Comparison of colonial breeding seabirds in the eastern Bering Sea and Gulf of Alaska
Stephensen, S.W.; Irons, D.B. (2003). Comparison of colonial breeding seabirds in the eastern Bering Sea and Gulf of Alaska. Mar. Ornithol. 31: 167-176
In: Marine Ornithology. African Seabird Group: Rondebosch. ISSN 1018-3337; e-ISSN 2074-1235, more
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| Keywords |
Aethia Merrem, 1788 [WoRMS]; Aethia cristatella (Pallas, 1769) [WoRMS]; Aethia pusilla (Pallas, 1811) [WoRMS]; Uria Brisson, 1760 [WoRMS]; Uria aalge (Pontoppidan, 1763) [WoRMS]
Marine/Coastal |
| Author keywords |
distribution, oceanography, Bering Sea, auklets, Aethia, murres, Uria , piscivores, planktivores |
| Authors | | Top | Dataset |
- Stephensen, S.W.
- Irons, D.B.
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| Abstract |
We examined populations of colonial breeding seabirds in Alaska. We compared data on populations from the eastern Bering Sea (EBS) and the Gulf of Alaska (GOA) using U.S. Fish and Wildlife Service (USFWS) data from the Beringian Seabird Colony Database. The EBS and GOA are vast areas that support large diverse populations of breeding seabirds. Seabird distribution in Alaska is highly clumped: 12 of the 1714 colonies support 50% of all breeding birds, with most of these large colonies located in the EBS. The EBS has nearly three times as many seabirds as the GOA. The large numbers of seabirds in the EBS are due in part because the EBS is larger than the GOA and to the millions of planktivorous auklets that breed in the EBS but are virtually absent from the GOA. In the Bering Sea, Least Aethia pusilla and Crested Aethia cristatella Auklet colonies appear to be restricted to volcanic islands near highly productive upwelling areas in the central and western Aleutian Islands, the shelf-break in the central Bering Sea and the Anadyr Stream in the northern Bering Sea. They are conspicuously absent from the volcanic eastern Aleutian Islands east of Samalga Pass that are surrounded by warmer, fresher, water from the Alaska Coastal Current compared to the cooler, saltier oceanic water in the western and central Aleutians. The piscivorous species are more evenly distributed between the two regions. The most abundant piscivore, the Common Murre Uria aalge, is evenly split between the two regions. The EBS is more productive than the GOA, but both areas support similar biomass/km2 of breeding seabirds. This pattern may in part be due to greater predation by foxes in the Bering Sea. Foxes still remain on some Aleutian Islands from introductions years ago and are indigenous on the northern Bering Sea Islands and the eastern Aleutian Islands. Relatively few islands in the GOA support foxes. |
| Dataset |
- Hyrenbach, D., S. Stephensen and D. Irons. 2013. FWS Beringian Seabird 2004. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/270) on yyyy-mm-dd., more
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