title: Habitat selection by two beluga whale populations in the Chukchi and Beaufort seas.
abstract: There has been extensive sea ice loss in the Chukchi and Beaufort seas where two beluga whale (Delphinapterus leucas) populations occur between July-November. Our goal was to develop population-specific beluga habitat selection models that quantify relative use of sea ice and bathymetric features related to oceanographic processes, which can provide context to the importance of changing sea ice conditions. We established habitat selection models that incorporated daily sea ice measures (sea ice concentration, proximity to ice edge and dense ice) and bathymetric features (slope, depth, proximity to the continental slope, Barrow Canyon, and shore) to establish quantitative estimates of habitat use for the Eastern Chukchi Sea ('Chukchi') and Eastern Beaufort Sea ('Beaufort') populations. We applied 'used v. available' resource selection functions to locations of 65 whales tagged from 1993-2012, revealing large variations in seasonal habitat selection that were distinct between sex and population groups. Chukchi whales of both sexes were predicted to use areas in close proximity to Barrow Canyon (typically <200 km) as well as the continental slope in summer, although deeper water and denser ice were stronger predictors for males than females. Habitat selection differed more between sexes for Beaufort belugas. Beaufort males selected higher ice concentrations (≥40%) than females (0-40%) in July-August. Proximity to shore (<200 km) strongly predicted summer habitat of Beaufort females, while distance to the ice edge was important for male habitat selection, especially during westward migration in September. Overall, our results indicate that sea ice variables were rarely the primary drivers of beluga summer-fall habitat selection. While diminished sea ice may indirectly affect belugas through changes in the ecosystem, associations with bathymetric features that affect prey availability seemed key to habitat selection during summer and fall. These results provide a benchmark by which to assess future changes in beluga habitat use of the Pacific Arctic.
authors.affiliation: School of Aquatic & Fishery Sciences, University of Washington, Seattle, WA, United States of America.|Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, United States of America.
authors.forename: Donna D W
authors.identifier: http://orcid.org/0000-0001-8236-7372
authors.initials: DD
authors.lastname: Hauser
authors.affiliation: School of Aquatic & Fishery Sciences, University of Washington, Seattle, WA, United States of America.|Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, United States of America.
authors.forename: Kristin L
authors.initials: KL
authors.lastname: Laidre
authors.affiliation: Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, United States of America.
authors.forename: Harry L
authors.initials: HL
authors.lastname: Stern
authors.affiliation: Office of Science & Technology, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA, United States of America.
authors.forename: Sue E
authors.initials: SE
authors.lastname: Moore
authors.affiliation: North Slope Borough, Department of Wildlife Management, Barrow, AK, United States of America.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Suydam
authors.affiliation: Freshwater Institute, Fisheries & Oceans Canada, 501 University Crescent, Winnipeg, Canada.
authors.forename: Pierre R
authors.initials: PR
authors.lastname: Richard
mesh_terms: D000818:Animals; D001110:Arctic Regions; D050643:Beluga Whale / Q000502:physiology*; D017753:Ecosystem; D004784:Environmental Monitoring; D008297:Male; D009792:Oceans and Seas; D011155:Population Control; D012621:Seasons