Life on (and in) sharks Shark eggcases from deep

Shark Focus
www.sharktrust.org THE MAGAZINE OF THE SHARK TRUST
ISSUE 52 March 2015
Life on (and in) sharks
Shark eggcases from deep time
Californian Thresher Sharks
plus
all your Shark Trust and EEA news
Supporting the
CAMPAIGN CORNER
Driven primarily by the global fin trade,
overfishing is currently the greatest
threat facing sharks. The Shark Trust’s
No Limits? campaign addresses this
threat head-on – but we urgently
need your support before the likes of
the Blue Shark, Shortfin Mako, Tope,
smoothhound and catshark follow other
previously abundant Atlantic stocks into
collapse. No Limits? focusses on the EU
fishing fleet, which includes some of the
world’s largest and most wide-ranging
vessels. The adoption of science-based
catch limits by the EU for all shark
species could be hugely beneficial for
shark populations worldwide.
Issue 52 March 2015
FEATURES
4 Life on (and in) sharks
6 Shark eggcases from deep time
12 Californian Thresher Sharks
14Sharks4Kids: spreading shark education to students around the world
16 Changing perceptions of sharks in the Red Sea
REGULARS
Pledge templates can be downloaded from
www.nolimitsnofuture.org, which you can use
to write your message of support, or put your
artistic talents to use by including drawings.
We encourage you to get creative and have
some fun! To see what others have to say, and to
demonstrate your support, visit our photo wall
at www.nolimitsnofuture.org/get-involved.
Consumer demand
for shark produc
the value of live
ts often surpass
sharks, despite
es
only producing
profits. Produc
short term
ts can include
cartilage, meat,
liver oil and skins.
fins, shark
Unsustainable
shark fishing is
to shark populat
a threat
ions
products can furtherworldwide and the demand for
such
deplete already
vulnerable species
.
Edited by the Shark Trust
www.sharktru
st.org
©Shark Trust 2015
Shark Focus is published three times a year in March, July and
November. Copy date for the next issue is 31st May 2015. Shark Focus
is copyrighted and therefore those wishing to reproduce articles must
first contact the Shark Trust. The views and opinions expressed by the
authors in Shark Focus are not necessarily those of the Shark Trust.
Housekeeping
SF2015-cover
Money is not the most important thing in the world,
love is. Fortunately I love money. – Albert Einstein.
This issue of Shark Focus celebrates my 15th year
working for The Shark Trust. I joined on 3rd March 2000
just in time to send out issue seven, so it is wonderful
to be able to say I hope you enjoy this issue, number
52. I would also like to say thank-you to those
members who have been with the Trust from the very
start and to those who joined at the same time as me.
As my husband has pointed out, if we had been in
the Navy we would have all got our long service and
good conduct medals. So whilst I celebrate 15 years’
service, in November the Trust will be 18, so thank you
to everyone who has supported us for all these years.
Your amazing contributions help us continue our vital
work and we are all extremely grateful.
It has been a busy few months, the end of the
financial year is upon us and the charity is due for
audit next month. Once completed, all accounts
are submitted to the Charities Commission and
Companies House in line with legal requirements.
These will then be available to view in PDF format on
the relevant web sites.
The economic climate is still rather like the weather
at present, mixed and unsettled, and like many
charities which rely on the generosity and goodwill
of the public, we are extremely grateful to all our
supporters. With the upcoming general election and
the ever present talk about budgets, deficits and
gloom & doom, it is always good to be able to tell
2
our supporters that not only are we continuing to do
exceptional conservation work but we do this with
financial credibility and your donations go where
you want them to go – on shark conservation.
Do keep an eye on the shop as we are looking at
introducing more branded goods in the coming
months to complement the mugs and rash vests we
already have. We have a small but very select range
and these are perfect gifts for friends and family.
Have a wonderful Easter/Spring and if you are
fortunate enough to be going to warmer climes and
see any sharks at all, or collect eggcases anywhere
on your travels, do let us know – photos are always
appreciated.
www.sharktrust.org/campaign
THE MAGAZINE
OF THE SHARK TRUST
ISSUE 52 March
issue 52.indd
3
Life on (and in)
sharks
Shark eggcases
from
deep time
Californian Thre
sher Sharks
plus
all your Shark
Trust and EEA
news
Supporting the
23/03/2015
17:27
Common Thresher Alopias
vulpinus © Chris Kowalski.
The Shark Trust
I am undertaking all the paperwork to send to HMRC,
scary I know, but this is to claim Gift Aid on donations
received for the year. Not everyone has signed a
declaration and it is so beneficial. If you do qualify
to do so, please complete a form for the charity, we
can then claim back on all your generous donations.
Forms can be obtained through the office or from the
website. If you are not sure if you have already signed
one, you can always just complete another one.
The office has also recently sent out renewal emails.
It is a shame to miss out on Focus if it slipped your
mind to renew so the way around this is to set up
a standing order. Again, forms can be downloaded
from the website or from the office, just email me
and I will happily send you one.
www.sharktrust.
org
Tel: +44 (0)1752 672008/672020
Email: enquiries@sharktrust.org
www.sharktrust.org
Glenys Heafield,
Company Secretary/
Head of Finance &
Administration
If you have any questions with regards, finance
and administration please do not hesitate to
contact me at glenys@sharktrust.org. I am
always happy to hear from you.
Shark Focus 52
2015
The Managing Director post, funded by a legacy grant from the Tubney
Charitable Trust, gives us the opportunity to secure new income
streams that will allow us to plan our next phase of conservation action
for the vital years ahead.
We are two years away from celebrating our twentieth anniversary,
and Paul’s arrival has served as a catalyst to examine our past work and
determine future strategies and direction. The future of the Trust’s work
is being decided through a collaborative process involving the new
Managing Director, staff, trustees, and our specialist sub-committees.
The process is ongoing and we all look forward to charting effective
directions for our future shark conservation work, while building on
successes of the past.
If, as some reports are suggesting, the demand for shark fins is starting
to reduce, this and other positive factors enable us to look to a future
where we can move away from crisis management expedients to
preventative actions and pre-emptive management measures. An
example of this sort of action is our No Limits? campaign. In tandem
with this approach we will be looking at consumer demand with a
view to driving non-consumption of unsustainably sourced products,
particularly fins and meat.
As our relationship with sharks evolves, many more of us are enjoying
engaging with sharks through tourism. A rough calculation shows that
in South Africa alone, over 200,000 people from all over the world take
part annually in a shark eco-tourism experience. Add the Caribbean
and other shark tourism hotspots, and this figure must exceed a
million. While some operators are excellent at using shark eco-tourism
to drive education and awareness, it appears that many are missing the
valuable opportunity. Perhaps this is an area that the Shark Trust might
take a lead in the future, supporting good practice globally. Into the
melting pot it goes!
4 Creykes Court, The Millfields,
Plymouth PL1 3JB
© The Shark Trust.
EDITORIAL
The Shark Trust started the New Year with a new Managing Director
when Paul Cox joined us from the National Marine Aquarium. Having
been a trustee for seven years Paul was no stranger to the Trust, and
was able to take up his post without the usual need for familiarisation
and introductions, so was into effective action very fast.
Shark Focus
glauca at London
Borough Market
© Timo Weber.
8 Shark Trust and world shark news
9 Policy
10 Supporter’s page
11 The Blowfish
18 The Shark Trust Range
cons
19 Shark conferences in 2015 umption
Blue Shark Prionace
There are many ways you can get involved, from
signing our petition to spreading the word far
and wide! We have now launched a campaign
photo-wall where you can upload an image
of yourself and tell us why you support the No
Limits? campaign. Alternatively, if you’re a fan
of Twitter or Instagram, you can include the
hash-tag #NoLimitsNoFuture in your post - this
will automatically be published to the photo
wall and help send the campaign viral on social
media.
Shark Focus
Supporting the European Elasmobranch Association
Established in 1997, the Shark Trust works to advance the worldwide
conservation of sharks through science, education, influence and action. The
Trust is the UK member of the European Elasmobranch Association and currently
provides the EEA’s secretariat services.
Sharks have been on the planet in one form or another for over 400
million years and this issue of ‘Focus’ spans the millennia, covering fossil
eggcases from 310 million years ago to projects like Sharks4Kids which
seeks to inspire future shark researchers and conservationists.
Stay safe, go well, and good shark spotting this summer.
Trustees: Richard Peirce (Chair), Stephen Allen, Sue Bates, Roger Covey, Sarah Fowler OBE, Alan Godwin,
Tom Kennard, Annabelle Lowe, John Nightingale and Sune Nightingale.
Patrons: Steve Backshall, Nick Baker, John Boyle, Leonard Compagno, Marc Dando, Bob Earll, Nigel Eaton,
Ian Fergusson, Mariella Frostrup, Loyd Grossman, John Gummer MP, Monty Halls, Martha Holmes, Kate Humble,
Sir David Jason OBE, Gordon Ramsay OBE, Simon Rogerson, Jeremy Stafford-Deitsch, Michaela Strachan and
Valerie Taylor
Design: Fluke Art. www.flukeart.com
Shark Focus 52
www.sharktrust.org/about
Richard Peirce
Chairman
3
Life on (and in) Sharks
Dr Tommy L. F. Leung
University of New England, Australia
2
and many others. They all line up at the cleaning
stations for a ‘once over’ and it turns out that the
Pelagic Thresher Shark is also on this wrasse’s list
of illustrious clients.
