Winter biomonitoring survey for the Waipaoa River and associated

Winter biomonitoring
survey for the Waipaoa
River and associated
catchments
Gisborne District
Te Turanganui a Kiwa
Prepared for the Gisborne District
Council, September 2014
Nga Mahi Te Taiao
0
Contents
Section
Executive summary
Discussion
Recommendations
Background to the Waipaoa and associated catchments bio-monitoring
project
Project objectives and deliverables
Bio-monitoring survey methodology
Site selection: Background
Site selection: Proposed methodology and selected waterways
Survey methodology: background
Survey methods: periphyton
Survey methods: macroinvertebrates
Quality control: macroinvertebrates
Survey methods: macrophytes
Survey methods: habitat
Survey methods: physico-chemical characteristics
Survey results
Background
Macroinvertebrate community indices
Periphyton
Macrophytes
Physical habitat
Physico-chemical
References
Appendices
1
Recommended variables and measurement protocols (Matheson
et al, 2012)
2
Macroinvertebrate sampling protocols (Stark and Maxted, 2007)
3
Provisional guidelines for instream macrophyte abundance
(Matheson et al, 2012)
4
Macrophyte monitoring field sheet and worked example
(Matheson et al, 2012)
5
Periphyton field sheet, scoring table and visual Chl-a assessment
table (Storey, 2014)
6
Visual estimation of periphyton Chl-a (Kilroy et al, 2013)
7
Physical habitat assessment (Storey, 2014)
8
Total macroinvertebrate taxa and animals present at the Waipaoa
and associated catchment survey sites
9
Habitat and water quality recording sheet (Palmer, 2014)
Figures
1
Monitoring site map
2
Periphyton weighted composite cover (PeriWCC) (Matheson et al,
2012)
3
Existing and new instream plant abundance guidelines to protect
river values (Matheson et al, 2012)
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Tables
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Some indicative taxa Te Tairawhiti
Indications of effects of macrophytes on periphyton and
macroinvertebrates (Matheson et al, 2012)
Provisional macrophyte abundance guidelines (Matheson et al,
2012)
MCI by altitude
STS/QMCI by altitude
MCI by land use
STS/QMCI by land use
Total EPT animals %
Periphyton enrichment score by altitude
Periphyton enrichment score by land use
Visual equivalent Chl-a mg/m2
Macrophyte channel clogginess
Instream plant abundance guidelines (Matheson et al, 2012)
Physical habitat assessment by altitude
Physical habitat by land use
QMCI scores by habitat
MCI scores by habitat
Conductivity and salinity levels
ANZECC default low-risk trigger guidelines for selected variables in
NZ rivers
Waipaoa and associated catchments data summary
Land use categories to be employed in the Waipaoa and
associated catchments survey
Candidate sites for bio-monitoring of the Waipaoa and associated
catchments
Periphyton scoring system
Macroinvertebrate Reference chart (Stark and Maxted 2004, 2007;
Storey 2014)
Physical Habitat Assessment (Storey, 2014): evaluation grades
Sources of current survey data
MCI Reference chart (Stark and Maxted 2004, 2007; Storey 2014)
Periphyton reference values (NPSFM 2014, Storey 2014, Matheson
et al, 2012)
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This report was produced by Murray Palmer of Nga Mahi Te Taiao consultants, for
Gisborne District Council. Field work was conducted by Murray, Joe Palmer, Vanessa
Awatere Tuterangiwhaitiri, Mihi Hannah, Grant Vincent, Cherie Te Rore and Janic Slupski.
79 Paraone Rd Gisborne Te Turanganui a
Kiwa
Phone 068687133
Email tairawhiti.info@clear.net.nz
Web www.nmtt.co.nz
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Executive summary
Background
A key focus for biological monitoring programs is to identify the state of health of
freshwater bodies, their life-supporting capacity, and their potential availability for
activities such as potable use, recreation, mahinga kai, amenity, cultural use,
irrigation and food production. In the context of the regional freshwater planning,
such monitoring can indicate the current state of water-bodies, the likely effects of
activities on water-bodies, and whether water quality in these may need to be
protected, maintained or improved (National Policy Statement for Freshwater
Management 2014, NPSFM2014). In the case of the Gisborne Tairawhiti region, the
inclusion of a bio-monitoring program will also complete New Zealand’s national
river data set, helping to advance the scientific understanding of our streams and
rivers.
This report contains information from 14 freshwater sites in the Waipaoa and
associated catchments (Waikanae, Taruheru) in terms of periphyton, macrophytes,
macroinvertebrates, overall physical habitat, and specified physico-chemical
parameters. This information is stored as raw data and, where the option is
available, reported on in terms of Attribute banding as in the NPSFM 2014, the
macroinvertebrate community indices (MCI, QMCI, % EPT taxa, % EPT animals),
periphyton enrichment levels, visually assessed Chl-a levels, and macrophyte channel
‘clogginess’.
The results and discussions around these are summarily categorised under land use
types. Land use and physical habitat proved to be the greatest predictors in terms of
the biological characteristics monitored during the Waipaoa survey. Although land
use categories are outlined in the New Zealand Land Cover Database, this survey
utilised a revised approach, more closely reflecting the unique matrix of land uses
and geophysical contexts comprising our region’s landscapes.
Extensive Pastoral
The three Extensive Pastoral sites surveyed (Rere Falls, Urukokomuka, Pykes Weir)
exhibited levels of periphyton growth in the Excellent category as measured by the
Periphyton Enrichment Score (PES), and in the A category for Chl-a levels (NPSFM
2014) as visually assessed. Similarly, the macroinvertebrate community index (MCI)
and quantified MCI (QMCI) scores were in the Good or Excellent categories.
Macrophytes were hardly present at any of the sites, and hence the Macrophyte
Channel Clogginess (MCC) scores were excellent also. Overall, the sites scored 70 to
81.6 out of 100 for physical habitat, positioning them in the upper Good category.
Winter flushing flows would have reduced levels of periphyton and fresh sediment
deposits at these sites, and it is anticipated that there may be changes in levels of
periphyton and macrophyte growth with warmer weather and changed land
management practices (e.g. increased spring fertiliser application and/or intensified
3
stocking). Re-monitoring of these sites during warmer weather will help indicate
seasonal patterns of water quality in terms of the biotic indices measured.
Key characteristics of the Extensive Pastoral sites were some level of control over
stock access to the stream (e.g. fencing above the upper stream bank), the retention
of the natural character and form of the channel and riverbed, and a level of woody
vegetation in the riparian zone (generally tree species comprising 10 to 45% of the
total riparian zone out to five metres).
Semi-intensive Pastoral
One stream site was included in this category (Waihuka at Otoko) with the aim of
more accurately depicting patterns of biological condition in subtly differing pastoral
settings. The site was in flat to rolling hill country with a strong grass sward, little
woody vegetation in the riparian zone, and free stock access to the stream.
There was strong periphyton growth (mainly sludge and green filamentous algae),
however the PES score was in the Good category. There was no macrophytic growth.
MCI and QMCI scores, were Fair, but just above the threshold for the Poor category,
at 86.6 and 4.4 respectively. Habitat scored at 51.88 out of 100 (Fair).
Lake Repongaere, the only lake surveyed and a candidate for Outstanding waterbody
status, exists in a pastoral landscape that can be described as Semi-intensive. The
Lake has high natural character, and the littoral form was intact at our winter survey,
despite full access for stock and periodic summer grazing. Macroinvertebrate
sampling at the Lake outlet yielded a community typical of shallow lake or wetland
still water ecosystems, although there were few taxa present (5) and no grazers.
Physico-chemical water quality from one sampling run, however, suggested a
eutrophic state in the littoral zone. While Ammonia N and Nitrate N levels were in
the A band for their Attribute States, Total N (590 mg/m3) and Total P (6700 mg/m3)
were significantly below the National Bottom Line for these Attributes. Chl-a level
(laboratory assessed) was 270mg/m3, also well below the National Bottom Line for
that characteristic (NPSFM 2014). These initial sample results suggest urgent further
attention.
Mixed Intensive
It is the consideration of this report that a significant land use within the alluvial
Waipaoa and associated catchment plains may usefully be referred to as Mixed
Intensive, reflecting the patterns of rotational grazing and perennial cropping that
are consistently carried out on these highly productive versatile soils.
Waterways in these settings are typically modified to allow for ease of cultivation
and land drainage (the Whakaahu site is the exception in this survey, with the
stream’s natural form largely retained). Apart from the Whakaahu (which scored
56.14 or Fair), the rural Mixed Intensive sites (Taruheru at Gordon’s Bridge, Waipaoa
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at Matawhero, Te Arai at Whatatuna) scored from 20 to 25.25 out of 100 for Physical
Habitat (Poor).
Where the Mixed Intensive land use coincided with Urban and Peri-urban
landscapes, habitat scores differed markedly however. Although the Waikanae at the
Airport site scored the lowest of any site surveyed (19.25/100), the Taruheru at
Campion Rd Bridge scored 48.21 (Fair), and the Te Arai at Footbridge 81.79 (Good).
This was largely due to the presence of tall, woody vegetation in wide riparian zones
around these two sites, whereas at the rural and Waikanae sites, stream shade and
woody riparian vegetation is absent. Streambanks at the Campion Rd and Footbridge
site were ungrazed, and at the Te Arai Footbridge site there is a diversity of available
fish habitat.
Whakaahu was the only Mixed Intensive site that showed notable periphyton
growth during our winter monitoring period. Here, however, the filamentous growth
was significant, positioning the site in the Poor PES category. Similarly, estimated
Chl-a Equivalent levels were at 307.04, well above the NPSFM 2014 Attribute
threshold of 200 mg/m2.1 It is suggested that the shallow stream profile, low stream
banks and broad flood plains, mitigate against the potential for high flushing flows to
remove the periphyton and macrophyte build-up from this site (as they would do in
a more incised stream channel). Further seasonal monitoring will assist with the
assessment of enrichment and plant biomass in this river.
Macrophyte beds were present at the Mixed Intensive sites at all but Waipaoa at
Matawhero and Te Arai Footbridge sites. Where present, these varied from 0.78 to
248.56 units of Macrophyte Channel Clogginess (MCC).
Macroinvertebrate survey results indicate Poor Water Quality at all the Mixed
Intensive sites, Rural, Peri-urban and Urban, except at the Campion Rd Bridge. The
Whakaahu site, which has largely retained a natural stream form and character,
provided highest scores at MCI 76.6 and QMCI 3.65 (both in the POOR category). The
very small number of animals present (26) however, may be indicative of low
overnight levels of dissolved oxygen (DO) associated with the prolific periphyton and
macrophyte biomass. All other sites scored below MCI 49.4 (Tuckers Rd) and QMCI
2.78 (Whatatuna). The MCI score of 85.4 from Campion Rd Bridge reflects the
presence of two individual animals (one Amphipod and one Acarina sp.) amongst a
total of 249 animals.
Reference sites
The establishment of ‘reference’, or high quality natural character freshwater sites
against which to compare impacted sites, has provided significant challenges for
biological monitoring practice as a whole, particularly in relation to the lower
1
It needs to be recognised that the NPSFM Attribute thresholds are based on laboratory Chl-a analyses,
whereas the current report uses the visual assessment protocols developed by Kilroy et al and identified as
providing a potentially accurate method of assessing Chl-a levels in-situ at a given site (Kilroy et al 2013).
5
reaches of river systems. For the purposes of this survey, the Waihirere Stream is
utilised as the Lowland reference site (altitude 8 metres ASL), and the Te Arai at
Waingake Intake (120m ASL) as the Hill Country site.
The Waingake Intake site is directly below the Gisborne City municipal water intake. 2
Despite the presence of the intake dam immediately above the site, and the
attendant flow alterations on the morphology and ecology of the site, the Waingake
site is one of the few in the Waipaoa catchments where upper catchment indigenous
forest protection occurs, and adjacent riparian protection is evident.
The Waihirere stream is set in a reserve and park. There is dense, established native
riparian vegetation adjacent to the site, and most of the upper catchment is a mix of
regenerating indigenous forest, pine plantation, and some extensive pastoral
farming.
The two sites surveyed both scored over 86/100 for PHA characteristics (Excellent).
PES were also in the Excellent category, and Macrophyte and estimated Chl-a levels
extremely low. For their invertebrate values, Waihirere scored MCI 150 and QMCI
8.06. Waingake scored MCI 145 and QMCI 8.17. Total percentage of EPT animals
(taxa sensitive to pollution) were 90.3 and 93.4 respectively. All of these
macroinvertebrate indices position the two reference streams in the relevant
Excellent (Clean water) categories.
Plantation Forest (growing)
Plantation Forest (harvested)
No plantation forest sites were surveyed during the current project. There is a
paucity of such sites where there is also existing GDC data, however we have access
to a small stream draining a catchment solely in Pinus radiata and for which there is
flow information. It is anticipated that this, and at least one other plantation forest
site (preferably recently harvested), will be surveyed when drier weather makes
access more available.
Discussion
The Gisborne Te Tairawhiti region is unique in the solubility and calcareous qualities
of much of the sedimentary geology that dominates the region’s landscapes. This is
expected to provide the source of high conductivity and pH levels evident in the river
systems here.
GDC freshwater monitoring sites tend to be on the main river stems, and focussed
more towards flow recording and prediction, than towards water quality monitoring
for ecosystem or recreational value. In terms of overall catchment assessment,
2
This site has subsequently been moved to above the city water supply intake.
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however, the sub-catchment tributaries surveyed are of higher biological condition
than the main stems, providing both better habitat and water quality.
Overlaying this, while the sites in extensively grazed landscapes retained good
condition, there was a general decline in biological value as land use becomes more
intensive. Factors associated with this decline are the modification of stream
morphology, free stock access, and nutrient leaching. In such a context, land use has
proved an accurate predictor of stream condition as measured by biotic indices.
Despite this trend, nutrient levels at some Good or Excellent scoring sites were
relatively high when surveyed, with little immediate impact apparent on the
biological communities present.
The importance of flushing flows, especially in the context of stream form (e.g.
incised cf open streams), was apparent at the Whakaahu site, where low bank
heights allow such flows to dissipate across the adjacent flood plain, leaving much of
the periphyton and macrophyte biomass in the stream intact.
It appears that habitat assessment as conducted during our survey is a similarly good
predictor of stream condition as land use, with a high correlation (R2=0.9367) with
the MCI site scores. Habitat evaluations, adapted to the particular waterway setting,
may also be of value in describing ecological value where other forms of biological
monitoring are inappropriate, such as at downstream river sites. This would be
enhanced at such sites when combined with Chl-a and nutrient sampling for
ecosystem health, and microbiological testing (e.g. E coli) for recreational use.
Improvements to stream physical habitat upstream and adjacent to the monitoring
sites are expected to mitigate against some impacts of land use.
Recommendations
The following are the recommendations of this report.
1. Correlate flow recording and water quality sampling with periphyton and
macrophyte surveying during the warmer months to help clarify the
relationship between river flow, land use and nutrient migration, stream
form, and nuisance or detrimental algal and plant growth. The use of
macroinvertebrate sampling and habitat assessments will further aid in this
process, providing an accurate picture of the state of the region’s waterways.
2. Integrate these data sets (flow, water quality, biotic indices, habitat and land
use) to provide a working model to assist in setting water quantity and
quality limits, and protect the life supporting capacity of water bodies.
Research will be required to better understand specific water quality
relationships in our region, e.g. nutrient uptake by in-stream plant growth
and subsequent impacts on fish and invertebrate communities. The
Whakaahu Stream appears one candidate for such research, which would be
expected to include continuous water quality recording.
