In Shark Fin Soup, A Dash of Biodiversity
August 9, 2012
New York Times
by Kelly Slivka
A warm, brothy bowl of fibrous shark fin cartilage may not appeal to many palates, but every culture has its delicacies. Think of crunchy fried tarantulas in Cambodia, or a plate of garlicky snails in France.
Of course, the stigma surrounding shark fin soup arises not from its texture or consistency, but the source of the fins. Several shark species are considered endangered or vulnerable, but the largely unregulated global trade in their fins is booming, making it easy for them to end up in a bowl of soup. What if a fast-food chicken nugget could be made out of any bird – from albatross to great horned owls?
“Consumers of shark fin soup really have no idea what they’re getting,” saidDemian Chapman, a biologist with the Institute for Conservation Science at Stony Brook University. So he and collaborators from the Field Museum in Chicago and the Pew Environment Group collected samples of shark fin soup in 14 American cities and used DNA sequencing to try and figure out what species were used.
The researchers were able to match 32 of the 51 shark fin samples they collected from those cities, which included New York, Las Vegas and Los Angeles. (A ban on the shark fin trade took effect in California on Jan. 1, but existing stocks can be used until July of next year.)
Among the eight shark species identified in the study were blue, shortfin mako and bull sharks. One soup sample from Boston contained scalloped hammerhead DNA. Scalloped hammerheads are listed as endangered on the International Union for the Conservation of Nature’s Red List. Four other species of sharks found in various soups are listed as vulnerable by the organization. (The I.U.C.N. designations do not have the force of law.)
None of the species found in the soups are on the United States Endangered Species List or are protected by the Convention on International Trade in Endangered Species, commonly referred to as CITES. “It’s all perfectly legal,” Dr Chapman said. (The American list does not include any shark species; under the international convention, countries can agree voluntary to refrain from trading in specific species from certain places.)
It’s not easy to identify a species from the remnants of DNA found in thoroughly processed soup. Once the fins are cut off the sharks, they are dried in the sun. Then they are often shipped long distances, chemically treated, broken down and then cooked, Dr Chapman said. “That’s not exactly the ideal thing to do to DNA,” he said. He and his colleagues had been unsure they would find long enough intact pieces of DNA to match to the sequences of known sharks that Dr Chapman had on file.
Because they were successful in identifying many of the shark fin samples, Dr Chapman hopes the researchers’ methods can be applied by law enforcement in states that have approved bans on the sale, trade and possession of shark fins or are on the road to doing so, including Oregon, Washington, Illinois and Hawaii in addition to California.
He said the team’s findings underlined the need for more thorough regulations, given that a lack of control on the trade leads to the dangerous exploitation of species.
“If the trade was better regulated and shark fishing was more tightly regulated, I don’t think anyone would have a problem with shark fin soup,” Dr Chapman said.
Read the article in the New York Times
Read the news release
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