Most sharks are solitary animals that usually prefer their own
company. But on closer inspection you will find that no shark is
alone; each is a swimming community, teeming with life. Many
people will know about remoras – fish that latch on to sharks and
other large marine animals using the sucker on the top of their
head – but most of sharks’ ‘companions’ are far smaller and more
numerous than those hitch-hikers.
Many of the external parasites that infest
sharks (known as ectoparasites) are
copepods. While the most commonly
recognised copepods are microscopic
crustaceans that live as free-swimming
zooplankton, at least a third of the
13,000 known species of copepod are
parasitic – some of which make their
home on the bodies of sharks. Research
into the external parasites of pelagic
sharks off the coast of Western Australia
identified 17 species of parasitic
copepod amongst a total of over 20
species of ectoparasite. This level of
parasite diversity is not unusual. Like
most other large vertebrate animals, the
body of a shark is not just a food source,
but an entire ecosystem to parasites,
each organ representing a different
potential habitat.
PHOTOS
Main image: A remora without a shark.
© Klaus Stiefl (CC BY-NC 2.0).
Image 1: Copepods on a mako © Dr Kate Hutson, James
Cook University.
Image 2: Attachment organ (known as the Scolex) of a
shark tapeworm © Dr Haseeb Randhawa, University of
Otago.
Image 3: White Shark tapeworm © Dr Haseeb
Randhawa, University of Otago.
Image 4: Port Jackson Shark and its parasites © Klaus
Stiefl (CC BY-NC 2.0).
4
The eye of the Tiger
Parasites living on a shark’s skin have special
adaptations that allow them to hang on for the
ride. For example, there is a parasitic copepod that
lives on the skin of Whale Sharks Rhincodon typus
called Pandarus rhincodonicus. These little guys are
usually found on the leading edge of the shark’s
lips and fins and when you consider that Whale
Sharks can swim at a speed of about half a metre
per second, their presence can actually be quite
a drag. Like sharks themselves, this copepod has
evolved a streamlined body that minimises drag.
It also has a series of sticky pads and hooks that
give it a good grip on the shark’s skin. On top of
that, the edge of the copepod’s flat body is a frilly
fringe which allows the parasite to generate a
vacuum underneath its body, so when it presses
down on the skin of the Whale Shark, it essentially
turns into a living suction cup. But the skin is
not the only body part these parasites live on.
Another species of parasitic copepod – Caligus
oculicola – lives on the eyes of Tiger Sharks, and
much like Pandarus, it has evolved to be a living
suction cup that clings tenaciously to the eye of
the Tiger.
adhesion pads Ommatokoita has a pair of highly
modified limbs that it plunges deep into the
shark’s eyeball. As horrific as it sounds, the sharks
do not seem to be too bothered by the parasite’s
presence. Sharks that have been blinded by
Ommatokoita seem to be able to carry on living
no worse off than their cousins with intact eyes.
So how do sharks defend themselves against
these numerous parasites, or at the very least
keep them under control? While one of sharks’
regular hitch-hikers – the remora – will sometimes
‘graze’ on parasites, some species of shark visit
specialists for a more thorough job. When
parasites become too much of a hassle, the
usually oceanic Pelagic Thresher Shark Alopias
pelagicus will visit shallow coastal seamounts
where cleaner wrasses set up shop. These little
fish specialise in picking parasites off the skin, gills,
and mouth of larger fish and provide a service for
many inhabitants of the sea. The cleaner wrasses’
clients include parrotfishes, moray eels, groupers,
But as thorough as cleaner wrasse might be, they
are unable to do anything about what lives inside
the shark. Under certain circumstances, external
parasites, such as the copepods mentioned
above, have found a way inside their shark
host. Scientists in Japan discovered a species of
parasitic copepod that is able to make its way
into the womb of angelsharks. These parasites
infect the uterine lining of female sharks, and are
even able to get first dibs on embryonic sharks in
the womb before they are born. During the first
phases of an angelshark embryo’s development, it
is enclosed in the womb bathed in amniotic fluid.
But in the second phase it moves into a chamber
where it is regularly flushed with seawater. So it is
possible that during that stage the parasites are
able to arrive inside the shark along with seawater.
Other parasites are less subtle, and instead of
finding an orifice in which to enter, they simply
dig right through the skin. Anelasma squalicola
is a very unusual barnacle: unlike other stalked
barnacles which are simply content to filter
food particles from the water while clinging
to rocks or riding on the back of whales and
turtles, Anelasma actually embeds itself into the
flesh of the Velvet Belly Lanternshark Etmopterus
spinax. Its limbs (which other barnacles use to
gather food) have withered away and it feeds by
sending filamentous roots into the flesh of the
lanternshark, literally sucking its life blood. This
peculiar barnacle is not the only parasite that lives
on the lanternshark; a study in Norway found
these sharks to be crawling with parasites, both
external and internal, and their guts are full of
tapeworms.
Heavy metal exposure
Sharks and tapeworms are inseparable and they
have lived with each other for millions of years.
In fact, a recent study by Professor Janine Caira1
and her colleagues found that the vast majority
of known tapeworm lineages are actually shark
parasites, and those that have colonised terrestrial
animals (such as ourselves) many millions of years
ago are just off-shoots from a larger group that
mostly infect sharks, rays and other cartilaginous
fishes. Given that sharks and tapeworms have had
such a long history together, it is no surprise that
some tapeworms have evolved to be very specific
in their choice of hosts, and have attachment
organs that are shaped to fit the intestinal folds of
only a very small number of specific shark species,
like a lock and key.
Studying a shark’s tapeworms can also tell us
about what environmental pollutants their host
has been exposed to. Scientists have found
that tapeworms are very good at accumulating
heavy metals, so much so that they can contain
concentrations of lead, cadmium, and other heavy
metals hundreds of times greater than that found
in their host. Over time, even minute background
levels of these pollutants are eventually
concentrated in these tapeworms, leading them
to serve as very sensitive biological indicators that
allow scientists to detect presence of such metals
in the marine environment. Furthermore, because
of their apparent affinity for heavy metals, the
tapeworm also acts as a pollutant sink, absorbing
and concentrating these toxins before they can
do harm in the shark’s tissue. So even though they
are technically parasites, the sharks may actually
benefit from their presence.
Unlike that barnacle, tapeworms live relatively
innocuous lives, hidden away in the belly of their
host, passively absorbing pre-digested food.
Sharks acquire such parasites from the prey they
eat, and by following the life-cycle of tapeworms,
scientists can figure out what the shark has
been eating, as different parasites are usually
associated with different prey animals. Dr Haseeb
Randhawa from the University of Otago has been
using segments of DNA from these parasites to
compare the identity of adult tapeworms found in
sharks to those of larval stages found in the prey
animals. By doing so, not only has he worked out
what the sharks have been eating, but also these
parasites’ complicated life-cycles.
For example, he was able to show that Porbeagle
Sharks Lamna nasus around the Falkland Islands
prey on squid, as the DNA of larval tapeworms in
those squids matched those of adult tapeworms
found in the gut of the Porbeagle Sharks2. In
another study, Dr Randhawa was also able to
match DNA extracted from tapeworms found
in the gut of a White Shark to that of larval
tapeworms recovered from the blubber of
dolphins3. He also noticed that these larval
tapeworms were fairly selective in where
they were distributed in the dolphin – mostly
aggregating in dolphins’ tail, back, belly and groin
region – the parts most preferred by White Sharks
when they take a bite from a dolphin.
Parasites are not just free-loaders, indeed some
of them go through extraordinary lengths just
to stay alive and complete their life cycle. They
are an integral part in the lives of sharks and are
fascinating organisms in their own right. There are
many sharks with unique parasites that are found
in no other host species: if their host species of
shark becomes extinct, they will also disappear.
So when you are protecting a threatened
shark population, you are doing more than just
conserving a single species – you are saving an
entire living community of organisms, each with
their own unique evolutionary histories and
stories.
References
1. Caira, JN. et al. 2014. Orders out of chaos–molecular
phylogenetics reveals the complexity of shark and
stingray tapeworm relationships. Int J Parasitol. 44(1): 5573.
2. Randhawa, HS. and Brickle, P. 2011a. Larval parasite gene
sequence data reveal cryptic trophic links in life cycles of
porbeagle shark tapeworms. Mar Ecol Prog Ser 431: 215222.
3. Randhawa, HS. 2011b. Insights using a molecular
approach into the life cycle of a tapeworm infecting great
white sharks. J Parasitol. 97(2): 275-280.
4
1
But some parasites go further than merely staying
on the eye of a shark. Ommatokoita elongata is
yet another parasitic copepod, but one that looks
completely different to Pandarus and Caligus.
Whereas those species have at least a passing
resemblance to their free-swimming cousins,
Ommatokoita looks more like a dangling piece
of fleshy jewellery. It lives partially embedded
in the eyes of the Greenland Shark Somniosus
microcephalus and instead of suction cups or
www.sharktrust.org
Tale of the tapeworm
3
Shark Focus 52
Shark Focus 52
www.sharktrust.org
5
Shark eggcases
from deep time
These specimens could be divided into a small
number of form genera based on their structure.
The most common was Palaeoxyris, a spindle
shaped object with spiral bands, often presenting
as a ribbed diamond pattern, narrowing to a
‘beak’ at one end and a longer pedicle (tail) at the
other. Not so common were Fayolia with spiral ribs
showing scar lines, and Vetacapsula comprising a
bulbous body with parallel ribs running from beak
to pedicle. Specimens have been found from the
Late Carboniferous Period (310 million years ago)
to the Lower Cretaceous Period (140 million years
ago) in Britain, Germany, France, Kyrgyzstan, North
America and Australia.