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3. Adopt a precautionary approach to setting threshold levels for Ammonia N
(NH4) and embark on research on the toxicity of this and other substances in
the context of the naturally high pH levels of waters in the Gisborne
Tairawhiti region (typically near 8).
4. Lake Repongaere is a site of high significance culturally, ecologically, and for
its landscape, mahinga kai and commercial fishery values. Regular and
appropriate water quality sampling (e.g. from a boat) is required to assess
the levels of eutrophication that may be occurring here, and potential
impacts on the values and significance associated with the Lake. This should
commence as soon as possible.
5. While the percentage of dedicated Reference sites utilised in the current
survey is consistent with other regional bio-monitoring practice, this report
recommends the development of a suite of reference site material regionally,
inclluding from lowland river settings, to assist an understanding of the
condition of the regions’ waterways, the impacts of land use activities on
these, and opportunities for maintenance or improvement.
6. Continue, and further assess and refine, the methodology and assessment
matrices utilised in this survey, including:
¾ MCI, QMCI and EPT
¾ Periphyton and Chl-a equivalent assessments (after Kilroy et al, 2011
and Kilroy, 2013)
¾ Macrophyte channel clogginess
¾ Physical habitat assessment
7. Develop a fish monitoring component for selected sites and purposes.
8. Continue full bio-monitoring on the following Waipaoa, Taruheru and
Waikanae river sites:
¾ Pykes Weir
¾ Whatatuna stream at Opou Rd
¾ Whakaahu at Bruntons Rd
¾ Lake Repongaere
¾ Rere Falls
¾ Urukokomuka
¾ Waihuka at Otoko
¾ Taruheru at Tuckers Rd
¾ Taruheru at Waihirere
¾ Waikanae at the airport
9. Include:
¾ A hill country Reference site (if Waingake access is deemed too
problematic)
¾ One or preferably two sites from the Waingaromia and upper
Waipaoa catchments
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¾ At least two plantation forest sites (one growing, one within two years
post-harvest)
10. Develop a revised physical habitat assessment incorporating lowland river instream values (e.g. such as fish spawning venues), and combined with Chl-a
and nutrient assays and fish surveys, to assess the biological condition of
downstream sites (e.g. Te Arai at the Footbridge; Waipaoa at the Matawhero
Bridge; Taruheru at Campion Rd Bridge) in lieu of periphyton macrophyte
surveys.
11. Establish research into the role of a range of riparian plant species in bank
stability and the uptake of nutrients migrating from adjacent land, and their
potential application to improving water quality and stream ecological
condition in the Gisborne Tairawhiti region.
12. Establish research into the impacts of Gambusia affinis on lowland stream
invertebrate and fish communities in the Waipaoa and associated
catchments.
13. Integrate the bio-monitoring and other regional monitoring programs with
local freshwater initiatives in the region, including the Awapuni restoration
project and other community driven catchment planning and restoration
work (e.g. Te Arai, Waiapu and Hikurangi Takiwa initiatives).
14. Develop an education and freshwater monitoring certification process, such
as used internationally via the GLOBE program, to provide communities with
the skills to effectively monitor local freshwater environments. Support this
with the provision of suitable equipment and resources, and ongoing links
with expert bodies in this field.
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Background to the Waipaoa and associated catchments biomonitoring project
Monitoring the biology of rivers, streams, wetlands and lakes, and their margins and
catchment characteristics, is considered a vital component in understanding water
quality and the state of water-bodies. This is especially so in the context of
environmental stressors, and an overall assessment of the life-supporting capacity
and health of aquatic ecosystems and the values they support.
The Resource Management Act (1991) requires councils to report on the state of the
environment in order to assess the effectiveness of their regional policy statement
or regional plans. Gisborne District Council is currently developing a regional plan for
freshwater, including policies for maintaining flow regimes and water quality. A key
element of the plan’s effectiveness will be the biological responses to the water
allocation limits set. These responses, however, cannot be inferred from physicchemical water quality monitoring alone.
Gisborne District Council is currently preparing a regional plan for freshwater
management that includes both water quality and water quantity. Because
river biota are affected by flow regimes as well as water quality, monitoring
the effectiveness of policies in the freshwater management plan (as required
under the Resource Management Act 1991) is best achieved by monitoring
biota in tandem with water quality. The National Policy Statement on
Freshwater Management provides additional reason to monitor biological
indicators, as Objectives A1 and B1 refer to “safeguarding the life-supporting
capacity, ecosystem processes and indigenous species…. of fresh water”.
Biological monitoring is the most direct way of assessing life-supporting
capacity and indigenous species (Storey, 2012, p5).
Further, as all regional councils and unitary authorities (except Gisborne District
Council) conduct regular biological monitoring of rivers for State of Environment
(SOE) reporting, establishing biological monitoring in Gisborne would complete the
national data set that Ministry for the Environment uses to assess the state and
trends of New Zealand’s fresh waters. This would significantly enhance the overall
scientific understanding of the nation’s waterways.
Several documents, including the Resource Management Act (1991), the National
Policy Statement for Freshwater Management (NPSFM2014) and the reports of the
Land and Water Forum (2012), also provide a policy framework that encourages
biological monitoring of rivers. Together, these factors provide the broad freshwater
policy and environmental monitoring context for the current Waipaoa biomonitoring project objectives and implementation strategies.
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Project objectives and deliverables
During April 2014, GDC staff managing the development of the Gisborne Tairawhiti
region’s freshwater planning process initiated discussions with Nga Mahi Te Taiao
consultants to undertake the development of a strategy and implementation
methodology for the monitoring of macroinvertebrates and periphyton in the region,
and to implement this in the Waipaoa and associated catchments through a physical
survey conducted over the May to June 2014 period. This work is also intended to
provide an input into the assessment of Outstanding Water Bodies, and into the
limits to be set for water quality in these catchments.
Further, it is anticipated that the strategy and implementation procedures for biomonitoring in the Waipaoa will inform the overall review of water quality monitoring
across the region.
The project guidelines require that the following tasks are fulfilled.
¾ Development of an overall approach to bio-monitoring of invertebrates and
periphyton, including the identification of sampling locations and methods.
This will be consistent with the National Objectives Framework (NPSFM2014)
and best practice approaches across the country, while also providing a level
of information necessary to assist the Council in evaluating whether key sites
within the Waipaoa catchment(s) should be considered Outstanding Water
Bodies.
¾ In accordance with the approach developed, bio-monitoring is conducted at
13 locations within the Waipaoa Catchment, providing GPS locations and
data for these sites (including habitat assessment and selected physicochemical parameters; periphyton survey; macroinvertebrate survey).
¾ The incorporation of relevant existing data into the survey results, and
provision to GDC of an Excel spreadsheet with the data included.
¾ Prepare a report outlining the findings of the research, including a description
of in-stream values for each site (via graded scales suitable for SOE reporting
and narrative interpretation) and any implications for the Waipaoa
Catchment Management Plan process and others in the region.
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Bio-monitoring survey methodology
Site selection: Background
A key element determining site selection for a catchment wide monitoring program
is the development of a representative spread of sites across the range of relevant
social and geophysical landscape characteristics present. In the context of the
current program, these characteristics include:
x
Geology, altitude and slope class;
x
Situation in the fluvial hierarchy e.g. upland or spring-fed (first, second
and/or third order stream); sub-catchment tributary; lowland; lowland
delta; estuarine;
x
Current and historical land use, both adjacent to the sites and in the upper
catchment;
x
Community values identified as of importance within the sub-catchments
within which these sites occur;
x
The proposed water management units (WMU).
Further factors influencing site selection include:
x
The presence of reference site information i.e. data from sites that are typical
of their fluvial setting and largely unmodified and/or not adversely impacted
by human activity. Reference sites would ideally include the following
settings: upland (headwater); final stream prior to junction with subcatchment tributary; lowland (tributary; main river stem; river delta). It
would be anticipated that some of those waterbodies put forward for
Outstanding, Regionally Significant or Special Interest Area status might also
be candidates for reference information.
x
Where possible and of value, the alignment of sites with existing GDC
monitoring sites, providing for an evaluation of biological survey data
alongside historical physico-chemical and flow-related information.
Such a consideration of representativeness allows for a comparison of the impacts
on water-bodies of varying land uses and land and water management regimes, the
effects of climate on differing geophysical and land use settings, and the potential
effects of anticipated land use change on both in-stream and abstractive values. In
such a context, the establishment of reference sites becomes a priority alongside
representativeness.
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Site selection: Proposed methodology and selected waterways
A total of 14 sites have been chosen to provide for the following monitoring
objectives:
x
An initial description of some of the biological and ecological characteristics
of the rivers and streams within the Waipaoa and associated catchments
alongside a background of current water quality data;
x
An preliminary assessment of the ecological characteristics of those waterbodies currently candidates for Outstanding, Regionally Significant or Special
Interest Area status;
x
An assessment of the ecological characteristics and ecosystem status of any
water-bodies currently candidates for Poor or Degraded status (due to biomonitoring outcomes of this survey and/or existing water quality data);
x
The potential impacts of specific patterns or types of land use.
In this context, a land use inventory for the Waipaoa and associated catchments
would be expected to include:
x
x
x
x
x
x
x
Mature indigenous forest;
Shrublands and regenerating indigenous forest;
Plantation forest (growing);
Plantation forest (during and post-harvest);
Tussockland or montane vegetation;
Extensive pastoral grassland (with some mixed woody vegetation);
Semi-intensive pastoral grassland (extensive grazing with intermittent
intensive stock feeding and mixed cropping);
x Intensive mixed farming;
x Intensive annual cropping;
x Intensive perennial cropping (e.g. orchard, viticulture);
x Peri-urban;
x Urban (urban residential and urban industrial).
Such a categorisation is an adaption of the New Zealand Land Cover Database (LCDB,
http://www.lcdb.scinfo.org.nz ) mapping approach, constituting a slightly revised
differentiation of land uses that relates more specifically to the wider Waipaoa land
use patterning. In this context, waterways in the following land use categories were,
or will be, surveyed:
x
x
x
Reference sites (indigenous forest, or where in-stream and adjacent and
upper catchment natural character are retained, and water quality achieves
Ecosystem Health Attribute State A status): 1 upland; 1 lowland.
Extensive pastoral sites: 3 sites, preferably reflecting differences in slope type
and geology.
Semi-intensive pastoral sites: 1 river site; 1 lake site.
13
x
x
x
x
Intensive mixed (rotational): 4 sites.
Peri-urban: 3 sites.
Exotic forest (growing)
Exotic forest (harvest)
Left above, from top: Mixed Intensive;
Reference; Semi-intensive Pastoral.
Right, from top: Urban/Semi-intensive
Pastoral; Mixed Intensive; Extensive Pastoral;
Peri-urban/Perennial cropping/Mixed
Intensive.
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Table 1
Land use categories to be employed in the Waipaoa and associated catchments survey
Waipaoa land use LCDB comparison
Waipaoa land use narrative description
type
Reference
Indigenous forest
In the current Waipaoa and associated catchments survey, the ‘Reference’ land use will be
indigenous forest. This reflects the dominant type of vegetation or land cover which would be
expected to occur at the sites chosen. If a similar survey was to be undertaken around a coastal
lake, for instance, the Reference sites would then be chosen to best reflect the land cover types
most closely approximating to a pristine or ‘natural’ environment for the surveyed site/s (e.g. flax
and shrub land).
Extensive pastoral Poor/High
The Waipaoa definition was chosen to reflect the differing characteristics of land uses in terms of
producing
their levels of effect on aquatic ecosystsems. The Extensive Pastoral category may include some
grassland
high producing grassland, however it is distinguished by a level of woody riparian vegetation (e.g.
>30% riparian cover) and subsequent level of stream bank integrity, and the absence of dense
stocking rates. All three streams in the current survey have some stock exclusion capacity around
them.
Semi-intensive
High producing
This typically includes pastoral landscapes where production is considered high or good for the
pastoral/unfenced grassland
slope and soil types present. This may reflect what is referred to anecdotally as ‘productive
grassland’. In this particular land use type stock have uncontrolled (unfenced) access to waterriparian
bodies within their grazing zones.
Intensive mixed
High producing
This land use type reflects the high production rotation cropping and pastoral systems common on
grassland/Cropping the versatile soils of the Waipaoa flats, and on some of the smaller alluvial valleys feeding into the
main river. Streams in these settings are frequently modified through channel straightening,
vegetation removal, etc.
Peri-urban
Urban/other
For the purposes of the Waipaoa survey, sites chosen to reflect the impacts of solely urban
landscapes were unavailable due to the estuarine nature of the water-bodies present in the
Gisborne city environs. The first available sites on these downstream river reaches were in areas of
mixed Peri-urban and Intensive mixed, Perennial cropping or Semi-intensive pastoral.
Exotic Forest
Pine forest - closed Exotic forests with a largely closed or closing canopy.
growing
canopy
1
Exotic forest
harvest
Pine forest harvest
Exotic forests post-harvest prior to the re-stabilisation of stream morphology.
2
Identified through the Freshwater Advisory Group process, a selection of waterbodies in the Waipaoa and associated catchments have been established as
candidates for Outstanding, Regionally Significant and/or Special Interest Area status
(Gisborne draft Freshwater Plan). In order to achieve an economical approach while
providing a robust introduction to the freshwater characteristics of these
catchments, it is recommended that these sites are surveyed as sites of special
interest, but that they may also be included as representative of their relevant
geophysical and land use patterns, key prioritised values, and place within the
proposed Water Management Unit framework. The following sites (Table 2) are
proposed for the Waipaoa and associated catchment planning program. Note that
they include one lake, Lake Repongaere.
Due to sporadic abundant rainfall at times throughout our survey period, and the
turbidity created in some waterways, we were unable to visit all the sites initially
selected, and we do not report on the Terrace site on the Waingaromia River, the
Homestead Creek site at the headwaters of the Waipaoa, and the main stem of the
Waipaoa at Kanakanaia Bridge. While we believe that the sites surveyed are
representative of most of the various geophysical and land use settings in the
Waipaoa and associated catchments, no plantation forest sites, either during growth
or post-harvest, are included. It is recommended that we visit the sites missed during
more stable weather, possibly as part of a wider bio-monitoring project, and include
at least two plantation forest sites also.
