Abstract
Albatrosses are among a group of upper trophic level consumers that are highly migratory yet relatively abundant in Alaskan waters. Therefore, albatrosses are an important ecosystem component, but also vulnerable to fishery interactions. We studied the marine habitat use of three species of albatrosses and their spatial and temporal overlap with commercial fisheries using stable isotope analysis, satellite tacking, satellite remote sensing, and fisheries effort/seabird bycatch data. Albatross species showed strong differences in foraging niches and habitat associations. Short-tailed albatrosses had the strongest association with continental shelf break and slope regions (although, juveniles also frequented shelf habitats). Black-footed albatrosses were the most varied in habitat use, whereas Laysan albatrosses most often used oceanic habitats well offshore of the continental slope, but still north of the sub-arctic transition domain.
Short-tailed albatrosses had the greatest overlap with Bering Sea walleye pollock and Pacific cod fisheries and all three albatross species with Aleutian Islands sablefish and Pacific halibut fisheries, although short-tailed and Laysan more so with fisheries in the western Aleutians, including Atka mackerel. Black-footed and juvenile short-tailed albatrosses had the greatest overlap with Gulf of Alaska and west coast Pacific halibut and sablefish fisheries and overlapped a portion of the high seas tuna fishery. Laysan albatrosses overall had the least spatial overlap with North Pacific fisheries, spending the majority of time in areas devoid of fishing activities. These results provide an improved understanding of ecological relationships among North Pacific albatrosses, as well as indicating inter-specific differences in potential interactions with regional fisheries.