Sharks swim closer to extinction
- From: chatnoir <wolfbat359a@xxxxxxxxxxxxxx>
- Date: Thu, 22 May 2008 19:12:42 -0700 (PDT)
http://news.bbc.co.uk/2/hi/science/nature/7413948.stm
Sharks swim closer to extinction
By Richard Black
Environment correspondent, BBC News website
More than half of the world's ocean-going sharks are at risk of
extinction, a new analysis concludes.
Specialists with IUCN (formerly the World Conservation Union) found
that 11 species are on the high-risk list, with five more showing
signs of decline.
Sharks are particularly affected by over-fishing as they reproduce
slowly.
The scientists are calling for global catch limits, an end to the
practice of removing fins, and measures to minimise incidental catches
(bycatch).
"There's this idea that because these are widely ranging species,
they're more resilient to fishing pressure," said Sonja Fordham,
deputy chair of the IUCN Shark Specialist Group (SSG) and policy
director for the Shark Alliance conservation group.
"In fact they're becoming species of serious concern because there are
no international catch limits for sharks. There are intense fisheries
on the oceans, and they remain pretty much unprotected."
New threats
The SSG assessed data on the 21 species of sharks and their close
cousins, the rays, that swim in upper portions of the open ocean where
they are exposed to fishing fleets.
Of the 21, one - the giant devilray - is assessed as Endangered, and
10 are Vulnerable.
A further five are listed as Near Threatened, which means the signs of
decline are not serious enough yet to merit a full listing.
The classifications are based on a range of criteria that look at past
or forecast declines in population size. For example, a population
shrinking by 50% in 10 years would usually qualify as Endangered.
Some of these species have been assessed before; but for others,
including the three species of thresher sharks with their
spectacularly long tails, the dangerlisting is new.
Fin cuts
The main threat to sharks is fishing, both accidental and targeted.
"They used to be taken as bycatch by boats targeting tuna and
swordfish," said Ms Fordham. "But now as those species are declining
we're seeing more fishermen targeting sharks.
"Porbeagle and shortfin mako are targeted for fins and meat; species
like blue shark are likely to be finned, but particularly in Europe
we're seeing more blue shark being landed."
Several of the bodies that regulate fisheries in international waters
- the Regional Fisheries Management Organisations (RFMOs) - have set
up measures to curb shark finning, but there are different standards
in place, a situation that enables fishermen to work around the
regulations.
As East Asian economies boom, conservation groups say the market for
fins is increasing.
"Fishery managers and regional, national and international officials
have a real obligation to improve this situation," commented Nicholas
Dulvy from Simon Fraser University in Vancouver, the report's lead
author.
"But it doesn't have to be like this. With sufficient public support
and resulting political will, we can turn the tide."
The report was released at the Convention on Biological Diversity
(CBD) meeting in Bonn, and will be published in the journal Aquatic
Conservation: Marine and Freshwater Ecosystems.
The new risk assessments will be included in the IUCN Red List of
Threatened Species when it is published later this year.
.
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