0
Table 2
Waterbody
Candidate sites for bio-monitoring of the Waipaoa and associated catchments
WMU
Site adjacent
land use
Te Arai (Pykes weir)
Hill
Extensive
pastoral
Te Arai (Waingake
water intake)* and **
Te Arai (footbridge)
Hill
Reference
Lowland
Intensive
mixed/Periurban
Te Arai at Whatatuna
Lowland
Whakaahu
(Brunton Road)
Lake Repongaere**
Lowland
Intensive
mixed
Intensive
mixed
Semi-intensive
pastoral
Extensive
pastoral
Extensive
pastoral
Extensive
pastoral
Lowland
Rere Falls**
Hill
Mangatu
(Urukokomuka
Stream)**
Hill
3
Upper
catchment land
use
Extensive
pastoral/Plantat
ion forest
Indigenous
forest
Intensive
mixed/Perennial
cropping/Periurban
Fluvial
order
Gradient***
Geology***
Climate***
Middle
Moderate
Soft
sedimentary
Warm wet
High
Moderate
Warm wet
High
Low
Soft
sedimentary
Alluvial
Intensive mixed
Middle
Low
Alluvial
Warm wet
Water supply
Ecological
Ecological
Mahinga kai
Fishing
Secondary
contact
Mahinga kai
Intensive mixed
Middle
Low
Alluvial
Warm dry
Ecological
Semi-intensive
pastoral
Extensive
pastoral
n/a
Low
Warm dry
Middle
High
Soft
sedimentary
Soft
sedimentary
Middle
Moderate
Soft
sedimentary
Warm wet
Mahinga kai
Cultural
Natural character
Ecological
Contact
recreation
Cultural, Wai tapu
Ecological,
Contact
recreation
Warm wet
Warm dry
Key subcatchment
values3
Water supply
Ecological
GDC draft Freshwater Plan 2014
1
Waihuka (Otoko Hill)
Waipaoa
(Matawhero)
Hill
Lowland
Waihirere Stream*
(Taruheru river)
Taruheru (Hansen Rd)
Hill
Lowland
Taruheru (Campion
Rd bridge)
Urban
Waikanae Stream**
Urban
Semi-intensive
pastoral
Intensive
mixed/Extensi
ve pastoral
Reference
Intensive
mixed
Urban
Urban/
Intensive
mixed
Semi-intensive
pastoral
Intensive mixed
Middle
Moderate
High
Low
Indigenous
forest (restored)
Intensive mixed
Low
Low
Middle
Periurban/Intensive
mixed
Urban, periurban/Intensive
mixed
Soft
sedimentary
Alluvial
Warm wet
Warm dry
Irrigation
Food security
Warm dry
Ecological
Low
Soft
sedimentary
Alluvial
Warm dry
Recreation
Middle
Low
Alluvial
Warm dry
Recreation
Middle
Low
Alluvial
Warm dry
Recreation
Mahinga kai
Cultural
* Reference sites
**Candidate sites for Outstanding, Regionally Significant or Special Interest Area status
*** It is suggested that the geophysical characterisation of the Waipaoa catchment may
benefit from a more fine grained approach than the current three tiered classification,
particularly when dealing with issues around land erosion, sedimentation and aquatic
communities.
2
Figure 1: monitoring site map
Lake Repongaere
3
Survey methodology: background
Previously, freshwater bio-monitoring in the Tairawhiti region has been confined to:
x
x
x
Three private research surveys that have included freshwater
macroinvertebrate sampling;
The widespread use by schools of freshwater biological and physicochemistry science techniques as educational activities (facilitated by Nga
Mahi Te Taiao);
Fish and shellfish survey and assessment work, and associated tertiary
aquatic education programs (facilitated by Maumahara Ltd).
The current project, however, signals a first for an inclusive catchment-wide
approach that aims to establish freshwater bio-monitoring as an integral part of
water quality monitoring, and ecosystem and life supporting capacity assessment, in
the Tairawhiti Gisborne region. As such, and in the absence of any similar previous
approaches, the project aims to provide a methodology that incorporates current
best practice, while providing the opportunity for innovative and region-specific
adaptions and initiatives, and the reassessment of data in the context of the
changing needs and aspirations of our communities for water management.
The protocols utilised for physico-chemical and biological sampling and assessment
derive from: the Ministry for the Environment Monitoring Protocols and Quality
Assurance Guidelines (Part 2) for regional freshwater reporting (‘the Protocols’,
Davies-Colley et al, 2012); Categories of periphyton for visual assessment (Kilroy
2011); A User Guide for the Macroinvertebrate Community Index (Stark and Maxted,
2007), and the Review of the New Zealand instream plant and nutrient guidelines
and development of an extended decision making framework: Phases 1 and 2 final
report (Matheson, F., Quinn, J. and Hickey, C. 2012). The survey also incorporates in
its reporting the Attribute State assessment methodology of the NPSFM2014, the
Australian and New Zealand Guidelines for Fresh and Marine Water Quality
(ANZECC) and the National Rapid Habitat Assessment Protocol Development For
Streams And Rivers (Clappcott, Storey et al, 2014).
The Protocols consider the practices at 2012 of all regional councils, and provide
guidelines for improved monitoring effectiveness and national consistency. Some of
the outcomes of recent work and discussions undertaken with Dr Richard Storey
(one of the authors of the Protocols) have also been included as components of the
current survey, as has the adoption of recommendations from Dr Storey of NIWA in
his review of our original proposal (pers com Storey, 2014). While some of this work
is relatively innovative and still in draft form, the information gathered is being
recorded in readily available ‘raw’ format, prior to being subject to the assessment
tools provided. This will allow for assimilation of the data into other evaluative
formats, should the need arise.
4
Survey methods: periphyton
Periphyton is the slimy organic layer attached to submerged surfaces such as stones
and wood, and is comprised mainly of microorganisms (e.g. algae, bacteria,
microscopic animals) and the materials they secrete. Periphyton can take two
general forms:
x Microscopic, single-celled algae forming thin layers (films) on stream bed
materials;
x Algal colonies, growing in the water as attached filaments or mats.
Periphyton is a foundation of many stream food webs, and an important food for
stream macro-invertebrates which in turn provide food for fish and birds. Excess
growths of periphyton, however, can make the stream habitat unsuitable for many
invertebrate species. This reduces the ecological health of the stream, and can make
it unattractive for swimming and other recreation (Storey, 2014).
Periphyton is also an important indicator of water quality, and responses of these
biological communities to contaminants can be measured at a variety of scales from
the physiological to the community. In general, periphyton serves as an indicator of
water quality because:
x
It has a naturally high number of species;
x
It has a fast response to environmental change;
x
It is relatively easy to sample;
x
The threshold for tolerance or sensitivity to change (in particular the
presence of nutrients e.g. nitrogen and phosphate) is reasonably well
documented.
Since the ecological tolerances for many species are known, changes in community
composition can be used to diagnose the environmental stressors affecting
ecological health, as well as to assess biotic integrity.
Along with Ammoniacal Nitrogen (NH4-N), Periphyton is a key attribute that must be
monitored for river Ecosystem Health (NPSFM 2014). Despite this requirement, the
expert panel developing the attributes framework, were unable to agree on the
primary objectives for periphyton monitoring, making the establishment of specific
monitoring protocols problematic. Despite this lack of agreement, the Panel suggest
that the most likely objectives will be:
x
x
x
Assessing nutrient enrichment;
Helping interpret invertebrate data;
Assessing impacts on aesthetics and recreation.
Prior to 2011, a simple ranking system identifying excessive filamentous algae
impacting on recreational, aesthetic or fishing values (RAM1), or a more detailed
approach incorporating 12 periphyton categories (RAM2) and providing a potentially
more comprehensive evaluation of stream nutrient enrichment and water quality,
5
were the periphyton assessment protocols widely adopted by regional councils,
alongside periodic quantitative lab assays of Chl-a derived from removal of
periphyton samples (Biggs and Kilroy, 2000).
The Protocols from the Expert Panel currently recommend a revised visual
assessment methodology, based around the work of Kathy Kilroy and others (DaviesColley et al 2012). This work considers seven generic visual periphyton types, and
has the potential to provide an accurate assessment of stream nutrient enrichment
and potential levels of Chl-a across river or stream substrate, with minimal
laboratory back-up testing (Kilroy et al, 2013).
Table 3
Periphyton scoring system (Kilroy, 2011)
Observations
Didymo
Cyanobacteria mats
Green filaments
Other filaments
Other Mats > 2mm thick
(excluding Didymo &
Cyano)
Sludge
Thin Films
Bare Area
Score
1
2
1
7
8
9
10
Based on the calculations of the Periphyton scoring system, the percentage cover of the
visible stone surface might be Green Filamentous 15; Mats 33; Film 27; Bare 25. This
would provide a PES of 7.79 and a weighted Chl-a index of 42.226 (see Figure below).
For the purposes of the Waipaoa project, we have adopted this visual assessment
methodology, also recommended by Richard Storey in his review of our original
proposal (Storey, 2014). The reasons for this are:
x
x
x
x
Research so far indicates this system provides real opportunities for the
robust visual assessment of stream algal biomass and nutrient loading,
similar to that of laboratory testing, thus reducing the costs associated with
such testing (Kilroy et al, 2013; pers com R. Storey, 2014);
Potentially toxic or invasive taxa comprise part of the ID process, linking
ecosystem assessment with public health and recreational water quality
information collection;
The methods and Protocols are relatively easily learned, implemented and
quality assured;
They sit well alongside, and may provide valuable information for, a Cultural
Health Index or Mauri assessment matrix.
6
In the Review of the New Zealand instream plant and nutrient guidelines and
development of an extended decision making framework: Phases 1 and 2 final report,
due to a deficit of empirical data as to its widespread application, the authors did not
recommend the use of the above Protocol for SoE reporting (Matheson et al, 2012)
although it was part of the bio-monitoring recommendations to GDC from Dr Richard
Storey (2012). Nevertheless, the system is identifiably consistent with previous
methods (e.g. RAM1 and RAM2 which is recommended by Matheson et al) and
hence the data be easily integrated into the earlier protocol. This is the approach we
have adopted for the current survey as, if adopted as a periphyton monitoring tool,
GDC data will then be available as an important component of:
x
x
x
Ongoing national assessment of the emerging Protocol;
A consistent national SOE reporting, especially amongst those councils
having adopted the Protocol;
The potential for an accurate and cost-effective bio-monitoring tool.
Overall recommendations for Periphyton Monitoring Protocols from the Panel are
tabulated in Appendix 1 below. This report has incorporated the above
recommendations in the Waipaoa project methodology, but suggests that alongside
monthly surveying during the warmest six months of the year and an annual survey
to assist macroinvertebrate interpretation, a post-high flow survey should also be
conducted for periphyton sites. In our region, such a survey would most probably
occur between the months of June and August, as is occurring in the current project.
This survey would provide an indication of the impacts (and hence potentially the
ecological and water quality significance) of ‘flushing’ flows at specific geophysical
and hydrological settings (such was apparent in the extensive periphyton and
macrophyte beds at the Whakaahu site during May) in creating a periphyton
baseline prior to warmer weather and more stable, reduced flows. This current
information would sit well within such a revised Periphyton Protocol and especially
the overall focus of the NPSM2014.
The USA EPA point out that, while periphyton monitoring protocols may be used
alone, they are most effective when used with one or more of the other evaluative
assemblages and protocols, particularly habitat and benthic macroinvertebrate
assessments, because of the close relation between periphyton and these elements
of stream ecosystems. This is the approach taken for the purposes of the current
survey, alongside recording of relevant physico-chemical site characteristics where
there is no historical data available.
7
Figure 2
Periphyton weighted composite cover (PeriWCC) (Matheson et al,
2012)
Section summary:
A periphyton weighted composite cover (PeriWCC) can be calculated as %
filamentous cover+ (% mat cover/2) with an aesthetic nuisance guideline of
≥30%.
Use of upper bound analysis (e.g., quantile regression) is recommended to
evaluate periphyton abundance thresholds associated with impacts on
benthic biodiversity metrics.
Based on analysis of the NRWQN matched invertebrate and periphyton cover
data, provisional general guidelines of <20%, 20-39%, 40-55% and >55%
periphyton weighted aesthetic cover are recommended as indicators of
‘excellent’, ‘good’, ‘fair’ and ‘poor’ ecological condition, respectively, at sites
where other stressors are minimal.
Further analysis of these periphyton-macroinvertebrate relationships by river
type is recommended to refine these provisional guidelines.
Overall, these data suggest that the New Zealand Periphyton Guideline of 50
mg chl a m-2 is appropriate for protecting “excellent” ecological condition
(MCI>120) in typical Southland streams, but a higher threshold of 100 mg chl
a m-2 may be warranted in some cases where other stressors on
macroinvertebrates are minimal. We suggest that other councils might
follow the simple approach demonstrated here (i.e., correlating MCI scores
with chl a) to evaluate the broad applicability of the 50 mg m-2 benthic
biodiversity threshold in their region.
If sufficient representation of different river types (e.g., REC classes) is
available, then this approach could also be applied separately by river type. It
would also be useful to attempt a further national scale analysis in the next
phase of this project if sufficient paired periphyton chla and
macroinvertebrate data are available from Regional Councils.
8
Figure 3
Existing and new instream plant abundance guidelines to protect
river values (Matheson et al, 2012)
9
Survey methods: macroinvertebrates
Aquatic invertebrates are recognised as an important component of contemporary
freshwater and marine monitoring programs, and have a long history of use both in
Aotearoa NZ and internationally. Such a role is due to a well-established
understanding of the responses of specific invertebrate taxa to environmental
conditions and change, and, in particular, their responses to environmental stressors
(e.g. sedimentation, rising water temperature, reduced dissolved oxygen and
elevated pH, ammonia toxicity, eutrophication, habitat degradation and climatic
variability).
Further, sampling macroinvertebrate communities is relatively straightforward, and
the findings can be easily quantified into several metrics of value in water quality
assessments. The use of macroinvertebrates in environmental monitoring is also in
an ongoing process of increasing sophistication as an understanding of particular
species and guild behaviour develops.
Figure 4
Some indicative taxa Te Tairawhiti
There are several methods of macro-invertebrate sampling utilised by experts in this
field. Recommendations for the current survey (Storey, 2012) derive from the
Protocols For Sampling Macroinvertebrates In Wadeable Streams (Boothroyd et al,
2007). These authors indicate that the particular sampling method utilised will
reflect the requirements of the survey being undertaken e.g. State of Environment
reporting (SOE); assessments of environmental effects (AEE).
10
For SOE monitoring programmes we have assumed that the study objectives
will be to provide biological information on a selection of streams in a region,
and allow for the comparison of sites through time. This approach obviously
requires the sampling of as many sites as possible, from reference through to
impacted condition. We anticipate that sampling will be on a seasonal basis
at best, but is more likely to be annual or semi-annual. Given these
constraints, it is unlikely that quantitative sampling will be cost-effective, and
semi-quantitative methods provide an appropriate alternative. In comparison,
AEE work and compliance monitoring may require more detailed site
comparisons where the additional information gained from quantitative
sampling may be justified (Matheson et al, 2012).
Initially we proposed an All Habitat sampling method, primarily as this was
considered most useful for identifying ecological integrity across a broad stream or
river reach, and would have been appropriate for an assessment of Outstandingness
or Special Interest Area (NPSFM 2014, Objectives A1 and B1). This proposal,
however, was amended on review by Dr Storey, and now focusses on riffle habitats
(where these are present) in hard-bottomed streams, enabling a consistency and
better comparison with other regional data. Although Dr Storey has also
recommended the use of Surber sampling as outlined in Protocol C3, the current
survey adopts the C1 protocol, as it was felt that the techniques utilised with this
protocol could better describe the diversity of stream macro-invertebrates across
the wide range of substrate types likely to be sampled in our region.
The sampling method adopted for soft-bottomed streams is Sampling Protocol C2.
Processing of the samples for both is based on Protocol P2: 200 Fixed Count + Scan
for Rare Taxa, and quality control on Protocol QC2: Quality Control for Fixed Count.
These Protocols are outlined in Appendix 2.
The MCI is calculated from presence-absence data as follows.
where S = the total number of taxa in the sample, and ai is the tolerance value for
the ith taxon (see Table 1).
The QMCI is calculated from count data as follows.
where S = the total number of taxa in the sample, ni is the abundance for the ith
scoring taxon, ai is the tolerance value for the ith taxon and N is the total of the
coded abundances for the entire sample.
