The new rules, released Thursday by the National Marine Fisheries Service, mean that longline fishing for swordfish will be prohibited in a 1,600-mile stretch of the Pacific Ocean between the West Coast and Hawaii.
The ban, scheduled to take effect on April 12, will affect about two dozen fishing boats based in California, Oregon and Washington. The fishermen, who are mostly Vietnamese American, have said that a ban on swordfish fishing would threaten their livelihood.
The United States makes up only about 5 percent of the global swordfish fishing fleet, Steiner said. Japan, Korea and Taiwan all have large fleets.
"It's an important step in protecting endangered sea turtles from going extinct," said Todd Steiner, director of the Turtle Island Restoration Network, which lobbied for the ban. "It won't save the sea turtles by itself, but when the U.S. takes proper action, it's in a better moral position to get other countries to also take action."
Tim Price, the National Marine Fisheries Service's assistant regional administrator for protected resources, said Thursday that the agency issued the ban after its scientists determined that continued swordfish fishing would jeopardize the survival of the leatherback and loggerhead sea turtles — two species protected by the federal law.
Longline fishermen use lines as long as 50 miles that carry thousands of baited hooks dangling within 100 feet of the ocean's surface to catch swordfish.
But many sea turtles — as well as sharks, dolphins and seabirds — also get caught on the hooks, causing injury or death. Federal officials have estimated that "long-lining" kills 61 loggerheads and 15 leatherbacks each year. Biologists say that the leatherback could become extinct in 10 to 30 years if current trends continue.
In 2002, environmental groups filed a lawsuit in the San Francisco-based federal appeals court after more than 30 swordfish boats moved to Southern California after they were barred by a 2001 federal ruling from operating out of Hawaii.
By Terence Chea