisons of the cognitive abilities of this understudied animal group with teleost
fishes, insects, birds, and mammals. It will further provide information on the potential effects of wildlife tourism and shark
provisioning on the behaviour and the energy requirements of sharks.
211
Black flounder otoliths show complex freshwater life histories
Brendan Hicks1, Nicholas Ling1, Freya Robinson1, John Charteris1
1. School of Science, University of Waikato, Hamilton, New Zealand
We aimed to investigate movement of endemic New Zealand black flounder (Rhombosolea retiaria) between the sea and
freshwater through otolith microchemistry. Most flounder are entirely marine, but the black flounder is unusual because it is
classified as a freshwater fish but as adults can inhabit the sea, estuaries, lakes, or rivers. Its migration downstream is thought to
occur in winter, with juveniles returning to freshwater in spring, but very little is known about its life cycle. To clarify the
importance of diadromy in its life history we used laser ablation inductively-coupled mass spectrometry to examine the otoliths
of freshwater-caught black flounder.
Black flounder from the Mokau River, Taranaki, North Island West Coast, had high strontium with low barium at the beginning of
the life cycle, indicating life in the estuary. A drop in strontium accompanied by a rise in barium in later life shows movement
into full freshwater. Black flounder from the Clive River, Hawkes Bay, North Island East Coast, however, showed quite complex
life histories, with several movements between the estuary and fresh water. In the adjacent Ngaruroro River, black flounder
showed low concentrations of strontium throughout life compared to flounder from other rivers, indicating an entirely
freshwater existence even when the primordium was laid down during egg development.
We conclude that black flounder show a variety of life histories, sometimes with complex patterns of occupancy of the estuary
and fresh water, with possible freshwater spawning.
212
Social licence of marine systems: Improving community knowledge and engagement in local marine industries using citizen
science
Rachel Kelly1
Our global oceans are threatened by climate change, overfishing, pollution and a growing list of other impacts that demonstrate
an urgent global need for sustainable ocean management. Yet still it lags behind other more ‘visible’ terrestrial sectors. ‘Social
licence to operate’ is used broadly across the terrestrial literature, but how can we apply it to marine management?
I aim to produce novel understanding as to how social licence may be used to bridge communication gaps and barriers between
diverse users of the ocean environment and how we can advance our understanding of social licence by applying it to the
marine sector. This project will outline the value of social licence and its global potential towards garnering the cooperative
industry-community involvement necessary to advise managers in sharing ocean resources sustainably in our changing world. By
means of social research case studies (national and international), I will conduct a qualitative investigation of community
understandings of the ocean and social licence of marine systems, including recreational fisheries and marine protected areas,
and identify how engagement, knowledge and perceptions of marine realm management might be improved.
This research will be among the first attempts to link social licence theory with citizen science, aiming to produce actual practical
outcomes that may be applied in sustainable management. The project has considerable potential to produce novel, and
influence future, theoretical understandings of social licence and citizen science, and their application in the management and
development of sustainable ocean use.
213
Correlations of metabolic rate and body acceleration in three coastal shark species under contrasting temperature regimes
Karissa Lear1, Nick Whitney2, Lauran Brewster3, Adrian Gleiss1
1. Murdoch University, Perth, WA, Australia
2. Mote Marine Laboratory, Sarasota, FL, USA
3. University of Hull, Hull, East Riding of Yorkshire, United Kingdom
The ability to produce estimates of the metabolic rate of free-ranging animals is fundamental to the study of their ecology.
However, measuring the energy expenditure of animals in the field has proven difficult, especially for marine and aquatic taxa.
Accelerometry is a relatively new technique that presents a means of translating metabolic rates measured in the laboratory to
individuals studied in the field, pending appropriate laboratory calibrations. Here these calibrations are presented for three
marine predators: nurse sharks (Ginglymostoma cirratum), lemon sharks (Negaprion brevirostris), and blacktip sharks
(Carcharhinus limbatus), through simultaneously measuring body movement, as overall dynamic body acceleration (ODBA), and
metabolic rate, through respirometry. Calibrations were made at a range of volitional swimming speeds and experimental
temperatures. ODBA scaled linearly with oxygen consumption rate, maintaining strong correlations in all three study species,
with R2>0.85. The best fit model used ODBA in combination with activity state (active or resting) and temperature to predict
metabolic rate in lemon and nurse sharks, and ODBA and temperature to predict metabolic rate in blacktip sharks. The error
associated with these predictions was less than 5% in all three species, indicating that accelerometry provides a powerful tool
for predicting field metabolic rate in these animals. This study lays the groundwork for calculating the metabolic rate and timeenergy budgets of these species in the wild using acceleration data alone, providing the opportunity for insight into how
energetic demands drive behavioural decisions and ecological interactions.
214
Activity patterns and habitat use of juvenile Pastinachus atrus in a coral reef flat environment.