Graham McLean
Studying the structure of ancient eggcases leads
to the question “how are modern shark eggs
formed?” In 1996 Knight and his colleagues in
Britain explained that the shell gland of a modern
shark is positioned above and in line with the
uterus1. Two lines of spinnerettes (tiny nozzles)
within this bulbous gland extrude two parallel
sheets of collagenous material which progress
along each inner side of the gland. The two
sheets are bonded at the edges and a jelly fills the
structure which resembles an inflating ’pillowcase‘.
While the ‘pillowcase’ is open the fertilised ovum
enters and the eggcase continues to form around
the ovum until it is closed and bonded at the
other end. Tendrils or horns are formed from the
corners of the collagenous sheets (or bands) at the
beginning and end of extrusion. The result is the
familiar skate eggcase structure, the “mermaid’s
purse”. But why does the bullhead shark eggcase
look so different? If this “mermaid’s purse” structure
is taken and twisted during its production the end
result is a spiral screw shaped object comprising
two bands whose overlapped and bonded edges
form collarettes. However, the ancient Palaeoxyris
eggcases appear to have four or even six bands.
This leads to conjecture that ancient egglaying
sharks had shell glands that were divided into four
or six sections, not two as in modern sharks.
Participants in the Great
Eggcase Hunt are gathering
valuable information about
the abundance, species
distribution and reproductive
habits of modern sharks, skates
and rays. Palaeontologists,
too, are carrying out their
own shark eggcase hunt back
into deep time, with the same
aims. Which environments did
ancient sharks inhabit? What
were their breeding practices?
Were sharks the first fishes to
have penetrative sex? Fossils
provide some fascinating clues.
Fossilised eggcases
Strangely shaped, enigmatic fossils have been
discovered by palaeontologists over a long period.
In 1828 Brongniart, a French natural scientist,
described and named a 230 million year old,
regularly patterned fossil as Palaeoxyris regularis,
stating it was probably a plant flower spike. The
specimen resembled a cone that you might
find in a pine forest, with a diamond pattern
of “scales” impressed upon its spindle shaped
body. In the ensuing years similar fossils were
found and some scientists began to question
their plant origins. In 1867 Schenk noted that, if a
spirally wound object was crushed flat the spirals
at the back would be impressed at an opposite
angle onto the spirals on the front, creating a
diamond pattern. If this was the case for these
enigmatic fossils, the original object would be
constructed of spiral bands similar to the eggcases
of the bullhead sharks (e.g. the Port Jackson
Shark Heterodontus portusjacksoni found on the
east coast of Australia), and these fossils could
therefore be shark eggcases. However, this view
was not generally accepted until the 1920’s when
Crookall, of the Museum of Practical Geology
(now within the Natural History Museum, London)
presented a series of studies of specimens found
in the Carboniferous Coal Measures of Britain and
Europe, dating from around 310 million years ago.
He stated that “the obvious comparison is with the
egg-cases of Elasmobranchs”.
6
Ancient sharks
If these fossilised objects were eggcases of ancient
sharks, what did the sharks look like? There is
fossil evidence of sharks – mainly teeth, fin spines
and scales – from the Late Devonian Period of
the Palaeozoic Era (from about 380 million years
ago). From rare impressions of their cartilaginous
skeletons, these early fishes were shown to have
broad, immoveable pectoral fins that acted as
hydrofoils, an upper jaw firmly fixed to the skull
and the males had claspers for internal fertilisation.
Palaeozoic sharks could be identified by the
cusp structure of their teeth. One genus, the
Xenacanthus [see image 2] reached a length of 1.5
metres, had an eel-like tail and a large dorsal spine
just behind the head.
1
PHOTOS
Main image: The shale slab containing two
Australian shark eggcase fossils of Palaeoxyris
duni (courtesy of the Geological Survey of New
South Wales).
Image 1: A line tracing of the Palaeoxyris duni
fossils with a sketch of their idealised structure
© Graham McLean.
Image 2: The ancient xenacanthid shark,
Xenacanthus sessilis (after Schaeffer and
Williams 1977:297, by permission of the Oxford
University Press).
Image 3: The ancient hybodontid shark,
Hybodus (after Schaeffer and Williams 1977:300,
by permission of the Oxford University Press).
www.eggcase.org
1
Shark Focus 52
A second radiation of sharks commenced in the
Carboniferous Period (from 360–229 million years
ago). This evolutionary development contained the
family of hybodontid sharks [see image 3] which
had a similar general appearance to some modern
sharks, with two dorsal fins – each with a leading
edge fin spine, advanced mobility of pectoral
fins which allowed steering, an asymmetrical tail
which provided forward and upward thrust and a
fixed jaw with dentition that allowed piercing and
crushing. The hybodontid sharks are thought to be
the egg producers of Palaeoxyris.
Shark Focus 52
The third evolutionary radiation of sharks occurred
in the Jurassic Period (from 200 million years
ago) and provided our modern sharks with their
overhanging snouts, hyostylic jaw suspension that
allows jaw protrusion during attack, thicker and
more complex tooth enamel to handle large prey,
and fused placoid scales that provided flexible
external armour. Skates and rays also evolved
during this radiation.
2
Ancient environment and
behaviour
3
In the early 21st century palaeontologists in Europe
and North America were gaining considerable
knowledge of ancient shark eggcases and were
using modern analysis techniques to discover clues
to the behaviour of the ancient egg producers.
Fischer and his colleagues in Germany discovered
eggcases in Kyrgyzstan in association with juvenile
shark teeth microfossils2. Oxygen isotopic analysis
of the teeth enamel indicated that the juvenile
sharks developed in fresh water. A study of plant
and animal fossils associated with many shark
eggcase fossils indicated the eggs had been
deposited in freshwater or brackish lagoonal
environments. In one example, five eggcases
were bunched together by their ‘beaks’. Another
was attached to a piece of wood. It appeared that
ancient sharks deposited their eggs in shallow
freshwater rivers and coastal lakes, possibly in
nurseries. These sharks either lived in a freshwater
environment or came from a marine environment
into coastal freshwaters to breed.
Most discoveries of shark eggcase fossils have
been made in the northern hemisphere. One
discovery was made in Australia in 1912, but was
subsequently misplaced due to the uncertainty of
its origins. One hundred years later it was located
and described by McLean in 20143. This single
southern hemisphere specimen was a small shale
slab containing two Palaeoxyris eggcases. It was
found in a Triassic shale deposit in the Sydney
Basin being quarried for bricks and was 230
million years old. The shale was laid down in a still
backwater that was within a freshwater, braided
river environment close to the sea. This was a
similar environment to that in which many of the
northern hemisphere specimens were found. At
that time Australia was part of Gondwana and the
Sydney Basin had drifted within the Antarctic Circle.
There was no ice at the poles and the climate was
cool-temperate. The modern Port Jackson Shark
that inhabits the marine waters of the Sydney
Basin now lays spirally banded eggs in shallow,
rocky, algae covered nurseries near the coast
and in Sydney Harbour. They have been tracked
on annual feeding migrations from Sydney to
Tasmania, a distance of 850km, returning to breed
in their chosen nurseries. It is interesting to imagine
ancient hybodontid sharks returning to the Sydney
Basin in the long days of the Antarctic summer to
swim up the coastal rivers to a quiet backwater, lay
their spiral eggs and anchor them to underwater
vegetation with the tendrils trailing from the ‘beaks’,
then migrating north again as the long nights
close in and their food sources migrate north also.
Meanwhile, the young sharks gestate over the
winter, safe within the eggcases, and emerge into
the Antarctic Spring.
www.eggcase.org
So, the big question still is – at what evolutionary
stage did the ancestor of ancient sharks develop
internal fertilisation? There is still no direct evidence
of the origins of this breeding strategy. But an
important discovery was made by the Australian
palaeontologist Long and his colleagues in 20084.
While studying a well preserved fossil fish of the
placoderm group from an ancient Devonian
reef formation at Gogo, Western Australia, they
discovered a tiny embryo in the uterus, complete
with mineralised umbilical cord. This 380 million
year old fossil was direct proof that this armoured
fish, not known to be in a direct evolutionary line
with sharks, also carried out internal fertilisation.
Further, subsequent examination of other
placoderm fossils revealed spiky structures on the
pelvic girdles of males for insemination. These were
equivalent to the claspers of sharks. Did sharks and
placoderms have a common ancestor? How did
land vertebrates such as reptiles and mammals
develop internal fertilisation when they came
through the evolutionary line of lobe finned fishes
which were external fertilisers? Do all vertebrates
carry genes for internal fertilisation which are
suppressed in some lines and expressed in others?
Long and his colleagues are working on these
intriguing questions.
Glossary
Placoderm – extinct class of armoured fish
Shell gland – found in female elasmobranchs;
involved in the secretion of eggcases.
Hybodontid – extinct group of Elasmobranchs
(sharks, skates and rays) which existed from the
Devonian to the Cretaceous Period.
Hyostylic jaw – an upper jaw fixed to the braincase
at the back only (unlike in ancient sharks).
Placoid scale – also known as dermal denticles –
‘shark skin’.
Collarettes - a spiral flange around a screwshaped eggcase formed by the overlapped
bonded edges of the eggcase bands.
Claspers – male reproductive organs in
elasmobranchs; also found on modern sharks.
References
1. Knight, DP. et al. 1996. Structure and function of the
selachian egg case. Biological Reviews of the Cambridge
Philosophical Society. 71: 81-111.
