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Title: Shark news
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Permanent Link: http://ufdc.ufl.edu/UF00090496/00005
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Title: Shark news
Series Title: Shark news
Physical Description: Serial
Language: English
Creator: Ichthology at the Florida Museum of Natural History, University of Florida
Publisher: Ichthology at the Florida Museum of Natural History, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: October 1995
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Bibliographic ID: UF00090496
Volume ID: VID00005
Source Institution: University of Florida
Holding Location: University of Florida
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List of Articles
What Future For Manta Rays?
Giuseppe Notarbartolo-di-Sciara
Chairman's Farewell Message
Samuel H. Gruber
Sarah Felectionser. in !-^- .
Editorial
Sarah Fowler P. 9.
Manta Rays in the Yaeyama
Islands 0../
Hajime Ishihara and Kimiya i
Homma
Erratum: Shark Nets in Hong r
Kong * *
Yvonne Sadovy 1jjN i -.
Yv nn Illustration @ R< Williams 1993
An Update on the CITES Shark
Resolution *.
Merry Camhi and Sonja Fordham -.
Status of the Giant Freshwater Stingray (whipray)
Leonard J.V. Compagno and Sid F. Cook
Critically Endangered Large Coastal Sharks, a Case Study: the Sandbar
Shark, Carcharhinus plumbeus (Nardo, 1827)
Jack Musick
Sensitive Skates or Resilient Rays? a North Sea Perspective
Paddy Walker
European News *
The Role of Aquariums in the Conservation of Sharks
Juan Sabalones
Shark Info
Galapagos Under Siege
Merry Camhi
Cyanide Spill in the Essequibo River, Guyana





Sid F. Cook

Australian White Shark News

Large Coastal Atlantic Shark Fisheries closure notice

Bibliography; Technical Reports and Publications


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What Future for Manta Rays?


Giuseppe Notarbartolo-di-Sciara, Tethys Research Institute

Rays belonging to the family Mobulidae, the devil rays, are considered by many,
scientists and lay-persons alike, among the most fascinating and mysterious of marine
animals. Yet, because of their present vulnerability to man's activities, we may no
longer have the opportunity of finding out the details of their biology, ecology and
behaviour.

Entire populations, if not species, may disappear without anybody even noticing it.
Back in the early 1980s, I approached a community of fishermen near the southern tip
of Baja California to collect data on mobulids for my doctoral thesis. According to the
existing literature, there should have been two species of Mobula in that area, however
the fishermen insisted that there were four. Of course they were right, and one of those
species turned out to be new to science. Unfortunately, I also found out that my friends
were mostly catching immature rays. Seventy-two per cent of bentfin devilray M.
thurstoni the most frequent species in their catch had not had the chance of
reproducing. I can hardly think of a better example for an unsustainable fishery.


I had stumbled on such conclusions .
by pure serendipity. However, how
many situations such as this one
exist, or have existed, scattered
around the world's tropics? How '' .
many mobulid populations have
been studied, what data are being or
have been collected and published -
concerning the presence of mobulid
rays in any of the world's fisheries' ..- .
catch or by-catch? I regularly .. '.
monitor Current Contents, and .'
obtained a clean zero during the A fisherman fillets a spinetail devilray Mobul
past ten years. Yet, we know from japanica in Baja Califonia. Photo: G.
anecdotal sources that mantas and Notarbartolo-di-Sciara
mobulas are often involved in fishing
activities, be it in organised direct catches, by opportunistic harpooning, or in the by-
catch of large-scale industrial fishing, such as pelagic driftnets or tuna purse seines.


Mobulids are extremely vulnerable animals. First of all, their reproductive rate is among
the lowest of all Elasmobranchs, with a single huge pup being produced by each
female presumably every 2 to 3 years, or longer. Secondly, although there are no data
on population sizes, one can presume that these large-bodied rays are rare and live in
very low densities. Finally, mantas and mobulas are very easy to harpoon or to
entangle in a gillnet, and for most fishermen living in precarious conditions these rays
provide a very tempting source of extra proteins for their table.


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One can think of several reasons why all possible action should be undertaken to
prevent the disappearance of mobulid populations and species from the world's
oceans. Obviously, to begin with, there is the catch-all but deservedly sacrosanct
concept of preserving biodiversity. Secondly, mobulids are evolutionarily extraordinary
batoids in many ways, having left the bottom for the surface, having attained the
largest body size, having adopted a filter-feeding habit, and having developed the
largest elasmobranch brain. It would be nice to be able to make some sense of all this
before eating them out of existence.

In addition, mobulids (and particularly manta rays) are becoming a major attraction for
many diving locations, and can thus be considered assets of economic importance for
the tourism industry. Finally, I think mantas and mobulas have an important symbolic
value, because they could be excellent indicators for the plight of the forgotten species
- those which are disappearing without anyone knowing it. As such symbols, they could
serve to greatly increase public awareness of the need for preserving marine
biodiversity. In the Mediterranean Sea, for example, a war has been raging for almost a
decade between fishermen and environmental groups over the use of driftnets. This
was mainly due to the environmentalists' awareness of the tremendously large
cetacean by-catch in this fishery. I feel personally very sympathetic with the plight of
cetaceans in the Mediterranean, and spend a great deal of my energies in this field,
realising that dolphins and whales are taking a very severe beating from human
activities in this region. But at least we all know about this. By contrast, how many
hundreds, or how many thousands of the giant devil ray Mobula mobular were
obliterated from the Mediterranean by the very same driftnets? We will never know.
Most environmentalists are not even aware of the existence of mobulid rays in the
Mediterranean.

Mantas should have now the spotlights turned on them, to remind us of all those
marine species, large and small, that are disappearing daily under our unseeing eyes.


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Chairman's Farewell Message

Samuel H. Gruber *
It was with great reluctance that on 15 July 1995 I resigned as chairman of the IUCN
Shark Specialist Group (SSG). Looking back on my tenure, I see a mixed record. From
the very beginning when Species Survival Commission Chairman George Rabb
nominated me as SSG Chairman, I questioned whether I was the right choice for the
job in as much as I had no formal training or practical experience in conservation
biology nor did I know the players or understand the rules of the international
conservation scene. Still I forged ahead, in some ways re-inventing the wheel, and
under George's authority established the IUCN SSG at the 1991 Sharks Down Under
meeting.

Over the past five years the all-volunteer SSG has been instrumental in changing the S-
public's perception of sharks from a hellish, nightmare fish to a sophisticated creature
that must be allowed to exist to complete the delicate balance of life in the sea. The
proof of this is the unprecedented priority given to sharks at the last CITES Convention.

Over this period the Group has also been reasonably productive. The highlights have
been: the meetings at Sydney, New York and Bangkok; the production of a slide series
and pamphlet on shark conservation; consultation on two CD-ROMs about sharks, one
of which led to funding the Bangkok meeting; establishment of a quarterly newsletter *
Shark News; funding of a shark project under the Darwin Initiative; funding of the SSG
Action Plan by the Peter Scott Foundation; outlawing of long-line fishing gear in the
waters of the Commonwealth of the Bahamas; the unprecedented resolution passed at
the 1994 meeting of Parties to CITES; and, most importantly, the writing of the
conservation action reports by our volunteer Vice Chairpersons. I think it is a record
that we can be reasonably proud of.