Ana Martins1, Colin Simpfendorfer, Andrew Chin, Michelle Heupel
1. JCU, Douglas, QLD, Australia
Stingrays (Family Dasyatidae) are common inhabitants of coral reefs. Their dorso-ventral compression allows the exploitation
of shallow tidal areas for prey by jetting water and beating pectoral fins to access infauna and meiofauna. This foraging
behaviour suggests they may be ecosystem engineers playing critical roles in broad ecosystem processes. As human pressures
increase on our oceans both stingrays and coral reefs are coming under increasing threat. A recent global analysis identified that
Dasyatidae is one of the most threatened families within this group. Fishing, climate change and other human pressures have
lead degradation to coral reefs around the world, placing stress not only on these natural treasures but also the human
communities that rely on them. The broad aim of this work was to understand stingrays' movement patterns and habitat use in
coral reef flat ecosystems, and also evaluate the importance of these systems to stingrays. For this end, juvenile cowtail
(Pastinachus atrus) stingrays were captured in shallow waters of Pioneer Bay (Orpheus Island, QLD) and fitted with Vemco V9
acoustic transmitters. The preliminary results have shown a clear movement pattern performed by juvenile cowtails. Based on
the collected track and depth data, juvenile stingrays’ movements appear to be related to tidal variations. The studied
individuals seem to prefer resting nearby or under mangrove roots at the high tide and feed during the low tide, using shallow
waters and sandy substrates for protection. For this reason, predation risk seems to be an important driver to juvenile stingrays’
movement and habitat use, while abiotic features, such as depth and temperature, seems to have minor influence.
215
Culturally significant fisheries: keystones for management of freshwater social-ecological systems
Mae M Noble1, Phil Duncan2, Darren Perry3, Kerry Prosper4, Denis Rose5, Stephen Schnierer6, Gail Tipa7, Erica Williams8, Rene
Woods9, 10, Jamie Pittock11
1. The Australian National University, Ainslie, ACT, Australia
2. Gamilaroi Traditional Owner, NSW Aboriginal Land Council, Parramatta, NSW, Australia
3. Chair of MLDRIN, Murray Lower Darling Rivers Indigenous Nations, Canberra, ACT, Australia
4. Chief of Paq'tnekek Mi'kmaq First Nations, Paq'tnekek Mi'kmaq First Nations, Paq'tnekek , Nova Scotia , Canada
5. Indigenous Protected Area Coordinator , Gunditj Mirring Traditional Aboriginal Corporation Owners, Heywood , VIC, Australia
6. School of Environment, Science and Engineering, Southern Cross University, Lismore , NSW, Australia
7. Manger of Tipa and Associates, Tipa and Associates, Outram , Otago, New Zealand
8. Māori Environmental Research (Te Kūwaha) , Maori and Aquatic Environments National Institute of Water and Atmospheric
Research, Viaduct Harbour, Auckland, New Zealand
9. Cultural Flows Research Committee., National Cultural Flows Program, Melbourne , VIC, Australia
10. Director of MLDRIN, Murray Lower Darling Rivers Indigenous Nations,, Canberra, ACT, Australia
11. Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
Formal recognition of the cultural significance of freshwater species to Indigenous people is an important part of equitable
ecosystem management that bridges gaps in our culturally sensitive management of these critical species and builds crosscultural relationships. Indigenous peoples of Australia, North America, and New Zealand have a long tradition of harvesting
freshwater animals over thousands of generations, and their profound understanding of these freshwater animals and
ecosystems have become embedded within their cultural identity. In recognizing such cultural connections, we can all better
appreciate the deep significance of changes in the conservation and management of freshwater animals for Indigenous peoples,
and work to integrate Indigenous stewardship and ecological knowledge into effective co-management strategies (e.g.,
Indigenous rangers, research partnerships, Indigenous Protected Areas). We recommend that future policy developments
should explicitly incorporate Cultural Keystone Species (CKS), which are species that support both Indigenous cultural identity
and key freshwater ecosystem processes. Moreover, CKS can provide focal points for promoting positive policy outcomes that
empower Indigenous people and develop innovative management and monitoring programs. In drawing on the understanding
of eight Indigenous authors from across Australia, North America, and New Zealand, we reviewed and highlighted the
importance of several freshwater CKS, many of which are of trans-Pacific importance. Our hope is that greater emphasis on the
equitable management of these CKS will improve the health and wellbeing of the social and ecological components of
freshwater ecosystems across the world.
216
Changes in the bycatch of undersized plaice in the North Sea brown shrimp fishery between the 1980s and 2000s.
Helen L O'Neill, Adriaan AD Rijnsdorp, Ingrid Tulp
Brown shrimp (Crangon crangon) support a lucrative fishery in the Netherlands with fishing effort of the Dutch fleet increasing
over the past 30 years. The brown shrimp fishery remains largely unregulated and the industry seeks management to ensure
sustainability and to obtain Marine Stewardship Council certification. A major challenge for the fishery are high bycatch rates.