2. Fischer, J. et al. 2013. Egg capsule morphology provides
new information about the interrelationships of
chondrichthyan fishes. Journal of Systematic Palaeontology.
DOI: 10.1080/14772019.2012.762061, 1-11.
3. McLean, G. 2014. A comparative study of the Australian
fossil shark egg-case Palaeoxyris duni, with comments on
affinities and structure. Proceedings of the Linnean Society
of New South Wales. 136, 201-218.
4. Long, J. et al. 2008. Live birth in the Devonian Period.
Nature 453, 650 - 652.
7
NEWS
WORLD
SHARK NEWS
WORLDWIDE SHARK NEWS SINCE LAST FOCUS
NOV 2014

Atlantic fishery managers fail sharks yet again
Fishing nations at the annual meeting of the International Commission for the
Conservation of Atlantic Tunas (ICCAT) failed to reach consensus on several shark
conservation proposals, including a joint US-EU effort to establish catch limits for
heavily fished Shortfin Mako, and an EU bid to protect threatened Porbeagles.

Historic advances in international shark and ray conservation
Conservationists rejoiced at the listing of 21 species of shark and ray under the
Convention on Migratory Species (CMS). Member countries agreed to grant strict
protection to the Reef Manta, the nine devil rays, and the five sawfishes, and
committed to work internationally to conserve all three species of thresher shark, two
types of hammerhead and the Silky Shark.

Thousands of fossilised shark teeth found in Canadian Arctic
Shark Trust patron Steve Backshall supports the No Limits? campaign at Whalefest
© Richard Boll Photography.
Project NEPTUNE Porbeagle dissections
In early February, Conservation Officers John and Cat travelled to
Lowestoft, Suffolk to help Cefas (Centre for Environment, Fisheries and
Aquaculture Science) examine and dissect a number of dead bycaught
Porbeagle Lamna nasus landed under scientific dispensation, for the Cefas
led, Defra funded NEPTUNE (National Evaluation of Populations of Threatened
and Uncertain Elasmobranch stocks) project. Measurements and weights
were recorded for each shark, liver and muscle samples were collected
and the spiral valve, eye lenses, stomach, vertebrae, fins and heads were
retained for further study (including contaminant and microplastic research,
dentition research, age determination, population studies etc.). Historically,
the Northeast Atlantic supported a commercial fishery for Porbeagle,
however overfishing led to significant population declines and in 2010 a
zero TAC (Total Allowable Catch) was introduced, preventing landing. At the
2014 December Fisheries Council, Porbeagle were listed as Prohibited for EU
vessels, meaning that no landings for scientific research will be permitted
for the foreseeable future, and therefore the information collected from
these dissections is incredibly valuable.
South West Marine Ecosystems conference
In early March, Cat and John once again attended the annual Southwest
Marine Ecosystems conference at Plymouth Marine Laboratories (PML) and
contributed with a presentation on ‘Skate Populations in the Southwest’. The
conference provides a fantastic opportunity to learn more about marine
research that has been taking place in the Southwest region, as well as
assessing ecological and oceanographic observations over the past 12 months.
Whalefest
The Shark Trust was invited to put the ‘Whale Shark’ into Whalefest at this
year’s March event in Brighton. Guest speakers included not just one, but
three Shark Trust patrons with Steve Backshall, Monty Halls and Michaela
Strachan all taking to the stage. Ali and Paul set up stand in the Shark Zone
to try and tempt people over to the shark-side!
Marine Champions Beach Conference
The Shark Trust team joined the National Trust, Marine Biological Association
and National Marine Aquarium (NMA) at the Marine Champions Beach
Conference run by Devon Wildlife Trust in late March. The project (funded
by the NMA) aims to get school children from across Plymouth to become
‘marine wildlife champions’ by discovering more about marine life and
doing something positive to help protect it. Workshop themes for the day
included terrestrial pollution, plastic pollution, overfishing (run by the Shark
Trust), climate change and protection of the sea.
8
Researchers on Banks Island in the Canadian Arctic made an unexpected find: more
than 8,000 shark teeth dating back 38–53 million years. Most teeth belong to just two
shark genera, Striatolamia and Carcharias (both thought to be similar to a modern
Sandtiger Shark). Analysis of the teeth revealed that salinity of the coastal waters was
very low at the time, much closer to freshwater than that of a modern ocean.
DEC 2014

Western Australian beach culture is changing
Following a series of fatal shark incidents, beachgoers in Western Australia (WA) are
swimming closer to shore than ever before, while many now restrict swimming to
daylight hours only. Swimmers are also mimicking the behaviour of dolphins and seals by
swimming in groups. Surf Life Saving WA noted these changes have taken place alongside
greater awareness about shark sightings, live Twitter feeds and aerial shark patrols.

Shortfin Mako washed up on North Wales beach
A 10ft Shortfin Mako shark was discovered dead on Barmouth Beach, in North Wales.
Although a seasonal visitor to British waters, it is unusual for Shortfin Mako to enter
coastal waters. Before being disposed of by the local council, a researcher from the
UK Stranding Investigation Unit removed the shark’s eyes, internal organs and skin for
analysis.

Video of rare deep-sea shark blows researcher’s mind
While watching hours of deep-sea video – as part of a project documenting the marine
biodiversity of the Russian High Arctic region – a researcher unexpectedly spotted a
Greenland Shark. Measuring about 6.5ft, the shark was sighted in Franz Josef Land, a
group of 192 islands north of the Barents Sea. Filmed at 211m depth, this was the first
time the elusive, poorly understood species has been recorded so far north-east.
JAN 2015

New research paints picture of Salmon Shark diet
An experimental process analysing isotopes from Salmon Sharks’ vertebrae has allowed
scientists to see what the sharks ate during each year of their life, and where they ate
it. The research revealed some sharks which hunted in Alaskan waters then turned up
much further south in Monterey Bay, California. Electronic tagging was also employed
in the study, to develop a more elaborate picture of the sharks’ travels. The information
could be used by fisheries managers to set regulations to protect the species.

Basking Shark recorded in Indonesian waters for first time
Shark Policy
High-seas highs and lows
High expectations
It is now widely recognised that coastal waters
are home to some of the world’s most highly
threatened species, including large, flat-bodied
sharks such as the Angelshark Squatina squatina,
as well as sawfish and large-bodied skate. These
species demand urgent attention, the instigation
of recovery plans and wider stakeholder
engagement to ensure population declines
are halted and regional extinctions reversed.
Further offshore, high-seas pelagic fisheries place
massive pressure on shark population, many of
which continue to be caught with no limits. From
2000-2012, over one million tonnes of sharks were
reported landed by the EU fleet worldwide. 88%
of these were caught in the Atlantic.
Following on from the successful CMS CoP there
was high expectations for the RFMOs to adopt
effective management for shark fisheries. The
Trust supported activities at a number of RFMO
meetings including the Northwest Atlantic
Fisheries Organisation (NAFO), the North East
Atlantic Fisheries Committee (NEAFC) and the
International Commission for the Conservation
of Atlantic Tuna (ICCAT). Outcomes from these
meetings were disappointing although, positively,
NEACF became the first Advisory Committee to
adopt a ‘fins-attached’ regulation. There was an
increasing level of support for fins-attached at
ICCAT with the EU co-sponsoring the proposal.
However, this was blocked by Japan and China;
similar disappointment ensued from NAFO with
Japan and Korea blocking in this instance.
Certain pelagic, open-ocean sharks such as
Porbeagle Lamna nasus, Oceanic Whitetip
Carcharhinus longimanus and the Scalloped,
Smooth and Great Hammerheads Sphyrna spp.
have gained increasing attention, management,
and even protection, over the last six months
with positive outcomes from the Conference of
Parties of the Convention on the Conservation
of Migratory Species (CMS CoP Quito, November
2014). This coincided with the implementation of
the 2013 shark listings on the Convention on the
International Trade in Endangered Species (CITES)
which came into force in September 2014.
Meanwhile, Shortfin Mako Isurus oxyrinchus and
Blue Shark Prionace glauca continue to be caught,
unrestrained by catch limits or management of
any nature. The Shark Trust’s No Limits? campaign
is advocating for an end to uncontrolled shark
fishing. A key route to securing this is through the
high-seas management bodies – the Regional
Fisheries Management Organisations (RFMOs),
many of which hold their annual meetings over
the autumn/winter period.
1
A 2013 stranding of a Basking Shark in Bali was confirmed as the first record of the
large, filter-feeding species in Indonesian waters. The adult male was found on
Klatakan Beach, 9km south of Gilimanuk Harbour. Researchers suggest the Indonesian
Throughflow – the warm ocean current moving water from the Pacific to the Indian
Ocean – may be an important route for the species during trans-equatorial migrations.
Why the shark stranded, and its origin, remain unknown.
FEB 2015

Tiger Sharks are big movers
Generally considered a tropical species, researchers tagging Tiger Sharks off Western
Australia (WA) have uncovered extraordinary details about the species’ movements.
One shark tagged off Ningaloo (on the north-west coast of WA) swam more than
4000km over 517 days, migrating between Indonesia and Esperance (on the southern
coast of WA). The tags showed that the sharks dived as deep as 300m in tropical
waters, though they stayed closer to the surface the further south they went.
2

White Sharks grow more slowly and mature much later than previously thought
Findings from a new study into Northwest Atlantic White Sharks found males sexually
mature around age 26 and females around age 33 – significantly later than currently
accepted estimates of 4–10 years for males and 7–13 years for females. These new
estimates could lead to new assessments of population replacement rates that are
much slower than those used in the past. The new information suggests White Sharks
are more sensitive to fishing pressure than previously thought.
www.sharktrust.org/news
Shark Focus 52
Shark Focus 52
The EU has the potential to be highly influential
within these RFMOs and is actively promoting
the adoption of a ‘fins-naturally-attached’ policy.
