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One in Three Open-Sea Sharks, Rays Headed for Extinction

Hammerhead sharks and giant devil rays are becoming globally edangered, largely because of serious overfishing driven by the voracious human appetite for shark fin soup and other seafood, a comprehensive survey by experts from 90 countries has determined. Many other sharks and rays–one third of all their species–are also in trouble.

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NGS illustration by Shawn Gould

The first study to determine the global conservation status of 64 species of open ocean (pelagic) sharks and rays reveals that 32 percent are threatened with extinction, primarily due to overfishing, according to the International Union for Conservation of Nature (IUCN) Shark Specialist Group.

The percentage of open ocean shark species threatened with extinction is higher for the sharks taken in high-seas fisheries (52 percent), than for the group as a whole, the organization said in a news statement today.

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“Despite mounting threats, sharks remain virtually unprotected on the high seas,” said Sonja Fordham, deputy chair of the IUCN Shark Specialist Group and policy director for the Shark Alliance.

“The vulnerability and lengthy migrations of most open ocean sharks call for coordinated, international conservation plans. Our report documents serious overfishing of these species, in national and international waters, and demonstrates a clear need for immediate action on a global scale.”

The report was released ahead of an international gathering next week in Spain of managers responsible for high-seas tuna fisheries in which sharks are taken without limit. It also coincides with an international group of scientists meeting in Denmark to formulate management advice for Atlantic porbeagle sharks.

A shark head is left behind by an Uruguayan fisherman.

NGS photo by Bruce Dale

IUCN experts classify great hammerhead (Sphyrna mokarran) and scalloped hammerhead (Sphyrna lewini) sharks, as well as giant devil rays (Mobula mobular), as globally Endangered, the statement said.

Smooth hammerheads (Sphyrna zygaena), great white (Carcharodon carcharias), basking (Cetorhinus maximus) and oceanic whitetip (Carcharhinus longimanus) sharks are classed as globally Vulnerable to extinction, along with two species of makos (Isurus spp.) and three species of threshers (Alopias spp.).

Porbeagle sharks (Lamna nasus) are classified as globally Vulnerable, but Critically Endangered and Endangered in the Northeast and Northwest Atlantic, respectively.

The blue shark (Prionace glauca), “the world’s most abundant and heavily fished open ocean shark,” is classified as Near Threatened.

“Species are increasingly targeted due to new markets for shark meat and high demand for their valuable fins.”

“Many open ocean sharks are taken mainly in high-seas tuna and swordfish fisheries,” IUCN said. “Once considered only incidental ‘bycatch,’ these species are increasingly targeted due to new markets for shark meat and high demand for their valuable fins, used in the Asian delicacy shark fin soup. To source this demand, the fins are often cut off sharks and the rest of the body is thrown back in the water, a process known as ‘finning.’

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“Finning bans have been adopted for most international waters, but lenient enforcement standards hamper their effectiveness.”

Sharks are particularly sensitive to overfishing due to their tendency to take many years to mature and have relatively few young, IUCN continued.

“In most cases, pelagic shark catches are unregulated or unsustainable. Twenty-four percent of the species examined are categorized as Near Threatened, while information is insufficient to assess another 25 percent.”

NOAA Office of Law Enforcement agent counting shark fins.

Photo courtesy NOAA

Fifteen experts from government agencies, universities, non-governmental organizations, and institutions around the world took part in the preparation of the report.

The IUCN Shark Specialist Group called on governments to set catch limits for sharks and rays based on scientific advice and the precautionary approach.

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Full Protection Urged

“It further urges governments to fully protect Critically Endangered and Endangered species of sharks and rays, ensure an end to shark finning and improve the monitoring of fisheries taking sharks and rays.

“Governments should invest in shark and ray research and population assessment, minimize incidental bycatch of sharks and rays, employ wildlife treaties to complement fisheries management and facilitate cooperation among countries to conserve shared populations,” according to the group.

This week scientists from the International Council for Exploration of the Sea (ICES) and the International Commission for the Conservation of Atlantic Tunas (ICCAT) are meeting in Copenhagen to assess all Atlantic porbeagle populations and formulate recommendations for fishery managers.

Next week, San Sebastian, Spain will be the site of the second Joint Meeting of the five Regional Fishery Management Organizations (RFMOs) for tuna.

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IUCN is the world’s oldest and largest global environmental organization, with more than 1,000 government and NGO members and almost 11,000 volunteer experts in some 160 countries.

Photo courtesy NOAA

The IUCN Shark Specialist Group (SSG) is a network of 180 experts from 90 countries who are involved in research, fisheries management, marine conservation or policy development and implementation for chondrichthyan fishes (sharks and their relatives; the skates, rays and chimaeras).

The group’s mission is to promote the long-term conservation of these species, effective management of their fisheries and habitats and, where necessary, the recovery of their populations.

The IUCN Red List of Threatened Species is the most comprehensive conservation inventory of the world’s plant and animal species and a widely used tool for focusing attention on species of conservation concern. The assessments evaluate the conservation status of individual species, identify threatening processes affecting them and, if necessary, propose recovery objectives for their populations.