On the other hand, because of my personality and style of leadership, I tend to set my
personal goals too high. In the case of the SSG perhaps I set them unrealistically high.
First, I felt unable to establish regular communication with the membership. Email went
a long way towards rectifying this but still communications were not what I would have
liked. This was compounded by the lack of Vice Chairpersons in several ocean areas.

Most frustrating and personally disappointing was my inability to raise funds to support
the work of the Group. One of my primary objectives in establishing the SSG was to
identify and prioritise key conservation research projects and fund the prioritised
projects. I regret that I was not able to even begin to identify research priorities. Over
the past several years as research budgets in the United States began to shrink,
pressures at my University mounted as more requests came in for me to write research
grant proposals and increase my teaching load. This put me in direct conflict with my
volunteer position as Chair of the SSG. Was I to raise money for shark conservation to
support the SSG or get grants for the University of Miami and my research station at
Bimini? It was thus that I had to make a hard choice and tendered my resignation.






I want to express my sincere gratitude to the members of the SSG who worked so hard
to make shark conservation more than an obscure footnote in the International
Conservation Community. I especially want to thank Sarah Fowler and Merry Camhi foi
bringing together the efforts of the membership and translating these into tangible
results: newsletter, slide set, grant proposals, funds etc.

I will miss the excitement and action of leading dedicated scientists and
conservationists in the good fight of trying to reverse the ever-escalating slaughter of
cartilaginous fishes in the world's oceans. I will miss it even more as I read about the
inevitable successes of the SSG now that we are on a roll. Again let me express my
deepest gratitude to the members and wish for your continued success in this
important task.

Sincerely yours,
Samuel H. Gruber, immediate past Chairman, SSG


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Editorial

Sarah Fowler *.
This issue of Shark News should remind us that, despite its name, the interests of the
Shark Specialist Group (SSG) also include the sharks' close relatives and more
numerous elasmobranch species, skates and rays. These fascinating fish often do not
attract the same attention as the highly publicised sharks, despite the fact that they are
probably as heavily exploited by directed fisheries and in fisheries by-catch. In some
cases they are even more vulnerable..

The mobulids (devil fish and mantas, pages 1 and 3) are particularly long-lived and
slow breeding species, with a potential economic value from sustainable tourism which
could far outweigh their value to fisheries. (Has the value to the diving industry and
local community of the famous rays of 'Stingray City' in the Caribbean, a major S -
attraction on the international sports diving circuit, ever been assessed? If so, please
send this information in to Shark News it would be an interesting case study to
feature.)

The rarely recorded and critically endangered freshwater stingrays, including the giant
rays first described from the Chao Phraya River in Thailand (page 5), are thought to be
perilously close to extinction as the result of fisheries combined with habitat
degradation. In contrast, the colder waters of the North Sea have supported long-term *
intensive fisheries of a few species of skate and ray at a level of exploitation which
some scientists might have thought impossible (page 8), while other species have
declined to vanishing point in some areas.

Some of the SSG's current initiatives are noted elsewhere. Members are being invited
to become involved in the process of Red Listing elasmobranchs (assessing their
conservation status) for several purposes: the new IUCN Red List (to be published in
1996), the Shark Action Plan (final draft due August 1996), and for our contribution to
the CITES review of the status of sharks in international trade. We are also cooperating
with those undertaking the study of international trade in sharks and shark products.

Progress toward the fulfilment of the CITES shark resolution is under way (see page
4). However, it is still far too early to determine whether CITES Appendix listings
should be recommended for any elasmobranch species, because we and others are
still collecting the necessary background information. Once the results of the above
studies are available, the SSG will need to assess whether any elasmobranch species,
subject to international trade, is or may be threatened with extinction. The SSG must
then discuss whether a CITES listing to monitor or control trade would be appropriate
or effective in improving its status. Fortunately, there is time for such discussions to
take place: listing proposals for additions of species to the CITES Appendices must be
submitted to the CITES Secretariat by no later than January 1997.

These subjects will be discussed at the next major meeting of the Shark Specialist -





Group scheduled to take place at the World Fisheries Congress in Brisbane, August
1996. A special one-day symposium, "Sharks and Man: Worldwide Management and
Conservation" will also take place at the Congress. Please note that, if you want to
submit a paper for any of the three symposium sessions (shark fisheries management,
shark control programmes (public safety), and shark conservation), you should send in
your abstract NOW (see page 12).

Finally, it is very sad to feature a farewell message from our former chairman alongside
this editorial. We will greatly miss Sonny's leadership and guidance. I have been
appointed as Acting Chair in his place and, with the help and support of the Group's
Deputy/Vice Chairs and members, will do my best to keep the SSG running smoothly
for the rest of the current triennium (until the end of 1996).

Sarah Fowler
Nature Conservation Bureau, 36 Kingfisher Court
Hambridge Road, Newbury, Berkshire, RG14 5SJ, UK.
Email: sarahfowler@naturebureau.co.uk


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Manta Rays in the Yaeyama Islands















Manta ray Manta birostris, showing omega-shaped swimming
style. Pohnpei Island. Photo: Kimiya Homma.


Hajime Ishihara and Kimiya Homma, Suido-sha and Kyowo Concrete Industry

Mr Takashi Itoh, a professional diver, has been living on Obama Island (near Iriomote
Island) for 18 years, and observing the manta rays Manta birostris which occur nearby
and are abundant in the Yonara Channel between Obama and Iriomote Islands. Using
an identification method based on a combination of patterns of ventral markings and
signs of shark bites, he has been able to distinguish more than one hundred and thirty
individual manta rays during this 18-year period. As a result, migration, schools, age,
feeding, predators, reproduction and behaviour have been described.

Migration

Manta rays are abundant in two kinds of locale; at feeding stations and cleaning
stations. At their feeding stations, manta rays swim slowly in the surface layer and are
absorbed in feeding. At their cleaning station, rays hover at a depth of 15-20 m and
wait to be cleaned by a wrasse, Labroides dimidiatus, or small shrimps. Rays migrate
daily between feeding and cleaning stations. While many manta rays stay near the
Yaeyama Islands all year round, some migrate annually to other islands such as
Kerama Island, which is about 350 km east of the Yaeyama Islands.

Schooling

Mr Itoh once observed a school of about 50 manta rays some 17 years ago, and one o
about 30 rays about seven years ago. Recently, schools have numbered 14 to 15 fish
at most, although the total number of manta rays in the area may not have decreased.





Young rays and pregnant females are also represented in a school. No other fish,
including no other mobulids, are involved in the group.

Swimming style

S-shaped, U-shaped and omega-shaped swimming styles (viewed from in front) have
been recorded.

Mating behaviour

Copulation has not been seen, but behaviour which appears to be related to mating
activity is often observed, with male and female manta rays somersaulting together in
the water column. This behaviour is observed in spring and autumn and lasts for as
long as one month.

Reproduction

One female was seen to bear a single pup three times during a six to seven year
period. Thus the pregnancy may last up to two or three years. Parturition was not
observed, although this has been recorded in the magazine Skin Diving, in a volume of
about 1975 to 1977. Nursing behaviour is not seen, the new-born pup is left in the
water after birth. Age at maturity for females may be about six years.