However, each failure to secure wider adoption of
a blanket policy results in increasing discontent
within sectors of the Spanish and Portuguese
fishing industry, who are calling on the EU
Commission to revoke the finning regulation as
discriminatory against their vessels. The Shark
Trust is closely monitoring and responding to
the current situation, and is working to ensure
that there is a clear understanding as to the vital
importance of continued EU support for finsattached as best practice.
Closer to home
Europe: Each December EU Member States meet
to discuss fishing opportunities for the coming
year and the 2014 December Fisheries Council
saw a greater than usual number of elasmobranch
(all sharks, skates and rays) proposals presented
by the European Commission. This increase
in activity was due in part to the impending
Pelagic Discards Ban (known as the ‘Landings
Obligation’), which commenced in January 2015.
The Landings Obligation requires the retention of
any quota species; however if that species has no
quota (due to a zero Total Allowable Catch [TAC])
then things become further complicated with
the potential for a single capture to temporarily
close, or ‘choke’, a fishery. Zero TAC species
such as Spurdog (also known as Spiny Dogfish)
Squalus acanthias and Porbeagle came under this
category. The Commission’s suggested solution is
to propose a list of species for ‘Prohibited’ status
– an appropriate approach for some species such
as Porbeagle, sawfish and the mobulid rays. But
it was felt that species such as Spurdog would
greatly benefit from a more pragmatic solution
– something (due to the potentially high level of
bycatch) that the Trust is pleased to be working
on as part of a government and industry led
initiative.
Undulate Ray Raja undulata management has
been evolving over the past 18 months with
the species migrating from a Prohibited status
to a zero TAC in late 2013 with a view to the
eventual reintroduction of a precautionary
bycatch fishery. At the time of writing, a final
decision was yet to be made with regards
the permitted level of bycatch retention for
2015, but with clear recommendations for
precautionary management presented by the
European Commission’s own Scientific, Technical
and Economic Committee for Fisheries (STECF),
and reinforced with advocacy from the UK
government and the Shark Trust, we have strong
hopes that the precautionary position will be
respected.
The demersal landings obligation is now under
consultation and the Trust will be urging the
UK Government and the European Commission
to take a strong position on species with a
high discard survival rate, with a view to seeing
bycaught elasmobranchs promptly released.
3
PHOTOS
Main image: 2015 Commercial Fisheries Advisory.
Image 1: Shortfin Mako. © Charles Hood.
Image 2: Great Hammerhead. © Jillian Morris.
Image 3: Undulate Ray Raja undulata © Cat Gordon.
www.sharktrust.org/policy
9
Supporter’s page
In Memorial to Adam Miller: July 1982 – November 2014
“On 13th November 2014 Adam passed away. As a young boy Adam was always
looking for the next stimulation, be that swimming, rugby, judo, or Taekwondo.
Highly proficient at school, this continued as he prepared for a future at university
studying Computer Science. Adam attained a Masters 1st Honours and went on to
work as a developer in the games arena.
In December 2011 and for a variety of reasons Adam resolved to tour the world
departing the UK for Australia, Tasmania, New Zealand, Nepal, Everest Base Camp,
South America…to name a few.
Adrenalin became the buzz word, bungee, climbing, running, Great White Shark
cage diving, hiking across Tasmania and walking the hard way to Everest Base Camp
– much of it achieved with mates from the UK who had joined him on the journey,
or for at least parts of it.
On 22 May 2012 Adam followed in his father’s footsteps and took his first dive
in Bali. After attaining Divemaster in the Gili Islands, followed by Instructor in the
Maldives, his “epic” journey into Technical Diving was completed in Dahab, Egypt
with Team Blue Immersion on 5th September 2013. “Free time” consisted of planning
future dive expeditions, running in the hills (mountains) outside of Dahab and
becoming an integral part of the Dahab community.
Adam was recognised as a great person, a true friend, someone that always
thought of and put others before himself, a great dive guide and instructor down
to 130 feet and someone that was destined to become recognised as a leader in
the tech diving community. Adam lived the last three years of his life true to his
values, following his dream, changing the people that he touched with his passion,
charisma and personal attitude.
Sadly his journey was cut all too short due to a congenital condition of the heart
that neither he nor his family were aware of, and on 13th November 2014 Adam
passed away of critical heart failure whilst out on his early morning run in the
hills around Dahab. Adam would not have wished for flowers or other tributes
Powerful parasites
sh open some minds on another
tal-based Blowfish here, about to sma
Hi guys and gals, it’s your friendly coas
t sharks are to the ocean’s
s! Now, we all know just how importan
marine matter of extreme awesomenes
y of you realised that sharks are also
food webs and biomes, but how man
ecosystems, forming a key feature in
a perfect place to call home. These
als, the body of a large shark or ray is
their own environment? To some anim
their survival is entirely linked to the
or pesky cling-ons, but friend or foe,
parasites can be friendly hitchhikers
oldest ocean predators.
great moving bodies of this planet’s
Firstly, we have to talk about the
remora, AKA the shark sucker. You
will have seen this streamlined
fish attached to many a shark or
large ray. Whale Sharks are usually
swarming with them! But how do
they keep up with their moving
home? Well the remora has a clever
ra has evolved into a
trick under its hat. The head of a remo
o at left] that allows
phot
the
out
muscular suction disc [check
of the host without any
the fish to stick directly onto the body
remora is so strong,
a
of
ion
excess energy wasted. The suct
Ocean use them to
n
India
the
that indigenous fishermen in
around the tail of the
rope
a
tying
catch sea turtles. By carefully
rapidly shoots
fish
the
d,
boar
remora before releasing it over
then carefully
rmen
fishe
The
on.
es
towards the turtle and latch
hed.
-2.0).
attac
BY-NC
h
(CC
Bryant
reel in the remora and the catc
Remora AKA the shark sucker. © Kevin
The Blowfish
nd
Having a passion for shark conservation, his social communications often cited
latest events in the natural and political environment of the shark world. Adam
would have continued his diving passion, probably living on a research vessel as a
dive consultant, using his technical diving skills to the benefit of research teams in
understanding the marine environment and, in his own way, impacted in a positive
manner the future of the shark.
Pup’s activity zone
Image © Miller family.
at his passing, his family believed however that donations to
shark conservation would be a fitting way in which to close the
final chapter in the book of Adam’s life, and therefore the family
nominated the Shark Trust to be the beneficiary of any donations.
His family and the Shark Trust would like to thank all those that
donated and know that Adam would be immensely proud of the
difference that his passing has made in helping the world of the shark.”
To date, £4,000 has been raised in memory of Adam.
Dr Eugenie Clark
rays that
Remora don’t really bother sharks or
the fish
of
ing
shift
tant
much, in fact, the cons
other
dge
dislo
help
can
over the sharks body
ile
mob
a
iding
prov
as
skin parasites. As well
et
buff
at
an-e
ou-c
home, it’s also an all-y
the
for the remora – not only do you have
of the
any
from
s
scrap
chance to feed on the
food
the
y
enjo
also
shark’s catches, you can
k… Yes.
again, on its way back out of the shar
Remoras eat poo.
Remora attached to a shark © Scubaben (CC BY-NC-2.0).
There is another parasite you may
know of, and this one is far less
e
obvious than the shark suckers. Ther
d
calle
an
tace
is a small white crus
Ommatokoita elongate, catchy name
eh? This tiny little creature attaches
itself to the eyes of the massive
Greenland Shark, often causing the
shark to go blind. Scientists are still
attempting to fully discover exactly
what this little eye-biter does! One
thing we do know is that it glows in
the deep dark, giving the Greenland
Shark a ghoulish gaze and perhaps,
enticing curious prey towards the
k.
green light and the teeth of the shar
Dr Eugenie Clark, a globally renowned marine biologist and expert on sharks, died at her
home in Florida on 4th March, at age 92. After earning a master’s degree in 1946, Clark went
on to complete a doctorate in 1950. In 1955 Clark was a founding director of Mote Marine
Laboratory in Sarasota, Florida – now an internationally renowned centre for shark research
– and remained a trustee until recently. In a career spanning 75 years, Clark also taught
marine biology at the University of Maryland from 1968 until her retirement in 1992.
Before Clark began her research career in the 1950s, the public perception of sharks largely
assumed the animals to be completely unintelligent and deadly. But as Clark noted in a
National Geographic interview “After some study I began to realise that these ‘gangsters of
the deep’ had gotten a bad rap.” Following this, much of Clark’s work focussed on dispelling
public fears and myths about sharks, particularly after the 1975 release of Jaws.
In addition to significant academic achievements, Dr Clark was also a figure of popular
culture, writing for National Geographic, appearing on programmes with Jacques Cousteau
and writing popular books including ‘Lady with a Spear’ (1953) on her explorations in
Micronesia and the Red Sea, and ‘The Lady and the Sharks’ (1969). Sonja Fordham, a former
student of Clark’s, and president of the Washington DC-based non-profit Shark Advocates
International wrote “She was a role model for women, not only as a scientist but as a
fearless adventurer.”
10
www.sharktrust.org
The mysterious Greenland Shark. ©
NOAA.
Mote Marine Laboratory and Aquarium © Walter (CC BY 2.0).
Inset: Eugenie Clark © U.S. Department of Labor.
