Polar Bear Range States Conference Termed a Productive Exchange
Potential Effects of Contaminants and/or Climate Change on
Ecological changes in the Arctic related to both anthropogenic and natural
patterns are poorly understood but are of significant conservation concern.
A circumpolar study is currently underway to determine contaminant levels
in polar bears and compare results with findings from a similar study
completed 10 years ago. A bio-monitoring program is ongoing in Alaska.
Changes in sea ice as a result of global warming are known to affect
polar bear productivity in other parts of the Arctic. An effort is currently
underway in Alaska to assess sea ice habitat selection by polar bears
using polar bear satellite radio locations and National Ice Center charts.
Potential Over-harvest of Polar Bears
Two populations of polar bears occur in Alaska: the Southern Beaufort Sea population which is shared with Canada and the Chukchi/Bering seas population which is shared with Russia. Based on recently conducted mark/recapture studies from 2001-2006, the Southern Beaufort Sea population has approximately 1500 bears and is currently thought to be declining. Although accurate estimates of the Chukchi/Bering seas population are unavailable, the best available information suggests that there may be about 2000 bears and that the population is declining.
Sport hunting for polar bears, which was thought to be the primary reason for the decline in the Alaska populations prior to 1972, was stopped with the passage of the Marine Mammal Protection Act of 1972 (MMPA). Under an exemption to the MMPA, only Alaska Natives are now permitted to take polar bears for subsistence purposes and making of handicrafts provided that the population is not depleted and that the harvest is done in non-wasteful manner. The FWS has been monitoring the polar bear harvest since 1980 and records information on the number, age, sex, and location on polar bears taken by Alaskan Native subsistence hunters. The harvest levels in the Southern Beaufort Sea are managed at sustainable harvest levels under the Native to Native agreement between the Inupiat (Alaska) and Inuvialuit (Canada) Agreement. The harvest levels in the Chukchi/Bering seas for the past 10-15 years (150-200 bears/year), which include the legal harvest in Alaska and an illegal harvest in Chukotka, Russia, are probably unsustainable. This harvest level is close to or greater than the harvest levels during the sport hunting era prior to 1972 (approximately 178 bears/year). The loss of sea ice habitat combined with the current harvest levels suggest that the Chukchi/Bering Seas population is declining and is now below historical levels. Implementation of the Agreement between the United States and the Russian Federation on the Conservation and Management of the Alaska-Chukotka Polar Bear Population will provide framework for the development of research and management actions including establishing enforceable harvest limits.
Human Development in Polar Bear Habitat
Habitat used by polar bears for denning, feeding, and seasonal movements
are important for the continued health of polar bear populations. Our
knowledge of polar bear use of the near shore environment is limited.
In the Beaufort Sea region, bear use of coastal areas appears to have
increased over the last decade, thereby also increasing potential effects
of human activities on polar bears, e.g. increased exposure to contaminants,
hunting, or other bear-human interactions during which either bears
or humans are potentially injured. Current efforts are underway to:
1) characterize distribution and abundance of polar bears along the
Beaufort Sea coastline;
2) describe the number, age, sex, behavior and habitat use of polar
bears concentrated around hunter-harvested bowhead whale carcasses;
3) re-institute incidental take regulations designed to minimize impacts
of oil and gas activities on polar bears and their habitat.
In the Bering/Chukchi seas, the majority of denning occurs on Wrangel
and Herald islands and the Chukotka Peninsula (Russia). Wrangel Island
Nature Reserve provides protection status for denning bears; monitoring
denning in these areas may be used to monitor population status and
trends. Increased harvest of polar bears in Chukotka is a concern.