Amount and patterns of beluga sightings in the eastern Beaufort Sea

• Main Authors: Asselin, Natalie C, Barber, David G, Stirling, Ian, Ferguson, Steven H, Richard, Pierre R
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2011
• Subjects: Beaufort_Sea; Beaufort Sea; International Polar Year (2007-2008); IPY; OBSE; Observation; Beluga; Beluga*; Boreogadus saida; Delphinapterus leucas; International Polar Year; Polar Biology; polar cod; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.807111; https://doi.org/10.1594/PANGAEA.807111

An understanding of the adaptability of belugas (Delphinapterus leucas) to changing ice conditions is required to interpret and predict possible changes in habitat selection in response to projected loss of sea ice throughout the circumpolar Arctic. We analyzed beluga observations made during spring aerial surveys for ringed seals conducted from 1975 to 1979 in the eastern Beaufort Sea. Despite interannual variability in the extent and distribution of sea ice, belugas consistently selected areas with water depths of 200-500 m and heavy ice concentrations (8/10 to 10/10) while areas of open water to light ice concentrations (0/10 to 1/10) were not selected. Belugas were also found in proximity to regions with >0.5 degrees seafloor slope which include the continental slope and other areas with the potential for oceanographic upwellings. In most years (4 of 5), fast-ice edges and coastal areas were not selected. In the lightest ice year analyzed, belugas showed less specificity in habitat selection as their distribution expanded and shifted shoreward to fast-ice edges. The observed distribution is discussed in terms of predator-prey relationships particularly with reference to beluga feeding on polar cod (Boreogadus saida). More research is required to examine and compare possible changes in distribution since the late 1970s and to investigate the factors driving the patterns described.