On the West Coast, the loggerhead turtles make their home in ocean waters off San Diego and Baja California.
Peter Dutton is a research scientist at the National Marine Fisheries Service in San Diego. He uses genetics and satellite telemetry as tools to study the life history, migration and habitat use of sea turtles. He said the turtles nest in Japan before finding their way to the west coast.
Dutton said one reason for the decline is development along Japan beaches where the turtles lay their eggs.
"And then the other thing is once they are on the high seas they do get caught in fisheries, unintentionally," said Dutton. "So it's really going to take an international effort because it's not one, any one fishery or country that's taking them all."
He said you're more likely to see loggerheads off Baja than in San Diego.
"Most of the time we see them in San Diego washed up on the beach if they get into trouble, get sick or die then they wash ashore, but they're out there," Dutton said.
On the East Coast, loggerheads nest from Florida to the Carolinas but migrate as far north as New England. In the eastern Pacific, they've been spotted in Alaska but most are in California waters.
The Center for Biological Diversity said the loggerheads have declined by at least 80 percent over the past decade.
The group said although loggerhead sea turtles have been listed as threatened since 1978, Friday's rule recognizes that some populations are nearing extinction from fisheries bycatch, climate change and marine pollution including oil spills.
"Pacific loggerheads need increased protections immediately to reverse their decline toward extinction," said Dr. Chris Pincetich, a marine biologist with the Sea Turtle Restoration Project of the Turtle Island Restoration Network. "Deadly high-seas longline fisheries, illegal poaching and the radioactive debris offshore of loggerhead nesting beaches in Japan all jeopardize these endangered sea turtles."
An attorney with the Center for Biological Diversity said the loggerheads need worldwide protection.
"This listing is a wake-up call that a whole host of threats, from oil spills, channel dredging and commercial trawling to longline and gillnet fisheries, continue to kill off turtles faster than the animals can possibly hope to reproduce," said attorney Catherine Kilduff.
In a news release, the Center said the decision by the National Marine Fisheries Service comes in response to two 2007 legal petitions by the Center for Biological Diversity, Turtle Island Restoration Network and Oceana for additional protections for the North Pacific and Northwest Atlantic loggerheads. The rule separates loggerheads into nine populations; five are now considered endangered.