By DAN JOLING, Associated Press

ANCHORAGE, Alaska (AP) — The federal agency that oversees the U.S. seal population has proposed 350,000 square miles of ocean off Alaska's north and west coast as critical habitat for the main prey of polar bears.

The National Oceanic and Atmospheric Administration announced Tuesday that it's proposing critical habitat for ringed seals throughout U.S. jurisdiction in the Beaufort and Bering seas and in much of the western Bering Sea.

"After reviewing the best available information, our scientists identified the habitat features that are essential for sustaining Arctic ringed seals — a species that is likely to become endangered in the foreseeable future due to climate change," said James Balsinger, NOAA Fisheries Alaska regional administrator, in the announcement.

The public will have 90 days to comment.

A critical-habitat designation means federal agencies that issue permits for activities within the designated waters, such as proposed petroleum drilling in the Chukchi, must consult with NOAA Fisheries to determine effects on ringed seals.

A species is threatened if it's likely to become endangered within the foreseeable future throughout a significant portion of its range. Ringed seal were declared threatened in December 2012 when federal scientists concluded that a significant decrease in sea ice was probable this century and the changes would likely cause the ringed-seal populations to decline.

The state of Alaska, which unsuccessfully fought the listing of polar bears, also objected to the listing of ringed seals, noting that the current population is in the millions and is not in decline.

U.S. Sen. Lisa Murkowski, R-Alaska, in a release called it "an unprecedented attempt to place restrictions on a larger than Texas-sized area of water surrounding our state."

She said she's skeptical of the listing based on a "100 year weather projection" that could restrict petroleum drilling, marine transportation, port development and commercial fishing.

Ringed seals are the only seals that thrive in completely ice-covered Arctic waters. They use stout claws to dig and maintain breathing holes.

When snow covers those holes, females excavate and make snow caves, where they give birth to pups that cannot survive in ice-cold water and are susceptible to freezing until they grow a blubber layer. Hungry polar bears often catch breeding females or pups by collapsing lairs.

Ringed seals also use sea ice for molting.

A more dire threat than polar bears is less sea ice, decreased snowfall or rain falling on lairs instead of snow, leaving pups exposed to the elements, according to proponents of the listing.

Shaye Wolf of the Center for Biological Diversity, who wrote the listing petition, hailed the proposed critical-habitat designation. At almost twice the size of California, it would be the largest ever.

The designation would be an added layer of protection from Arctic activities, she said, but will not keep sea ice from melting. She also called on the Obama administration for bold action on greenhouse gases that are making the Arctic uninhabitable for ringed seals and other ice-dependent animals.

"It's climate disruption, it's global warming, that's causing the ice to melt," she said.