*Southwest Fisheries Science Center, Honolulu Laboratory, 2570 Dole Street, Honolulu, HI 96822–2396 U.S.A.
Inter-island variation in the diet of female northern fur seals (Callorhinus ursinus) in the Bering Sea
Article first published online: 24 MAR 2009
Journal of Zoology
Volume 242, Issue 3, pages 435–451, July 1997
How to Cite
Antonelis, G. A., Sinclair, E. H., Ream, R. R. and Robson, B. W. (1997), Inter-island variation in the diet of female northern fur seals (Callorhinus ursinus) in the Bering Sea. Journal of Zoology, 242: 435–451. doi: 10.1111/j.1469-7998.1997.tb03847.x
- Issue published online: 24 MAR 2009
- Article first published online: 24 MAR 2009
- Accepted 26 June 1996
The diet of adult female northern fur seals (Callorhinus ursinus) is examined through the analysis of faecal material collected during the summer breeding season at three breeding locations in the Bering Sea: St. Paul Island (1988, 1990) and St. George Island (1988, 1990) of the Pribilof Islands Group (USA), and Medny Island (1990) of the Commander Islands Group (Russia). Prey consumption varies annually and accordingly with the physical and biological environment surrounding each island. Juvenile walleye pollock (Theragra chalcogramma) is the most common prey of northern fur seals from St. Paul Island; the island is surrounded by a broad neritic environment with widely separated frontal zones and is the greatest distance from the continental shelf-edge. Gonatid squid (Gonatopsis borealis/Berryteuthis magister and Gonatus madokail Gonatus middendorffi) were the most common prey of northern fur seals from Medny Island; the island is surrounded by a compressed neritic environment and is adjacent to the continental shelf-edge and the oceanic marine environment. A combination of walleye pollock and gonatid squid is consumed by northern fur seals from St. George Island; the island has a surrounding oceanographic environment intermediate between the other two islands.
Variability in predation on walleye pollock is consistent with fishery information concerning the relative abundance and availability of walleye pollock around St. George and St. Paul Islands. The abundance and availability of these prey resources during the summer breeding season are key factors which influence the health and growth of the northern fur seal populations in the Bering Sea.