European plaice (Pleuronectes platessa), a commercially and ecologically important species, are frequently caught within
nursery areas. Increased fishing effort, in combination with the changing distribution of plaice and brown shrimp could have
implications on the amount of juvenile plaice bycatch experienced within the brown shrimp fishery. Combined survey, logbook
and Vessel Monitoring Survey data were analysed to estimate bycatch based on the overlap between the shrimp fleet and the
distribution of plaice in autumn, during 1980-1989 and 2005-2014. Scenarios were developed to assess the likelihood of plaice
bycatch in response to changes in the intensity and depth distribution of the shrimp fleet, and changes in the abundance and
depth distribution of plaice. Bycatch estimates for 0-, 1- and 2- group plaice are 1,924,287, 613,047 and 82,872 (in thousands)
during 1980 – 1989, and 665,932, 25,963 and 2,051 (in thousands) for 2005 – 2014 respectively, suggesting plaice bycatch has
reduced since 1980–1989. Scenario comparisons indicate that the changed depth distribution of plaice has the greatest
influence on plaice vulnerability, decreasing bycatch rates by 75%, 82% and 95% for 0-, 1- and 2- group plaice respectively.
217
The effect of magnets on the behaviour of draughtboards sharks (Cephaloscyllium laticeps)
Elizabeth Chinnappa1, William Hansen2, David Maynard3, Elkana Ngwenya4, Muhammad A Rahman5, Nicholas Rawlinson4, Emma
Westlake6, Mike Williams4
1. Wildlife Officer, Wildlife Protection Unit, Department of Environment and Heritage Protection, Townsville, Queensland
2. Australian Fisheries Management Authority, Canberra, ACT, Australia
3. Queen Victoria Museum & Art Gallery , Launceston, TAS, Australia
4. Institute for Marine and Antarctic Studies, University of Tasmania, Launceston, TAS, Australia
5. Faculty of Fisheries and Marine Science, University of Brawijaya, Malang, Indonesia
6. Research Services Officer, Fisheries South Australian Research and Development Institute – SARDI, West Beach , South
Australia
Draughtboard sharks (Cephaloscyllium laticeps) are a major bycatch in the Tasmanian Southern Rock Lobster fishery (TSRLF).
Magnets are effective at deterring sharks around a range of different fishing methods and were tested as an option for reducing
the ingress of draughtboard sharks into pots. Over the course of four separate (honours) projects conducted by students from
the Australian Maritime College and the Institute for Marine and Antarctic Studies, we measured the reactions of draughtboard
sharks to strontium ferrite and neodymium-iron-boron magnets. Two studies were conducted in the natural habitat of the
draughtboard sharks and two were controlled experiments with the sharks held in tanks. The two field studies produced
inconclusive results due to small sample sizes and the inability to identify the individual sharks that approached the magnets. In
the controlled experiments we were able to measure changes in the behaviour of individual draughtboard sharks in close
proximity to a magnet, a control and procedural control. The behaviour of the individual sharks varied. Overall, the results of the
most recent tank experiment showed that avoidance reactions were observed at the magnet in 10 out of the 12 sharks but for
only 6% of the approaches to the magnets. This would suggest that it is unlikely that magnets will significantly deter
draughtboard sharks in the TSRLF, however the next proposed series of controlled experiments will involve observing the
behaviour of draughtboard sharks around a pot with magnets fitted to the entrance. This poster outlines the relative merits of
the different experimental approaches used. It is suggested that measuring the underlying behaviour that is predicted to
decrease the catch rates of bycatch species should be considered as an initial step before testing the proposed mitigation
measure in a commercial fishery.
218
How the Behaviour of the Gummy Shark During Longline Capture Reduces the Physiological Stress Response
Leonardo Guida1, Terence I Walker1, Richard D Reina1
1. Monash University, Clayton, VIC, Australia
Many factors influence the physiological stress response to fisheries capture in elasmobranchs.
However, the influence of sea surface temperatures (SST) and behaviour are
unknown and crucial considering global fishing pressures. We investigated the effect of
SST and behaviour on the physiological stress response to capture of the gummy shark,
Mustelus antarcticus, and compared our results to a laboratory study using similar conditions
to test whether stress responses of in situ capture are consistent with those from laboratory
simulations. Capture time for 23 M. antarcticus ranged 32–241 min as measured by
hook timers or time depth recorders (TDR) in SSTs ranging 12–20°C. TDR data from 13 M.
antarcticus were analysed to quantify capture behaviour as the percentage of time spent
moving during capture. Several physiological variables measured from blood samples
obtained immediately upon the animals’ landing indicated that although warmer SSTs
increased metabolic rate, the stress response to capture was not exacerbated by capture
duration. During capture movement occurred for an average of 10% of the time and since
M. antarcticus can respire whilst stationary, restricted movement probably mitigated potential
influences of increased SSTs and capture duration on the stress response. Previous
laboratory findings were also shown to be indicative of in situ conditions and we thus advise
that studies control for water temperature given the influence it has on variables (e.g. lactate)
used to measure capture stress in elasmobranchs. We highlight the importance of seasonal
water temperatures and capture behaviour when assessing the resilience to fisheries
capture and the implementation of appropriate fisheries management strategies.