Jumping behaviour

Jumping behaviour is often observed. It appears that the rays do this for fun, and that
this behaviour does not seem to be related to parturition or the removal of parasites
and remoras. Three types of jumping are observed: jumping forwards and landing
head-first, jumping forwards and landing tail-first, and backward somersaults.

Age

One male ray, which appeared to be some four to five years old when first sighted, has
been observed for 15 years. It is, therefore, considered that the ray's life span is more
than 19-20 years.

Predators

Sharks may be the most common predator of manta rays, because the marks of shark
bites are often seen. However, it is uncertain whether sharks eat the whole body of
manta rays. Killer whales are not seen near the Yaeyama Islands.

Black manta

Manta rays whose ventral surface is dark are usually called 'black manta' at Pohnpei
Island, where about 50% of all manta rays are black. At Yaeyama Island only two black
manta rays have been observed. Both were male and the first of these has not been
seen for several years.

Mr Itoh intends to continue to observe the behaviour of manta rays in the Yaeyama
Islands and we will continue to have a fair relationship with him. We ourselves will be
conducting a survey of manta rays at Pohnpei Island, in the Caroline Islands.


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Erratum: Shark Nets in Hong Kong

It was stated in the article entitled "Shark nets in Hong Kong" in Shark News 4 that a
shark hunt which took place in Hong Kong in 1993 was government-funded. This is not
correct. The shark hunter brought into Hong Kong was funded by a Hong Kong
newspaper and subsequently received assistance and support from various
government departments in effecting the hunt.

Yvonne Sadovy, University of Hong Kong

Editor's note: This detail was correct in subsequent reprint, generously sponsored by
Maritime Mechanic Ltd, the company responsible for the installation and maintenance
of shark prevention nets in Hong Kong.

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An Update on the CITES Shark Resolution

Merry Camhi, National Audubon Society,
and Sonja Fordham, Center for Marine Conservation
The Convention on International Trade in Endangered Species of Wild Fauna and
Flora (CITES) was created in 1973 to protect species from over-exploitation by
international trade. Species that are threatened with extinction and that are, or may be,
affected by trade are listed on Appendix I, whereas species that may become
threatened if such trade is not properly controlled are listed on Appendix II. As of -
October 1995, 130 countries are Parties to CITES.

Of the approximately 400 species of sharks in the world, about 100 species are
exploited for the global shark trade. TRAFFIC (the wildlife trade monitoring programme
of WWF and IUCN) has reported that international shark fin exports doubled between *
1980 and 1990. The rapid growth in shark fisheries has been driven primarily by the
Asian demand for fins, but sharks are increasingly exploited for their cartilage and meat
as well. Although no shark species are currently listed on the CITES Appendices,
delegates at the 1994 CITES meeting acknowledged the impact that international trade
may be having on sharks by passing a unanimous resolution aimed at improving our
knowledge of shark populations in trade (see Shark News 3, p. 1).

The CITES shark resolution

The shark resolution directs the CITES Animals Committee to compile and review
existing data on the biological and trade status of shark species subject to international
trade, and to prepare a discussion paper on these data prior to the 10th CITES
meeting in June 1997 (see resolution text in Shark News 4, p. 9). It also requests that
the Food and Agriculture Organization of the United Nations (FAO), in conjunction with
international fisheries management organizations, establish data collection
programmes for monitoring shark status and trade. New information generated from
these programmes will be presented at the 11th CITES meeting in 1999. The
unprecedented resolution, spearheaded by the delegations from the US and Panama, *
was the first time that CITES members agreed to review the effects of international
trade on a group of species that was not already listed on the CITES Appendices. *i ff.

Implementing the resolution

In March 1995, Dr Francisco Palacio, representing the delegation of Panama,
presented the CITES resolution to the FAO Committee on Fisheries (COFI) and asked
for COFI's support in fulfilling the resolution. As a result, the Fisheries Department of
FAO has agreed to collaborate with CITES in the preparation of documents for an
expert meeting on shark status and trade. In addition, Dr Jose Castro, representing the
US delegation, requested information from CITES Parties to begin the process of data
collection and analysis as called for in the resolution.
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Sharks were again on the agenda when the CITES Animals Committee convened in
September 1995 in Guatemala. Panama and the US continued their leadership role at
the meeting.

Panama, represented by Dr Palacio, suggested that FAO should be the focal point for
data collection and actions necessary to implement the CITES resolution. The Chair of
the Animals Committee noted, however, that the resolution directs CITES to undertake
certain actions, such as the status review, and therefore it was neither possible nor
appropriate to ask another organisation, such as FAO, to take on primary
responsibility. Yet it was also noted that, because FAO has significant experience with
fisheries issues, their cooperation and input will be very valuable to the Animals
Committee in fulfilling the terms of the CITES resolution.

Dr Castro, of the US delegation, gave a compelling presentation to the Parties
explaining why sharks are so vulnerable to fishing pressure and international trade. In
addition, TRAFFIC gave the Parties an update on their 18-month study of the
international trade in sharks and shark products, which is being undertaken in
cooperation with the IUCN Shark Specialist Group (SSG). TRAFFIC and the Center for
Marine Conservation have teamed up to develop management recommendations
based on the trade study findings. The final joint report will be published in 1996. The
SSG, represented by Dr Merry Camhi and Sonja Fordham, introduced the participants
to an array of global shark conservation initiatives that the SSG is currently
undertaking, including the production of a Global Shark Action Plan and an IUCN Red
List of threatened elasmobranchs. In helping to fulfil the resolution, the SSG also plans
to provide information to CITES on the status of shark species, with an emphasis on
those species most important in international trade.

Where we go from here

It was decided in Guatemala that:

1) the CITES Secretariat will formally request that all Parties submit data on their shark
fisheries and trade to the Secretariat;

2) these data will be provided to both Panama and the US for analysis and report; and

3) Panama will host an expert consultation early next year among FAO and other
intergovernmental organizations to discuss the current status of sharks, shark fisheries
and international trade.

NGO participation will be restricted to IUCN, TRAFFIC and other organizations that
have data to contribute to the goals of this meeting.

The use of CITES for marine fish conservation

Although CITES is considered to be one of the most successful international wildlife
conservation tools for species in trade, few marine fish have received the conservation
benefits of CITES to date. This stems in part from the misconception that many marine
fish populations are inexhaustible and extinction-proof because of their wide ranges
and high fecundity.

In addition, marine fish, including sharks, have not benefited from CITES because mosi
people think of fish primarily as a food and commodity. Yet fish are also wildlife. They
are subject to the same biological constraints, and therefore suffer similar impacts from
international trade, as many terrestrial wildlife species already monitored or controlled
under CITES. Sharks, in particular, can be seriously threatened by such trade because
their K-selected life history strategies make them highly vulnerable to over-exploitation.

Because of the tremendous economic value of fish, there is strong political resistance
to addressing the problems of depleted and over-exploited fish populations within the
context of CITES. Contrary to the concerns of many fishing nations, an Appendix II
listing would only regulate, not prohibit, international trade in sharks. Such regulation


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can be used to protect species for their ecological value (i.e. keeping populations at a
level that maintains their role in marine ecosystems -Article IV.3). Until shark fisheries
throughout the world are managed by effective management agreements, CITES may
provide the best mechanism to help protect shark populations from over-fishing,
through the monitoring and control of international trade.