Shark Focus 52
Shark Focus 52
www.sharktrust.org/juniors
11
Biology, fisheries
and recent studies
on the Common
Thresher Shark
off the coast of
California
The Southern California Bight
The Southern California Bight (SCB) is a productive
region of the eastern Pacific that seasonally
supports dense aggregations of sardines Sardinops
sagax, Northern Anchovies Engraulis mordax, and
Chub Mackerel Scomber japonicas. Consistent
sources of prey within the SCB make the area an
important foraging and nursery ground for several
pelagic shark species, including Blue Sharks Prionace
glauca, White Sharks Carcharodon carcharius,
Shortfin Mako Sharks Isurus oxyrinchus, and thresher
sharks Alopias spp. The SCB is particularly important
for the Common Thresher, a species that uses
the area as both a feeding and pupping ground.
During the spring months adult female threshers
migrate through the waters of the SCB carrying 2–4
offspring. The pups are born at a large size (>1.25m
total length) and typically inhabit inshore waters
along the continental shelf (<200m depth).
Previous tagging studies have demonstrated that
juvenile and sub-adult Common Threshers typically
inhabit inshore waters, making relatively small
seasonal migrations along the coast in response to
changing water temperatures and prey availability.
Once they approach sexual maturity, the sharks
begin larger scale migrations that extend into
higher latitudes and colder water temperatures.
The precise movements of these migrations are
not known; however, over the course of a year
Common Threshers can be found along the coast of
North America, from southern Mexico to Canada.
Chugey Sepulveda, PhD
and Scott Aalbers, MS
Pfleger Institute of Environmental Research (PIER)
This work was made possible through the George T.
Pfleger Foundation and the NOAA Bycatch Reduction and
Engineering Program.
Additional support was provided by the Harris Foundation
and the NOAA Southwest Fisheries Science Center. To read
more about PIER research visit www.pier.org.
Fisheries
Common Thresher caught as part of PIER/NOAA project
© PIER/NOAA.
The Common Thresher Shark Alopias vulpinus belongs to a unique group of sharks
(Family Alopiidae) that use their caudal (tail) fin for both locomotion and to stun
prey. The elongated caudal fin enables the Common Thresher, and presumably
the other two thresher species (A. pelagicus and A. superciliosus), to successfully
prey on the likes of anchovies and other small schooling fishes. Evidence for their
feeding strategy has historically been in the form of gut content studies and reports
of capture by the caudal fin. More recently, video records of feeding in the wild
have highlighted threshers’ use of their caudal fin to stun prey1. While this unique
adaptation has enabled thresher sharks to fill a distinct ecological niche, the use
of the caudal fin to stun prey may be disadvantageous for Common Threshers
captured in recreational fisheries. The capture of large pelagic sharks by the tail is
problematic given their need to swim forward in order to extract oxygen from the
water through ram ventilation.
Given the susceptibility of most elasmobranch species to overexploitation, recent
trends in recreational fisheries have moved towards the use of ‘catch and release’
fishing activities. Although catch and release has been shown to be an effective
management strategy for many species around the world, conservation goals can
only be met if the fate of released individuals is known and survivorship is high.
For this reason, the Pfleger Institute of Environmental Research (PIER), a nonprofit research institute in Oceanside, California teamed up with partners from the
National Oceanic and Atmospheric Administration (NOAA) to address important
questions regarding the post-release condition of thresher sharks caught in
California’s recreational fishery.
12
www.sharktrust.org
Common Thresher
caught as part of
PIER/NOAA project
© PIER/NOAA.
Shark Focus 52
Off the U.S. West Coast the primary commercial
fishery for the Common Thresher is the
California drift-gillnet fishery (DGN). In the 1980s
the Common Thresher fishery supported a
relatively strong market, with over 1,800 tons
harvested by local vessels fishing off the coast
of California. As catch rates declined – likely the
result of overexploitation – fisheries managers
implemented seasonal area closures to protect
pregnant females during the pupping season. In
subsequent years, changes in market dynamics
and consumer demand have reduced Common
Thresher marketability, forcing the price to historic
lows. Given the reduced demand and low market
price, the DGN fleet has subsequently moved
away from targeting this species directly, despite
the presence of a rebuilding population.
The Common Thresher also supports vibrant
recreational fisheries that target all age-classes
using a variety of tackle and techniques. The most
notable recreational fishery occurs in the spring
months off Southern California, when large (150
to 250kg) adults filter through the coastal waters,
with many of the large females carrying young.
With the rebuilding of the Common Thresher
population, recreational landings nearly tripled
from 2006 to 2009, with more and more anglers
fishing for the species. Although many of the
sharks captured on recreational fishing gear
are subsequently released, it is not possible to
quantify the impact recreational fishers have on
the population without information on postrelease condition of the sharks.
Shark Focus 52
Common Thresher mouth-hooked ©
PIER/NOAA.
Survivorship studies
highlighted the need to reduce fight time if the
intention was to release the shark2.
To address the effects of capture stress on Common
Thresher Sharks, PIER scientists teamed up with
regional fishery managers. The focus of the work
entailed a three-phased project that examined
post-release condition, in what the team considered
to be the main sources of recreational fishery
mortality. Phase I focused on the traditional angling
method, which uses trolling techniques and heavy
lures with baited “J” hooks to target Common
Threshers by their caudal fin. This method typically
targets larger sharks in waters deeper than 200m
in the spring and early summer months. Phase II
was aimed at understanding post-release mortality
in threshers that are unintentionally broken off
or lost during the fight, a situation that results in
the released shark swimming away with gear left
embedded in their caudal fin. Angler surveys and
anecdotal accounts suggest that this is a common
occurrence in the fishery, given the large size of
some sharks and the immense force generated by a
tail-hooked individual. Lastly, Phase III concentrated
on assessing the post-release condition of sharks
that are hooked in the mouth, using circle hooks
and angling protocols commonly used by several
Southern California angling clubs.
Phase II focused on assessing post-release
condition in sharks that are unintentionally
released in the troll fishery. Initial surveys identified
trailing gear (i.e., hooks and terminal gear left
embedded in the caudal fin) as a prevalent issue
in the troll fishery. Given that thresher sharks use
the caudal fin for both locomotion and feeding,
it was hypothesised that trailing gear could be
lethal, especially if accompanied by long pieces of
trailing monofilament. Using recreational fishing
techniques commonly employed off Southern
California, terminal tackle was left embedded in
the caudal fin of tagged thresher sharks. Tagged
individuals with trailing gear revealed heightened
post-release mortality rates, with the majority of
sharks dying within five days of release. This work
was coupled with Phase III3.
Results
This study used angler surveys to document the
most common gear used in the thresher shark
troll fishery off Southern California and employed
similar techniques to target a size range of
Common Threshers that were representative of the
fishery. Post-release condition was determined with
Pop-up Satellite Archival Tags (PSATs) that record
information on depth, temperature and light
intensity at regular intervals over a set duration of
time. PSAT technology has been used in dozens
of studies to assess post-release condition and
provides a reliable way to document movement
patterns. From this work it was determined that all
sharks with short fight times survived, regardless
of size or condition. All individuals that spent more
than 85 minutes on the line died shortly after
release (1–4 days), most likely in response to the
capture stress and oxygen deficiency caused by the
inability to effectively breath using ram ventilation.
Findings from this work were used to sculpt a best
fishing practice manual that was disseminated to
fishing clubs and the general public. The brochure
www.sharktrust.org
Phase III of the thresher shark survivorship work
was focused on developing recreational fishing
techniques to reduce post-release mortality. The
study used circle hooks and sport gear to capture
and tag mouth-hooked individuals. Unlike previous
trials, this work revealed 100% survivorship,
confirming that thresher sharks are capable of
tolerating catch and release fishing when hooked
in the mouth and allowed to ram ventilate during
the fight. Collective findings were incorporated into
a final ‘best fishing practices’ brochure for thresher
sharks and widely publicised among anglers and
interested groups around Southern California.
Overall, these studies have successfully shown how
fisheries managers can team up with non-profit
research institutes, like PIER, to perform focused
research that improves public awareness and
provides the necessary information for sustainable
fisheries management.
References:
1. Aalbers SA. et al. 2010. The functional role of the caudal
fin in the feeding ecology of the common thresher shark
Alopias vulpinus. Journal of Fish Biology 76:1863-1868.
2. Heberer C. et al. 2010. Insights into catch-and-release
survivorship and stress-induced blood biochemistry of
common thresher sharks (Alopias vulpinus) captured
in the southern California recreational fishery. Fisheries
Research 106 (3): 495-500.
3. Sepulveda CA. et al. 2014. Post-release survivorship studies
on common thresher sharks (Alopias vulpinus) captured
in the southern California recreational fishery. Fisheries
Research. 161: 102–108.
13
Sharks4Kids:
3
2
spreading shark education to students
around the world
Jillian Morris
Sharks4Kids
I was recently asked if there was one thing I could do to change the world, what
would it be? My answer…I want to empower and inspire kids to speak up and
realise they have a voice, and they can make a difference. I genuinely believe
that kids can save sharks and Sharks4Kids was created out of this belief and the
desire to provide kids around the world with the tools to make a difference!
I have spent a lot of time studying sharks, diving with them and filming them
around the world, so stepping into the classroom to share these stories was a
natural progression. I teamed up with my husband Duncan Brake, an extremely
talented cinematographer and my best friend Dr. Derek Burkholder, who did his
PhD in shark ecology. We worked for nearly two years to combine science and
media to create curriculum, teaching guides, videos, activities and a format to
deliver them on. The main goal was to get shark education into as many schools
as possible, by not only offering classroom presentations, but also providing
materials and guides for teachers. Sharks are often seen as very intimidating,
so we wanted to create resources that would break stereotypes and not only
engage students, but also get educators excited about sharing the information
with their students. Whether you live on the beach or 3000 miles from the coast,
shark education matters.
