Occurrence, Habitat Use, and Behavior of Seabirds, Marine Mammals, and Arctic Cod at the Pond Inlet Ice Edge

Résumé

In 1979, 17 species of birds were seen during studies near the Pond Inlet ice edge. Northern fulmars (Fulmarus glacialis) black-legged kittiwakes (Rissa tridactyla) thick billed murres (Uria lomvia) and black guillemots (Cepphus grylle) all avoided the ice edge when bordered with heavy pack ice and all but kittiwakes used the ice edge primarily for feeding. Guillemots and fulmars occurred in highest numbers in water along rough and moderately rough landfast ice: murres and kittiwakes showed no preference for such areas or for the other habitat surveyed (smooth landfast ice). Narwhals (Monodon monoceros) white whales (Delphinapterus leucas) and ringed seals (Phoca hispida) were the only marine mammals common at the ice edge. Whales repeatedly dived under the edge - probably feeding, searching for open water west of the ice edge, or both. Densities of seals near the ice edge were higher than elsewhere on landfast ice. Divers observed arctic cod (Boreogadus saida) close to the undersurface of landfast ice. Fish offshore were generally smaller, younger, and smaller-at-age than those inshore. Offshore, arctic cod were more numerous in areas with a rough under-ice surface than under smooth ice. Cod concentrated in crevices within rough under-ice surfaces. Inshore, cod were captured from ice cracks over shallow water. I conclude that vertebrates occur at ice edges for one or more of several reasons. Ringed seals and arctic cod live in close association with landfast ice: they probably occur near ice edges simply because landfast ice is present there. Ice edges seem to be primarily barriers against the further movements of whales toward summering locations. Finally, for murres and some other birds, ice edges seem to be favored feeding locations (relative to open sea conditions) due to greater access to preferred foods.

Key words: arctic seabirds, ringed seal, narwhal, arctic cod, ice edges, Pond Inlet, habitat use, behavior, arctic waters, Lancaster Sound, Baffin Bay