219
Global fisheries models: historical estimates and future developments.
Yannick Rousseau1
1. UTAS, Hobart, TAS, Australia
The potential yield of oceans has been a research topic since the early 60s. Direct extrapolation of catch data has led to regional
and global models. These models attempt to capture and integrate ecological, economical and social aspects, or so it seems.
Looking into the parameterization of such models is paramount to understand uncertainties in current estimates of global
fisheries yield.
A review of the literature from the past 50 years reveals a range of estimates varying between a predicted collapse and over 2
billion tonnes of seafood harvestable per year. These estimates are, however, the direct results of various global models, which
still show a strong rift between biomass-based and socioeconomic approaches. The definition of what is “harvestable” still
depends on the perspective - ecological or human. Although bioeconomics and end-to-end models aim at bridging this rift, their
focus still reflects the disciplinary biases of their components, and they have fallen in the fallacy of complexity. Truly integrated
socio-ecological models are rare at global levels, although expanding on the range of regional ones available. The challenge is
not expanding regional models globally, but developing models complex enough to represent the feedback effect between
biological, economical and human components, while simple enough to reach a broad audience.
Even so, many points of focus in these components require attention. Landings (reported catch) still is used as a proxy for
mortality, ignoring illegal fishing or discards, which can account for over a third. Drivers of the global fleet remain vastly
unknown, leading to estimates of future catch still extrapolated from past trends. Future socio-ecological model of global
fisheries should aim at addressing these uncertainties and reach a balance between parsimony, scope and fit.
220
Using network analysis to explore co-occurrence patterns of white sharks (Carcharodon carcharias) aggregating at the
Neptune Islands, South Australia
Adam Schilds1, Stephan Leu1, Charlie Huveneers1
1. School of Biological Sciences, Flinders University, Bedford Park, SA, Australia
Group living and social behaviour have been documented in a wide range of animals and are driven by an ongoing trade-off
between the benefits and costs of associating with other individuals. Although white sharks (Carcharodon carcharias) are
considered to be mostly solitary, they are known to aggregate at several sites worldwide. Exploring co-occurrence of individuals
in relation to the characteristics of the aggregation sites can be a useful tool to provide insight into the ecology of white sharks
and better understand the drivers underpinning these aggregations. Network analysis techniques coupled with photoidentification data was used to infer co-occurrence patterns of 97 sharks over 32-months, split into two 16-month periods. Eight
dyads occurred with a greater frequency than would be expected by chance and were temporally stable. None of these dyads,
however, persisted over the two periods. Although association patterns were evident at the dyadic level, we found limited
support for stable communities or network structure. Quasi-Akaike’s information criterion fitted to standardised lagged
association rates described the persistence of associations to be best characterised using a ‘two levels of casual acquaintances’
model. Associations primarily occurred between individuals of the same sex, and groupings of individuals, where discernible
were primarily based on sex. These were linked to seasonal differences in abundance between the sexes. Nevertheless, some
males associated with females in autumn and early winter. These males may contest a potential dominance hierarchy of females
in this period or employ scramble competition tactics, enabling feeding during the Neptune Islands highest period of food
availability. Our network analysis shows that the white shark population visiting the Neptune Islands is not gregarious, but that
some individuals form associations for several days and across several months.
221
Connecting the dots: The movements of reef manta rays (Manta alfredi) and its implications for manta conservation and
management in Raja Ampat, Indonesia
Edy Setyawan1, Calvin Beale2, Mark Erdmann3, Andrew Fischer1, James Haddy1, Sarah Lewis4, Ronald Mambrasar5, Abraham
Sianipar6
1. University of Tasmania, Newnham, TAS, Australia
2. Misool Eco Resort, Sorong, Indonesia
3. Conservation International, Auckland, New Zealand
4. Manta Trust, Bali, Indonesia
5. Conservation International, Sorong, Indonesia
6. Conservation International, Jakarta, Indonesia
222
Size-at-settlement and its relationship to population of origin in the Southern Rock Lobster, Jasus edwardsii
Cecilia Villacorta-Rath1, Jan M Strugnell2, Nick P Murphy2, Carla Souza, Klaas Hartmann1, Caleb Gardner1, Bridget Green1
1. Institue for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
2. Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, VIC, Australia
Settlement is a key factor determining recruitment into the fishery in marine organisms. However, little is known about the
processes driving settlement patterns due to the difficulties associated to tracking larvae in the ocean. An alternative to this
problem is to use molecular markers in recently settled individuals in order to determine population of origin and level of kinship
between settlers. The present study aims to investigate whether Jasus edwardsii settles in genetic cohorts and to examine the
relationship between puerulus morphological attributes and genetic identity. Recently settled puerulus were collected in 2012
from three sites in Tasmania during three winter months. Samples were sequenced through five double-digest restriction site
associated DNA sequencing (ddRADseq) libraries using the Illumina HiSeq platform. Demultiplexed reads were used to create a
reference catalog of loci and individual reads were then mapped to the reference catalog and variant calling was performed.