Shark fishery management has always been hampered by a lack of data on historical
catches, imports and exports in shark products, life history characteristics, and species-
specific population status. The information gained from this pivotal resolution could be
a critical first step toward the establishment of effective shark management
programmes.

SSG members interested in contributing information toward the implementation of the
CITES resolution should contact Sarah Fowler or Merry Camhi at the addresses below:

Sarah Fowler
Nature Conservation Bureau, 36 Kingfisher Court
Hambridge Road, Newbury, Berkshire, RG14 5SJ, UK.
Email: sarahfowler@naturebureau.co.uk

Merry Camhi
National Audubon Society, Scully Science Center,
550 South Bay Avenue,
Islip, NY 11751, USA
Email: mcamhi@audubon.org




















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Status of the Giant Freshwater Stingray (whipray)
Himantura chaophraya (Monkolprasit and Roberts 1990)

Compiled by Leonard J.V. Compagno and Sid F. Cook

Taxonomy

The giant freshwater stingray (whipray) is one of eight apparently obligate freshwater
species of dasyatids (four Dasyatis spp. and four Himantura spp.) of the much larger
Family Dasyatidae (whiptail stingrays). Other members of the family believed to be
found at least occasionally in freshwater include the brackish-marginal Himantura
schmardae and several euryhaline species: two Dasyatis spp., two Himantura spp. anc
Pastinachus [= Hypolophus] sephen.

H. chaophraya was only formally described in 1990, though its existence had been
known for some years. The type locale is listed as the Central Chao Phraya River of
Thailand. It has been previously mis-identified in Australia as Dasyatis fluviorum
Ogilby, 1908 [estuary stingray] and may have been listed under the old name of
Himantura polylepis (Bleeker) in Indonesia.


Distribution


The giant freshwater stingray is known from highly disjunct locales including fresh
waters in Thailand in the Chao Phraya, Nan, Mekong, Bongpakong, Tachin and Tapi
Rivers. It is also recorded from Mahakam Basin [Borneo], the Fly River Basin [New
Guinea], and from Australia in the Gilbert River [Queensland], the Daly and South
Alligator Rivers [Northern Territory], Pentecost and Ord Rivers [Western Australia]. It
may occur in most of the large rivers of tropical Australia. However, it has not been
recorded from marine waters in any of its known range.


Description


This species, one of the largest
living dasyatids, has a characteristic
rounded disk, a prominent snout tip
and a long whip-like tail without
cutaneous folds. It reaches a size of
up to 200 cm disk width, and 600 kg
in weight (Thailand and most other
locales in range). However,
Australian specimens are reported
as only reaching slightly more than
100 cm (disk width). Males mature
by 110 cm disk width. Young are
born at about 30 cm disk width.
Maximum lifespan in the wild is


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Sid Cook with air-dried specimens of adult and
newborn Himantura chaophraya at Chainat,
Thailand. Photo: Sarah Fowler.





unknown.

Conservation status

The giant freshwater stingray has been taken by fishermen on the rivers of Central
Thailand, in fisheries for bony fishes, notably giant gouramy ( Osphrenemeus gouramy)
and giant river catfishes (Pangasius spp.). In 1992 Thai fishermen reported 25
individuals of H. chaophraya in their catch, but by 1993 reported landings had dropped
to three.

Due to a complex series of factors causing degradation or habitat alteration in riverine
habitats in the region, only about 30-31 of the 190 species of indigenous Thai
freshwater fishes are estimated to reproduce in the wild, although it is likely that a
somewhat higher biodiversity exists in backwater habitats where small, isolated
pockets of endemism undoubtedly occur.

Habitat-degrading factors having a negative impact on Thai riverine environments
include over-harvesting of forest canopy, leading to drought upstream and flooding
downstream during monsoon conditions which further leads to excess siltation; dam
building to control flooding, which leads to silt build-up and retention of agrochemicals
behind impoundments; and development of lands adjoining river habitats, which
facilitates degradation and destruction of ray habitats with deposition of broad-
spectrum wastes. The dams effectively isolate portions of the reproductive populations
of all riverine stingrays ( H. chaophraya, H. oxyryncha [= krempfi], H. signifer and
Dasyatis laosensis) from intermixing during mating, dramatically cutting the diversity of
the gene pool for any given species. In the case of some very low density riverine
elasmobranch species, like the sawfishes, a combination of fisheries and habitat
changes have effectively eliminated them from the Chao Phraya and adjoining
freshwater habitats, where they have not been reported for some 40 years.

The precipitous decline of riverine stingrays in Thai fresh waters has led the Thai
government to implement an experimental program for captive propagation to try to
stabilise levels of biodiversity while they attempt to solve problems with degradation of
river habitats. The authors observed the operations at Chainat, Suppraya Province,
Central Thailand, in December 1993, where healthy individuals of H. chaophraya
ranging in size from 0.45 m to 1.6 m in disk width and ranging from an estimated 50 kg
to 500 kg were observed, along with healthy individuals of Himantura signifer (white-
edged freshwater whipray) and Dasyatis laosensis (Mekong freshwater stingray). One
Himantura oxyryncha [= krempfi] (marbled freshwater stingray) in poor condition died
while the authors were at the facility.

In the South Alligator (and possibly East Alligator) River which runs through Kakadu
National Park, concern has arisen for both the giant freshwater stingray and riverine
occurrences of the bull shark ( Carcharhinusleucas), related to possible adverse
effects of silt carrying heavy metals and radio-isotopes from experimental uranium
mines around Coronation Hill and along the Alligator Rivers in the Park. Further
research is urgently needed to ascertain the status and possible threats to this species
in other parts of its range (Borneo, New Guinea and Indonesia).

IUCN threatened species assessment

This species should be considered Critically Endangered throughout its known range. I1
has been and will continue to be affected by the complex and synergistic effects of the
restrictions of its obligate freshwater habitat, fishing pressures and habitat alteration/
destruction. The possibility of biological extinction in the wild is considered extremely
high.

Editor's note: The above is a greatly abbreviated version of the draft account supplied
by the authors for the Shark Action Plan. The original includes many references and is
available from the Editor. The threatened species assessment is provisional until
agreed by the Shark Group, and based on criteria given in: IUCN (1994). IUCN Red
List Categories. Gland, Switzerland.


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Critically Endangered Large Coastal Sharks, a Case
Study: the Sandbar Shark, Carcharhinus plumbeus
(Nardo, 1827)

Jack Musick, School of Marine Science,
Virginia Institute of Marine Science,
College of William and Mary, Gloucester Point, VA 23062
Taxonomy

The sandbar shark, Carcharhinus plumbeus (Nardo, 1827), is a medium to large-sized
requiem shark (Carcharhinidae) with a relatively short rounded snout, distinctive high
triangular dorsal fin placed over or before the pectoral insertions, dermal ridge between
the dorsal fins, large serrated triangular upper teeth, and narrow awl-shaped lower
teeth. In life this species is light grey above and pristine white below, often with a
brassy hue and white stripe along the flank. Originally described from the Adriatic Sea,
it was subsequently described under various other names from other localities. Some
names in recent use include: Carcharhinus millberti, Eulamia milberti, Galeolamna
stevensi and Carcharhinus japonicus.

