for National Geographic News
Clarification: After this story was published, the editors were made aware of additional methods the study authors used to determine the number of sharks killed for their fins, as well as the inability to genetically trace shark meat to the animals' home waters. This information was added on October 25, 2006.
Some chicken stock, a few mushrooms, chicken breast, scallions, a little sherry, oil, spices—shark fin soup is fairly easy to prepare. But to make soup for six, you'll also need about a pound (half a kilogram) of shark fin meat.
Demand for that crucial ingredient has led to the killing of a median of about 38 million sharks a year, according to a new study that offers what may be the first reliable estimates of the number of sharks killed for their fins.
The United Nations has estimated that only about ten million sharks are harvested each year. Some conservationists, however, put the number at closer to a hundred million.
But until now estimates of the shark harvest were little more than guesses, because the numbers depended on shark fishers to report their catches.
The shark-fin industry, concentrated in a few Asian trading centers, is secretive and wary of any attempts to regulate, or even investigate, its practices.
To make matters murkier, most fisheries-management groups give little attention to sharks, because they are often considered bycatch—fish caught by accidentgiven their low value per pound.
"Apart from implementing various restrictions on the finning of sharks at sea in some countries—e.g., the U.S. and the EU—investment in setting up fisheries-management systems for sharks has been nonexistent for most shark fisheries," said study co-author Murdoch McAllister of the United Kingdom's Imperial College London.
How It Works
Murdoch and his colleagues' new, mathematical estimating method uses trade records from commercial markets and genetic techniques to identify species.
In their effort to accurately estimate the number of fins harvested—and therefore the number of sharks killed—the scientists conducted interviews with traders, studied thousands of auction records, observed auctions and shops for 18 months, and analyzed hundreds of fin samples.
In the end the researchers concluded that from 1996 to 2000 26 to 73 million sharks were traded yearly. The annual median for the period was 38 million—nearly four times the UN estimates but considerably lower than those of many conservationists.
SOURCES AND RELATED WEB SITES