Kinship analysis revealed that a large proportion of pueruli had 2 nd and 3rd degree relationship and a small proportion of samples
were full siblings. Population structure was investigated through a Discriminant Analysis of Principal Components and identified
two clusters among all locations and settlement pulses. A logistic model identified a negative relationship between DAPC
grouping and body size, suggesting that individuals from one of the groups were significantly smaller than the other. These
results give insight into the non-random nature of settlement in a species with protracted pelagic larval duration and could
suggest the existence of chaotic genetic patchiness in J. edwardsii adult populations.
Index
36
Berghuis, A
99
Cameron, M.J
15
Graham, P
192
Berkenpas, E
118
Campbell, H
185
2016-01, C
122
Berry, O
22,76
Campbell, R
160
Adams, M
196
Berry, T.E
86
Cannella, L
157
Alexander, K.A
157
Bice, C
104
Canning, A
90
Allen, G
195,56
Bierwagen, S.L
46
Caprentier, L
44
Allen, M
109
Black, K
16
Carter, C
65,95
Amtstaetter, F
103
Blanchard, J.L
20,21
Carton, A.G
93
Anderson, J
27
Blanchard , J.L
156
Cassey, P
136
Andrews, J
70
Blower, D.C
75
Andrzejaczek, S 34
Blythe, J
135
Castillo-Jordan,
18
C
Appleyard, S
Bockel, T
44
Catalano, S.R
152
33
Garcia, V
110,125
Appleyard, S.A
142
Bode, M
13
Cawich, C
Apps, K
137
Bohensky, E
208
Chambers, S.L
12
Armstrong, A.J
78
Bonaldo, R
47
Champion, C
204
Armstrong, A.O 201
Bone, E
141
Chapple, T.K
34
Armstrong, E
Booker, D.J
158
Chapuis, L
26
211
132
Ashe, H
202
Boon, C
181
Charteris, J
Asmus, M
192
Booth, D
165
Cheshire, K
105,106
Attard, C
195
Borg, D
103
Chin, A
Augspurger, J
38
Boubée, J.A
159
153,214,31,32,49,
50,74
Awruch, C.A
62
Bowen, C.D
182
Chinnappa, E
217
Baje, L
110,49
Boys, C.A
190
Choukroun, S
13
Balcombe , S
108,194,54
Bradford, R
172
Clark, J
58
Ballesta, L
88
Bravington, M
76
Clark, T
203
Barnes, A.C
140
Brewster, L
213
Clark, T.D
93
Barnes, P
81
Brierley, A
147
Clear, R
200,39
Barnett, A
118
Brinkman, R
146
Closs, G
38
Barrett, N.S
169
Broadhurst, B
200,39
Clua, E
88
Barton, D
60
Broadhurst, M
130
Cobcroft, J.M
119
Barton, D.P
59,61
Brodie, S
167,89
Cockayne, B
17
Bass, N.C
161
Brooks, S
195
Coleman, M
86
Battaglene, S
65
113,12,161,195,21
0,58
Collier, K
179
Brown, C
Collin, S.P
26
93
Baumgartner, L 101
Bax, N
76
Brown, P
70
Collins, G.M
Bayliss, P
102
Bruce, B
172,68
Commens, S
187
Beale, C
221
Buckle, D
166,37
Conchon, A
123
Beatty, S
109,203
Bulman, C
22
Connell, S.D
86
Beckman, C
68
Bunce, M
86
Constable, A
148,20
Beerkens, N
203
Burgess, K
67
Coote, E.A
205
Beheregaray, L 195
Burndred, K
17
Copeland, C
105,106
Beitzel, M
191
Burnell, O
130,131
Copland, P
133
Bell, J
8,9
Burrows, D
195
Cottrell, R.S
156
Bellwood, D
47,57,94
Burrows, M.T
63
Couch, A
139,98
Bellwood, D.R
48
Bustamante, C
207
Coulton, L
141
Bennett, M.B
24,67,78
Bylemans, J
40
Cowman, P.F
124
Bennett, M
115,79
Cadiou, G
86
Cox, M
148
Benthuysen, J
146
Cahill, M
128
Cox, M.J
147
Calmettes, B
123
Cresswell, A
43
Cribb, B
115
Ellis, I
