The leatherback sea turtle is the largest marine turtle in the world, weighing up to 2,000 pounds and stretching 8 feet long. The turtles have been listed as endangered since 1970.
Catherine Kilduff with the Center for Biological Diversity said the rule protects the turtles' foraging grounds where the leatherbacks feed on jellyfish after swimming thousands of miles across the ocean from nesting grounds in Indonesia, Australia and Mexico.
"These turtles have been on the endangered species list for decades now and this is the first protections in U.S. continental waters for leatherback sea turtles," said Kilduff. "And so we're hoping this can really jumpstart the recovery of the species."
The protection is effective February 25.
The Center for Biological Diversity sued the federal agency in 2009 after it missed a deadline to designate the area as a safety zone.
Kilduff said the designated protection area is fewer square miles than originally proposed and the final rule overlooks the need to protect turtles' migratory paths from commercial fishing, water pollution and marine vessel traffic.
She said the new regulation excludes protections for migration through these habitats and also excludes consideration of dangers to the turtles from fishing, such as mile-long drift nets used for swordfish off California.
The final protection comes in response to a petition submitted in 2007 by Oceana, Turtle Island Restoration Network and the Center for Biological Diversity.
Kilduff said Pacific leatherback sea turtles have declined more than 95 percent since the 1980s and as few as 2,300 adult female western Pacific leatherbacks remain.
The leatherback sea turtles feeding off the U.S. West Coast make the longest known migration of any reptile, across the Pacific Ocean where they nest on beaches in Papua, Indonesia.
