A federal agency is proposing habitat protection for Alaska sea otters in the Aleutian Islands, where numbers have dwindled by more than half in 20 years.
The U.S. Fish and Wildlife Service proposal issued Tuesday would designate 5,879 square miles of ocean near the shoreline in Southwest Alaska as critical habitat.
About 90 percent of the world's sea otters live in coastal Alaska. The ones in the Aleutian Islands were declared threatened three years ago under the Endangered Species Act.
Eight years ago, the Center for Biological Diversity petitioned the government to protect Southwest Alaska's sea otters. The move came after numbers dropped from an estimated 100,000 animals in the 1970s to about 40,000 now.
The reasons for the drop-off are not known, although increased predation by killer whales is suspected to be a factor.
The conservation group maintains that proposals to open Bristol Bay in the Bering Sea to oil development, overfishing and changes caused by global warming are threatening sea otters.
Fish and Wildlife is proposing that all nearshore waters in the sea otter's current range in Southwest Alaska be designated as critical habitat. The agency says the nearshore waters are particularly important because they provide sea otters with cover and shelter from marine predators, particularly killer whales.
Once critical habitat is designated, all federal agencies would be required to ensure that any activities in the area would not harm sea otters.
Fish and Wildlife does not anticipate that the designation would result in any commercial fishing closures in Southwest Alaska. That's because the foods that sea otters eat, mostly sea urchins, crabs, octopuses and some bottom-dwelling fish, have little or no commercial value.
The agency says the areas proposed for critical habitat also are not areas where significant commercial fishing occurs.
Brendan Cummings, the Center for Biological Diversity's oceans program director, said the designation is a good beginning but doesn't go far enough. The critical habitat designation should extend not just a few hundred feet offshore but to at least a mile, he said.
By the early 1900s, the commercial harvest had reduced sea otter numbers to a few hundred. In Alaska, there are about 70,000 animals now.
The agency is accepting comments on its proposal until Feb. 17. The critical habitat designation must be finalized by Oct. 1.