105,106
Georgeson, L
173
Crook, D
102,166,59,60
Erdmann, M
221,56
Gerhardt, K
208
Crook, D.A
206,61,69
Espinoza, M
30
Gervais, C
117,121
Crook, D.D
188
Evans, K
10
Gervias, C
116
Crow, S.K
158
Evans, L
191
Ghanawi, J
157
Crumlish, M
157
Everett, J
36
Giles, J
154
Cruz, D
36
Everett, J.D
167,35
Gillanders, B
1,136,209,86
Cubillos, L
18
Every, S.L
206,69
Gillanders, B.M 96
Cui, P
197
Cumming, G
135
Fairweather,
P.G
170
Currey, L.M
189
Farkaš, J
81
Farrell, T
Gilligan, D
196
Gilmore, K.L
96
209
Giri, K
70
155
Gladstone, W
51
D'Alberto, B.M 49
Fassler, S
132
Gledhill, D
125
Daley, R
11
Fassler, S.M
133
Gleeson, D
40
Daniel, A
184
Fernandes, P.G 132,133
Gleiss, A
203,213
Daning Tuzan, A 65
Ferrari, R
86
Gleiss, A.C
34
Davis, A
42
Feutry, P
76,77
Goatley, C
47
161,58
Figueira, W.F
86
de la Chesnais,
23
T
Finucci, B
207,27
Goldsworthy,
S.D
86
Fischer, A
221
Graham, A
125
de Winton, M
179
Fisher, E.A
176
Grammer, G
152,6
Death, R
90
Fisk, A.T
87
Grant, M.I
50
Deng, R
160
Fitzgibbon, Q
65,95
Gray, C.A
167
Dennis, D
160
Fleming, A
156
Graziano, M
157
Devloo-Delva, F 77,87
Fogarty, H.E
63
Green, B
222
Diedrich, A
208
Fontes, J
14
Green, M.E
142,25
Diggle, J
197
Ford, A
85
Grewe, P.M
76
Dimmock, K
137
Forestier, R
21
Grewe, P.M
77
Dodd, L
84
Fowler, A
164,165
Grieg, A
59,61
Doidge, C
37
Fox, C.J
157
Grutter, A.S
64
Domeier, M
88
Fox, R
47
Grutzner, F
197
Donaldson, J.A
85
Francis, M.P
7
Guida, L
218,62
Doubell, M
129
Franklin, C
185
Gunasekera, R
76
Doubleday, Z
136
Fredberg, J
198
Habary, A
121
Doubleday, Z.A 96
Freeman, R
155
Hackett, G
187
Douglas, M
166
Frusher, S
134,168,18
Haddy, J
221,52
Douglas, M.M
102
Fulton, B
19
Hale, R
188
Drew, M
162
Fulton, C
200,28,94
Hall, K
70
du Dot, T
171
Fulton, C.J
206,45,69
Hall, N.G
72
Dudgeon, C
60,61
Fulton, E.A
21
Hamer, P
16,164,177,18
Dudgeon, C.L
141,78
Fulton, E
22,23
Hamer, P.W
71
Duffy, C.A
7
Fulton, E.A
156
Hammer, M
107,195
Duggan, I
199
Furlan, E
40
Hams, A
203
Duncan, M
192
Garcia , E.A
102
Hansen, S
70
Duncan, P
215
Garcia, J
44
Hansen, W
217
Dunn, M.R
207,27
Gardner, C
222
Harasti, D
172
Dwyer, R
185
Gastauer, S
132,133
Harding, J
107
Dyer, F
139,39,91,98
Gauthier, A
115
Hardy, C.M
40
Ebner, B.C
85
Gauthier, M
24
Hardy, N.A
86
Edson, J
24
Gauthier, S
132,199
Harrison, H
13
Cvitanovic, C
Day, J
Hart, N.S
26
Jenkins, G
16
Lintermans, M
139,193,195,200,4
0,91,98
Hartmann, K
222,73
Johansen, J
117,121
Hartog, J.R
167
Johnson, C
21
Little, R
128
Harvey, E
169
Johnson, C.R
15
Lloyd, D
137
Hatton, S
91
Johnson, G
76
Loneragan, N
138
Haward, M
134
Johnson, G.J
154
Longmore, A
16
129
Hawes, S
36
Johnson, J
107
Luick, J
Haywood, M
43
Johnson, M.S
116
Lyle, J
75,8,9
Hearnden, M
59,60,61
Jones, A
136
Lyle, J.M
73
Hegarty, A
51
Jones, E
207,27
Lymbery, A
109
Heinrich, D
210
Jones, G.P
13
Lyon, J
187
166
Heinrich, D.D
116
Jones, P.L
112
Maas, R
Helidoniotis, F
174
Jones, P
38
132,133
Hernández, S.I
77
Jordan, A
42
MacLennan,
D.N
214,30,31,32,46,5,
74
Kelaher, B.P
86
Maes, G
87
Heupel, M
Kellie, S
140
Maes, G.E
143
Heupel, M.R