Distribution and ecology \

The sandbar shark is a coastal species
typical in many aspects of its biology of
many other common coastal sharks. The
species has been recorded from the
western Indian Ocean, south-east Asia,
Japan, Australia, and Hawaii. Its
occurrence in the Eastern Pacific is
debatable. The sandbar shark occurs in
the eastern Atlantic and Mediterranean
and is the most abundant large coastal
shark in the western north Atlantic and
eastern Gulf of Mexico. Tagging and
genetic studies suggest that sandbar
sharks from Cape Cod, Massachusetts,
to the northern Yucatan peninsula in
Mexico are comprised of a unit stock
separate from the population reported
from Trinidad to Brazil.

In the western North Atlantic, the
sandbar shark exhibits strong seasonal Figure 1. Sandbar shark being landed on
movements. Adult female sandbar long-line vessel
sharks migrate north into the middle





Atlantic Bight in May and early June, when sea water temperatures approach 19C,
and use estuarine waters such as Chesapeake Bay and Delaware Bay as pupping
grounds. Immediately after pupping these large females move offshore to 20-50 m
depth. Neonates and juveniles aged 1-4 years utilise estuarine habitats during the
summer. Larger juveniles use shallow coastal habitats (<20 m). Although the juvenile
population in the middle Atlantic Bight exhibits approximately a 1:1 ratio of females to
males, the adults are represented almost solely by females (very occasionally adult
males are taken at greater than 100 m depth at the edge of the continental shelf). Adult
males appear to inhabit the southern part of the range and are common off Florida and
in the Gulf of Mexico. Sandbar sharks migrate south below Cape Hatteras, North
Carolina, and further in September or October when seawater temperatures fall to 18-
200C. Some large juveniles and adults may migrate as far as southern Florida, Cuba
and Mexico, while small juveniles and other larger juveniles and some adults may
winter in warm waters at the edge of the Gulf Stream off the Carolinas. Off South Africa
similar seasonal migrations into high latitudes in spring and lower latitudes in fall
appear to occur. Island populations such as in Hawaii appear to be seasonally
resident.

Sandbar sharks are euryphagous predators feeding on a wide variety of smaller
demersal teleosts and elasmobranchs, as well as on cephalopods, and various
crustaceans.

The sandbar shark is viviparous with a yolk sac placenta. Gestation has been
estimated at 9-12 months in the western North Atlantic, 11-12 months off South Africa
and the East China Sea, and 10-12 months off Taiwan. Females apparently have
young onlyevery other year, with about 50% of mature females being pregnant off
Taiwan. Conversely, only 17-27% of mature females captured off Florida were
pregnant. However, most of the mature females examined in the mid-Atlantic Bight of
the US in summer are pregnant or recently have born young. Therefore, the pregnancy
rate in the western North Atlantic is probably near 50%, but it is difficult to obtain a
synoptic sample of the entire population of mature females because of their wide
geographic distribution and seasonal movements. Litter size is variable and depends in
part on the size of the mother. In the western Atlantic, where female sandbar sharks
mature at about 179-183 cm TL, litter size averages 8.4-9.3 (range = 1-14). Whereas in
Hawaii where females sandbar sharks mature at 150 cm TL, mean litter size is only 5.5
(range = 1-8). Within a given geographic area litter size is only very weakly correlated
with the size of the mother. In general, size at maturity, maximum size and litter size
decrease from the western Atlantic to the western Indian Ocean, to Taiwan and
Australia, to the east China Sea, and to Hawaii. Size at birth varies slightly by region,
but does not follow the same geographic pattern. New born pups range from 56-75 cm
TL with pups averaging 60-65 cm TL in most areas. Maximum reported size is 234 cm
TL for females and 226 cm TL for males.

Sandbar sharks are slow-growing K-selected species. Although growth and age at
maturity may be accelerated under captive conditions, wild populations grow very
slowly and mature at a relatively late age. In the western Atlantic the von Bertalanffy
growth coefficient, K, has been estimated to be very low (0.039 to 0.089) in validated
studies using annuli on vertebral centra. Maturity in these studies was estimated at 13-
16 years. However, in another study based on growth rates calculated from tag/
recapture data, growth was considerably slower and age at maturity was estimated to
be 29 years. Considerable debate has arisen concerning the discrepancy between the
two methods, including the small tag/recapture sample size and the possible effects of
tagging on growth rates. Regardless, sandbar sharks grow slowly and mature late.

Conservation status

Sandbar sharks are significant components of coastal shark fisheries world-wide. In the
western Atlantic this species contributes up to 60% of the catch and 80% of the
landings in the directed long-line fishery. In addition, the sandbar shark is second only
to the blue shark (a pelagic species) in the US Atlantic recreational shark fishery.


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During the last twenty years, recreational and commercial fisheries for sharks along the
US Atlantic coast and in the Gulf of Mexico have expanded at rapid rates. Recreational
catch has been estimated at 2.5 million sharks (ca. 35,000 mt) annually; 20-40% of
this is killed. Driven by increased marketability, the commercial fishery has rapidly
expanded since 1985, with landings exceeding 7,100 mt in 1989.

Increased exploitation of sharks prompted the development of a US Fisheries
Management Plan (FMP), implemented in 1993 for the shark resources of the Atlantic
and Gulf coasts. In addition, several states (Virginia, North Carolina, Texas and
Florida) have enacted laws to regulate shark fishing in their respective regions (14% of
commercial and 64% of recreational catches occur in state controlled waters).

Regardless, a Scientific Review Panel of Experts concluded in April 1994 (Anon.,
1994) that the stocks of large coastal sharks were depleted to much lower relative
levels than realized in the FMP, and that stock recovery would take decades rather
than two years as stated in the plan. Consequently, the Panel recommended that the
total allowable catch (TAC) of sharks not be increased in 1995 as recommended in the
management plan, but that the TAC remain constant. Some members of the Panel
suggested that the TAC be reduced instead of being held constant or that the fishery
be closed.

The annual rate of CPUE VIMS LONGLINE
replacement (r) 7 -VIRGINIA CONTINENTAL SHELF ONLY
used in the FMP
model, 26% per
year, is much higher
than that calculated SANDBAR SHARKS
to be biologically g .
possible for both 4. -
fast-growing and U ./
slow-growing -' } -
carcharhinids using / ;:
accepted -
demographic .' /" ..
models. Recent : : :
modelling in our -
laboratory suggests a
that for sandbar 74I 7 190 s98 82-5 aes ease 0 1r rBB1 9I I
sharks the annual Figure 2. Catch per unit of effort of sandbar sharks expressed
population increase as sharks per 100 hooks for the years 1974-1993. Data
rate can vary from collected during scientific surveys conducted by the Virginia
2.5% to 11.9% with Institute of Marine Science in coastal waters of the mid-Atlantic
an age at maturity of Bight of the USA. (Some years pooled to equalise sampling
15 years. If a more effort.)
conservative age of first maturity of 29 years is used, then the maximum annual
population increase rate would be 5.2%. These low rates of intrinsic increase are
probably close to the real situation and reflect the K-selected life history parameters
typical of virtually all sharks. The unrealistic r value used in the FMP was calculated
using a surplus production fishery model based on a time series of commercial catch
data. Such models may be useful for fast-growing, short-lived teleosts, but are
inappropriate for slow-growing, long-lived fishes such as sandbar sharks. Most sharks,
and large coastal species in particular, have life history characteristics that make them
particularly vulnerable to overfishing. In the western Atlantic sandbar shark stocks have
been reduced by 85-90% in just ten years because of over-exploitation. In addition, the
age structure of the population has been shifted dramatically toward younger age
classes. Adult females are very uncommon. Under the IUCN criteria for listing
threatened species, the western North Atlantic population of sandbar sharks would be
classified as "Critically Endangered" (IUCN, 1994).

