Habitat selection by foraging northern fur seals : assessing in-situ ocean temperature and links to Oceanographic features in the Eastern Bering Sea ...

• Main Author: Nordstrom, Chad Andrew
• Format: Text
• Language: English
• Published: University of British Columbia 2012
• Subjects: Bering Sea; Callorhinus ursinus
• Online Access: https://dx.doi.org/10.14288/1.0072803; https://doi.library.ubc.ca/10.14288/1.0072803

Habitat characteristics and mechanisms that enable predators to successfully forage are poorly understood in open marine ecosystems. I addressed this problem in the eastern Bering Sea using animal-born data-loggers carried by lactating northern fur seals (Callorhinus ursinus) from two populations breeding in distinct oceanographic zones — a declining population on St. Paul Island on the continental shelf, and an increasing population on Bogoslof Island over the oceanic basin. The data-loggers recorded water temperatures, dive depths and animal locations throughout foraging trips that lasted as long as 17 days and extended as far as 460 km from the islands. I contrasted tag-derived ocean temperatures with concurrent shipboard measurements and found that the fur seal data revealed finer-scale hydrographic processes with less estimated error than ship-derived data, particularly in dynamic oceanographic areas. I also identified probable foraging hotspots using first-passage time analysis of at-sea locations of ...