11
However, whereas the MCI score is achieved by gaining an average sensitivity score
of taxa present and multiplying by 20 (in order to differentiate this figure from the
QMCI score), this report will also retain the original average of the taxa present’
sensitivity scores, and report on this as the Site Tolerance Score (STS). This latter
metric is currently being employed in the Parallel Water Monitoring Project (Te
Roopu Waitohu o Turanganui a Kiwa) with the intention of making the comparison
between the MCI and the QMCI more easily recognisable to untrained participants
(Storey, 2014).
Further assessments of the invertebrate data are also performed, including total taxa
and animal abundance, the percentage of the sensitive Ephemeroptera, Plecoptera
and Trichoptera (EPT) taxa, the aquatic invertebrate families most sensitive to
impacts of contaminants and degraded aquatic environments, and the relative
abundance of EPT animals present at the site.
Table 4
Macroinvertebrate Reference chart (Stark and Maxted 2004, 2007;
Storey 2014)
Index
Taxa total
Macroinvertebrate community index (MCI)
Quantitative macroinvertebrate community index
(QMCI)
Site tolerance score (STS)
EPT Taxa %
EPT animals %
Excellent Good
Fair
Poor
TBE
TBE
TBE
TBE
>119 100-119
80-99
<80
>5.99
>5.99
TBE
>50
5-5.99
5-5.99
TBE
15-49
4-4.99
4-4.99
TBE
1 to 14
<4
<4
TBE
<1
Quality control: macroinvertebrates
Quality Assurance (QA) is the measurement and control of errors, and refers to
inspections or tests which determine whether or not a product or service meets a
required standard. Although the authors identify that the protocols set out in the
Monitoring Protocols and Quality Assurance Guidelines (Davies-Colley, et al, 2012) do
not represent a formal or accredited QA system, they suggest that the existence of
well-documented standard methods, including QC procedures, should promote the
production of accurate, reliable and consistent macroinvertebrate data at all times.
Further, they also believe that the adoption of the protocols will confer considerable
value and reliability on the information gained from both new and existing programs.
Quality Assurance programmes exist for biological monitoring programmes using
rapid assessment protocols in the UK (Dines & Murray-Bligh 2000), USA (Plafkin et al.
1989, Cuffney et al. 1993), and Australia (Humphrey et al. 2000). These methods
form the basis of the protocols suggested by Davies-Colley et al and focus on the two
most likely sources of error: sorting and taxonomy. The authors have attempted to
make the procedures as simple as possible, without adding substantially to effort
12
and expense. Thus, in general, the QC protocols recommended would be expected to
add 10 - 15%, at most, to the cost of the data.
These protocols would generally involve re-examination of 10% of samples selected
at random. The second taxonomist will be provided with the results obtained by the
original taxonomist to check the identifications and counts or relative abundances.
The authors considered whether the second taxonomist should check the samples
independently (i.e., without having the results from the first sorter) but decided that
a comparison of results would be more cost-effective and educational. For example,
the second taxonomist can explain any differences in identifications that arise,
rather than this reconciliation requiring an additional stage.
Furthermore, the condition of macroinvertebrates in samples tends to deteriorate
with handling, so the comparative approach is less likely to disadvantage the second
sorter. If two equally-experienced taxonomists disagree on an identification then a
third opinion should be sought from an agreed independent expert.
The authors point out that it is not their expectation that formal QC will necessarily
be carried out on all sampling programmes at all times. Rather, that QC effort be
directed at significant SOE, AEE or compliance monitoring programmes periodically
(e.g., once every three years), or following a change of personnel involved in
macroinvertebrate sorting and identification. Thus a QC report noting that the
personnel who sorted the samples had recently passed QC on a previous project
would suffice, but an outdated testimonial (say > 3 years old), or the use of
personnel of unproven capability, would not be acceptable evidence of quality
assured data. Where casual personnel are used for sorting and identification a QC
report would be expected for each significant project (Davies-Colley et al, 2012).
Survey methods: macrophytes
Macrophytes are conspicuous aquatic plants from a diverse assemblage of
taxonomic groups that are often separated into four categories based on their habit
of growth: floating unattached, floating attached, submersed, and emergent.
Macrophytes are an important component of wetland, lake and river ecosystems,
contributing to services such as carbon fixation, nutrient cycling and sequestration,
and providing food and habitat for fish, invertebrate and bird populations.
Overabundance of macrophytic growth can, however, impact on aquatic and human
values, such as:
x
Hindering recreational use;
x
Reducing aesthetic quality;
x
Restricting land drainage;
x
Clogging water intakes;
13
x
Reducing ecological habitat quality (e.g. through depleting DO levels
and/or altering pH, smothering substrate and increasing levels of
deposited sediment).
Although macrophytes have been a part of state of environment reporting for some
time, due to insufficient data, no macrophyte abundance or nutrient guidelines for
macrophytes have been identified for NZ rivers and streams. Recently, however, and
despite a continuing paucity of empirical data, collation of available information has
made possible the application of provisional guidelines for the protection of instream ecological condition, flow conveyance, recreation and aesthetics. These are
50% or less of channel cross section area or volume (CAV) or water surface area (SA)
(Figure 6 below).
Figure 5
Indications of effects of macrophytes on fish and
macroinvertebrates (Matheson et al, 2012)
14
Figure 6
Provisional macrophyte abundance guidelines (Matheson et al,
2012)
These guidelines provide the basis for our assessment categories for the Waipaoa
catchment. They are, however, modified to provide a quantitative assessment of
Macrophyte Channel Clogginess (MCC) (Storey, 2014). The MCC is estimated by use
of the following equation.
The field worksheet for the MCC is contained at Appendix 3. As with other
monitoring indices and stream characteristics and parameters measured, the raw
figures are included in the site summary data sheets, should the guidelines need to
be revisited and a re-assessment of the categories made.
Survey methods: habitat
Survey protocols for physical habitat include a wide range of in-stream, riparian, and
catchment characteristics of a given site or stream reach. In the Stream Habitat
Assessment Protocols for Wadeable Streams and Rivers of New Zealand (Harding et
al, 2009), three Protocol levels are outlined in detail. In his recommendations to GDC
(Storey, 2012), Dr Richard Storey considered Protocol 2 to be the most likely to be
adopted for survey work. After discussions with Dr Storey, it was decided to record
the raw information suitable to inform a Protocol 2 assessment, much of which is
included in the macrophyte and periphyton assessments, but also to implement a
Physical Habitat Assessment (PHA) (Storey 2014), which provides a quantified index
of ecological habitat value, based around a detailed visual assessment.
15
While the PHA is currently in a draft discussion stage, the ability to delineate sites
into quality categories based around informed visual assessments, has the potential
to provide a cost-effective method of signposting stream condition, prior to a
detailed survey of biotic components. This approach appears consistent with the
work of Kilroy et al around periphyton, and Kelly et al around the ecological integrity
of coastal lakes. Outcomes of this approach in the current survey are reported on
below. The PHA evaluation matrix is attached as Appendix 4. As specific components
of the matrix are not relevant to all stream and river sites, this report trials a variable
scoring system, utilising only those matrix components that do relate to the physical
habitat of a site. The scores attained from the site evaluation are then calculated as a
percentage of the relevant components. The ranking we have utilised is thus as
follows.
Table 5
Grade
Score (as %)
Physical Habitat Assessment (Storey, 2014): evaluation grades
(Palmer, 2014)
Excellent
>84
Good
61-83
Fair
39-60
Poor
<39
Application of these grades is contained in the survey results below.
Survey methods: physico-chemical characteristics
Overall, an attempt was made to align the Waipaoa bio-monitoring sites with GDC
water quality and flow measurement sites, the goal being to have a body of physicochemical and microbial information to underpin the biological characteristics of the
sites. In effect, partially complete data sets were available from four sites, and
similar sets from four sites on the same river stem. This reflects the differing
rationale for the bio-monitoring site selection from that for the original suite of GDC
sites in the Waipaoa and associated catchments, where the focus is more towards
flow assessments and flood management (pers com Dennis Crone, 2013).
For these reasons, and as the costs associated with full physico-chemical and
microbial analysis of all of the sites had not been incorporated into the original
survey project proposal, three forms of reporting have been selected for the
parameters chosen. These are as outlined in Table 5.
The choice of parameters was based around:
x
x
x
Those recommended by GDC officers;
NOF Attribute states;
Freshwater monitoring protocols (Davies-Colley et al, 2012).
16
Table 6
Sources of current survey data
Parameter measured
Existing GDC
site
New site
Clarity
Water temperature
pH
Dissolved oxygen
Total N
Ammoniacal N
Nitrate N
Total P
DRP
E coli.
Periphyton
Macroinvertebrates
Macrophytes
Physical habitat
NOF Attribute
(rivers)
9
9
9
9
9
9
9
9
9
Existing GDC data
Hydro-Technologies/Hills Laboratories
Nga Mahi Te Taiao field assessment
17
Survey results
Background
The results of our bio-monitoring assessments, physical habitat and landscape
surveys, and field and laboratory physico-chemical sampling, were collated onto
Excel spreadsheets and assessed against the following environmental and socioeconomic gradients.
x
x
x
x
x
Altitude and position in the fluvial hierarchy;
Recent rainfall;
Adjacent and upper catchment land use;
Identified catchment and sub-catchment values;
Water Management Zones.
Results are as follows.
Survey results: macroinvertebrate community indices
As a river moves from its headwaters or spring-fed source towards the coast, there
tends to be a natural process of accumulating and depositing sediment, debris,
nutrients and other materials as it passes through alluvial valleys and into the delta
area. Often subject to reduced flow velocities, the presence of soft mobile
substrates, an increase in water temperature and turbidity and potentially reduced
levels of dissolved oxygen, biological communities in these lower reaches tend to
include more tolerant taxa, suited to such conditions. These more tolerant
downstream communities are typically associated with a reduction in biological
index values, such as MCI, QMCI, EPT abundance, and an increase in macrophyte and
periphyton proliferation and levels of Chl-a.
Such a process of the gradual lowering of water quality as measured by biological
indices is referred to within the concept of a river’s natural altitudinal gradient (River
Environment Classification). Further, a lowland site with relatively high natural
character and habitat value, may exhibit low in-stream biological condition due
largely to upstream activities. In this context, the results of the survey indicated that
in the Waipaoa and associated catchments we visited, any potential correlation
between altitude and stream condition as measured by MCI indices was confounded
by the pattern of land use at the stream site and upper catchment, and that such
land use characteristics were a far greater anticipator of stream condition than
altitude.
As rivers extend closer to the coast some waterways become unsuitable for the
surveying of periphyton, macroinvertebrates and macrophytes, due to depth, bank
steepening, lack of suitable habitat, or tidal movement. In our current survey of the
Waipaoa and associated catchments, however, twelve of the thirteen river sites
were able to be sampled for macroinvertebrates, and 11 for macrophytes and/or
18
periphyton. Macroinvertebrates were gathered from Lake Repongaere but were not
evaluated by MCI processes.
Figure 7
MCI by altitude
350
160
140
120
100
80
60
40
20
0
300
250
200
150
Excellent
Good
Fair
Poor
100
50
0
MCI
Figure 8
Altitude
MCI score
MCI by ALTITUDE
Altitude
Expon. (Altitude)
QMCI by altitude
350
9
8
7
6
5
4
3
2
1
0
300
250
200
150
100
Altitude
QMCI/STS
QMCI by Altitude
Excellent
Good
Fair
Poor
50
0
MCI
QMCI
Altitude
Expon. (Altitude)
19
There were, however, strong correlations between Land Use types and all the
macroinvertebrate indices employed, as outlined in Figures 9 and 10 below.
Figure 9
MCI by LAND USE
MCI score
MCI by LAND USE
180
160
140
120
100
80
60
40
20
0
-20
Excellent
Good
Fair
Poor
R² = 0.9763
LAND USE TYPE
Figure 10
QMCI by LAND USE
QMCI by LAND USE
9
8
7
6
5
4
3
2
1
0
Excellent
Good
Fair
Poor
R² = 0.8371
MCI
QMCI
Linear (QMCI)
20
Table 7
MCI Reference chart (Stark and Maxted 2004, 2007; Storey 2014)
Index
Taxa total
Macroinvertebrate community
index (MCI)
Site quantitative tolerance score
(QMCI)
EPT Taxa %
EPT animals %
Excellent
Good
Fair
Poor
80-99
<80
5-5.99
4-4.99
In progress
15-49
1 to 14
<4
In progress
>119
>5.99
>49
100-119
<1
These considerations suggest that, when taking into account the natural river
gradients amongst the diverse sub-catchments that comprise the Waipaoa River
system, land management of the adjacent environment and upper catchment of the
sites was the dominant contributing factor to biological condition as determined by
the macroinvertebrate indicators employed.
Considering the MCI and QMCI outcomes, the physical habitat of the Extensive
Pastoral farming sites (Rere Falls, Pykes Weir and Urukokomuka) was characterised
by:
x
x
x
A level of woody vegetation retained or restored along the riparian zone;
The retention of the natural stream form;
The control of stock access to the stream (although not the total exclusion)
from adjacent paddocks.
At these three sites, stream condition as measured by the macroinvertebrate indices
was measured within the upper Good or Excellent categories.
The physical habitat of our Semi-intensive Pastoral site on a tributary of the Waihuka
River at the foot of the Otoko Hill, was characterised by minimal woody vegetation
(20% in the total riparian zone), little shading, and free stock access to the stream.
Although the natural form of the stream was largely intact, MCI and QMCI scores
positioned the stream in the lower quartile of the Fair category.
Where stocking rates and annual cropping combine to provide an Intensive Mixed
land use setting, stream condition at the three sites in the current survey (Whakaahu
at Bruntons Rd, Taruheru at Tuckers Rd and Waipaoa at Matawhero) as measured by
macroinvertebrate indices were seen in this survey to sit within the Poor category.
Only the Whakaahu had the stream’s natural character retained, and this site scored
best of the four, in the upper of the Poor Category (MCI 76.6, QMCI 3.65). The other
three rural sites (Taruheru at Tuckers Rd, Waipaoa at Matawhero and Te Arai at
Whatatuna) were in the middle of the Poor to abiotic category, with scores of MCI
41.6, 42, 49.4 and QMCI 2.78, 2.1, 2.12 respectively.
21
The stream form of the Taruheru and Matawhero sites was highly modified to
provide for water drainage and ease of cultivation, and this is reflected in the
Physical Habitat Assessments provided for the sites. At the Whakaahu site, however,
where algal and macrophyte proliferation was most pronounced, natural stream
morphology (e.g. shallow stream bed and low channel banks) and nutrient and/or
sediment migration into the waterway, appear implicated in the excess growth of
filamentous algae and macrophytes, and smothering of the stable substrate, further
impacting on the habitat for macro-invertebrate species requiring good water quality
and habitat conditions.
The Mixed Intensive/Urban streams had QMCI scores of 2.02 (Waikanae at the
Airport) and 2.12 (Taruheru at Campion Bridge), and MCI scores of 42 and 85.4
respectively. The latter higher MCI score reflecting the presence of only three taxa,
including one estuarine amphipod and one Acarina mite, along with 274 freshwater
snails (Potamopyrgus). The presence of estuarine species in the lower reaches of our
rivers indicate a tidal presence that may tend to mitigate against an otherwise low
MCI and QMCI scoring.
Our two reference Indigenous Forest sites scored MCI 150 and QMCI 8.06 (Waihirere
at Bush Edge) and MCI 145 and QMCI 8.17 (Te Arai at Waingake Intake), positioning
them well within the Excellent, Clean Water category. Overall, a similar trend can be
observed in the percentage of EPT animals gathered from the 12 stream sites).
