Bowhead whale Balaena mysticetus seasonal selection of sea ice

Abstract

Highly mobile large-bodied organisms are adapted to seasonal variation associated with polar environments. We used satellite tracking data from 27 bowhead whales Balaena mysticetus of the Eastern Canada-West Greenland population to test for movement and habitat selection of the highly variable sea ice landscape that encompasses near-complete coverage in winter to nearcomplete absence in summer. We demarcated 2 bowhead whale seasons based on movement behaviour identified from inflection points of polynomial regression analysis of movement rate: winter (28 December to 15 March, 16.6 ± 2.65 km d ). Resource selection functions were used to evaluate bowhead whale seasonal selection of sea ice landscape (coverage, thickness, and floe size). Movement and habitat use differed between Nunavut tagging sites likely as a consequence of sexual and reproductive segregation. Whales selected relatively low ice coverage, thin ice, and small floe areas in winter close to the maximum ice extent, presumably to reduce risk of ice entrapment while remaining within ice. In contrast, whales selected high ice coverage, thick ice, and large floe size areas in summer, presumably to reduce risk of killer whale predation while providing enriched feeding opportunities. Our results indicate that this largebodied animal can moderate use of the large-scale fluctuations in seasonal sea ice typical of polar environments.

Seasonal Trends in Acoustic Detection of Marine Mammals in Baffin Bay and Melville Bay, Northwest Greenland + Supplementary Appendix 1 (See Article Tools)

“…Previous studies on movements of the Eastern Canada -West Greenland bowhead whale population show that these animals are widely distributed throughout the eastern Canadian Arctic and West Greenland, where they perform long seasonal migrations (Heide-Jørgensen et al, 2003b). They overwinter in Hudson Strait, Cumberland Sound, West Greenland, and the North Water polynya (Ferguson et al, 2010). In spring, they inhabit the west coast of Greenland (particularly Disko Bay, Tervo et al, 2009), Cumberland Sound, Foxe Basin, and Lancaster Sound in Canada (Ferguson et al, 2010).…”

Current state and trends in Canadian Arctic marine ecosystems: II. Heterotrophic food web, pelagic-benthic coupling, and biodiversity

“…Based on resource selection functions to evaluate seasonal selection of ice (coverage, thickness, and floe size), Ferguson et al (2010b) showed that sea ice was a major factor influencing bowhead whale seasonal distribution. Bowhead whales were found to select relatively low ice coverage, thin ice, and small floe areas in winter close to the maximum ice extent as opposed to summer when whales selected high ice coverage, thick ice, and large floe size areas.…”

Ancient DNA reveals that bowhead whale lineages survived Late Pleistocene climate change and habitat shifts

“…These samples originated from an area south of 59°N, over 1,000 km south of the current Arctic range of the bowhead whale [11][12][13][14][15][16][17][18][19][20][21][22] . We successfully genetically identified the species of 27 ancient samples, of which 15 were bowhead whales ( Supplementary Fig.…”

“…The bowhead whale is a true Arctic species that remains in polar waters throughout the year 12 . Like the polar bear, it is a sentinel species of the Arctic marine ecosystem due to its dependence on the sea ice 13,14 .…”

“…Like the polar bear, it is a sentinel species of the Arctic marine ecosystem due to its dependence on the sea ice 13,14 . Bowhead whales specialize in feeding on copepods and euphausiids, which are associated with primary production around the sea ice [12][13][14] . This ecological specialization and a long lifespan 15 make the bowhead whale a poor candidate for adapting to rapid climate change 13,14 ; thus the species is listed by the International Whaling Commission as being vulnerable to climate-induced disturbance 16 .…”