Two environmental groups are asking the Interior Department to declare loggerhead sea turtles that inhabit the Atlantic Coast officially endangered, maintaining that tens of thousands of the turtles are killed annually by commercial fishing and because of coastal development.

The loggerhead sea turtle is already classified as "threatened" under the federal Endangered Species Act, but environmentalists say a higher level of protection is needed for the turtles which nest primarily along the southern Atlantic Coast and to some extent off the Gulf Coast of Florida.

Loggerheads are the most common sea turtle seen in the Chesapeake. While they do not nest along the Chesapeake, they commonly feed in the Bay in the summer.

Oceana, a sea life advocacy group, and the Center for Biological Diversity filed a petition with the Interior Department and National Oceanographic and Atmospheric Administration in November asking that the Western Atlantic Sea Turtle be declared a sub-species and officially endangered.

The designation would provide the turtle and its habitat increased protection under the Endangered Species Act.

"Loggerhead sea turtles in the western Atlantic are in grave peril," said the petition. "Their numbers have plummeted to historic lows."

Elizabeth Griffin, a marine wildlife scientist at Oceana, said the biggest threat to the turtle comes from commercial and sport fishing as turtles often are caught in nets, fishing lines and other devices. The petition says turtles are also killed by ingesting refuse from plastic items to balloons.

Griffin said the turtles nest primarily along the Atlantic Coast from Florida to the Carolinas but they migrate as far north as New England. It's uncertain how many turtles there are, but a recent government report said tens of thousands are killed every year when caught in fishery nets and lines.

Commercial fishing is the single greatest human threat to the turtles but they have also been harmed by coastal development, which has deprived them of beach habitat and disturbed their nesting, the petition said.

Among the disturbing trends cited by the environmental groups is that loggerhead nesting in South Florida has declined by 39.5 percent since 1998.

The loggerhead sea turtle can grow to as big as 3.5 feet in length, weigh 400 pounds and live 30 years or more. Its population has been in decline for decades. The turtle was declared "threatened" under the Endangered Species Act in 1978.

While its population has been declining, Griffin said the actual number of turtles along the Atlantic coast is unclear. "That's a huge problem," she said in an interview, adding that if the government doesn't know how many there are, it can't set a number that it considers acceptable to be killed.

The environmental groups argue in their petition that climate change may put the loggerhead in yet more peril. If sea levels rise along coasts where there is development, beaches the turtles use for nesting may disappear and even a 1 degree temperature increase could significantly affect their reproduction, Griffin said.

"We need to ensure that there are robust and resilient populations of sea turtles that will be able to withstand the new and potentially deadly challenges of climate change," she said.

Interior's Fish and Wildlife Service and NOAA's National Marine Fisheries Service both have jurisdiction over the Endangered Species Act. Action on the turtle involves both agencies.