Figure 11
Total EPT animals %
% TOTAL EPT ANIMALS
120
100
80
60
40
20
0
Certain factors, however, may potentially be confounding the Poor MCI water quality
indices in the lower Waipaoa reaches. These include the presence of Gambusia
affinis (Mosquito fish) in the streams of the Taruheru below Courtney’s Bridge, and
in the Waikanae. These small fish are prolific and voracious predators, and may be
impacting on invertebrate and fish populations there.
22
Survey results: periphyton
While periphyton communities are common on submerged surfaces in most aquatic
ecosystems, it is the harder, more stable substrates (bedrock, boulders, cobbles,
woody debris) where periphyton communities are most diverse, and reflect in detail
levels of enrichment and flow patterns. Where periphyton communities exist in soft
substrate waterways, these tend to be attached to materials in the littoral margins
(macrophyte beds or wetland plants) or to woody or other in-stream debris, and do
not colonise the substrate extensively as they do in harder bottomed streams.
Further, many lowland soft substrate waterways are subject to herbicide or
mechanical vegetation clearance. Thus, there exists some difficulty in consistently
comparing indices such as periphyton enrichment and Chl-a production between
hard and soft substrate stream types.
Utilising the assessment protocols recommended by Matheson et al (2012), Kilroy et
al (2011) and Storey (2014), we report on the presence of periphyton in those
streams where reasonable comparisons can be made, and on macrophyte
abundance for both hard and soft substrate streams. During warmer weather,
however, a better comparison of periphyton assemblages and abundance may be
possible where soft substrate streams remain undisturbed by high flow flushing of
stream vegetation. A review of the assessment protocols and current discussions
around this topic may also provide a more comprehensive way of assessing
periphyton growth and coverage that includes both soft and hard bottomed
waterways.
Table 8
Periphyton reference values (NPSFM 2014, Storey 2014, Matheson
et al, 2012)
Measure and
Grade
Periphyton
Enrichment Score
(PES)
Visual Chl-a
(mg/m2)4
Periphyton
weighted
composite cover
(PeriWCC)
Excellent
Good
Fair
>8
6-7.99
4-5.99
Somewhat
poor
2-3.99
<505
50-119
120-200
>200
<20%
20-39%
40-55%
>55%
Poor
<2
4
Based on laboratory assessment results.
< 17% Productive Class and < 8% Default Class streams per annum over a three year monthly sampling period
(NPSFM 2014).
5
23
Our results for periphyton concur with those from the MCI scoring process, namely,
for those sites exhibiting periphyton growth, a greater concurrence between land
use categories and periphyton enrichment exists than between the enrichment
indices and altitude.
Figure 12
Periphyton enrichment score by altitude
PERIPHYTON ENRICHMENT SCORE by ALTITUDE
12
10
8
6
4
2
0
350
300
250
200
150
100
50
0
PERIPHYTON ENRICHMENT SCORE
Figure 13
Altitude
Periphyton enrichment score by land use
PERIPHYTON ENRICHMENT SCORE by LAND USE
12
10
8
6
4
2
0
Similar concurrence can be seen to occur with levels of visually assessed Chl-a
mg/m2, although this is also a consequence of the results being based around the
periphyton data gathered. What is significant, however, is the excessive Chl-a levels
assessed for the Whakaahu site, where conditions appear ideal for periphyton
24
blooming, and where the shallow wide stream and low stream banks require greater
flow volumes to ‘flush’ the build-up of nuisance and deleterious periphyton and
macrophyte growth.
Figure 14
Visual equivalent Chl-a mg/m2
Equivalent CHl-a mg/m2
350
300
250
200
150
100
50
0
Overall, from the seven sites surveyed for periphyton enrichment, five, including the
Indigenous Forest and Extensive Pastoral sites, showed little signs of excessive
periphyton growth, and scored in the Excellent category for this biotic index.
Similarly, based on the visual assessment protocols for Chl-a, the same five sites
approximate to the NPSFM2014 Attribute state A for Chl-a, the Semi-Intensive
Pastoral site (Waihuka at Otoko) into the B state, and the Mixed Intensive site
(Whakaahu) fell below the national bottom line into the D state (NPSFM2014).
As the current survey project was the first of its kind to be implemented in the
region, inference from one set of results cannot be expected to provide definitive
conclusions around the relationships between land use, nutrient transport, riparian
management, flow levels, and periphyton types and abundance. Nevertheless, as the
current survey was conducted after initial autumn rains and amongst subsequent
winter flushing flows, it might reasonably be expected that the current results reflect
least optimum conditions for periphyton growth (elevated flows, cooler water,
reduced agricultural activity) and thus a ‘best case scenario’ for nuisance stream
periphyton cover.
Of particular interest, the Whakaahu Mixed Intensive site provided the highest level
of periphyton and macrophytal enrichment of all sites surveyed. The site appeared
unaffected by the autumn high flows, and some of the green filamentous periphyton
reached over 4 metres long. One notable characteristic of the stream is the wide,
shallow bed, and low stream banks. While there was little fresh sediment remaining
25
on the stream bed, there were extensive, deep, fresh deposits along the banks. This
suggests that any high flows are dissipated across the shallow stream channel and
broad adjacent flood plain, and may be insufficient to clear the warm-season buildup of periphyton and macrophyte growth.
The Whakaahu Stream at Bruntons Rd, displaying the shallow form and extensive
periphyton and macrophyte beds. Photo 27th May 2014.
The potential role of flushing flows in clearing such build up was also evident in the
Taruheru at Tuckers Rd, Waikanae at Airport, and Waipaoa at Matawhero sites,
however this effect is assumed from the relative absence of periphyton communities
at this time, and will need to be assessed against warm weather outcomes, and any
management activities impacting on these (e.g. herbicide or mechanical stream
clearance; nutrient deposition). In such soft substrate stream environments it may
well be that Macrophyte Channel Clogginess proves a more accurate indicator of
stream enrichment.
For the strongly tidal sites (Te Arai Footbridge and Taruheru at Campion Bridge)
periphyton and macrophyte growth is not assessed, as the tidal changes (velocity
and salinity) distinguish these sites from those further inland, and limit periphyton
and plant growth. The Waipaoa at Matawhero site may also be best included with
these, and summer reporting is expected to clarify such considerations. For these
sites, which might be clarified as upper estuarine, the best tests for enrichment may
be water clarity and laboratory measures of Chl-a by volume (assessed by water
column samples), with possible consideration for identifying a level of micro-algal
and planktonic communities.
In this context, our initial survey of the Te Arai Footbridge site (Mixed Intensive/Periurban) indicated a water clarity of 55cm, although at one spot, a log could be seen
several metres beneath the water surface. Despite a mid-green coloration of the
river water, Chl-a was quantitatively measured at <0.003 g/m3 (3 mg/m3),
26
positioning the result in the NPSFM2014 Attributes A category (for still water) and at
the limit of detection (Hills Laboratories, 2014).
The one lake site included in the current survey, Lake Repongaere (Mixed Intensive),
exhibited water clarity of 7cm, and Chl-a content of 270 mg/m3, placing this result
well into the NPSFM2014 Attributes D category for Lake environments.
Survey results: macrophytes
Typically, macrophyte growth is at a minimum during winter months when flows are
regularly above base flow and temperatures at their lowest. This is reflected at 6 of
the 13 sites reported on for macrophyte growth. Nevertheless, at the lowland Mixed
Intensive Whakaahu and Tuckers Rd (Taruheru) sites, significant macrophyte beds
were evident, and there was evidence of a variety of macrophyte beds submerged
by recent rains at the Whatatuna site.
Figure 15
Macrophyte channel clogginess
MACROPHYTE CHANNEL CLOGGINESS
300
250
200
150
100
50
0
Matheson et al, noting that there have yet to be developed overarching guidelines
for stream wellbeing in terms of macrophyte abundance, have nevertheless
suggested interim threshold levels for ecological condition, flow conveyance and
recreation. These are identified in Figure 14 below and Figure 6 above. The MCC data
as reported corresponds to a combination of the ‘channel volume/cross sectional’
and ‘surface cover’ components. These details are recorded separately, however, in
oprder to assess the possible range of macrophyte related metrics. Overall in-stream
plant guidelines for ecosystem health, recreation and aesthetics, do, however, also
need to include levels of periphyton present.
27
Figure 16
Instream plant abundance guidelines (Matheson et al, 2012)
Physical habitat assessment
Detailed quantitative visual assessments of freshwater physical habitat have
comprised environmental reporting for some time (NIWA, 2002; Kelly et al 2009;
Harding et al, 2009). The current Waipaoa survey aims to provide a semiquantitative recording of physical habitat values based on Protocol 2 (Harding et al,
2009), while providing a new form of qualitative assessment provided by R. Storey
(Appendix 3: Rapid Habitat Assessment, RHA, Storey et al 2014). We thus provide a
bifurcate reporting approach to habitat assessment, namely:
x
x
Detailed recording of the quantitative data (substrate, riparian
characteristics, stream form, etc);
An interpretive assessment score.
Utilising this latter tool, and based around condition categories provided by Storey
for a simplified method (Storey, 2014), this report provides a set of categories based
on the percentages of the maximum score each site achieves for the overall physical
habitat characteristics relevant to its specific fluvial setting (e.g. upland, main stem,
semi-estuarine, etc).
28
Figure 17
Physical habitat assessment (RHA) by altitude
100
80
60
40
20
0
350
300
250
200
150
100
50
0
ALTITUDE
PHA SCORE
PHYSICAL HABITAT ASSESSMENT (RHA) by
ALTITUDE
SITE NAME
PHYSICAL HABITAT % ASSESSMENT
Altitude
It is evident, as with our MCI and Periphyton assessments, there is little correlation
between physical habitat as assessed by the current method, and altitude or natural
river gradient across the range of sites surveyed. There is, however, a much stronger
correlation between land use as characterised by our current system, and physical
habitat as scored by the Storey method.
Figure 18
Physical habitat by land use
RHA SCORE as %
PHYSICAL HABITAT ASSESSMENT (RHA) BY LAND
USE
100
90
80
70
60
50
40
30
20
10
0
SITE LAND USE TYPE
The two exceptions (Te Arai Footbridge and Taruheru at Campion) should not,
however, be viewed as outliers. Rather, they reflect the quality of habitat at the
29
particular Peri-urban/Mixed Intensive and Urban/Mixed Intensive sites (Te Arai
Footbridge and Taruheru at Campion Bridge scoring 81.79 and 48.21 respectively) as
compared with that of the remaining Urban/Mixed Intensive site (Waikanae at the
Airport, scoring 19.25). In particular, the qualities that the Arai site exhibited
included: extensive established riparian vegetation, in-stream habitat (including
large wood), shading, stream bank integrity, and subsequent low levels of stream
bank erosion.
The relevance of the quantified assessment scoring method is further exemplified in
its apparent ability to indicate stream ecosystem condition. This is evident if we
consider the current site scores against the MCI and QMCI scoring.
Te Arai River at Opou Rd (left above) and adjacent to the village (right).
Figure 19
QMCI scores by habitat (RHA)
Habitat score
QMCI SCORES BY HABITAT (RHA)
100
90
80
70
60
50
40
30
20
10
0
R² = 0.8333
Fair Good
Excellent
Poor
0
2
4
6
8
10
Quantified site tolerance score
30
Figure 20
MCI scores by habitat (RHA)
MCI SCORES BY HABITAT (RHA)
100
R² = 0.9367
90
Habitat score
80
70
60
Poor
50
Excellent
Good
40
Fair
30
20
10
0
0
1
2
3
4
5
6
7
8
Site tolerance score (MCI)
Such predictive responses have been identified elsewhere for similar habitat
assessment models (NIWA, 2002).
Survey results: physico-chemical
Physico-chemical data either gathered in situ or retrieved from GDC sources has
been included in the current survey to provide a ‘snapshot’ of these abiotic stream
and lake characteristics to accompany the detailed biological assessments. As such,
our reporting on these characteristics is not intended to provide a definitive review
of the data.
There are, nevertheless, certain patterns evident from the fourteen sites surveyed,
and some important insights signposted, particularly where ‘one off’ samples
indicate an unacceptable ecological condition. In this context, the following
considerations are described.
1. Stream pH across the district as recorded with our field equipment is
consistently high (alkaline) against national levels (LAWA 2014). Even the
Reference and best performing Extensive Pastoral sites displayed pH levels
consistently above 8. Generally, only where there was evidence of a saline
influence (>0.3ppt) were pH levels reduced (7.7 to 8.12).
2. Similarly, conductivity levels were high across all streams and Lake
Repongaere, including those exhibiting the best biological monitoring results.
This is also uncommon nationally, and is expected to reflect the particular
nature of the Gisborne Tairawhiti region’s geophysical setting, and the
widespread presence of a calcaereous sedimentary geology.
31
3. Levels of Ammonia (NH4) across the region, both from our one-off laboratory
samples and from GDC historical median records, are typically low. Only the
Whatatuna site, in a major Mixed Intensive landscape, exhibited elevated
levels during our survey (0.23 mg/L). However, ammonia toxicity increases
dramatically at higher pH, being ten times more severe at a pH of 8 than it is
at pH 7 (LAWA). Considering the naturally high pH of most waterways in the
region, a precautionary approach to setting levels for NH4 and further
research on the toxicity of substances in this context is recommended.
4. Nitrate (NO3) levels at the survey sites were more variable. While the
majority of sites m,easured by either historical median levels, or laboratory
or field assessments, positioned the samples within the A category Attribute
State, the Waihirere, Whatatuna and Waikanae sites provided elevated
sample results. Of these, Waihirere was the greatest at 4.2mg/L at 27.7.2014.
As Waihirere is an indigenous forest Reference site, this result was surprising.
We thus resampled Waihirere for NO3 on 20.8.2014, resulting in a measure
of 1.91mg/L. Although it is possible an external incident or land use activity
led to these results, such elevated nitrate levels in forested streams have
been noted elsewhere in the region (Palmer, 2014) and require further
research, as is recommended by this report.
5. The majority of sites surveyed, either by one-off sampling or by historical
GDC median levels, fell within acceptable levels for DO, Ammonia N, Nitrate
N, Total P and DRP. Three sites, however, highlighted areas of specific
concern. These are:
a. Waihirere: as noted above, which exhibited high nitrate (4.2mg/L) and
very high Total N (4500mg/L) samples on the 27th July 2014;
b. Whatatuna: where Ammonia N (0.23mg/L) and Nitrate (3.4mg/L)
samples were high, Total P (101mg/M3) and Total N (4800mg/L) very
high; and
c. Lake Repongaere: where Total P (590mg/L) and Total N (6700mg/L)
were greater than ten times and eight times the National Bottom Line
for their respective Attribute States (NPSFM 2014).
32
Figure 21
Conductivity and salinity levels
1400
1200
1000
800
600
400
200
0
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Conductivity
Salinity (ppt)
Conductivity
CONDUCTIVITY and SALINITY (by altitude)
Salinity
The full list of physic-chemical characteristics surveyed are contained at Figure 23
below. Thresholds for assessing the characteristics described in our survey are
contained in the Attribute States of the NPSFM2014 (MfE, 2014). Figure 22 below,
however, also outlines a general series of default low-risk trigger values provided by
the ANZECC 2000 Guidelines (currently under review). Relevant to the development
of bio-monitoring for the Gisborne Tairawhiti region, the Guidelines stress that the
preferred approach to determining low-risk trigger values is for territorial authorities
to develop site-specific guidelines using biological effects data, comparison with local
reference conditions and/or considering effects of ecosystem-specific modifying
factors (Guidelines, 2000).
