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Modeled distribution and abundance of a pelagic seabird reveal trends in relation to fisheries

Marine Ecology Progress Series

By:
, , , , , and
DOI: 10.3354/meps10347

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Abstract

The northern fulmar Fulmarus glacialis is one of the most visible and widespread seabirds in the eastern Bering Sea and Aleutian Islands. However, relatively little is known about its abundance, trends, or the factors that shape its distribution. We used a long-term pelagic dataset to model changes in fulmar at-sea distribution and abundance since the mid-1970s. We used an ensemble model, based on a weighted average of generalized additive model (GAM), multivariate adaptive regression splines (MARS), and random forest models to estimate the pelagic distribution and density of fulmars in the waters of the Aleutian Archipelago and Bering Sea. The most important predictor variables were colony effect, sea surface temperature, distribution of fisheries, location, and primary productivity. We calculated a time series from the ratio of observed to predicted values and found that fulmar at-sea abundance declined from the 1970s to the 2000s at a rate of 0.83% (± 0.39% SE) per annum. Interpolating fulmar densities on a spatial grid through time, we found that the center of fulmar distribution in the Bering Sea has shifted north, coinciding with a northward shift in fish catches and a warming ocean. Our study shows that fisheries are an important, but not the only factor, shaping fulmar distribution and abundance trends in the eastern Bering Sea and Aleutian Islands.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Modeled distribution and abundance of a pelagic seabird reveal trends in relation to fisheries
Series title:
Marine Ecology Progress Series
DOI:
10.3354/meps10347
Volume
484
Year Published:
2013
Language:
English
Publisher:
Inter-Research
Contributing office(s):
Alaska Science Center
Description:
19 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Marine Ecology Progress Series
First page:
259
Last page:
277
Other Geospatial:
Bering Sea;Aleutian Islands