189,87
Kelly, R
212
Maes, G.E
77
Maher, S
60,61,79
Maher, S.L
24
Mahmud, R
180
Heymans, S.J
157
Kemp, J
164
Hicks, B
179,211
Kendrick, G
43
Hicks, B.J
199
Kennelly, S
130
Hill, N
169
King, A
166,37
Hillary, R
76
Kloser, R.J
144
Hobday, A
11,134,149,204,80
,81,95
Knip, D
31
Knott, N
161,42
Kock, A.A
118
Koehn, J
108,187
Koehn, J.D
84
Koster, W.M
188
Kraver, D.W
116
Kyne, P.M
206,69,76
Lacksen, K
166
Laird, R
172
Lam, C.H
10
Lange, M
163
Langlois, T
43
Lara-Lopez, A
127,35
Laurenson, L.J
112
Lawson, C
89
Layton, C
15
Lear, K
213
Leathwick, J
179
Ledee, E
30,32
Lee, K.A
172
Lehodey, P
123,163
Leis, J.M
13
Leroy, B
10
Leu, S
Hobday, A.J
167
Hodges, K
100
Hoeksma, S
203
Hoey, A
94
Hoey, A.S
48
Hohnberg, D
192
Holdsworth, J
7
Holland, K
171
Holmes, B
79
Holmes, B.J
24
Hooper, G
130
Howson, T
191
Huey, J
194
Hughes, A
157
Hughes, J
194
Hughes, J.M
151
Hume, S
195
Humphries, P
84
Hunt, D.E
119
Hutson, K.S
64
Hutton, T
160
Huveneers, C
114,137,170,210,2
20,68
Ikedife, D.N
186
Izzo, C
209
James, C
129
Jekabsons, M
191
Mallen-Cooper,
104
M
Malthouse, P
129
Mambrasar, R
221
Marcus, L
66
Margraf, J
120
Marie, A.D
33
Marquez, M.C
111
Marsden, T
101,99
Marshall , A.D
67
Marshall , L
154
Marthick, J.R
76
Martin, K
195
Martins, A
214
Mason, L.B
13
Matley, J.K
87
Maynard, D
217
Maynard, J.A
88
Mcallister, J.S
77
McCauley, R.D
26
McCormack, S.A 20
McDonald, J
81
McGregor, F
202
McGuffie, P
40
Meekan, M
66
Meekan, M.G
34
220
MelbourneThomas, J
148,20
Lewis, S
221
Messmer, V
178
Ling, N
179,184,199,211
Meyer, C
171
Linklater, M
42
Meyer, L
68
Meyer, L.C
25
Patten, N
129
Revill, A
22
Middleton, J.F
129
Pattiaratchi, C
145
Richardson, A.J 144,35,78
Militz, T.A
64
Miller, C
33
Pattiaratchi ,
C.B
34
Miskiewicz, T
36
Payne, J.L
209
Moloney, P
103
payne, N.L
127
Pazmino, D.A
Rico, C
33
Rigby, C.L
53
Rijnsdorp, A.A
216
114,118,92
Roberts, D.T
185
143
Robinson, F
211
70
Pearce, L
84
Robinson, L.M
63
Moore, G
107
Pease, B
190
Robinson, W
192
Moreno, D
8,9
Pecl, G
168,204,23,3,95
Rogers, P.J
162
Moreno, D.A
75
Pecl, G.T
63
Rose, D
215
109,184
Pelletier, D
44
Ross-Magee, P
83
24
Penrose, L
70
Rousseau, Y
219
75
Pepperell, J
79
Rowling, K
175
Pepperell, J.G
24
Rummer, J
116,117,121,4
Moltmann, T
Moore, A
Morgan, D
Morgan, J.A
Morgan, J.A
Morrongiello,
J.R
188,84
Perry, D
215
Ryan, K.L
72
Mourier, J
161,88
Peterken, C
99
Ryan, K
82
Moy, K.G
55
Peterson, E
54
Ryan, L.A
26
Munroe, S
31,32
Pethybridge, H 122,22,66,68
Ryan, S
198
Murphy, H
85
Sabub, B
110
Murphy, N.P
222
Pethybridge,
H.R
Nash, K
21
SandovalCastillo, J
195
Nash, K.L
135
Saunders, R
60
Nash, K.L
156
Saunders, R.J
61
Nay, T
117,121
Saunders, T
59,60,61
Nay, T.J
116
Schaefer, K.M
10
Near, T
124
Schaffer, J
195,85
Newman, S.J
59,61
Schilds, A
220
Newman, S
60
Schilling, H
36,89
Ngwenya, E
217
Schilling, H.T
151
Nichols, P
66
Schnierer, S
215
Nichols, P.D
68
Scoulding, B
132,133
Nicol, S
10,163,173,70
Scrivens, S
136
Nielsen, E
79
Scutt Phillips, J
10,163
Nielsen, E.E
24
Semmens, J
11,114,8,9
Noble, M.M
215
Semmens, J.M
118,75
Noell, C
130