This species continues to support a substantial fishery after such a severe population
decline only because of the very large size of the original stock. Under the current





FMP, the target fishery mortality (F = 0.25) can only lead to a continued population
decline (Sminkey and Musick, in press). The western North Atlantic shark fishery is a
multi-species fishery. Many species less common than the sandbar shark have
undergone similar population declines, and at least one, the dusky shark Carcharhinus
obscurus, has undergone an even greater population decline. This species matures at
a larger size and later age than the sandbar shark and may reproduce only every three
years.

The naive assumption of some resource managers that marine fish populations are not
vulnerable to extinction because they are 'open', with large geographic ranges and
unlimited immigration, is unfounded (Huntsman, 1994). Coastal stocks of even large
migratory species such as sandbar sharks have discrete geographic boundaries. Over-
fishing can rapidly deplete K-selected species. It may be true that fisheries will collapse
of their own accord when stocks become so reduced that they are no longer profitable
to pursue, but the notion that fisheries will become economically extinct before
extinction of target species is not true. In a mixed-species fishery, where all species are
subjected to the same fishery mortality rate, less-abundant species could be driven to
extinction while numerically dominant species still continued to support the fishery.
Thus, Manire and Gruber's (1990) concern that many shark species might be
vulnerable to extinction appears to be well founded. Even if the fishery were completely
closed, stock recovery of the sandbar shark and other large coastal species in the
western North Atlantic would take several decades. The collapse of large coastal shark
stocks in the western North Atlantic provides strong support for Congdon et al.'s (1993)
contention: "The concept of sustainable harvest of already-reduced populations of long
lived organisms appears to be an oxymoron".

Bibliography

Anonymous. 1994. Report of the shark evaluation workshop, March 14-18, 1994.
NOAA, NMFS, Southeast Fishery Center, Miami: 47pp.

Congdon, J.P., A.E. Dunham and R.C. Van Loben Sels. 1993. Delayed sexual
maturity and demographics of Blanding's turtles ( Emydoidea blandingii). Implications
for conservation and management of long-lived organisms. Conservation Biology 7(4):
826-833.

Huntsman, G.R. 1994. Endangered marine finfish: Neglected resources or beasts of
fiction. Fisheries 19(7): 8-15.

IUCN. 1994. IUCN red list categories. IUCN Species Survival Commission, Gland,
Switzerland: 13 pp.

Manire, C. and S. Gruber. 1990. Many sharks may be headed toward extinction.
Conservation Biology 4(1): 10-11.

Sminkey, T.R. and J.A. Musick. In Press. Demographic analysis of sandbar sharks in
the western North Atlantic. Fishery Bulletin.

Editor's note: The above is an abbreviated version (excluding most references) of the
material supplied by the author for the Shark Action Plan. The IUCN threatened
species assessment is provisional until agreed by the Shark Specialist Group.



















SSielections...
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Sensitive Skates or Resilient Rays? a North Sea
Perspective

Paddy Walker, NIOZ, P.O. Box 59, 1790 AB Den Burg, Texel, NL
At the beginning of the century rays and skates were considered quite common in the
North Sea. For example, between 1907 and 1909 the biomass of rays and skates
caught by Dutch trawlers was as high as that of whiting, haddock, cod and small plaice.
More than 600 tonnes were landed annually, of which half were thornback rays Raja
clavata and half common skates Raja batis. Nearly 5,000 fishing boats were in -
operation; small sailing boats which operated locally. The estuaries of the rivers
Schelde and Maas were regularly fished and in the summer stingrays Dasyatis .
pastinaca, as well as thornback rays, were often caught. There was a lively standing
net fishery for stingrays in the Wadden Sea, which lasted until the 1930s. The stingrays
were caught for their liver oil, a guaranteed cure for ailments such as rheumatism.
Fishermen even soaked their underwear in the oil to protect themselves
frombitterweather. Thornback rays were regular visitors in the Wadden Sea in the
summer months, although there is no evidence that this species spawned there.

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Figre 1. Landings of rays and skates as reported to ICES in thousand metric tonnes.


The present situation is quite different.The common skate is seldom caught in the l
southern and central North Sea and has not been caught in Dutch coastal waters since
the mid 1950s. With the exception of a few individuals, no rays (thornbacks or
stingrays) have been caught in the Wadden Sea since 1966.1n the 1930s fishermen
started complaining about the lack of rays in the Wadden Sea which was then
attributed to the extensive fishing of the stocks in the North Sea. Thornbacks and
stingrays have been rare off the northern coast of Holland since the 1970s, although
stingrays are still caught in the estuaries in Zeeland.






The situation in the North Sea as a whole is not much more optimistic and there has
been concern about the status of the stocks of rays and skates in the North Sea,
following a steady decline in landings since the 1960s. Analysis of landing statistics
from the International Council for the Exploration of the Sea(ICES), which have been
published annually since 1903, shows that landings of rays and skates have decreased
significantly since the beginning of the century, both between the two World Wars and
after WWII (see Figure 1). Present landings (approximately 4,000 tonnes) are a quarter
of what they were in the 1920s. Landing statistics are obviously a poor indication of the
actual abundance of fish. However, considering the increase in fishing effort which has
occurred in the past three decades, the returns would seem to be decreasing.
Unfortunately, because the majority of the landing statistics are not detailed to species
level, it is difficult to identify the current status of the skate and ray stocks in the North
Sea. Although the North Sea represents only part of the area of distribution for most
species, it is unlikely that local depletion of stocks will be alleviated from elsewhere at
the current level of fisheries exploitation, as most species appear to be quite sedentary
The Dutch coastal waters form an example.

Rays and skates represent a by-catch in the beam trawl fisheries for other demersal
fish species such as sole and plaice. Although usually only the large individuals will be
landed for consumption, the size and shape of the juveniles and their thorniness
means that they have a large chance of being caught. Normally they would be
discarded, but juvenile thornbacks and spotted rays Raja montagui have been known
to be sold at fish markets. There are nine different species of rays and skates, of which
the most abundant (the starry ray Raja radiata) is not landed for consumption but is
discarded. The chances of survival of discarded rays are unknown. The fact that these
species are a by-catch makes it difficult to take management measures which will
protect them, without affecting the catch of commercially more important fish species.

