Alaska Science Center

Response of Polar Bear Populations to a Rapidly Diminishing Sea Ice Environment

A long–term research program focused on population dynamics, habitat use, foraging ecology and health of polar bears in the Southern Beaufort Sea subpopulation of Alaska and neighboring Canada.


The polar bear is recognized worldwide as a vulnerable species due to loss of its required sea ice habitats. USGS science played a central role in informing the decision to list the polar bear as threatened under the Endangered Species Act in 2008. This science was founded in understanding gained from long-term studies of the southern Beaufort Sea (SB) population, one of 19 worldwide, and one of only two populations with long-term data. In these studies, USGS documented a negative relationship between length of the open water season over the continental shelf and population growth rate. Applying future sea ice conditions to the relationship between sea ice availability and population growth rate allowed us to project a future trajectory of the population. We are monitoring the survival and habitat use of the SB population to determine whether the habitat base for this population changes as projected and whether the population responds to those habitat changes as we projected in 2007. Information about how polar bears in this population respond to sea ice loss will inform projections for the worldwide population.
Title Type
Changing Arctic EcosystemsProject Website
Polar Bear ResearchProject Website


Atwood, Todd C., 907-786-7061
Durner, George M., 907-786-7082
Rode, Karyn D., 907-786-7106

Status: onGoing
Start Year: 1984
End Year: 2024

Project Sites

BLM - Fairbanks District Office
CWS - Canadian Wildlife Service - Yukon Territory
FWS - Alaska Region
FWS - Arctic National Wildlife Refuge
National Oceanic and Atmospheric Administration
North Slope Borough
USGS - National Wildlife Health Center

Prudhoe Bay

USGS Mission Area and Program
EcosystemsWildlife Program

Major Initiatives
USGS - Changing Arctic Ecosystems Initiative