WASHINGTON (Reuters) - Overfishing has driven several species of shark to near extinction in the North Atlantic, researchers in Canada reported on Thursday.
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Jan 16, 2003
Populations overall are down by 50 percent over the past 15 years, with hammerhead shark populations down 89 percent, Julia Baum and colleagues at Dalhousie University in Halifax, Nova Scotia, report.
"Scalloped hammerhead, white and thresher sharks are estimated to have declined by over 75 percent in the past 15 years," they wrote in their report, published in the journal Science.
They analyzed logs kept by fishing boats seeking tuna and swordfish -- also heavily hit by fishing -- in the northwest Atlantic between 1986 and 2000. The fishing crews kept a record of every sea creature hooked on their longlines, which have 550 hooks on each line.
"We estimate that all recorded shark species, with the exception of makos, have declined by more than 50 percent in the past 8 to 15 years," they wrote.
Some areas have no white sharks at all, they reported.
"Our results show that overfishing is threatening large coastal and oceanic sharks in the North Atlantic," the researchers said. Marine reserves are not the answer, they added, because sharks range beyond the borders of such reserves.
In fact, a reserve can do harm if it concentrates fishing in smaller areas, they said. They recommended that protections for other large marine predators, such as sea turtles and tuna, be extended to sharks.
Why save sharks? They are extremely important to the marine ecosystem, scientists point out.
And despite media hype, they are not much of a threat to people.
George Burgess, director of the International Shark Attack File at the University of Florida, said 76 people were injured in unprovoked shark attacks around the world in 2001, and five were killed.
In contrast, as many as 100 million sharks are caught and killed around the world each year. They are hunted for their fins or killed accidentally by fishing boats.
Even Peter Benchley, the writer who brought sharks to worldwide prominence with his 1974 novel "Jaws," now campaigns on behalf of saving sharks.