The level of exploitation that rays and skates can withstand is unknown and is species-
specific. Possibly the situation is less dramatic than it appears; some scientists believe
that rays and skates are quite resilient because they are still around (with a few notable
exceptions) despite intensive fisheries. It's a complex problem, and one which
deserves more attention.


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European News
ICES Elasmobranch Study Group meeting

The August meeting produced synopses for elasmobranch stocks and fisheries in
European and eastern North American waters (ICES/NAFO regions).lts
recommendations include collaboration on key issues for the sustainable exploitation o
elasmobranchs an important first step towards a more organised and integrated
approach to the study of elasmobranchs and their fisheries in the North Atlantic. The
report should be available from the ICES Secretariat, Palaegade 2-4, DK-1261
Copenhagen K, Denmark (http://www.ices.inst.dk/).
There will be an article on this meeting in issue 6 of Shark News, including the
response of the 1995 Annual ICES Scientific Committee.
Proposal to improve EC fisheries records

A new proposal for an EC Council Regulation (COM(95) 322 final) will, if agreed,
establish a list of fish species to be recorded in fisheries logbook and landing
declarations. The proposal is intended to form a basis for fisheries management and
enforcement of conservation measures and contribute to systematic recording of
regulated and highly migratory species. A total of 194 'species' of fish and invertebrates
are listed, including all those subject to TAC, protected, newly fished, and of particular .
scientific or commercial interest. Simplified lists will be adopted for specific zones and
only contain relevant species. However, the proposal does 'lump' many species
together (e.g. all skates and rays fall within a single category). Other elasmobranchs
listed are the basking shark, spiny dogfish, dogfish sharks (Squalidae), porbeagle,
smoothhounds (Mustellus spp.), and mako shark.
European Elasmobranch Society

A meeting of potential national partners in the initiative to establish this non-
governmental organisation was held in Brussels in September, partly grant-aided by
Scottish Natural Heritage. Representatives attended from eight European countries:
France, Germany, Italy, Netherlands, Portugal, Spain(Catalonia), Switzerland and the
UK. Delegates discussed the related national and regional initiatives underway or
planned in Europe, agreed the aims and objectives of the proposed EES, and
discussed the type of organisational structure which would be appropriate for the
headquarters and the national or regional branches or member bodies. It was agreed
that formation of the EES should go ahead and another meeting should be held early in
1996 to report on progress. Contact the Editor for more information.


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The Role of Aquariums in the Conservation of Sharks

Juan Sabalones, SeniorAquarist, National Aquarium in Baltimore,
Maryland, USA
Sharks have been a source of fascination for centuries. With a few notable exceptions,
the nature of most human contact with sharks was likely to be brief and fraught with
negative overtones. This led to much speculation about what they were really like,
most of it inaccurate. Only recently has technology (scuba diving, submersibles,
underwater photography and cinematography) allowed us to observe sharks in the wild
and learn more about their true nature. Unfortunately, such first hand observation is
available only to a relatively small sector of the public, with most of the rest relying on
the media (print, film and television). The only other place to observe sharks first hand
is at a public aquarium. In terms of a shark conservation movement, this is where
aquariums can be most valuable.

One definition of conservation is "the
planned management of a natural
resource to prevent exploitation,
destruction or neglect." It is
reasonable to expect that such
management effort needs public
support as a major component. The
total number of people that attend
public aquariums in a year in North
America alone is over 100 million.
These institutions are frequently
These institutions are frequently Photo: National Aquarium in Baltimore, George
used by the media as information Grall.
resources because aquariums are in
the business of educating their audience by providing the most accurate, well-informed
picture of sharks available. Aquariums, then, can significantly influence the image of
sharks beyond the millions of people that walk through their doors. Helping to correct
the negative image of sharks and highlighting their positive aspects will go a long way
towards increasing public support for their conservation. Several other species with
similar concerns have benefited from such image makeovers.

At the National Aquarium in Baltimore (NAIB), this desire to upgrade the image of the
shark affects our approach in several ways

In terms of exhibitry, it means dealing with the negative image by highlighting the
multifaceted nature of a very old, very successful class of animal. This means
explaining their role in the environment and talking about their conservation needs. In
terms of species displayed, the impression that all sharks are large man-eaters such as
Great Whites, Bulls or Tigers can be corrected by displaying and highlighting the
smaller, more exotic looking sharks. This will emphasise the fascinating diversity of





shark species and the fact that the vast majority of sharks are of the smaller, non-
threatening type.

When educating the media and the public, all presentations on sharks are divided into
three parts. In the first part the negative image of the shark is dealt with by using
strategies such as discussing the relatively low incidence of shark attacks, especially in
comparison to other animals (saltwater crocodiles, elephants, farm pigs and bees, for
example, kill more people per year). The second part stresses the positive
contributions and features of sharks, such as their importance to the environmental
balance. The third part deals with the conservation needs of the shark. When properly
rehearsed, this presentation can be condensed to a few minutes or expanded to an
hour lecture. If this approach is consistently used during all contacts with the media
and the public, it soon becomes second nature.

Another way in which aquariums can promote the conservation of the shark is through
the promotion of research. Research into better methods of husbandry is a good place
to start. A recent report to the IUCN by the Shark Specialist Group (SSG) noted that
the impact of aquariums on wild populations of sharks was insignificant. Nevertheless,
it is important to constantly strive for even higher standards in the husbandry of sharks
and to encourage captive breeding. This will lessen the need to take them from the
wild. Another place to promote research is in areas of the wild used as collecting sites.
The NAIB participates in a National Marine Fisheries Service (NMFS) shark tagging
study. Over the last ten years we have tagged and released nearly 200 sharks during
the course of our collecting trips. We (in cooperation with the NMFS) are also in the
preliminary stages of a population index of juvenile sandbar sharks in the Delaware
Bay. This Bay, which we have fished regularly for nearly 14 years, is an important
nursery ground for juvenile sandbars and sand tiger sharks.

The Shark Specialist Group of the IUCN is currently developing a shark conservation
Action Plan. As members of the SSG, we are proposing to create a subsection of this
group composed of representatives of as many aquariums world-wide as are willing to
enlist. In this fashion those aquariums that display sharks can add their input to the
shark conservation movement.

Sharks are a proven draw for the public. At the NAIB the shark exhibit has been the
most popular exhibit for almost the entire history of the aquarium. It is probable that this
is also the case at most institutions that display sharks. That popularity can be used to
the good advantage of the shark conservation movement.


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Shark Info
Shark Specialist Group member Erich Ritter has just launched a new Zurich-based
media information service. Shark Info will provide clearing house to convey accurate
and interesting information from the shark research community to educate the general
public through the news media. Initially focused on German-speaking Europe, the
service will make articles and photographs available free of charge to newspapers,
magazines, TV and radio stations. Its objective is to ensure that the increasing public
interest and awareness in sharks and rays is maintained without the need to resort to
sensationalist and inaccurate reporting. -.