Sen Gupta, A
163
Norazmi, L
197,41
Senina, I
123
Novak, P.A
102
Senina, I.N
163
Nyegaard, M
138
Setyawan, E
221
O'Connor, J
103
Shao, Y
209
O'Mahony, J
187
Shelamoff, V
15
O'Neill, H.L
216
Sheldon, F
54
Ovenden, J
142,60,61,75,79
Shepard, C.M
118
Ovenden, J.R
24,78
Sianipar, A
221
Oxley, A.P
152
Parravicini, V
88
Partridge, G
203
Patil, J
41
Patil, J.G
180,197
206,69
Phonekhamphe
101
ng, O
Pillans, R.D
76
Pilling, G.M
10
Piovano, S
33
Pita, C
157
Pittock, J
215
Plagányi, E
160
Planes, S
88
Pogonoski, J
125
Pogonoski, J.J
126
Poloczanska, E.S 63
Pratchett, M
178
Prosper, K
215
Proud, R
147
Prowse, T
136
Purser, J
180,197,41
Purser, J.G
119
Pusey, B
102
Rahman, M.A
217
Rawlinson, N
217
Rawlinson, N.J
119
Raymond, S
108
Real, K
194
Redondo, A
129
Rees, M
42
Reina, R.D
218,62
Reis-Santos, P
209
Renshaw, G
117
Renshaw, G.M
116
Simpfendorfer, 153,208,214,30,31
C
,32,46,50,74
Simpfendorfer,
143,49,53,87
C.A
Singhanouvong,
101
D
Sippel, T
7
Tipa, G
158,215
Ward, D
29
Smart, J
153,50
Titaud, O
123
Ward, P
70
Smart, J.J
49
Tobin, A
153,30
Ward, T
136,35
Smith, J.A
167,35,92
Tobin, A.J
87
Watanabe, Y
114
Smith, M.D
71
Todd, C
108
Watanabe, Y.Y
118
Smith, S
165
Todd, C.R
84
Watsham, J
203
Souza, C
222
Tonin, H
146
Watson , R
156
Spillman, C.M
167
Tonkin, Z
187
Webb, L
105,106
Steel, A
54
Townsend, A
105,106
Welch, D
60
Steer, M
152
Townsend, K.A 78
Welch, D.J
59,61
Steffensen, J
117,121
Townsend, S
166
Weltz, K
75
Stehfest, K.M
118
Tracey, S
18,204,23,70
Wenger, L.N
45
Steinberg, C
146
Tracey, S.R
142,73
Westlake, E
152,217
Sternberg, D
194
Travers, M.J
61
Stewart, J
151,165,51
Travers, M
60
White, W
110,142,153,50,56
,74
Stitchbury, G
179
Trebilco, R
148,20
White, W.T
49,53
115
150
Stobutzki, I
173,70
Trinnie, F.I
112,72
Whitehead, D
Streit, R.P
48
Tuck, G
18
Whiterod, N
Strugnell, J.M
222
Tulp, I
216
Whitmarsh, S.K 170
Stuart, I
103,108
Turschwell, M
54
Whitney, N
213
Sumner, M
148
Twiname, S
95
Whitten, A
177
146
Suthers, I
151,36,89
Udyawer, V
185
Wild-Allen, K
Suthers, I.M
167,35
Unmack, P
195,196
Williams, D.K
146
Svozil, D.P
97
Unmack, P.J
139
Williams, E
215
Swadling, K
35
Usu, T
10
Williams, E.K
159
Sweetman, P
52
Williams, M
217
Williamson, D
13
Taillebois, L
59,60,61
van Herwerden,
143
L
Tatsumi, M
15
van Keulen, M
202
WIlson, G
55
Taylor, J
60,61
van Lier, J
28,45
Wise, B.S
72
Taylor, J.A
59
van Ruth, P
129,35
Wood, G
86
Taylor, M.D
167
van Sebille, E
163
Wood, S
199
Teixeira, J
14
Vaughan, D.B
64
Woodhead, J
166
Tempero, G
184
Veale, L.J
150
Woods, R
100,215
Thomas, G.A
119
Vila Pouca, C
113,12
Wos-Oxley , M.L 152
Thomas, S
141
Wright, J.T
15
Thomson, D
43
Villacorta-Rath,
222
C
Yates, J
135
Virtue, P
66
Yick, J.L
183
Wainwright, P
94
Yopak, K
2
Walker, T.I
112,218,62
Yopak, K.E
26
Walter, S
115
Zampatti, B
104,108
Walters, A
148
Zoccola, E
140
Waples, K
81
Thomson, R.B
77
Thorncraft, G
101
Thuesen, P
85
Thwaites, L
198
Tibbets, I
115
Tickell, S
166

the book of Abstract for the 2016 ASFB OCS Conference

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