Special protection for Alaska

A vast swath of icy sea, barrier islands and coastal land on Alaska's oil-rich North Slope will be granted special protection because of its importance to the threatened polar bear, under a proposal released by the US Fish and Wildlife Service.

The agency proposes that 518,000 sq km of coastline and shallow Arctic Ocean waters be designated as critical habitat, a status of heightened protection afforded under the Endangered Species Act.

The area, which would be the largest ever designated for an Endangered Species Act-listed population, overlaps the territory with the largest existing oil fields in the US where companies operate and plan to explore more.

Tom Strickland, assistant Interior Secretary for Fish, Wildlife and Parks, said that the critical-habitat designation should not hinder further development as long as operations are responsible and careful.

Oil companies are already subject to rules for protecting polar bears imposed by the Marine Mammal Protection Act and under other aspects of the Endangered Species Act.

"The activities going on in the energy community, both onshore and offshore, were already subject to significant regulatory review and consideration as they might affect the bear prior to this step that we're taking today," Mr Strickland said.

"We believe that it will not be a significant additional burden on the industry for that reason, but it does further highlight the importance of trying to minimise any kind of activity in these critical areas that might adversely impact the bear."

Included in the designation are areas where polar bears establish their dens, give birth and nurse their cubs and forage for food, officials said. Over 90 per cent of the habitat is water that is often covered by sea ice.

Environmentalists said they were pleased with the plan, which is subject to a 60-day public review before it becomes final.