For more information contact Shark Info, Walchestr. 17, CH-
8006 Zurich. Switzerland. Phone: (+41) 01 363 1270, Fax: (+41)
01 363 1706.
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Galapagos Under Siege
Recent events in the Galapagos Islands continue to raise concern about the future of
all living marine resources, including sharks, in the archipelago. On 3 September 1995,
a group of individuals in Galapagos closed the road to the National Park Headquarters
and Charles Darwin Research Station, occupied the Park Headquarters, closed the
road to one airport, and took over another airport. In addition, they threatened to take
tourists hostage and burn parts of the National Park. This is the third time since August
1994 that a small interest group has threatened violence against the conservation
institutions of the Galapagos Islands. -

The 'strike' resulted from discontent over a decision by Ecuador's President Duran-
Ballen to veto a new special law for the Galapagos. The law would have, among other
things, turned over the majority of the control and management of the Galapagos
National Park and other natural resources to local political interests. Such a precedent *
would pose a grave threat to the integrity of the Galapagos Marine Resource Reserve.
These same political interests have fought necessary controls on sea cucumber fishing
and have pressed to open the Galapagos to large-scale export fisheries (Camhi 1995).

As we go to press, the situation is worsening. Although the sea cucumber fishery is
officially closed, more than 600,000 sea cukes per month are being exported to Asian
markets, along with sea horses, pipefish and sea urchins. Despite the official ban on
shark fishing in the Reserve, there is evidence that illegal shark fishing and finning ^ *
continues.

The conservation community supports President Duran-Ballen in his refusal to
negotiate with individuals that incite violence and threaten destruction of public
resources. A special law is needed for Galapagos to address the issues of
unsustainable marine resource exploitation, uncontrolled immigration, introduction of
exotic species, and appropriate socio-economic development for Galapagos residents.
But Ecuador must reject the path of intensive fishing for export markets if the
Galapagos Islands are to remain an ecological treasure of national and global
significance and a long-term and dependable source of income for Ecuador.
Camhi, M. 1995. Industrial fisheries threaten the ecological integrity
of the Galapagos Islands. Conservation Biology 9(4): 715-719.
Merry Camhi
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Cyanide Spill in the Essequibo River, Guyana
Regrettably fulfilling one of the predictions made by Compagno and Cook (1995), the
Essequibo, Guyana's largest river, was affected in August by a major cyanide waste
spill. More than 325 million gallons of the toxic chemical were reported in Earthweek
(Chronical Press) to have escaped from a gold mine operated by US and Canadian
companies. Large numbers of fish, mammals and birds were killed and public drinking
water supplies threatened as the spill flowed 50 miles downstream. International relief
teams rushed to divert the cyanide into a holding pond near the mines, which use the
chemical to extract gold. -.

Species potentially affected by this spill may have included the bull shark Carcharhinus
leucas, largetooth sawfish Pristis perotteti, and smoothback river stingray
Potamotrygon orbignyi. The stingray is well-recorded from the Essequibo as part of a
wider distribution that includes Venezuela, Guyana, French Guiana, Suriname, the 6
Columbian and Brazilian Amazon and Para River drainages.

Cyanide and related cyanogen glycosides are listed as "supertoxic" compounds by
Turkington (1994). Fewer than seven drops of most liquid forms can kill a 68 kg (150
Ib) man in less than 15 minutes, depending upon factors that alter rate of absorption.
Cyanides act through interference with enzyme activity at oxygen sites in haemoglobin
of red blood cells and myoglobin in muscle tissue for vertebrates, and the counterpart
oxygen-carrying porphyrins for invertebrates (haemocyanin etc.). Binding of sites is *
regarded as irreversible, with death depending on how much oxygen deprivation
occurs as a percentage of total innate oxygen-carrying capacity for given porphyrins
and animal size. Small animals are considered to be disproportionately susceptible to
fatality at lower ambient cyanide levels.

References

Compagno, L.J.V., and S.F. Cook. 1995. The exploitation and
conservation of freshwater elasmobranchs: status of taxa and
prospects for the future. In: Volume VII -The biology of freshwater
elasmobranchs (ed. Oetinger & Zorzi). Journal of Aquariculture and Aquatic Sciences,
VII: 62-90.

Compagno, L.J.V., and S.F. Cook. 1995. Freshwater elasmobranchs:
a questionable future. Shark News 3: 4-6.

Turkington, C. 1994. Poisons and antidotes: everything you need to
know. Facts on File Press. New York. 372 pp.

Sid Cook
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Australian White Shark News


Earlier this year, the
South Australian
Fisheries Department
circulated A discussion
paper which included a .
proposal for the -
protection of the great
white shark in State
waters. Responses to
paperW ae st bei hite shark. Copywrite 1989 by Sid Cook. All rights
this paper are still being reserved.
considered. In res
September, the Australian Seafood Industry Council announced that it had adopted a
recommendation to seek an end to targeted fishing for this species in the waters of all
Australian states, and would be writing to the states' fisheries management agencies to
seek their views on the recommendation. (Targeted fishing is actually only a very
limited activity in Australia; far more white sharks are taken as by-catch in fisheries or
beach meshing programmes.) This recommendation has been welcomed and
supported by the Australian Marine Conservation Society.

We hope to feature an article updating readers on progress with these initiatives in the
next issue of Shark News (No. 6).



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Large Coastal Atlantic Shark Fisheries Closure Notice
The National Marine Fisheries Service closed the commercial fishery for large coastal 9
sharks in the Western North Atlantic Ocean, including the Gulf of Mexico and
Caribbean Sea, at 2300 hours local time 30 September 1995, through 31 December
1995. This action was necessary to prevent exceeding the semiannual quota for the
period 1 July through 31 December 1995. Fishing for pelagic and small coastal sharks
could continue and the recreational fishery was not affected by this closure.


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Bibliography; Technical Reports and Publications
A Global Representative System of Marine Protected Areas. 1995.

G. Kelleher, C. Bleakley and S. Wells (eds). Four volumes.
Joint publication of The Great Barrier Reef Marine Park Authority,
The World Bank and The World Conservation Union (IUCN). Contact:
Environment Department, The World Bank, Room S 5-143, 1818 H
Street NW, Washington, D.C. 20433. Fax. (+1) 202 477 0568.

Copeia. 1995. No. 3. Papers from the American Elasmobranch Society symposium on
Elasmobranch Genetics, 1992.

Includes: Gaida, Evolutionary aspects of gene expression in the Pacific angel shark,
Squatina califomica; Eitner, Systematics of the genus Alopias with evidence for the a -.
existence of an unrecognized species; Heist, Graves and Musick, Population genetics
of the sandbar shark Carcharhinus plumbeus in the Gulf of Mexico and Mid-Atlantic
Bight; Dunn and Morrissey, Molecular phylogeny of elasmobranchs; and Chang, Sang,
Jan and Chen, Cellular DNA contents and cell volumes of batoids.

A database compiled from early case histories in the International Shark Attack
file. 1995. H.D.Baldridge.
Covers cases 1-1655 of the File, dating to early 1971. -

Shark Attack: a program of data reduction and analysis. 1974.
H.D.Baldridge.
Summarises trends in shark attack world-wide.

Both the above may be purchased from
The International Shark Attack File,
Florida Museum of Natural History, Division of Fisheries,
University of Florida, Gainesville, FL 32611, USA.
Fax. (+1) 904 3921721, email [gburgess@flmnh.ufl.edu].
Send check or money order for US$11.00 each,
payable to the American Elasmobranch Society.
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