Pacific Walruses Studied as Sea Ice Melts
U.S. Geological Survey (USGS) Alaska Science Center researchers, in cooperation with the Native Village of Point Lay, Alaska, attached 74 satellite radio tags to Pacific walruses last summer as part of their ongoing study of how the animals are responding to reduced sea-ice conditions in late summer and fall. (To view tracking animations of the tagged walruses' movements, updated approximately every week, visit http://alaska.usgs.gov/science/biology/walrus/2011animation_Norseman.html.)
Walruses spend most of their lives at sea, diving hundreds of feet to forage on the seafloor. Typically, they haul out on sea ice to rest between feeding bouts, but when the sea ice recedes past the continental shelf into very deep waters of the Arctic Basin, the walruses haul out on land. The extent of sea ice has been less in recent summers, and walruses have been hauling out on beaches in Alaska and Russia in the past few years.
Since 2004, the USGS Alaska Science Center Pacific Walrus Research Program has collected data on walrus foraging behavior and movements throughout areas of the Bering and Chukchi Seas, both when sea ice is present and when it is absent over the continental shelf. Female walruses and their young have come ashore during late summer and fall in 4 of the past 5 years on Alaska's northwest coast. In 2010 and again in 2011, thousands of walruses gathered on beaches north of Point Lay. In 2010, walruses came ashore in late August. In 2011, the sea ice disappeared from the shelf earlier and walruses were coming ashore by mid-August.
"Sea ice is an important component in the life cycle of walruses," said Chad Jay, research ecologist with the USGS Alaska Science Center. "These tracking studies will help us to better understand how top consumers in the Arctic ecosystem may be affected by changes in sea-ice habitats."
In July 2011, scientists attached 40 radio tags on walruses hauled out on distant offshore sea ice near the edge of the continental shelf, northwest of Barrow, Alaska. In late August, they tagged 34 walruses that had hauled out on the coast of northwestern Alaska after retreat of sea ice from the shelf.
With increased awareness of the walrus haulouts comes the need for protecting the resting animals from human disturbance. Walruses face danger from stampedes when they gather on shore. For example, more than 130 mostly young walruses were crushed in September 2009 at Alaska's Icy Cape from a disturbance of unknown cause. The U.S. Fish and Wildlife Service, the Eskimo Walrus Commission, the North Slope Borough, and the Native Villages of Barrow and Point Lay are working with local hunters, pilots, operators of marine vessels, and the public to distribute guidelines that will protect the herds.
In April 2011, Point Lay received an "Outstanding Partner" Award from the U.S. Fish and Wildlife Service Alaska Region for its work to protect walruses in September 2010, when tens of thousands of migrating walruses hauled out on the Chukchi Sea barrier beach within sight of the small Inupiaq community. Point Lay once more took the initiative in late August 2011, when the walruses again hauled out nearby. Community leaders took an Incident Command System approach to protecting the walruses. They issued a news release and walrus photographs to reporters but also requested that media crews not travel to Point Lay. When media did arrive, the leaders participated in interviews and advised visitors on how to get the stories they needed without disturbing the animals. Thus continued Point Lay's long tradition of collaboration with science while showing respect for the thousands of weary animals resting nearby.
To view high-resolution video of Pacific walruses hauling out near Point Lay in late August 2011, visit http://gallery.usgs.gov/videos/445. An information sheet about the ongoing walrus studies, titled "The Science Behind the 2011 Walrus Haulout FAQ," is posted at http://alaska.usgs.gov/science/biology/walrus/. For additional photographs and information related to USGS Pacific walrus studies, visit http://www.usgs.gov/blogs/features/2011/08/16/walruses-and-arctic-sea-ice-retreat/.
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Walruses Studied as Sea Ice Melts