ANCHORAGE, Alaska – A conservation group filed Thursday to protect Pacific walruses because of the threat to their northern habitat by global warming.
The Center for Biological Diversity petitioned the U.S. Fish and Wildlife Service to list walruses as threatened under the Endangered Species Act because of warming and its effect on sea ice used by the animals as a feeding and resting platform. The group also said oil and gas development throughout the animals' range was a threat.
The listing request was filed as the Fish and Wildlife Service decides whether to list polar bears as threatened because sea ice has diminished due to global warming.
"The Arctic is in crisis from global warming," said Shaye Wolf, lead author of the petition and a biologist with the conservation group. "Arctic sea-ice is disappearing at a stunning rate that vastly exceeds the predictions of the best climate models."
Bruce Woods, a spokesman for the U.S. Fish and Wildlife Service in Anchorage, said the law calls for a review to determine whether the petition contains "substantial information" within 90 days if practicable.
If the petition passes that first hurdle, the agency would have nine months to perform a status review on walruses.
Summer sea ice last summer receded to 1.65 million square miles, the lowest level since satellite measurements began in 1979, according to the National Snow and Ice Data Center at the University of Colorado. In September, sea ice was 39 percent below the long-term average from 1979 to 2000.
Sea ice in the Chukchi Sea, the part of the Arctic Ocean between Alaska's northwest coast and the Russian Far East, receded well beyond the shallow outer continental shelf over water too deep for walruses to dive to reach clams and other benthic creatures they eat.
As many as 6,000 walrus in late summer and fall abandoned ice over deep water and congregated on Alaska's northwest shore.
Herds were larger on the Russian side, where one group reached up to 40,000 animals. Russian observers estimated 3,000 to 4,000 mostly young walrus died in stampedes when herds rushed into the water at the sight of a polar bear, hunter or low-flying aircraft.
Aside from stampedes, biologists worry that if current ice trends continue, and walrus are based on coastlines every summer, they will put tremendous pressure on nearby foraging areas rather than rich offshore feeding areas they historically have reached by living on the edge of the ice pack.
"The Pacific walrus is an early victim of our failure to address global warming," Wolf said. "As the sea ice recedes, so does the future of the Pacific walrus."
Unlike seals, walruses cannot swim indefinitely. Females and their young traditionally use ice as a diving platform, riding it north in spring and summer like a conveyor belt over offshore foraging areas, first in the northern Bering Sea, then into the Chukchi Sea.
An adult walrus can eat 200 pounds of clams in a day.
Scientists at the National Snow and Ice Data Center have said they do not expect summer sea ice to bounce back without changes in current warming trends. Mark Serreze, senior research scientist, said in December that the complete loss of summer sea ice by 2030 was a reasonable expectation.
Two scientists at the Naval Postgraduate School in Monterey, Calif., said last month the Arctic Ocean could be entirely ice-free during the summer months by 2013. Wieslaw Maslowski, research associate professor in the Navy school's Department of Oceanography, and researcher Jaclyn Clement Kinney modeled and monitored Arctic ice melt by analyzing data provided by submarines and satellites, scientific studies and records over the past several decades.
Wolf also said walrus are likely to be affected by petroleum development. The U.S. Minerals Management Service on Wednesday accepted high bids on 2.76 million acres of Chukchi Sea ocean bottom. Five other lease sales in the Pacific walrus's habitat in the Chukchi, Beaufort and Bering seas off Alaska's shore are planned by 2012.
Increased oil and gas development and a proliferation of shipping routes pose threats to the Pacific walrus from the heightened risk of oil spills and rising levels of noise pollution and human disturbance, according to the group.
Wolf said the window of opportunity to act is closing rapidly and rapid action is needed to reduce greenhouse gas emissions. She called for a moratorium on oil and gas development.
Oil and gas development, shipping, and greenhouse gas emissions affecting the Arctic would be subject to greater regulation under the Endangered Species Act if the walrus is listed.