Encouraging future shark scientists
In June 2014 we headed to Guelph, Ontario for our first official Shark Tour. Our education director
Joe Grabowski coordinated the fundraising and logistics and we were able to speak to over 5000
students at 20 different schools. This landlocked community in Canada was extremely supportive and
welcoming and we are thrilled to now have thousands of junior shark advocates spreading the word
and doing their part to save sharks. We are currently working on several tours in the United States for
later this year. It is powerful to see how a 30–45 minute presentation can change the way people see
sharks and how they feel about them.
Our mission statement is to create the next generation of shark advocates through education, outreach
and adventure, so we are working to get more students on, and in, the water. We have teamed up with
Force-Divers and South Florida Diving Headquarters to run our shark snorkelling trips for kids, which have
been an absolute blast. Derek does a shark biology and conservation lesson and then everyone gets
to snorkel or dive with Nurse Sharks. Later this year we will also be funding student shark tagging trips
with Nova Southeastern’s Guy Harvey Research Institute, as well as shark encounters for kids throughout
the Bahamas.
1
Each of us in Sharks4Kids has a science degree, so this has played an integral role in our desire to
introduce students to a wide range of shark and ray scientists around the world. Science is at the heart
of conservation, but is often not translated to the general public. We want kids to have a favourite
shark scientist just like they might have a favourite basketball player, especially young girls. As the only
female on the team, I especially want to encourage girls to explore science as a career – including shark
science and shark diving! Each week we share a blog about a scientist or conservationist and the work
they are doing. As a young girl growing up in a small town in Maine, I admired Dr. Sylvia Earle and Dr.
Eugenie Clark, but didn’t really know about any other female scientists.
Living on the island of Bimini, home to the Bimini Biological Field Station (the Sharklab) and some of
the world’s best shark diving, is ideal for creating new and engaging shark education materials as well
as working with the local schools. Through our Sharks4Kids program we have done several school
visits as well as two documentary shoots, taking kids out into the field to encounter the sharks that
are literally found in their back-yard. We have also teamed up with the Sharklab to teach kids around
the world about shark science using Skype. During our teaching sessions we bring a Nurse Shark
Ginglymostoma cirratum into the lab and keep it in a large oxygenated tub. Nurse Sharks are extremely
hardy, so we are able to safely transport the shark and do a work-up for the students, including length
measurements, DNA and stable isotope sampling and tagging. The students also learn about the
general biology of sharks and why this type of science is so important for shark conservation.
Skype sessions
14
www.sharktrust.org/juniors
5
3
Bimini Shark Summit
PHOTOS
Skype has become an invaluable tool in education and in 2014 Derek and I were able to connect with
over 16,000 kids in 40 US States and 24 different countries. In 2015 we have already reached another
five new countries and three new States. Our Skype sessions offer a wide range of topics including
shark tagging and science, shark diving and underwater photography/videography, shark diversity and
adaptions, shark biology and ecology, with all lessons emphasising shark conservation. Whether we
are speaking with orphans in Kenya or middle-school students in Ohio, the message is the same no
matter the topic: we want kids to realise the devastation happening to shark populations, understand
why sharks need their help and ways they can help. We encourage students to get creative in their
delivery of the message to save sharks, which has yielded incredible shark posters and artwork as well
as projects and videos. It is amazing to see how excited they get and how passionate they quickly
become about saving these animals. One of my favourite posters came from a four year old from Perth,
Western Australia, which simply said, “Don’t kill sharks because children want to see them.” We love the
simplicity and power of this statement.
4
Main image: Jillian speaking to students in Canada as
part of the 2014 Sharks4Kids Shark Education Tour ©
Dony Zaidi.
Image 1: Jillian happy with her shark friends in the
Exumas © Duncan Brake.
Image 2: Skype class with Sharks4Kids © Jillian Morris.
Image 3: Jillian and Duncan with students in Bimini.
© Lisa Wallace.
Image 4: Jillian and Sharklab manager Rachael Cashman
doing a shark ‘work-up’ over Skype © Chris Lang.
Image 5: Duncan and Jillian at the sshark mural in Bimini
painted by students at Louise MacDonald High School.
© Lisa Wallace.
Image 6: Duncan and Derek with students on a Shark
Snorkel in South Florida © Nikole Ordway-Heath.
Shark Focus 52
6
We recently took part in a Shark Summit here in Bimini. Bimini was selected as a model to show other
countries in the Caribbean why protecting sharks is important and how valuable it can be on numerous
levels. Global estimates have established a range of values, but all agree on one thing: a live shark is worth
exponentially more than a dead shark. Dignitaries visited from several Caribbean islands and Samoa
and got the chance to visit the school and dive with some of Bimini’s world famous hammerheads.
Members of local government and tourism, The Bahamas National Trust, Bimini Sharklab, Cape Eleuthera
Institute, The Waterman Project and Ocean Elders were also part of this incredible event bringing science,
conservation, policy and the economy together to protect sharks and the oceans. The event culminated
with a discussion lead by former President of Costa Rica, José María Figueres and Sir Richard Branson.
For this event we worked with Louise MacDonald High School, where the students created some
outstanding artwork and presented each of the visitors with a handmade shark gift. Seeing so many
facets come together and work toward a common goal was really inspiring.
The journey to create Sharks4Kids has been remarkable and we are all really excited about more shark
adventures for kids, our new video series and our first book – all happening this year. As I write this, we
are also scheduling our first Skype classroom visit with a school in China! This is something we have
been working towards and are hoping it will be the first of many. We believe everyone has a voice and
we will continue to spread this message to students around the world and hopefully inspire them to
speak up on behalf of these magnificent creatures we all love and want to continue to see swimming
in oceans around the word.
To learn more about our projects or to book a shark lesson, check out www.sharks4kids.com.
Shark Focus 52
www.sharktrust.org/juniors
15
Changing perceptions of
sharks in the Red Sea
Emma-Louise Nicholls
Project Curator Science and Nature,
British Museum
Hitting the headlines
In 2010, a series of shark related incidents in the Red Sea caught the attention of
the world’s media. Over a 48 hour period four tourists - three Russians and one
Ukrainian - were seriously injured during shark incidents in the popular Red Sea
diving destination of Sharm el Sheikh, Egypt. The beaches were initially closed
by local authorities who also suspended all diving and other watersports. An
investigation into what happened was led by the Egyptian environment ministry
and two sharks – a 2.25m Oceanic Whitetip Carcharhinus longimanus and a Shortfin
Mako Isurus oxyrinchus – were killed after being declared responsible. The beaches
were subsequently reopened, but just four days after the first set of events a
German woman was fatally bitten by a shark in the same area. Media stories around
the world were filled with damning adjectives describing the shark/s responsible
and theorised, sometimes wildly, about the causes of these unprecedented events.
The reality behind the 2010 shark incidents is a much more complicated story in
which human activities have clearly had an impact on the natural behaviour of
sharks within the Red Sea. A number of well-grounded theories exist centring on
human activities, such as dive operators feeding sharks, as well as carcasses dumped
into the sea by ships transporting live sheep, attracting sharks closer inshore. These
changes have resulted in an overlap of sharks looking for food (normal behaviour)
and humans trying to enjoy their wide variety of water-sports. Unfortunately, when
such overlaps involve certain shark species, accidents can happen.
1
SINAI
Gulf of
Aquaba
Gulf of
Suez
EGYPT
Sharm
el-Sheikh
Shark Trust comment:
22nd March 2015, Al-Qusair, Egypt
A German tourist bitten by a shark (species
currently unconfirmed) in waters off Al-Qusair
on Sunday 22nd March has sadly died in hospital.
This is thought to be the first such incident
in Egyptian Red Sea waters since the tragic
events of 2010. Although shark bite incidents
will always remain unpredictable, awareness
programmes such as that described in this article
can play an important role in mitigating the
occurrence of negative human-shark incidents.
Detective work
Professor Magdy El-Alwany, Director of the Marine
Environmental Centre at the Suez Canal University
in Ismailia, Egypt, says he has a clear idea of what
has been altering the normal range of sharks in
the Red Sea and what led to the tragic events
of 2010. He says that he has witnessed locals
working in hotel kitchens and restaurants along
the coast bringing scraps of chicken and other
meat down to the water. They attract sharks
and other fish to amuse tourists who delight
in watching the animals being fed. So, happy
tourists…check. Happy fish…check. It’s all good.
Until you consider the implications of attracting
sharks into an area where humans readily enter
the water on a daily basis – see paragraph one for
the consequences.
Magdy believes that if humans knew how to act
appropriately, it would greatly reduce the chances
of negative human-shark interactions – including
bites and fatalities. He says “It is the fault of the
people. They feed the sharks without thinking
it through”. Rather than be an armchair critic of
human behaviour, or misbehaviour, he decided
a proactive response was required and applied
to his university for funding to start a shark
awareness programme. Magdy’s programme
has two goals. The first is to increase awareness
amongst fishermen and dive masters in order to
afford both humans and sharks greater protection.
The second aim is to use the same sources to
collect presence and absence data on shark
species in order to generate baseline information
on shark species found in the Red Sea region
against which future studies can be compared.
The fishermen and divers working with Magdy
therefore need to be adept at shark identification,
a skill which Magdy is helping them to develop.
