GLAND, Switzerland, June 24, 2009, ENS
One-third of open ocean sharks are threatened with extinction yet are virtually unprotected, according to new research by the fShark Specialist Group of the IUCN's Species Survival Commission.
The first study to determine the global conservation status of 64 species of open ocean sharks and rays reveals that 32 percent are threatened, primarily due to overfishing, and 52 percent of the shark species taken in high-seas fisheries are threatened.
"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," said Sonja Fordham, deputy chair of the IUCN Shark Specialist Group and policy director for the Shark Alliance.
In most cases, open ocean shark catches are unregulated or unsustainable, the study finds. Twenty-four percent of the species examined are categorized as Near Threatened, while information is insufficient to assess another 25 percent.
Many open ocean sharks are taken in the high seas tuna and swordfish fisheries. 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.
Finning bans have been adopted for most international waters, but lenient enforcement standards hamper their effectiveness, the shark specialists say.
Sharks are particularly sensitive to overfishing due to their tendency to take many years to mature and have relatively few young.
The IUCN Shark Specialist Group calls on governments to set catch limits for sharks and rays based on scientific advice and the precautionary approach.
Porbeagle sharks, Lamna nasus, are classified as globally Vulnerable, but are considered Critically Endangered in the Northeast Atlantic and and Endangered in the Northwest Atlantic.
IUCN experts classify Great Hammerhead, Sphyrna mokarran, and Scalloped Hammerhead, Sphyrna lewini, sharks, as well as Giant Devil Rays, Mobula mobular, as globally Endangered.
Smooth Hammerheads, Sphyrna zygaena, Great White, Carcharodon carcharias, Basking, Cetorhinus maximus, and Oceanic Whitetip, Carcharhinus longimanus, sharks are classed as globally Vulnerable to extinction.
The Blue Shark, Prionace glauca, the world's most abundant and heavily fished open ocean shark, is classified as Near Threatened.
The IUCN Shark Specialist Group is a network of 180 experts from 90 countries who are involved in research, fisheries management, marine conservation or policy development and implementation for sharks and their relatives; the skates, rays and chimaeras. The group is responsible for assessing the conservation status of the more than 1,000 species.