At least 60,000 whales, dolphins, and porpoises die due to fishing-gear entanglements each year, according to a new estimate. Cetacean experts say the tally--the first of its kind--highlights the need for greater protection efforts.
Commercial whaling during the 20th century killed some 22,000 animals annually, causing severe declines in almost all large whale species before most nations stopped whaling in 1986. And tens of thousands of dolphins were trapped and killed by tuna fishing nets during the 1970s and 1980s, before many commercial fishers adopted "dolphin-safe" techniques. Despite these advances, 25 scientists at a cetacean bycatch workshop in Annapolis, Maryland, in January concluded that bycatch still kills more whales and their kin than any other human activity.
To gauge the severity of the problem, marine conservation biologist Andy Read of Duke University in Durham, North Carolina, tabulated estimates of fishing-related cetacean deaths reported by the U.S. National Marine Fisheries Service from 1990 to 1999. To derive the death toll worldwide, Read and his team calculated the ratio of cetacean bycatch to total U.S. fish catches and applied it to global catches. This is a "really conservative" measure, he says, since the U.S. takes more steps than other fishing nations to reduce bycatch. He reported the new estimate at the 23 July meeting of the U.S. Commission on Ocean Policy in Boston. The study also showed that U.S. mitigation efforts reduced cetacean deaths by about two-thirds between 1990 and 1999, "so we have some effective solutions to share with other countries," Read says.
Christopher Clark, a whale behavior specialist at Cornell University in Ithaca, New York, says that while the estimate isn't surprising, it's cause for concern. "Read has identified and helped focus attention on a real problem that is most probably critically impacting several endangered species of cetaceans," he says.
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