Anchorage Daily News

Fresh off a successful campaign to list polar bears as a threatened species, a conservation group Wednesday petitioned to provide Endangered Species Act protections to the bears' main prey because of global warming.

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Ringed seals, above, as well as spotted and bearded seals live in the Bering, Chukchi and Beaufort seas.

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The Center for Biological Diversity petitioned the National Marine Fisheries Service to list ringed seals and two other species -- spotted and bearded seals -- as threatened or endangered.

All three seals live in the Bering, Chukchi or Beaufort seas off Alaska's coast and depend on sea ice that is receding rapidly, according to the petition.

"Ice is essential for them to give birth and rear their pups," said Shaye Wolf, a biologist and the lead author of the petition. "They won't be able to reproduce without ice."

The seals also rely on ice for molting.

"They have to replenish their fur every year," Wolf said from her San Francisco office. "They rely on the safety of the sea ice to molt their fur."

Sheela McLean, NMFS spokeswoman in Alaska, said the agency had not received the petition Wednesday afternoon but is already reviewing seals. The Center for Biological Diversity in December petitioned the agency to list ribbon seals, and McLean said biologists were preparing status reviews for all four seals. Each uses sea ice in a different way, she said.

"Careful status of each species is warranted," she said.

NMFS is part of the U.S. Department of Commerce. Polar bears are managed by the U.S. Fish and Wildlife Service, part of the Interior Department.

Interior Secretary Dirk Kempthorne two weeks ago announced polar bears would be listed as threatened because of sea ice loss. The Center for Biological Diversity announced Tuesday it would sue to force the Interior Department to respond to its petition to list walrus as a threatened species because of threats from global warming and offshore petroleum development.

Wolf said warming is occurring at a pace exceeding predictions of the most advanced climate models. Winter sea-ice extent in 2006 and 2007 declined to a minimum that most climate models forecast would not be reached until 2070, she said, and summer sea ice in 2007 shrank to record minimums.

Ringed seals are the most numerous of the seals that thrive off Alaska's coasts and the only seals that can survive in completely ice-covered waters.

They do so by digging out breathing holes in the ice with an adaptation on their front flippers -- unusually stout claws -- that allow them to excavate ice.

Holes dug by ringed seals eventually get covered by drifting snow. Within the drift, females dig out lairs to give birth and nurse pups. Pups stay on ice as their mothers dive below the ice to feed on fish and crustaceans.

With warming, ice and snow on top of it is disintegrating during critical rearing times, Wolf said, making pups vulnerable to predation by polar bears and their other enemy, the arctic fox. Polar bears can eat more than 40 ringed seals per year.

Pups also are susceptible to temperature stresses until they grow a blubber layer and shed their lanugo, the white, woolly coat they're born with.

"Mothers and pups get separated prematurely and the pups don't get nursed as long as they should be and they're not able to accumulate those critical blubber stores," Wolf said.

Bearded seals are the largest true seals off Alaska's coast and can reach weights of more than 750 pounds, according to the Alaska Department of Fish and Game. They are sought by subsistence hunters in Alaska for hides and meat. Bearded seals reproduce and rest on drifting pack ice.

Spotted seals are strongly associated with sea ice from autumn to late spring and bear young on drifting pack ice, according to state biologists.

Listing a species as "threatened" means it is likely to become endangered. "Endangered" is more dire and means a species is in danger of extinction throughout all or much of its range.

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