60秒科学:DNA Testing to Help Sharks Keep Fins（在线收听）

DNA Testing to Help Sharks Keep Fins
In a study in the journal Endangered Species Research, shark fins on sale were shown to be from a specific region in which shark populations have collapsed, evidence that may help change fishing regulations. Cynthia Graber reports

I should start this podcast off with an admission—I have a serious problem with shark fin soup. Fishermen slice the fin off the shark and toss the creature back into the water to die. This happens to millions of sharks around the world, and some of those shark populations are endangered. Scientists have been trying to figure out which shark populations are most at risk by the slash-and-toss. Now there’s new DNA evidence that’s aiding the effort.

Researchers used a tool called “genetic stock identification” to test samples of 62 scalloped hammerhead shark fins—an endangered species—from the Hong Kong fin market. They analyzed the mitochondrial DNA, which is passed down from the mother and is traceable to the sharks’ birth waters. Fifty-seven of those sharks came from Atlantic and Indo-Pacific waters, and 21 percent live in the western atlantic, where sharks’ numbers have now collapsed. The results were published online in the journal Endangered Species Research.

Scientists will bring these results to the 2010 Convention on International Trade in Endangered Species meeting. A change in the sharks designation at that meeting could lead to better protection from commercial exploitation.