In his report for the Gisborne region, Richard Storey further identifies the
significance of GDC developing a bio-monitoring program.
Ministry for the Environment is currently attempting to rationalise SoE
freshwater monitoring nationally so that it can use SoE data to report on the
state and trend of New Zealand’s fresh waters. An important aspect of this
initiative is improving the coverage of monitoring sites to better capture the
range and variability of New Zealand’s streams and rivers and to reduce bias.
To complete the national picture of New Zealand’s fresh waters, data from
Gisborne District is essential. In addition to SoE reporting, scientific studies
often draw on national-scale river data (e.g., Scarsbrook et al. 2000, Larned et
al. 2004, Matheson et al. 2012). Regional council data have been used for
several of these studies, thus completing the coverage of council monitoring
would help greatly to advance the scientific understanding of New Zealand’s
streams and rivers. (Storey, 2012, p11)
33
Figure 22
ANZECC default low-risk trigger guidelines for selected variables in
NZ rivers
34
Figure 23
Waipaoa and associated catchments data summary
SITES
RERE FALL URUKOKO WAIHUKA WAINGAKEPYKES WEI WHAKAAH WAIHIRER TUCKERS AIRPORT MATAWHEWHATATU FOOTBRID CAMPION REPONGAE
Date
3.07.14 27.06.14 01.08.1430.07.2014 4.07.14 27.5.1427.07.2014 26.5.14 09.06.14 28.5.14 15.8.2014 7.07.201423.06.2014 18.6.14
LAND USE
EP
EP Semi-IP
R
EP
IM
R
IM
IM/U
IM
IM
IM/PU
IM/PU Semi-IP
108.8
128.6
86.6
145
117.2
76.6
150
41.6
46.6
42
49.4
85.4
MCI
STS
5.44
6.43
4.33
7.25
5.86
3.83
7.5
2.08
2.33
2.1
2.47
n/a
4.27
QMCI
5.79
6.61
4.4
8.17
7.48
3.65
8.06
2.78
2.02
2.1
2.12
n/a
2.12
EPT TAXA %
50
60
50
81.2
57
33
75
0
0
0
0
0
EPT ANIMALS
60
94
13
93.4
96
26
90.3
0
0
0
0
0
PES
9.605
10
7.397
9.6765
9.54
2.022
9.8045
n/a
n/a
n/a
n/a
n/a
n/a
n/a
ALGAL BIOMASS (equivalent to mg/m2 Chl-a)
9.245
1 110.7805
3.588
17.46 307.494
6.377
n/a
1.12
n/a
n/a0.003 g/m3
n/a 0.27 g/m3
MACROPHYTE CHANNEL CLOGGINESS
0
0
0
0
0
205.19
0
248.56
0.78
0
48.88
n/a
n/a
PHYSICAL HABITAT ASSESSMENT
179.5/220 169/220 128/220 191/220 154/220 123.5/220 196.5/220
40/200 38.5/200 50.5/200
43/200 114.5/140 67.5/140
PHA VALUE (%)
81.6
76.82
58.18
86.82
70
56.14
89.32
20
19.25
25.25
22
81.79
48.21
E Coli (MPN/10ml)
550
39
10
328
176
56
353
540
240
66
335
52
DO
10.1
10.1
11.3
10.5
10.3
4.2
11.6
7.4
5.6
10
10.4
11.2
7
Clarity
68
150
160
330
62
65
100
42
55.7
36
62
55
28
7
Ammoniacal N (g/m3)
<0.010
<0.010
<0.010
<0.01
<0.01
0.01
<0.01
<0.01
0.23
0.031
0.023
Nitrate N (g/m3)
0.24
<0.002
0.012
<0.015
0.085
4.2
0.67
1.78
<0.22
3.4
0.29
0.89
<0.002
TKN (g/m3)
0.16
<0.11
n/a
0.54
Total P (g/m3)
0.011
0.007
0.009
0.024
0.101
0.02
0.59
DRP
<0.004
0.009
<0.004
<0.006
Total N (g/m3)
0.27
4.5
4.8
6.7
Phosphate
<0.08
0.61
1.22
0.08
2.3
pH
8.36
8.5
8.62
8.66
8.52
8.13
8.49
8.12
7.77
8.19
7.95
8.12
7.94
Conductivity
160
250
360
250
550
870
450
730
890
560
900
1330
770
430
Salinity
0.1
0.1
0.2
0.1
0.3
0.5
0.2
0.4
0.4
0.3
0.5
0.6
0.4
0.2
Air temp c
12.7
18.7
14.8
15.4
11.4
9
11.3
15.5
15.8
8.1
12
9.7
13.6
17.2
Water temp c
6.5
12.1
8.6
9.2
8
9.9
6.4
11.6
14.7
8.3
7.8
7.4
11.9
12.5
RECENT RAIN (week)
2.2
2.2
4.2
18.8
0.2
6
18
2.8
12.2
7.8
5.6
0
1.2
13
RECENT RAIN (4 weeks)
111
185.4
70.8
56.2
111
23.6
69.4
20.4
95.4
25.5
189.2
113
185.8
191.8
Field assessment
GDC historical data
Laboratory sample
Recreational water quality
35
References
ANZECC. 2000. Australia and New Zealand guidelines for fresh and marine water
quality, Volume 1, The guidelines. Australian and New Zealand Environment and
Conservation Council, Agriculture and Resource Management Council of Australia
and New Zealand, Canberra.
Biggs and Kilroy, 2000. Stream periphyton monitoring manual. Ministry for the Environment.
Davies-Colley, R.J., Hughes, A.O., Verburd, P. and Storey, R. 2012. Monitoring Protocols and
Quality Assurance Guidelines (Part 2). Ministry for the Environment.
Drake D, Kelly D, Schallenberg M, Ponder-Sutton A, Enright M. 2009. Shallow coastal lakes
in New Zealand: assessing indicators of ecological integrity and their relationships to
broad-scale human pressures. NIWA.
Kilroy, C. 2011. Categories of periphyton for visual assessment. For ECan periphyton
monitoring program.
C Kilroy, DJ Booker, L Drummond, JA Wech & TH Snelder. 2013 ‘Estimating periphyton
standing crop in streams: a comparison of chlorophyll a sampling and visual
Assessments’. New Zealand Journal of Marine and Freshwater Research, 47:2, 208224, DOI:10.1080/00288330.2013.772526
Matheson, F., Quinn, J. and Hickey, C. 2012. Review of the New Zealand instream plant and
nutrient guidelines and development of an extended decision making framework:
Phases 1 and 2 final report. Ministry of Science and Innovation.
New Zealand Government. National Policy Statement for Freshwater Management 2014.
Palmer, M.J. 2014. Freshwater environments of the Longbush eco-sanctuary. Longbush
Ecological Trust.
Snelder T., Biggs B., Weatherhead M. 2010. New Zealand River Environment Classification
User Guide. MfE.
Stark, J.D. and Maxted, J.R. 2007. A User Guide for the Macroinvertebrate Community Index.
Ministry for the Environment. Cawthron Report No.1166.
Storey, R. 2012. Biological monitoring of rivers in Gisborne District: Benefits, costs and
recommendations. Prepared for Gisborne District Council.
Storey, R. 2014. Guidelines for Stream monitoring in NIWA’s community monitoring study.
NIWA.
36
Appendix 1 Recommended variables and measurement protocols (Matheson et al,
2012)
37
38
39
Appendix 2
Macroinvetebrate gathering and assessment protocols (Stark and
Maxted, 2007)
Collection Protocols
Two methods for hard-bottomed streams (Protocols C1 & C3) and two
methods for soft-bottomed streams (Protocols C2 & C4) are presented.
A stream is considered hard-bottomed when gravel, cobble, boulder and
bedrock substrates dominate (>50% by area) the streambed. Shallow riffle
substrate is common in these streams, and provides a consistent, easily
recognisable, and biologically productive habitat for sampling. In contrast, no
single substrate is found over the full range of stream types and levels of
disturbance in soft-bottomed streams. Therefore, a variety of stable substrates
(e.g., bank margins, woody debris and macrophytes) are recommended for
sampling in soft-bottomed streams. A soft-bottomed streambed may be
dominated by sand, silt, mud, clay, macrophytes, and woody debris, whereas gravel,
cobble, boulder and bedrock substrates may be rare or absent. The proportions of
each habitat sampled should be recorded.
SAMPLECOLLECTION
17
Where both hard and soft substrate types are found at a site, sampling should
concentrate on the habitat type that is most representative of the stream reach
being sampled. Alternatively, samples should be collected and processed separately
from each habitat type.
Protocol C1 – Hard-bottomed, semi-quantitative.
Protocol C1 is designed for collection of semi-quantitative macroinvertebrate
data. It is most appropriate for riffle habitat in stony streams, but may also be used,
less effectively, in deeper water. It is suitable for use with both relative abundance
and fixed count processing protocols (Protocols P1 & P2), and provides data
suitable for SOE and compliance monitoring and AEE’s where quantitative data
are not considered necessary. A variety of species richness and relative abundance
metrics and multivariate analyses can be calculated.
A D-net (Cuffney et al. 1993) with 0.5 mm mesh is recommended for Protocol
C1. Carter & Resh (2001) noted that D-nets were the most commonly used
sampling device for biomonitoring by state agencies in the USA (being used in
35.6% of programmes). In fact, 64.5% of programmes used some form of kicktype
sampler (cf., fixed quadrat like Surber 8.9%, artificial substrates 13.3%, grabs
2.2%) (Carter & Resh 2001). Although D-nets are suitable for collecting samples
from a wide range of habitat types in hard-bottomed streams (from sand through
to boulders or bedrock), sampling in riffle habitat is recommended to minimise
variability and improve the validity of between-site or temporal comparisons.
The shape (e.g., D, rectangular, triangular, or circular) and size of the net can
vary provided it has the proper mesh size although a D-net 30 – 40 cm wide along
the base is recommended. If the net is too narrow, the current may carry dislodged
macroinvertebrates and debris past the net rather than into it. The net will remain
serviceable for longer if the mesh is attached to the frame by a sleeve of tough
calico or plastic, or has a metal or plastic-covered leading edge. The net should be
at least 50 cm long to minimise clogging and backflow around the mouth.
To operate a D-net, the substratum (organic and/or inorganic) must be
disturbed immediately upstream of the net. The distance depends on the flow
regime, but generally should be less than 0.5 metres from the mouth of the net.
In the interests of national consistency, we recommend the foot-kick method
(Frost et al. 1971). Some workers pick stones up and scrub them by hand or with a
40
brush. This is likely to make a difference to the data collected, so whatever
approach is selected it should be used consistently. Kick sampling works best in
areas of hard-bottomed substrate, where there is little or no vegetation. The
effectiveness of kick sampling is affected by its duration, kicking intensity,
behaviour of the fauna, mesh-size, and flow (Frost et al. 1971).
To improve comparability of samples between sites and/or studies it is
important to standardise sampling effort. We recommend a pre-defined area
approach where a single hand-net sample contains material obtained from
0.6 – 1.0 m2 of streambed (see Guiding Principles section for more discussion of
standardisation of sampling effort and sample size).
SAMPLECOLLECTION
18
Protocol C1:
Hard-bottomed Semi-quantitative
Requirements:
1. Waders or sturdy boots
2. D-net (0. 5 mm mesh)
3. White tray or bucket
4. Sieve or sieve bucket (0.5 mm mesh)
5. Plastic screw-top sample containers (600-1000 ml volume)
6. Fine tweezers
7. Preservative
8. Labels and waterproof marker pen
Protocol:
1. Ensure that the sampling net and bucket/sieve are clean.
2. Select the appropriate habitat (e.g., riffle).
3. Sample beginning at the downstream end of the reach and proceed across and upstream.
4. Select an area of substrate (0.1 - 0.2 m2) to sample with a natural flow that will direct organisms into the net.
Place the net on the streambed and step into the sampling area immediately upstream of the net, disturb the
substrate under your feet by kicking to dislodge the upper layer of cobbles or gravel and to scrape the underlying
bed. The area disturbed should extend no further than 0.5 metres upstream from the net. Remove the material
from the net into the tray, bucket or sieve bucket if the net begins to get clogged.
5. Repeat Step 4 at several different locations within a 50 m stream reach and covering a variety of velocity regimes
until a total area of 0.6 – 1.0 m2 of riffle habitat has been sampled. Transfer this material to a white tray or
bucket approximately half full of water, or to a sieve bucket. Wash or pick all animals off the net.
6. Rinse and remove any unwanted large debris items (e.g., stones, sticks, leaves) that may not fit into the sample
container or will absorb and diminish the effectiveness of the preservative.
7. Transfer the sample to the sample container via a 0.5 mm sieve if a sieve bucket is not used. Inspect the sieve
or sieve bucket and return any macroinvertebrates to the sample container. (Tweezers may be useful).
8. Add preservative. Aim for a preservative concentration in the sample container of 70 – 80% (i.e., allowing for
the water already present). Be generous with preservative for samples containing plant material (leaves, sticks,
macrophytes, or moss).
9. Place a sticky label on the side of the sample container and record the site code/name, date, and replicate
number (if applicable) using a permanent marker. Write on the label when it is dry and do not rely on a label on
the pottle lid! Place a waterproof label inside the container. Screw the lid on tightly. Make notes on the field
data sheet describing the substrates sampled (cobble size, periphyton, embeddedness, etc.), the collector’s name,
sample type (e.g., D-net, 0.5 mm), and preservative used.
SAMPLECOLLECTION
19
Protocol C2 – Soft-bottomed, semi-quantitative
Protocol C2 is the soft-bottomed stream equivalent of Protocol C1. It is
suitable for use with both relative abundance and fixed count processing protocols
(Protocols P1 & P2), and provides data suitable for SOE and compliance
monitoring and AEE’s where quantitative data are not considered necessary. A
variety of species richness and relative abundance metrics and multivariate analyses
can be calculated.
There is no single substrate that is suitable for the collection of
41
macroinvertebrates in most soft-bottomed streams. Woody debris is considered the
soft-bottomed stream equivalent to productive riffle habitat targeted for sampling in
hard-bottomed streams, but woody debris is not found in all soft-bottomed streams.
Similarly, aquatic macrophytes often dominate open channel streams, but are rare or
absent in well-shaded soft-bottomed streams. We recommend an approach where a
single sample is collected from a fixed area of approximately 3 m2 (10 replicate
unit efforts of 0.3 m2 each), with habitats sampled in proportion to their occurrence.
Woody debris is a particularly important substrate in soft-bottomed streams
providing habitat for some taxa not found in other habitats (see Table 2.1).
Submerged logs provide a long-term stable substrate for colonisation. Many
pollution sensitive taxa feed on periphyton present on the wood surface, or use
wood as a direct food source or as a refuge from predators. In Auckland softbottomed
streams, up to 40% of the total taxa and 44% of the EPT taxa were found
only on woody debris sampled using the recommended method (Table 2.1). For
these reasons, woody debris should be included in the composite sample wherever
this habitat type occurs.
Table 2.1 Number and percentage of total taxa and EPT taxa (species level) only on
woody debris (i.e., logs only) compared with a combination of bank margins
and woody debris (logs+banks) (J. R. Maxted, unpublished data).
