The U.S. Fish and Wildlife Service proposed designating more than 128 million acres (200,541 square miles) of coastal lands and waters along the north coast of Alaska as “critical habitat” for the polar bear, the worlds largest carnivore species found on land and listed as a threatened species under the Endangered Species Act since May 2008.
Once habitat is designated, federal agencies are prohibited from taking any actions that may “adversely modify” it. Species for which critical habitat has been designated have been found to be more than twice as likely to be recovering, and less than half as likely to be declining, as those without it.
Polar bears live in the Arctic on land and the surrounding sea. The total population is estimated at 20,000-25,000 individuals of which the North American population accounts for about 70% of the global population. Of the 19 recognized polar bear subpopulations, 8 are declining, 3 are stable, 1 is increasing, and 7 have insufficient data.
BBC: mother with cubs
Polar bears mate in spring, from late March to late May. Cubs are born in winter, between November and February in an average of 2 cubs per litter. The females nurse and care for their cubs for 2.5 years and are subsequently only available for mating once the cubs are independent, every three years. This accounts for the low reproductive potential of polar bears.
They seem to be at home in the Arctic seas and are remarkably good swimmers. However, they stay along the perimeters of the ice pack where the prey density is higher. Global warming is their most significant threat – if the climatic trend continues it appears likely they will lose their habitat within 100 years.
Andrew Wetzler, director of NRDC’s Wildlife Conservation Project said:
“We all know that polar bears are in serious long-term trouble. The designation of critical habitat is an essential step toward saving this increasingly imperiled species. But we have to do much more if we are to save the polar bear from extinction. Controlling greenhouse gas emissions, reducing commercial hunting in Canada, and stemming the tide of toxic chemicals in their habitat are all necessary to ensure this magnificent animal’s future.”
BBC: male polar bear swimming
The settlement agreement to the lawsuit that prompted this critical habitat designation and that had been filed by the Center for Biological Diversity, the Natural Resources Defense Council, and Greenpeace also requires the Department of the Interior to finalize guidelines for the nonlethal deterrence of polar bears deemed to pose a threat to public safety. As the ice retreats further from shore and more polar bears are stranded on land, the number of human-bear interactions is increasing, with numerous bears being shot as a consequence. The guidelines must be finalized by March 31, 2010. As with the critical habitat designation, the guidelines will be preceded by a proposed rule, along with public comment and public hearings.
Under the terms of the settlement agreement, the Interior Department has until June 30, 2010 to finalize critical habitat designation for the polar bear.
Read also about the Impacts of Global Warming in Alaska.
Visit the Polar Bear International website to learn more about this species, its threats, what is being done and what you can do to help.
Copyright © 2009 by Marine Science Today, a publication of OceanLines LLC