The Arctic ice pack is home to thousands of Pacific walrus. Their preferred habitat is an ice floe that has enough density and surface area to support a herd of 12-foot-long, 3,000 pound mammals. In the spring, walrus haul out on this floating ice to rest, mate and rear their young. Recently, NASA collaborated with the Department of Interiors U.S. Fish and Wildlife Service (USFWS) in Alaska to determine the usefulness of satellite imagery for studying the effect of climate change on the Pacific walrus ice habitat in the Bering and Chukchi seas.
Pacific walrus (Odobenus rosmarus divergens) is the only subspecies of walrus that inhabits U.S. waters. Native Alaskans rely on a bountiful walrus population for their food, clothing and shelter, and as a spiritual totem, making it an important part of Alaskas economy and cultural subsistence. Because the walrus is vital to these native people, a stable walrus population is crucial to their survival and way of life.
Walrus live on sea ice where wind-driven rills and flats vary in thickness and landscape. The dynamic nature of sea ice and its uniform appearance pose unique challenges to remote-sensing studies. In the past, researchers were literally in the dark when searching for walrus.
To study the population dynamics and supporting habitats of the Pacific walrus, students from the NASA Develop program worked with the U.S. Fish and Wildlife Service in Alaska to determine the relationship between polar sea ice formations and the preferred habitat of the Pacific walrus. For the first time, radar sensors were used to study the walrus in the Alaskan Yukon-Kuskokwim Delta.
"Last spring, the largest census ever performed on the walrus population was undertaken," said Jay Skiles, senior research scientist in biosphere science at NASA Ames Research Center, Moffett Field, Calif. "The count took almost two months, required the use of ships and smaller craft, airplanes and helicopters with
Contact: Rob Gutro
NASA/Goddard Space Flight Center