The IUCN/SSC Shark Specialist Group
Shark News 7: June 1996
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Marine fish added to list of world's most threatened animals
Elodie Hudson, Zoological Society of London, UK
The conservation of marine species, especially fish, has long taken
second place to terrestrial conservation concerns. Little is known
about the health of the marine environment, and whether the risk of
extinction is a real threat to fish species, many of which are a major
source of food to the world's growing human population.
A first attempt to assess threats to species in the seas was made by
31 leading scientists at a workshop held by the Zoological Society of
London (ZSL), the World Wide Fund for Nature (WWF) and the World
Conservation Union (IUCN) in April this year. Using the new IUCN
categories and criteria for assessing threat, they evaluated 148 species
of marine fish, ranging from seahorses and coral reef fish, to sharks and
tunas. The aim of the meeting was twofold. First to assess the threat
status of the candidate marine species, and second to assess the
applicability of the new IUCN categories to marine fish.
The threat classification system of the IUCN recently underwent
a major revision. The new system is intended to be flexible, objective
and systematic. It operates on a system of five criteria which reflect the
biological and environmental factors which can cause extinction.
Only one of these five criteria needs to be met for a species to qualify
for threatened status, and quantitative thresholds are given for each
criterion to define the category of threat (Critically Endangered,
Endangered, or Vulnerable) the species will fall into. There are also
categories for species at low risk, not evaluated, or for which data is
insufficient (Data Deficient), so effectively all animals can be placed
somewhere in the system.
The workshop participants evaluated a candidate list of 148
species of marine fish and found 118 of them to be threatened. Of
these, ten were classified in the highest threat category, Critically
Endangered. Among the threatened fishes were several species of
shark (including the great white), tuna, groupers, cod, haddock,
swordfish, halibut, many coral reef fish, and seahorses. The major
threat to these fishes is chronic overfishing, be it for food, shark fin
soup, aquaria, the Chinese medicine trade, the live food trade or for
sport. Habitat destruction is also a problem, especially for fishes living
in coastal habitats such as coral reefs or mangrove swamps. These fish
will appear alongside other threatened animals in the IUCN Red List
of Threatened Animals, which will be published in October at the
World Conservation Congress in Montreal. Their presence on the list
will hopefully elevate the importance of protecting the marine
environment in the minds of decision makers and conservationists
alike. The list has no specific legal force, but is used by governments
and other organisations as a guide to setting priorities for conservation.
From the evaluation process emerged guidelines to help future
evaluators to use the IUCN categories - these continue to be developed.
In most cases, the criteria were felt to be appropriate for assessing the
threat status of marine fish. In some cases they were not, and these are
the focus of continuing work. The overriding problem with applying
the criteria is that scientists are hampered by a lack of knowledge of
marine ecosystems and their component species. Hopefully this
stimulating and interactive workshop will act as a catalyst for further
efforts in the current climate of growing concern over the oceans and
the valuable resources they contain.
(The above was originally commissioned for Living Oceans News.)
Elodie Hudson, Institute of Zoology, Zoological Society of
London, Regent's Park, London, NW1 4RY, UK.
Tel: 44 (0)171 449 6690, fax: 44 (0)171 483 2237,
email e.hudson@ucl.ac.uk
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