Total taxa (%) EPT taxa (%)
Site name Land use Season Logs
+
banks
Logs
only
Logs
+
banks
Logs
only
Upper Nukumea Bush Spring 39 11 (28) 18 5 (28)
Upper Nukumea Bush Summer 38 8 (21) 17 4 (24)
Lower Nukumea Bush Spring 40 16 (40) 16 7 (44)
Upper Vaughan Lifestyle Spring 43 9 (21) 21 4 (19)
Upper Vaughan Lifestyle Summer 50 12 (24) 18 2 (11)
Mid Vaughan Lifestyle Spring 31 5 (16) 10 2 (20)
Mid Vaughan Lifestyle Summer 45 9 (20) 17 2 (12)
Mid Awaruku Urban Spring 25 2 (8) 2 0 (0)
Mid Awaruku Urban Summer 19 4 (21) 0 0 (0)
Lower Vaughan Paddock Spring 23 2 (9) 3 0 (0)
Lower Vaughan Paddock Summer 23 0 (0) 0 0 (0)
Lower Awaruku Paddock Spring 22 4 (18) 1 0 (0)
SAMPLECOLLECTION
20
Sampling is undertaken while moving progressively upstream so that submerged
substrates can be seen easily and are undisturbed until sampled. Hard substrates
such as boulders, rock shelves, and man-made materials (e.g., concrete, gabions,
shopping trolleys) are avoided or sampled separately to promote data comparability
between soft-bottomed sites. The proportions of each habitat sampled should be
recorded on the field sheets and final data spreadsheets to aid interpretation (e.g.,
5/4/1, wood/bank margins/macrophytes).
As with Protocol C1, several sampling efforts should be pooled to create the
sample for soft-bottomed streams. A single sample comprises 10 unit efforts of
approximately 0.3 m2 area each (total 3 m2). Each unit effort should be transferred
separately to a bucket or sieve bucket to avoid net clogging or loss of
macroinvertebrates. The material collected in bank margins and macrophytes may
42
be transferred to the bucket by banging the net over the mouth of the bucket to
save time.
The following techniques should be used for different habitats to collect a unit
effort of an area of approximately 0.3 m2.
Bank Margins A section of bank containing stable structure including roots
and woody snags should be selected for sampling. The substrate is disturbed
aggressively (i.e., jabbed) with the D-net for a distance of 1-metre followed by 2 - 3
cleaning sweeps to collect dislodged organisms. Collection is done above the
bottom of the stream to avoid scraping the streambed and filling the net with fine
detritus, sand, and mud. Filamentous algae should be avoided where possible. Each
unit collection effort represents an area of approximately 0.3 m2.
Submerged Woody Debris Woody debris should be placed over the mouth of
the bucket or sieve bucket, and water poured over the material as it is brushed by
hand (this requires 2 people). Several pieces of woody debris may be placed in the
bucket at once before hand-brushing separately. Brushes are not recommended
because the hard bristles may damage delicate specimens and generate large
amounts of detritus. Woody debris includes large branches (50 - 100 mm diameter)
and small logs (200 - 300 mm diameter). The woody material should be inspected
visually and any organisms removed (with the aid of forceps) before placing back
into the stream. Medium to large logs (> 300 mm diameter) should be left in place,
and may be sampled by hand brushing the substrate underwater while holding the
net immediately downstream, provided there is sufficient velocity. Each metre of
woody debris is a unit collection effort and represents an area of approximately 0.3
m2.
Aquatic Macrophytes Macrophyte beds are sampled by jabbing the net in
submerged plants for a distance of approximately 1-metre to dislodge organisms,
followed by 2 - 3 cleaning sweeps. Place clumps of plants that have been disturbed
in the net (do not uproot) and shake and brush by hand to dislodge organisms.
Sample a variety of velocity regimes and macrophyte species. Collection is done off
the bottom of the stream to avoid the collection of fine detritus, sand, and mud.
Filamentous algae are avoided where possible. Each unit collection effort represents
an area of approximately 0.3 m2.
SAMPLECOLLECTION
21
Protocol C2:
Soft-bottomed, Semi-quantitative
Requirements:
1. Waders (chest)
2. D-net (0.5 mm mesh)
3. White tray or bucket
4. Sieve or sieve bucket (0.5 mm mesh)
5. Plastic screw-top sample containers
(600-1000 ml volume)
6. Fine tweezers
7. Preservative
8. Labels and waterproof marker pen (or
pencil)
Protocol:
1. Ensure that the sampling net and bucket are clean.
2. Sample a unit effort (0.3 m2) of woody debris, bank margins, or aquatic macrophytes using the following
procedures. Avoid dredging the net along the bottom in mud or sand, and avoid leaves and algae if possible.
Avoid hard (stony) substrates (or sample them separately using Protocol C1).
Woody Debris – Select submerged and partially decayed woody debris (50-250 mm diameter preferred).
Place over the mouth of the bucket or sieve bucket. Pour water over the substrate while brushing the substrate
43
gently by hand to remove organisms. Larger pieces may be sampled in situ by brushing the log while holding
the net directly behind it. Each 1-metre section of woody debris has a sample area of about 0.3 m2.
Bank Margins – Locate an area of bank with good structure and aggressively jab the net into the bank for a
distance of 1-metre to dislodge organisms, followed by 2-3 cleaning sweeps to collect organisms in the water
column. Each sample unit is about 0.3 m2.
Macrophytes – Sweep the net through macrophyte beds for a distance of 1-metre to dislodge organisms,
followed by 2-3 cleaning sweeps to collect organisms in the water column. Each sample unit is about 0.3 m2.
3. Repeat Step 2 at 10 locations while moving progressively upstream. Remove sample material to a bucket or
sieve bucket after each collection to avoid clogging the net. Select substrates to be sampled in proportion to
their prevalence along a 50 - 100 m reach of stream. Record the reach length and the proportion of the sample
taken from each substrate type (e.g., 50% wood, 25% banks, 25% macrophytes). After the 10 th unit effort, wash
or pick all animals off the net. The bucket or sieve bucket should now contain one entire sample comprising
material dislodged from 3 m2 of substrate.
4. Fill the bucket with water and rinse and remove any unwanted large debris items (e.g., sticks, leaves) that may
not fit into the sample container or will absorb and diminish the effectiveness of the preservative.
5. Transfer the sample to the sample container via a 0.5 mm sieve if a sieve bucket is not used. Two containers
may be needed; each container should be no more than 2/3 full with sample material. Inspect the sieve or sieve
bucket and return any macroinvertebrates to the sample container. (Tweezers may be useful here).
6. Add preservative. Aim for a preservative concentration in the sample container of 70-80% (i.e., allowing for the
water already present). Be generous with preservative for samples containing plant material (leaves, fine detritus,
algae, moss, and macrophytes).
7. Place a sticky label on the side of the sample container and record the site code/name, date, and replicate
number (if applicable) using a permanent marker. Write on the label when it is dry and do not rely on a label on
the pottle lid! Place a waterproof label inside the container. Screw the lid on tightly.
8. Note the sample type (e.g., D-net), collector’s name and preservative used on the field data sheet.
9. Record notes on the field data sheet describing the proportion of habitat units sampled (e.g., 4/5/1, woody
debris/bank margins/macrophytes). Also describe on the field sheet the condition of the substrates sampled
(woody debris diameter range, type of wood, %cover, periphyton, macrophytes species, bank structure, etc.).
SAMPLEPROCESSING
33
Protocol P2:
200 Fixed Count + Scan for Rare Taxa
Requirements:
1. Running water – tap with hose recommended
2. 0.5 mm sieve
3. Clean, flat-bottomed, white tray marked in 6 cm
x 6 cm grids
4. 6 cm x 6 cm cookie cutters
5. Fine forceps
6. 70% ethanol preservative
7. Specimen vials with stoppers
8. Bench lamp
9. Labels and sharp pencil
10. Counter
11. 500 ml wash bottle
12. Identification keys & taxonomic references
13. Binocular dissecting microscope and light source
for species identification
Protocol:
1. All samples received should be recorded in a “laboratory log”. A unique job number, the date received, number
and type/s of samples, analyses required, results-required-by date, job manager, and sample processor’s name
should be recorded. The date completed should be entered once sample processing has finished. The fate of
samples can be verified in conjunction with a Chain–of-Custody form.
2. Thoroughly rinse sample in a clean 0.5 mm sieve to remove preservative and fine sediment. Large organic
material (whole leaves, twigs, algal or macrophyte mats, etc.) not removed in the field should be rinsed, visually
inspected for organisms, and discarded. Gently mix the sample by hand while rinsing, and continue until wash
water runs clear and the sample is thoroughly homogenised (i.e., break down lumps of algae etc). A coarse sieve
(e.g., 4 mm) can be helpful for removing larger pieces of unwanted organic material so long as all
44
macroinvertebrates are picked out and placed into the 0.5 mm sieve.
3. After washing, transfer contents of sieve to a white sorting tray marked with grids approximately 6 cm x 6 cm
(use black indelible marker). Visually check sieve before washing in preparation for next sample. Using the
wash bottle spread the sample evenly across the tray. There should be enough water to just cover all material. If
the samples have been preserved in alcohol some organisms (particularly ostracods and early instar insects) may
float on the surface. If this is occurs add a drop of washing detergent and stir gently.
4. Use a random numbers table to select a starting grid square within the tray. A cookie cutter (6 x 6 cm) is
recommended to delineate the chosen grid square. Moving systematically across the square remove all
organisms visible to the naked eye. Place captured organisms in a separate labelled vial (add preservative),
counting each individual with a counter. When complete, do a final check of the square’s contents to ensure no
animals have been missed.
5. Any organism that is lying over a line separating two grids is considered to be in the square containing its head.
In those instances where it may not be possible to determine the location of the head (worms for instance), the
organism is considered to be in the square containing most of its body.
6. After all visible organisms have been removed use forceps and/or a suction device to transfer remaining detritus
to a container labelled as “sorted residue”. Include location and date information (as per original sample label).
Add preservative. This provides material for sorting QA/QC procedures.
7. If a total of at least 200 organisms have been obtained sample sorting ceases. However, if less than 200
organisms have been enumerated, place another cookie cutter on a second randomly chosen square. Continue
this process until at least 200 animals have been captured.
8. Once a square has been started it should be finished, even if the 200 individual total is exceeded. The total
number of grid squares covered should be noted, along with the total individual count.
9. Save the remaining unsorted sample debris residue in a separate container labelled "sample residue"; this
container should include the original sample label. Add preservative.
10. The “sample residue” and vial containing the 200 individuals must be sorted by an experience taxonomist.
(Note: In situations where the sorter is an experienced taxonomist, invertebrate identification and counting can
be carried out during the sorting process to save time). Pour the 200 individual sample into a Petri-dish or
Bogorov tray and observe under a binocular microscope. Compile a taxa list and count the numbers of each
taxon. Return the 200 individuals to a labelled vial and add preservative. This sample will be used for
taxonomic QA/QC (see below).
SAMPLEPROCESSING
34
11. The minimum level of identification required is that specified in Appendix B. Do not include aerial adult
insects, pupae, terrestrial invertebrates, empty snail shells, caddisfly cases or exuviae. Examination of late pupae
can, however, assist greatly with larval identifications.
12. Complete the taxa list by scanning the “sample residue” for rare taxa. This is carried out with the sample spread
in white sorting trays. Any rare taxa obtained should be placed in a labelled vial with preservative. This is also
an opportunity to remove larger (e.g., late instar) or better-conditioned individuals of taxa already encountered
to assist in identification.
13. The vial containing the 200 individuals, and the vial containing rare taxa should be taped together. Record the
taxa found in the scan for rare taxa separately from the 200 fixed count data.
14. Return the “sample residue” to its container with the original labels.
15. On completion of sample processing there should be: (1) A labelled container holding the sample residue
(already scanned for rare taxa); (2) A labelled container holding the sorted residue (required for QC procedures
to assess sorting efficiency); (3) A labelled vial containing the 200+ individuals; and (4) A labelled vial
containing the rare taxa (not included in the 200+ sample) removed from the sample residue.
Quality Control for Protocol P2
Protocol QC2:
Quality Control for Fixed Count
Protocol:
1. All samples received, processed and identified should be recorded in a “laboratory log”. The fate of samples
can then be verified in conjunction with a Chain–of- Custody form.
2. Ten percent of the sorted samples to be re-examined by another sorter. The second sorter must be familiar
with sorting procedures and the full range of macroinvertebrate taxa from running waters in New Zealand and
will be provided with the results from the first sorter.
3. The fixed count protocol requires examination of the sample residue (were all rare taxa removed by the first
sorter?) and the sorted residue (were any animals missed during the collection of the 200+ individual subsample?).
A check on the taxonomic efficiency of both the 200+ sub-sample and the vial of rare taxa are also
required.
4. Taxonomic accuracy. On average, the number of taxa that are identified as different taxa, in either the full
45
200+ individual vial, or the rare taxa vial, between the two taxonomists must be < 10% of the total taxa
recorded from the sample. For example, a sample with 31 taxa passes QC when no more than 3 taxa are
identified differently between the two taxonomists. If the correct taxonomic identification of an organism is
disputed, then a specimen should be checked by an agreed expert.
5. Sorting accuracy 1 (missed taxa). If average > 10% new species are found in the sample residue then
the scan for rare taxa is deemed to have failed and a further 10% of samples are to be re-checked. If the
criterion is still not met then all samples must be re-processed.
6. Sorting accuracy 2 (missed individuals). If average > 10% more organisms are found in the sorted
residue then a further 10% of samples are to be re-checked. If the criterion is still not met then all samples must
be re-processed.
7. Trainee sorters should have at least 50% of samples re-checked for QC, and can be considered competent
sorters when < 10% of checked samples are returning < 10% new taxa, or < 10% re-codes than first sort.
8. After a sample has been completely sorted all sieves, trays and equipment should be thoroughly cleaned and
picked free of organisms and debris before the next sample is begun.
46
Appendix 3
Provisional guidelines for instream macrophyte abundance (Matheson
et al, 2012)
47
Appendix 4
Macrophyte monitoring field sheet and worked example (Matheson et al, 2012)
48
49
Appendix 5
Periphyton field sheet, scoring table and visual Chl-a assessment table (Storey, 2014)
Date:
Days since last rainfall >5 mm:
Site information:
Run
Method:
20 x 0.5 m circles
(observer in stream)
Observations
1
or
2
Riffle
3
(circle one)
4
5
Open
or
Shaded
OR
20 x 0.5 m circles (observer on
bank/bridge)
6
7
8
9
10
11
(circle one)
OR
12
13
20 x rocks
14
15
16
17
18
19
Didymo
Cyanobacteria mats
Green filaments
Other filaments
Other Mats > 2mm thick
(excluding Didymo &
Cyano)
Sludge
Thin Films
Bare Area
TOTAL
Main colour of filaments:
Main colour of mats
Main colour of films:
50
20
Periphyton Scoring Table
Sum of
observations
/20
Average of
observations
Periphyton
weighting
factor
Average
cover x
weighting
factor
Amount
(biomass)
of algae
-
Do not
score
Do not
score
Observations
CE, DE or BG0*
Didymo
/20
0
/20
0
1
0
0
/20
0
2
0
0
Other filaments
/20
0
1
0
0
Other Mats > 2mm
thick (excluding
Didymo & Cyano)
/20
0
7
0
0
Sludge
/20
0
8
0
0
Thin Films
/20
0
9
0
0
Bare Area
/20
0
10
0
0
0
0
Cyanobacteria
mats
Green filaments
Sum
Divide sum
by 100
Periphyton
enrichment
score
Divide sum by
100
/100
0
Amount
(equivalent
to mg/m2 Chl
a)
/100
0
51
Appendix 6
Visual estimation of periphyton Chl-a (Kilroy et al, 2013)
52
Appendix 7 Physical habitat assessment (Storey, 2014)
PHYSICAL HABITAT ASSESSMENT (R Storey 2014)
<10% of the stream bed in run
10-20% of the stream bed in run
20-50% of the stream bed in run
habitats covered by fine sediment
habitats covered by fine sediment
habitats covered by fine sediment;
score lower if deposits are deep
20 = 0%, 16 = 8%
15 = 10%, 11 = 18%
Thin film: 10 = 30%, 9 = 35%, 8 =
40%, 7 = 45%, 6 = 50%
Deep/sandy deposits: 10 = 20%, 9 =
25%, 8 = 30%, 7 = 35%, 6 = 40%
>50% of the stream bed in run
habitats covered by fine sediment;
score lower if deposits are deep
Thin film: 5 = 60%, 4 = 70%, 3 =
80%, 2 = 90%, 1 = 100%
Deep/sandy deposits: 5 = 55%, 4 =
60%, 3 = 65%, 2 = 70%, 1 = 75%+
SCORE
20
5
2. Invertebrate habitat
Abundant and diverse
>75% substrate favourable for EPT
colonisation. Present year-round.
