Mass-mortality of guillemots (Uria aalge) in the Gulf of Alaska in 1993

Marine Pollution Bulletin
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During the first six months of 1993, about 3500 dead and moribund guillemots (Uria aalge) were observed throughout the northern Gulf of Alaska coast (ca 1800 km range). Mortality peaked during March. Highest numbers were observed in western Prince William Sound and along the south coast of the Kenai Peninsula. Large flocks of live guillemots gathered in nearshore waters, in contrast to most winters when guillemots reside offshore. Most guillemots recovered were extremely emaciated (ca 60% of normal weight) and sub-adult (80%). Based on carcass deposition and persistence experiments, we calculate that about 10 900 birds eventually came ashore on beaches that were surveyed. Even if most birds killed made it to shore, only a fraction of beaches in the Gulf of Alaska were surveyed and we estimate that a minimum total of 120 000 guillemots died. Results of other investigations on potential causes of mortality (biotoxins, pathogens, parasites, metals, etc.) were either negative or inconclusive, and necropsies lead us to believe that starvation was the proximate cause of death. Reduced food availability could have been related to anomalous sea conditions found during the prolonged 1990–1995 El Niño-Southern Oscillation event.

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Publication type Article
Publication Subtype Journal Article
Title Mass-mortality of guillemots (Uria aalge) in the Gulf of Alaska in 1993
Series title Marine Pollution Bulletin
DOI 10.1016/S0025-326X(97)00008-8
Volume 34
Issue 8
Year Published 1997
Language English
Publisher Elsevier
Contributing office(s) Alaska Science Center
Description 7 p.
First page 656
Last page 662
Country United States
State Alaska
Other Geospatial Gulf of Alaska
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