The IUCN/SSC Shark Specialist Group
Shark News 11: July 1998
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The American Zoo & Aquarium Association: Elasmobranchs in Public Aquaria
Doug Warmolts, The Columbus Zoo, USA
The American Zoo & Aquarium Association (AZA) consists of over
180 accredited zoological parks and aquariums in North America.
Collectively, AZA institutions reach over 122
million visitors annually. AZA members
support a growing number of cooperative
wildlife research and conservation efforts,
both regionally and internationally. In 1995
alone, members initiated or supported over
1,200 conservation projects in over 60
countries and published 660 articles on
wildlife management and biology. Through
its newly reorganised Marine Fishes Taxon
Advisory Group (MFTAG), the AZA plans to
expand its support of and participation in
elasmobranch conservation. Three examples
of on-going programmes by AZA institutions follow:
Photo:Sea Life Centres, UK. ©
Waikiki Aquarium
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Waikiki Aquarium shark researcher Gerald
Crow, Brad Wetherbee, and Chris Lowe from
the University of Hawaii are studying the
effect of fishing control programmes on shark
populations around the main Hawaiian
islands. Their series of papers (review of shark control, diet of the
tiger shark, and a paper in preparation on the reproductive biology
of the tiger shark) have raised awareness of the limits of our
knowledge of shark population biology. The researchers also
testified at the Hawaii State Legislature to stop a planned shark
control fishing programme.
The Waikiki Aquarium has served as a vital source of factual
information on shark biology. A current project at the Aquarium is
a study of the thyroid gland. This research will determine baseline
thyroid hormone concentrations from healthy and goitred whitetip
reef sharks. The project also will investigate worldwide pathology
records of goitred animals from the Registry of tumours of lower
vertebrates. Goiters are one of the most common long-term
problems in the husbandry of elasmobranchs in captivity. Although
rare this condition has also been reported from the wild. This
project will summarise pathology conditions and suggest possible
solutions to this disease. The paper will be the first comprehensive
review of goiters in elasmobranchs ever conducted.
The Waikiki Aquarium is currently maintaining the following
sharks and rays: four blacktip reef sharks Carcharhinus
melanopterus, one zebra shark Stegostoma fasciatum, one brown
banded bamboo shark Chiloscyllium punctatum, and one pelagic
ray Dasyatis violacea.
Monterey Bay Aquarium
The exhibits at the Monterey Bay Aquarium (MBA) are designed as
habitat displays exhibiting fish and invertebrate communities. The
Monterey Bay Habitats exhibit features sevengill sharks
Notorynchus cepedianus, leopard sharks Triakis semifasciata,
spiny dogfish Squalus acanthias and big skate Raja binoculata.
The Outer Bay exhibit features soupfin shark Galeorhinus
galeus. Almost all of the other exhibits have elasmobranchs along
with teleosts, and some exhibit tanks are dedicated to big skate
and swell shark Ephaloscyllium ventriosum egg cases. MBA
maintains a bat ray Myliobatis californica 'petting pool' that will
change in the future to a habitat display exhibiting animals that use
wetlands as nursery grounds.
MBA interprets shark conservation messages, with its education
programmes including a shark night for members and volunteers.
The overfishing of shark stocks is interpreted with videos in our
auditorium and also during our kelp forest feeding show.
MBA research on captive elasmobranchs includes looking for
new husbandry techniques to allow the maintenance of blue
sharks Prionace glauca on exhibit in the Outer Bay exhibit, as well
as deep water animals such as filetail catsharks Parmaturus xaniurus,
and ratfish Hydrolagus colliei, to be featured in a new exhibit on
the animals of the Monterey submarine canyon.
Description of mating in the ratfish and an ongoing captive
growth study of the pelagic ray have also been part of the
programme. MBA staff are also looking at tooth shedding rates and
metabolic rates of the pelagic ray.
A captive growth study on the sevengill shark was conducted
at MBA in the past (Van Dykhuizen and Mollet 1992) and now we
tag all sevengill sharks that are released from the aquarium due to
snout abrasions, and send the information to California Department
of Fish and Game for their pelagic shark database. MBA also
learned that one animal released from the aquarium was at liberty
for two years and also showed homing behaviour, swimming over
three hundred miles to the point of original capture. This incident
makes us believe that sevengill sharks may be released back into
the wild with good chances of survival.
The Wildlife Conservation Society
The mission of the Wildlife Conservation Society's (WCS) Fisheries
Programs is to generate scientific information vital to the
maintenance, conservation, and recovery of fish populations and
the habitats that support them, and to promote the responsible and
sustainable use of fisheries resources.
A critical lack of scientific information, combined with poor
and inadequate management policies and practices, has resulted
in widespread overfishing and the severe depletion of oceanic,
coastal and freshwater fish populations around the globe. WCS's
Fisheries Programs, based at the Society's Osborn Laboratories of
Marine Sciences (OLMS), seek to address the current fisheries
crisis through the integration of basic and applied research and
policy work. Current areas of thematic emphasis include: 1)
quantitative fishery analysis and assessment; 2) bycatch; 3) small-scale
fisheries; 4) threatened freshwater fishes; and 5) coastal
sharks and highly migratory pelagic fishes.
Sharks and other ocean giants such as tuna, marlin and swordfish
are being depleted at an alarming rate. While declines of all these
species are being driven, in part, by market demands, bycatch
remains the major source of mortality for sharks on a global basis.
Many shark species are long-lived, grow slowly, mature late and
produce few offspring, which makes them particularly susceptible
to overfishing, and very slow to recover once depleted. Highly
migratory sharks routinely cross national boundaries, yet
international management plans for these species are non-existent.
Moreover, there are serious gaps in data and methodologies
needed to assess and manage these populations properly.
WCS's work on sharks integrates several Fisheries Program
themes: quantitative assessment, bycatch and the international
aspects of fisheries issues. At present, novel quantitative fishery
analysis and assessment methods are being developed and applied
to assist recovery of populations of large coastal sharks in the
Northwest Atlantic Ocean, some of which have declined by 80%
in the past decade. The expertise of WCS scientists in developing
techniques for reducing bycatch is being applied to shark bycatch
concerns. This year we are testing the feasibility of using satellite
telemetry to track sand tiger sharks and to evaluate the ability of
this technique to estimate bycatch survival. A shark research
facility at WCS's Osborn Labs is currently in planning. Through
WCS's science, policy and international expertise, and through
our work with the Ocean Wildlife Campaign (OWC) - a coalition
of conservation organizations dedicated to conservation and
restoration of giant ocean fish - WCS's Fisheries Programs is
working to effect policy changes that will conserve, restore and
manage shark populations both regionally and globally.
Reference
Van Dykhuizen, G. and Mollet, H. F. 1992. Growth, age estimation,
and feeding of captive sevengill sharks, Notorynchus
cepedianus, at the Monterey Bay Aquarium. In: Sharks: Biology
and Fisheries. J.G. Pepperell ed. Australian Journal of Marine
and Freshwater Research 43:297-318.
Doug Warmolts,
Columbus Zoo,
9990 Riverside Drive, Box 400,
Powell, Ohio 43065-0400, USA.
Fax: +1 614 645 3465
Email: dwarmolt@colszoo.org
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