Diver education
The five people involved in the 2010 incidents
were all tourists and were swimming or
snorkelling on the surface, near reefs and
nearshore drop-offs – exactly the type of places
oceanic sharks such as the Oceanic Whitetip and
Shortfin Mako may move through when feeding.
Magdy says that, to his knowledge, people have
never had a problem with sharks when scubadiving, but he feels that aiming a programme
at tourists is sadly unrealistic as such a small
proportion of them speak English (or Arabic).
However, people who visit Sharm el Sheikh to
scuba-dive are more than likely to swim or snorkel
on other days. So instead, Magdy is concentrating
on educating dive masters about sharks, as he
sees them as being in the best position to protect
those at risk. By educating dive masters, Magdy
is also ensuring tourists learn about shark safety
whether they are diving or swimming.
Working with fishermen
Marine Protected Areas (MPAs) have been set
up at a number of sites along the Red Sea
coast of Egypt, including Hurghada and Ras
Mohamed. Local Bedouin artisanal fishermen
are permitted to fish in designated areas of
these MPAs. Although it is illegal to catch large
sharks, the odd individual caught as bycatch is
overlooked. Of greater concern is the growing
volume of sharks caught in Egyptian waters by
foreign vessels fishing illegally, on which there
is very little information [see image 1]. Magdy is
therefore using his contacts within the fishing
community not just to record shark sightings,
but to encourage them to release any individuals
whenever possible. “Sharks keep the equilibrium
in the sea” he says, and so educating fishermen
about the importance of sharks for the overall
health of the Red Sea is an important part of his
work.
Teaching the next generation
Although the programme is primarily
aimed at dive masters and fishermen for the
aforementioned reasons, Magdy also runs
a secondary branch of his shark awareness
programme for school groups. He shows films
and gives presentations on sharks to both primary
and secondary school classes, targeting children
aged between 10 and 15. Magdy says that the
nature of Sharm el Sheikh means that a high
number of school children will go into tourism
when they leave, and dive centres in particular
form a large part of local industry. If the students
leave school with a respect for sharks and a
better understanding of their behaviours and
importance to the ecosystem, they will be in a
better position to protect humans and sharks
alike once working in the tourist industry. Magdy
2
PHOTOS
Map: Northern Red Sea and the Sinai.
Image 1: Sharks caught in Egyptian waters by foreign
vessels fishing illegally; carcasses were seized by the
Egyptian Navy and vessels and fishermen apprehended
© Magdy El-Alwany.
Image 2: Participants at the Red Sea Sharks Workshop
© Magdy El-Alwany.
Image 3: Professor Magdy El-Alwany, Director of the
Marine Environmental Centre at the Suez Canal University,
Egypt © Sharm el Sheikh Shark Awareness Programme.
www.sharktrust.org
Shark Focus 52
visits five schools locally in Sharm el Sheikh, with
more further afield along the coast. He says it is
important to debunk the reputation of sharks as
indiscriminate eating machines and so he doesn’t
show any films that incorrectly depict sharks as
ruthless killers.
As a marine biologist, Magdy used his extensive
background in the subject to write a presentation
unique to this shark awareness programme. He
describes the different species found in the Red
Sea, of which around ten are seen frequently in
Sharm el Sheikh. His aim is to concentrate on
nurturing a respect and appreciation of sharks
in an effort to encourage the children to want
to protect them. So far he has had an excellent
response from schools and promising feedback
from the children and their teachers alike.
However, a lack of resources prevents Magdy, who
runs the programme outside of his full time job,
from visiting more schools.
The future
Magdy stated “Further accidents like the events
of 2010 are likely to occur throughout the
world if people continue to feed sharks and
act inappropriately, rather than follow proper
procedures”. The funding he acquired from the
university was for two years of work, undertaking
research and promoting awareness. He desperately
wants to continue with his shark awareness project
but it requires further funding from another
source. The Darwin Initiative has previously
awarded researchers at the university funding for
two projects: one on sea turtles and a second on
echinoderms (e.g. starfish, urchins), but funding
for shark projects is harder to obtain. Magdy says
“Getting funding for shark projects is difficult
because it’s a very complicated problem. A lack
of funding is frustrating as awareness has to be a
continual thing. People forget what you’ve told
them, or move on and new people need training”.
As human fishing activity continues to deplete fish
populations in many ocean areas, it is thought that
some shark species may be venturing outside of
their natural range in order to find prey. This, along
with feeding by humans, such as Magdy described
in the Red Sea, can encourage them closer to shore.
As a result, shark awareness programmes such as
Magdy’s are absolutely vital to avoid repetitions
of the tragic events of 2010 - and in areas such as
Sharm el Sheikh, one of the most popular diving
areas in the world, it could not be more important.
Main image: Oceanic Whitetip Shark © Bryce Groark.
16
3
Shark Focus 52
www.sharktrust.org
17
Peniche, Portugal
October 9-11, 2015
2015 Annual Symposium
of the Fisheries Society
of the British Isles
The Portuguese Association for the Study and Conservation of
Elasmobranchs (APECE), the Marine Resources Research Group of the
Polytechnic Institute of Leiria and Flying Sharks are the proud hosts of
the 19th Annual Scientific Conference of the European Elasmobranch
Association from the 9th – 11th of October in Peniche, Portugal.
The conference will provide a platform for those involved in
international science and policy, and aims to coordinate information
necessary on the development and implementation of management
measures for sharks, skates and rays in European waters. APECE is
delighted to welcome Dr. Samuel Gruber of the Bimini Sharklab as keynote speaker.
VENUE
The conference will be held in Peniche, one hour north of Lisbon, at the
School of Tourism and Maritime Technology.
Rash vests
●Short-sleeve
REGISTRATION
● Fits both men and women
● All sizes – including children’s
● Available in graphite and navy blue
● 100% nylon and UV 50+
Back by popular demand, the Shark Trust’s campaign branded rash vests are available for both men and women in navy
blue and graphite. Arriving just in time for a sun-filled British summer, our vests provide UV 50+ protection and are the
perfect beach-surf-dive accessory.
With so many requests for children’s rash vests we now also offer these in a cool sharky grey.
Download the registration form from www.apece.pt and email your
registration form to APECE at mail@apece.pt.
Regular registration fee: €100 for EEA members, €120 for non-EEA
members, €75 for students.
Early-bird registration fee (until 30th June): €80 for EEA members, €100
for non-EEA members, €50 for students.
Saturday gala dinner: €30
PRESENTATIONS
Download the abstract submission form from www.apece.pt and
send it to Nuno Queiroz (APECE) at nuno.queiroz@gmail.com by 31st
August.
STUDENT BURSARIES
Please contact Glenys Heafield at the Shark Trust (glenys@sharktrust.org)
for information on student bursaries – please note that you may only
apply for a bursary after you have registered.
If you have any questions contact APECE at mail@apece.pt. We look
forward to seeing you in Peniche!
Smeaton’s Tower © Nilfanion (CC BY-NC-ND 2.0).
All profits go back into the work of the Shark Trust.
The 19th Annual
European Elasmobranch
Association Conference
Peniche © Karen (CC BY-NC-ND 2.0).
To view or buy these products – and more –
visit the Shark Trust’s online shop at
www.sharktrust.org/shop.
Great Hammerhead © Duncan Brake.
The Shark Trust Range
Plymouth, England
July 27-31, 2015
The aim of this symposium is to bring together scientists interested
in fundamental biological characteristics and the ecological and
evolutionary relationships of sharks, skates and rays. The topics
covered will span biological organisation from molecules and cells
to systems biology, and from individuals and populations, up to
communities and ecosystems.
THEMES
The symposium will cover the following themes:
●Genomics and molecular biology
●Developmental biology and evolutionary ecology
●Physiology and adaptations to changing environments
●Movements, behaviour and habitat use
●Population genetics, structure and distributions including phylogeography
●Ecological relationships, community and food web ecology
●Fisheries biology, ecology and management
●Conservation
●Methodological advances; e.g. biotelemetry/biologging; molecular markers
KEYNOTE SPEAKERS
Gregor Cailliet – Moss Landing Marine Laboratories, California, USA
Julia Baum – University of Victoria, Canada
Kevin Feldheim – The Field Museum of Natural History, Chicago, USA
Sylvie Mazan – University of Paris and Station Biologique de Roscoff,
France
Gregory Skomal – Massachusetts Division of Marine Fisheries &
Woods Hole Oceanographic Institution, USA
Sonja Fordham – Shark Advocates International, Washington DC,
USA
VENUE
University of Plymouth’s Sherwell Centre and Portland Square
Building.
REGISTRATION
For information on how to register visit www.fsbi.org.uk.
Symposium fees are:
Full fee: £200 (£175 online early bird if payment received online
before 3rd April 2015).
Student fee: £100
Day delegate fee: £100
Shark Trust mugs – featuring three exclusive designs:
British Sharks, British Skates and Rays and Eggcases.
Ceramic mug, 100% microwave and dishwasher safe.
Exclusive products, not available anywhere else!
18
www.sharktrust.org
Shark Focus 52
Shark Focus 52
www.sharktrust.org/events
19
Blue Shark Prionace glauca at London Borough Market © Timo Weber.
consumption
Consumer demand for shark products often surpasses
the value of live sharks, despite only producing short term
profits. Products can include cartilage, meat, fins, shark
liver oil and skins. Unsustainable shark fishing is a threat
to shark populations worldwide and the demand for such
products can further deplete already vulnerable species.
www.sharktrust.org