FWS Publishes Final Stock Assessments for Pacific Walrus and Polar Bears
On December 30, 2009, the U. S. Fish and Wildlife Service published Federal Register notice that FWS has revised its stock assessment reports for the Pacific walrus stock and for each of the two polar bear stocks in Alaska: the Southern Beaufort Sea polar bear stock and the
Chukchi/Bering Seas polar bear stock. These revised and final SARs incorporate public comment on previously published assessments. The SARs are prepared and published by FWS under the U.S. Marine Mammal Protection Act, and its implementing regulations.
One of the MMPA's goals is to ensure that stocks of marine mammals occurring in waters
under U.S. jurisdiction do not experience a level of human-caused mortality and serious injury that is likely to cause the stock to be reduced below its optimum sustainable population level. OSP is defined as ``the number of animals which will result in the maximum productivity of the population or the species, keeping in mind the carrying capacity of the habitat and the health of the ecosystem of which they form a constituent element.''
The MMPA requires the FWS and the U.S. National Marine Fisheries Service to prepare a SAR for each marine mammal stock that occurs in waters under U.S. jurisdiction. A SAR must be based on the best scientific information available.
FWS' final SARs estimate that there are 129,000 Pacific walruses; 1397 Southern Beaufort Sea polar bears; and 2000 Chukchi/Bering Seas polar bears. They further estimate that 4,963-5,460 walruses are killed or seriously injured by humans annually; 54 Southern Beaufort Sea polar bears are killed or seriously injured; and 37 Chukchi/Bering Seas polar bears are killed or seriously injured.
These estimates exceed the PBRs for all three stocks. The PBR, or potential biological removal level, is defined as ``the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing that stock to reach or maintain its OSP.'' The OSP, or optimum sustainable population level, is defined as ``the number of animals which will result in the maximum productivity of the population or the species, keeping in mind the carrying capacity of the habitat and the health of the ecosystem of which they form a constituent element.''
In its response to public comment, FWS emphasized the importance of working with Russia to protect the polar bears, which have been listed as a threatened species under the U.S. Endangered Species Act.
Click here to read FWS' Federal Register notice