Polar bear aerial survey in the eastern Chukchi Sea: A pilot study

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Alaska has two polar bear populations: the Southern Beaufort Sea population, shared with Canada, and the Chukchi/Bering Seas population, shared with Russia. Currently a reliable population estimate for the Chukchi/Bering Seas population does not exist. Land-based aerial and mark-recapture population surveys may not be possible in the Chukchi Sea because variable ice conditions, the limited range of helicopters, extremely large polar bear home ranges, and severe weather conditions may limit access to remote areas. Thus line-transect aerial surveys from icebreakers may be the best available tool to monitor this polar bear stock. In August 2000, a line-transect survey was conducted in the eastern Chukchi Sea and western Beaufort Sea from helicopters based on a U.S. Coast Guard icebreaker under the "Ship of Opportunity" program. The objectives of this pilot study were to estimate polar bear density in the eastern Chukchi and western Beaufort Seas and to assess the logistical feasibility of using ship-based aerial surveys to develop polar bear population estimates. Twenty-nine polar bears in 25 groups were sighted on 94 transects (8257 km). The density of bears was estimated as 1 bear per 147 km² (CV = 38%). Additional aerial surveys in late fall, using dedicated icebreakers, would be required to achieve the number of sightings, survey effort, coverage, and precision needed for more effective monitoring of population trends in the Chukchi Sea.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Polar bear aerial survey in the eastern Chukchi Sea: A pilot study
Series title Arctic
DOI 10.14430/arctic633
Volume 56
Issue 4
Year Published 2003
Language English
Publisher Arctic Institute of North America
Contributing office(s) Alaska Science Center, Alaska Science Center Biology MFEB
Description 8 p.
First page 359
Last page 366
Country United States
State Alaska
Other Geospatial Chukchi Sea
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