Chukchi Sea Polar Bears

Research & Management

The Chukchi Sea polar bear population straddles the boundary between Russia and the United States, and its management is coordinated by the U.S.-Russia Polar Bear Commission, which first met in 2009. Each country nominates two commissioners, one of whom is federally-appointed and one of whom is a representative of Indigenous organizations.

On the U.S. side, the official Indigenous partner is the Alaska Nannut Co-Management Council (ANCC), a tribally authorized organization consisting of the 15 tribes in Alaska that have traditionally harvested polar bears for subsistence. The ANCC is developing a co-management agreement with the U.S. Fish & Wildlife Service, which, if adopted, would grant a greater degree of self-determination to Alaska Natives to regulate their subsistence hunt.

At present, the subsistence harvest limit is 85 bears, of which no more than one-third may be female, split evenly between the two countries.

Numbers, Status, and Trends

How many bears are in the Chukchi Sea subpopulation?

The first formal study of the Chukchi Sea subpopulation, led by Eric Regehr and published in 2018, estimated that it contained approximately 3,000 bears, and that the population had generally good reproductive rates and cub survival. Concurrent studies led by Karyn Rode of the U.S. Geological Survey concluded that they had similar levels of body fat as 25 years previously, suggesting that the population is in good health, numerically and nutritionally.

Subsequent studies by air and on Wrangel Island support the notion that the population is generally in solid shape, but there are warning signs on the horizon.

What does the future look like?

Because sea ice is melting earlier in summer and forming later in the fall in the Chukchi Sea, as elsewhere in the Arctic, polar bears in the region have access to their preferred habitat for a month less each year than historically was the case. That means less time to hunt seals and procure the energy they need. The fact that, so far, Chukchi bears appear to be weathering these changes is almost certainly a testament to the fact that the extremely high levels of productivity in the region are providing a buffer of sorts; however, if sea ice trends continue, it is inevitable that at some point, the impacts will begin to be felt.

As Regehr told Arctic Today following the publication of his study:

“When we find that for the past 10 years this population looked like it was doing well doesn’t necessarily imply that it will continue to do so in the future. There’s a lot we don’t know about how or when the effects of ice will show up in the subpopulations. But if ice continues to change as it has been, it definitely will [have an impact] at some point, whether that’s in two years or 20 years.”

What Polar Bears International Is Doing

Because Russia’s Wrangel Island is a critical resting place and denning location for the data-deficient Chukchi Sea polar bears, Polar Bears international helped support a collaborative study, now on pause due to the war in Ukraine, that focused on these bears. Led by Eric Regehr, the studies:

• Used ground-based observations and non-invasive genetic samples (hair traps) to examine gene flow, diversity, and population dynamics to improve our understanding of how these bears fit into global polar bear diversity

• Worked to improve our understanding of how Wrangel Island’s bears were handling the effects of increasing industrial activities and longer ice-free seasons due to climate warming

Project partners included the University of Washington, the Wrangel Island Nature Reserve, All-Russian Research Institute for Environment Protection and the U.S. Fish and Wildlife Service.