1. Fine sediment
deposition in naturally
hard-bottomed streams
Example score
19
18
17
16
SCORE
x2
14
13
12
11
10
9
8
7
6
4
3
2
1
Common and adequate
50-75% substrate favourable for
EPT. Some habitat may be
transient or not persist beyond a
season.
and
Moderate variety (4-5 types) of
substrate sizes and types.
Patchy and limited
25-50% substrate favourable for
EPT. Score lower if large proportion
of habitat not persistent.
Rare or absent
<25% substrate favourable for EPT.
and
Limited variety (2-3 types) of
substrate sizes and types.
and
Homogenous substrate
(predominantly 1 substrate type).
and
Interstitial spaces open.
20 = 95% cobbles & gravels, with
boulders, sand, wood & leaves
present.
19 = 90%, 18 = 85%, 17 = 80%, 16 =
75%
and
Interstitial spaces open.
15 = 70% stable substrate with 4
additional substrate types
and
Very limited interstitial space.
5 = 25% gravel rest of stream
covered in unstable sands
20
15
and
Interstitial spaces limited.
10 = 50% cobble/gravel with leaves
and small wood with 25%
periphyton/macrophyte cover
6 = 30% cobble/gravel with leaves
and small wood, with >40%
periphyton/macrophyte growth
10
9
8
7
6
and
Wide variety (> 5 types) of
substrate sizes and types. Inorganic
includes boulders, cobbles, gravels,
sand. Organic includes wood,
leaves, root mats, macrophytes.
Example score
15
19
18
17
16
11 = 50% stable substrate and
macrophytes/periphyton present
14
13
12
11
1 = 5% gravel rest of stream
covered in silt/mud
5
4
3
2
1
53
3. Fish cover
Abundant and diverse
>70% fish cover in reach
and
Wide variety (>4) of persistent fish
cover providing spatial complexity
such as woody debris, root mats,
undercut banks, overhanging/
encroaching vegetation,
macrophytes, boulders, cobbles
Common and adequate
40-70% fish cover
and
Moderate variety (3) of fish cover
types providing spatial complexity;
woody debris and overhanging
vegetation or undercut banks score
higher if persistent
Patchy and limited
10-40% fish cover
and
Limited variety (2) of fish cover
types, woody debris, overhanging
vegetation or undercut banks are
rare; only larger cover elements
are persistent
Rare or absent
<10% fish cover
and
Fish cover rare or absent; few
hiding places or interstitial spaces
Example score
20 = 95% of habitat favoured by
expected fish community, lots
instream and bank complexity
19 = 90%, 18 = 85%, 17 =80%, 16 =
75%
20 19 18 17 16
15 = 70% of habitat favoured by
expected fish community,
o/hanging veg/banks stable
11 = 40%
10 = 40%, fish cover is boulders and
logs in water
5 = 8%, fish cover is a few seasonal
macrophytes instream
6 = 10%
15
10
1 = 0% fish cover, uniform
substrate
5
4
3
2
1
Wide variety (4+) of hydraulic
components such as pool, riffle,
run, glide, chute, waterfalls
(appropriate to gradient of the site)
and
Variety of pool sizes and depths
(appropriate to size of stream)
Moderate variety (3) of hydraulic
components, scores lower if riffle
habitat relatively scarce
Limited variety (2) of hydraulic
components (e.g. a run and a riffle)
Uniform depth and velocity
and
Deep and shallow pools present
(pool size relative to stream size)
and
Deep pools absent (pool size
relative to stream size)
and
Pools absent (includes uniformly
deep streams)
15 = runs pools riffles
11 = runs pools but less riffles
10 = run riffle but pools only after
riffles
6 = no deep pools
5 = mainly run/glide, pools or riffle
hard to find
1 = no pools
SCORE
20 = riffle run pool and backwaters
with shallow and deep pools
16 = riffle run pool, backwaters
hard to find
20 19 18 17 16
15
10
5
5. Bank stability
High
Moderate
SCORE
x2
4. Hydraulic heterogeneity
Example score
14
14
13
13
12
12
11
11
Low
9
9
8
8
7
7
6
6
4
3
2
1
Very low
54
Banks stabilised by geology,
moderate vegetation cover and/or
root depth
and
5-30% recently eroded, mainly
scouring
15 = 5% erosion scars at water line
Left bank
Banks stabilised by geology,
vegetation cover and/or deep roots
(1-2x bank height)
and
<5% recently eroded, mainly
scouring
20 = mature bank vegetation, no
sign of erosion
16 = younger bank vegetation,
limited erosion at water line
20 19 18 17 16
Right bank
20
15
Example score
SCORE (mean LB&RB)
6. Bank vegetation
19
18
17
16
14 = 10%, 13 = 15%, 12 = 20%, 11 =
25%
15 14 13 12 11
14
13
12
11
Uncohesive bank materials, sparse
vegetation cover and/or shallow
roots (< bank height)
and
30-60% recently eroded, mainly
slumping
10 = 30% erosion, slumping of bank
above water line
9 = 40%, 8 = 45% , 7 = 55%, 6 = 60%
Uncohesive bank materials and few
roots
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
and
>60% recently eroded, mainly
slumping
5 = 65% erosion scars, slumping of
bank above water line
4 = 75%, 3 = 80%, 2 = 85%, 1 ≥ 90%
Mature native vegetation, with
diverse and intact understorey and
groundcover
Regenerating native vegetation or
mature with damaged understorey
or dense mature exotic vegetation
or dense mature flaxes/sedges
Shrubs or sparse tree cover with
little understorey vegetation or
long grasses or early-stage planted
trees
Heavily grazed or mown grass or
bare ground or impervious cover
Example score
20 = mixed age and height
vegetation within 5 m of wetted
width, 16 = mixed veg but less
mature trees, gaps in groundcover
20
19
18
17
16
10 = mix native and exotic young
veg, 9 = mix with some high trees, 8
= mix mainly shrubs, 7 = mix veg
mainly grass, 6 = mainly young
exotic
10
9
8
7
6
5 = mainly exotic grass, 4 = mown
grass, 3 = bare ground, 2 =
impervious cover, 1 = no bank veg
Left bank
15 = young native veg, 14 = native
but understorey damage obvious,
13 = low native veg only, 12 = mix
mature exotic trees and native, 11
= mature exotic trees dominate
15 14 13 12 11
5
4
3
2
1
Right bank
20
19
18
17
16
15
10
5
4
3
2
1
14
13
12
11
9
8
7
6
SCORE (mean LB&RB)
55
7. Riparian buffer (width)
Grazed grass or sparse litter layer
and pathways present for stock
access to stream at watering points
e.g. unfenced but may have
vegetation barrier
and
Narrow (<5m)
Bare ground with high soil
compaction or uncontrolled stock
access or human impact obvious
and
Wide (>15m)
Mostly continuous vegetation with
moderate grass cover or medium
litter layer and limited stock access
or human impacts e.g. single-wire
fence and/or vegetation barrier
and
Moderate (>5m)
Left bank
20 = fully fenced, mature and dense
veg >20m wide, 19 = 20m wide, 18
= 15m wide est veg, 17 = 15m wide
recently planted/fenced, 16 = 15m
fenced but no new veg
20 19 18 17 16
15 = 10m wide potentially not
permanent fence, mixed stage veg,
14 = 10m wide new planting, 13 =
8m wide mix veg, 12 = 5m wide
mix veg, 11 = 5m wide new veg
15 14 13 12 11
10 = 5m wide unfenced but dense
mix veg, 9 = 4m wide mix veg, 8 =
4m wide scattered veg, 7 = 3m
wide scattered veg, 6 = 2m wide
scattered veg
10
9
8
7
6
5 = unfenced some scattered large
veg mainly grass, 4 = grazed grass,
3 = regular watering hole for stock,
2 = bare gound, 1 = impervious or
highly modified streamside zone
5
4
3
2
1
Right bank
20
15
10
5
Example score
SCORE (mean LB&RB)
8. Riparian shade
Example score
SCORE
9. Channel alteration
Continuous parallel vegetation
with dense groundcover or thick
litter layer and all livestock
excluded e.g. fully fenced
19
18
17
16
14
13
12
11
9
8
7
6
and
Absent or infrequent
4
3
2
1
Vegetation (or banks) provide
substantial shading of wetted
width at baseflow (>70%)
Moderate shade (40-70%)
Minimal shade (10-40%)
Little or no shading of wetted
width at baseflow (<10%)
20 = ≥ 90% average canopy cover
throughout day, 19 = 90%, 18 =
85%, 17 =80%, 16 = 75%
20 19 18 17 16
15 = 70%, 14 = 65%, 13 = 60%, 12 =
55% 11 = 50%
10 = 40%, 9 = 35%, 8 = 25%, 7 =
20%, 6 = 15%
5 = 10%, 4 = 8%, 3 = 6%, 2 = 4% 1 =
0%
15
10
5
Natural stream bed and bank form
unmodified
Natural stream bed, some evidence
of bank stabilisation (e.g. near
bridges). No instream structures or
embankments alter natural flows.
14
13
12
11
9
8
7
6
Significant proportion of stream
bed or banks altered by man-made
materials (e.g. concrete lining,
wooden boxing, riprap or gabion
baskets). Or embankments
constrain major floods within
channel
4
3
2
1
Stream bed or banks altered over
most of their length or natural
flows significantly altered by
instream structures (e.g. weirs,
culverts) or embankments.
56
or
Stream with natural channel profile
and sinuosity
Example score
20 = unmodified bed, bank,
sinuosity, 16 = evidence of
historical channel straightening but
mainly unmodified
or
<20% of channel length
straightened, widened or
deepened
15 = natural in stream substrate
some man-made bank materials up
to 5% channel alteration, 11 = 15%
alteration
SCORE
20
15
19
18
17
16
14
13
12
11
or
20-50% of channel length
straightened, widened or
deepened
10 = 20% channel alteration, 20%
in stream/bank man-made
materials, 6 = 50% channel
alteration, 50% in stream/bank
man-made materials
10
9
8
7
6
or
>50% of channel length
straightened, widened or
deepened
5 = 60% channel alteration 60%
bank dominated by man-made
materials, 1 = ≥75% channel
altered ≥75% man-made structures
5
4
3
2
1
TOTAL (sum 1 to 9)
COMMENTS
57
Appendix 8
Total macroinvertebrate taxa and animals present at the Waipaoa and
associated catchment survey sites
MACROINVERTEBRATE TAXA
Sample protocol
Plecoptera/Stoneflies
Acroperla
Stenoperla
Zealandoperla
Ephemeroptera/Mayflies
Coloboriscus
Deleatidium
Ichthybotus
Nesameletus
Trichoptera/Caddisflies
Aoteapsyche
Costachorema
Edpercivaliae
Hydrobiosis
Olinga
Heliopsyche
Hydrobiosidae (Edpercivalia)
Hydrobiosella
Oecitis
Paroxyethira
Psilochorema
Pycnocentria
Pycnocentrodes
Triplectides
Megaloptera/Dobson.F
Archicauliodes
Coleoptera/Beetles
Elmidae
1
1
15
68
590
2
31
74
7
7
61
83
13
6
1
3
9
2
4
39
2
17
5
Odonata/Dragonflies
and Damselflies
Xanmthocnemis
Diptera/True flies
Aphrophilia
Austrosimulium
Berossus
Chironimidae
Chironomus
Stratiomyidae
Hemiptera/Bugs
Sigara
Microvelia
Crustacea
Amphipoda
Cladocera
Copepoda
Isopoda
Ostracoda
Arachnida
Acarina
Mollusca
Gyraulus
Potamopyrgus
Physa
Nematoda
Nematomorpha
Platyhelminthes
Cura
Oligachaete
Oligachaete
Hirudinea
5
2
3
3
32
14
1
174
1
1
12
33
1
227
2
38
797
14
8
185
24
58
Appendix 9
Habitat and water quality recording sheet (Palmer, 2014)
SITE RECORD SHEET
CATCHMENT/RIVER:
Site name
Site #
Date
Time
Altitude (m.asl)
STREAM FORM %
Pool
Run
Undercut
Riffle
PHYSICO-CHEMICAL
Air temp ©
Water temp ©
Clarity (cm)
Conductivity (μS)
Easting
Northing
Tide (high)
RECENT RAIN (week)
RECENT RAIN (4 weeks)
RIPARIAN & LITTORAL MARGINS
(%)
Taha matau
indigenous woody
indigenous low
indigenous wetland
pasture grasses
exotic woody
exotic low
riverbed
man made
Taha maui
indigenous woody
indigenous low
indigenous wetland
pasture grasses
exotic woody
exotic low
riverbed
manmade
SHADE %
BANK EROSION %
Taha matau
Taha maui
STREAM TYPE (hb/sb)
Rapid
Debris jam
Macrophytes
Slumped bank
Other
EMBEDDEDNESS %
pH
Salinity (ppt)
Ammoniacal N
Nitrate
Phosphate
DO
Tight
Good
Moderate
Loose
RECENT DEPOSITS % COVER
RECENT DEPOSITS THICKNESS
STREAM SUBSTRATE (mm) % cover
Bedrock
Boulders > 250
Lg cobbles 120-249
Sm cobbles 60-119
Gravel
2-59
Sand
0.1-1.9
Mud/silt (not gritty)
Organic mud
Woody debris
Other
STREAM WETTED WIDTH (Av)
STREAM DEPTH (Av)
STREAM CHANNEL WIDTH(Av)
VELOCITY (m/sec)
FLOW (cum/sec)
BANK HEIGHT and DETAILS (TAHA
MATAU)
BANK HEIGHT and DETAILS (TAHA
MAUI)
Other
ADJACENT LAND USE
MCI SAMPLING METHOD
Total animals
Total taxa
Total EPT taxa
Total % EPT animals
Total %EPT taxa
MCI score
QMCI score
SQMCI score
PERIPHYTON % COVER
CE, DE or BG0*
Didymo
Cyanobacteria mats
Green filaments
Other filaments
Other Mats > 2mm thick
(excluding Didymo & Cyano)
Sludge
59
UPPER CATCHMENT LAND USES
Thin Films
Bare Area
MACROPHYTES % cover
Emergent plants
Surface-reaching plants
Below-surface plants
Av height below-surface plants as %
channel depth
Total plants
OTHER DATA and OBSERVATIONS
60