The announcement Oct. 22, in a Washington, D.C., teleconference, opens a 60-day public comment period on the measure, which identifies three separate areas of habitat: sea ice, barrier islands and ice.

Identification of critical habitat was triggered by the listing of polar bears in 2008 as threatened under the federal Endangered Species Act. Under an agreement reached by several environmental groups, the Interior Department has until June 30, 2010, to finalize critical habitat designation for the polar bears.

"This administration is fully committed to the protection and recovery of the polar bear," said Interior Assistant Secretary for Fish, Wildlife and Parks Tom Strickland, addressing media at the teleconference.

Proposing critical habitat for this "very iconic and beloved species is one step in the right direction to help this species stave off extinction, recognizing that the greatest threat to the polar bear is the melting of Arctic sea ice caused by climate change," he said. "As we move forward with a comprehensive energy and climate strategy, we will continue to work to protect the polar bear and its fragile environment."

The 200,541 square miles proposed for critical habitat is mainly sea ice located over the continental shelf and includes waters 300 meters and less in depth. Also proposed for inclusion are coastal barrier islands and spits along Alaska's coast used for denning, refuge from human disturbances, access to maternal dens and feeding habitat, as well as for travel along the coast.

The designation of critical habitat may affect future oil and gas activity through increased scrutiny and longer permitting times, said Karen Matusic of the American Petroleum Institute.

Shell Oil spokesman Curtis Smith said that Shell's polar bear current policy "meets or exceeds all existing regulatory requirements, including reporting, training and avoidance measures. If regulations change, Shell will work with stakeholders and permitting agencies to determine what, if any additional mitigation measures are needed."

The federal Minerals Management Service currently is reviewing Shell's plan for exploration drilling in the Chukchi Sea next year. Shell officials have said they hope to drill one or two wells in the Chukchi, as well as two exploration wells in the Beaufort Sea, west of Kaktovik, in Camden Bay. The latter plan has received conditional approval from MMS.

Matusic said that API is encouraged that the notice of critical habitat was crafted in such a way that allows oil and gas production to take place in the proposed polar bear habitat area.

"Our industry's track record speaks for itself and it shows we have operated safely in the area inhabited by the polar bear (in a way) that minimizes or avoids harm to the species," Matusic said in a telephone interview from Washington, D.C. "We believe the (government) agencies acknowledge this and we will continue to demonstrate the ability to operate safely. We do respect the polar bears and we are used to working around wildlife."

The oil industry will continue to demonstrate its ability to operate in a responsible manner, she said.

Environmental groups applauded the proposal.

"As sea ice habitat shrinks, it becomes increasingly important to protect areas that are crucial for the bears' survival," said Geoff York, senior program officer for polar bear conservation at World Wildlife Fund, an organization based in Washington, D.C., that has worked with Arctic communities, scientists and governments to enhance polar bear conservation.

Spokespersons for the Center for Biological Diversity, the Natural Resources Defense Council and Greenpeace also lauded the proposed habitat protection, but some noted that the announcement came in the same week that the Interior Department approved Shell's plan to drill exploratory wells on two leases in the Beaufort Sea.

Brendan Cummings, senior attorney with the Arizona-based Center for Biological Diversity, called the Interior Department "schizophrenic" for "declaring its intent to protect polar bear habitat in the Arctic, yet simultaneously sacrificing that habitat to feed our unsustainable addiction to oil."

Melanie Duchin, a Greenpeace campaigner in Anchorage, said "as long as the secretary of the Interior maintains that he can do nothing about greenhouse emissions and global warming, protections for the polar bear will ultimately be ineffective."

The state of Alaska, meanwhile, has filed a supplement to the state's earlier lawsuit in federal court in Washington seeking to overturn the listing of polar bears as threatened under the Endangered Species Act.

Gov. Sean Parnell said during a news conference in Anchorage that the motion was filed Oct. 20 in federal district court in Washington, D.C. The state has argued that potential limits the designation would impose limits on resources development in Alaska.

"If the legal theory underlying the polar bear listing is accepted and becomes widespread," it would mean "any species that lived in an Arctic environment could be listed under the Endangered Species Act," said Alaska Attorney General Dan Sullivan, who joined Parnell at the news conference.

Such a decision, said Sullivan could make "Alaska the world's largest zoo."