Harbor seal population decline in the Aleutian Archipelago
Populations of Steller sea lions, northern fur seals, and northern sea otters declined substantially during recent decades in the Bering Sea and Aleutian Islands region, yet the population status of harbor seals has not been assessed adequately. We determined that counts obtained during skiff-based...
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ftunivnebraskali:oai:digitalcommons.unl.edu:usdeptcommercepub-1152 2023-11-12T04:15:19+01:00 Harbor seal population decline in the Aleutian Archipelago Small, Robert Boveng, Peter Byrd, G. Vernon Withrow, David 2008-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/usdeptcommercepub/144 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1152/viewcontent/Boveng_MMS_2008_Harbor_seal_population_decline.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/usdeptcommercepub/144 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1152/viewcontent/Boveng_MMS_2008_Harbor_seal_population_decline.pdf Publications, Agencies and Staff of the U.S. Department of Commerce Environmental Sciences text 2008 ftunivnebraskali 2023-10-30T09:43:17Z Populations of Steller sea lions, northern fur seals, and northern sea otters declined substantially during recent decades in the Bering Sea and Aleutian Islands region, yet the population status of harbor seals has not been assessed adequately. We determined that counts obtained during skiff-based surveys conducted in 1977–1982 represent the earliest estimate of harbor seal abundance throughout the Aleutian Islands. By comparing counts from 106 islands surveyed in 1977–1982 (8,601 seals) with counts from the same islands during a 1999 aerial survey (2,859 seals), we observed a 67% decline over the ∼20-yr period. Regionally, the largest decline of 86% was in the western Aleutians (n = 7 islands), followed by 66% in the central Aleutians (n = 64 islands), and 45% in the eastern Aleutians (n = 35 islands). Harbor seal counts decreased at the majority of islands in each region, the number of islands with >100 seals decreased ∼70%, and the number of islands with no seals counted increased ∼80%, indicating that harbor seal abundance throughout the Aleutian Islands was substantially lower in the late 1990s than in the 1970s and 1980s. Text Bering Sea harbor seal Aleutian Islands University of Nebraska-Lincoln: DigitalCommons@UNL Bering Sea |
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University of Nebraska-Lincoln: DigitalCommons@UNL |
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ftunivnebraskali |
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Environmental Sciences |
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Environmental Sciences Small, Robert Boveng, Peter Byrd, G. Vernon Withrow, David Harbor seal population decline in the Aleutian Archipelago |
topic_facet |
Environmental Sciences |
description |
Populations of Steller sea lions, northern fur seals, and northern sea otters declined substantially during recent decades in the Bering Sea and Aleutian Islands region, yet the population status of harbor seals has not been assessed adequately. We determined that counts obtained during skiff-based surveys conducted in 1977–1982 represent the earliest estimate of harbor seal abundance throughout the Aleutian Islands. By comparing counts from 106 islands surveyed in 1977–1982 (8,601 seals) with counts from the same islands during a 1999 aerial survey (2,859 seals), we observed a 67% decline over the ∼20-yr period. Regionally, the largest decline of 86% was in the western Aleutians (n = 7 islands), followed by 66% in the central Aleutians (n = 64 islands), and 45% in the eastern Aleutians (n = 35 islands). Harbor seal counts decreased at the majority of islands in each region, the number of islands with >100 seals decreased ∼70%, and the number of islands with no seals counted increased ∼80%, indicating that harbor seal abundance throughout the Aleutian Islands was substantially lower in the late 1990s than in the 1970s and 1980s. |
format |
Text |
author |
Small, Robert Boveng, Peter Byrd, G. Vernon Withrow, David |
author_facet |
Small, Robert Boveng, Peter Byrd, G. Vernon Withrow, David |
author_sort |
Small, Robert |
title |
Harbor seal population decline in the Aleutian Archipelago |
title_short |
Harbor seal population decline in the Aleutian Archipelago |
title_full |
Harbor seal population decline in the Aleutian Archipelago |
title_fullStr |
Harbor seal population decline in the Aleutian Archipelago |
title_full_unstemmed |
Harbor seal population decline in the Aleutian Archipelago |
title_sort |
harbor seal population decline in the aleutian archipelago |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2008 |
url |
https://digitalcommons.unl.edu/usdeptcommercepub/144 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1152/viewcontent/Boveng_MMS_2008_Harbor_seal_population_decline.pdf |
geographic |
Bering Sea |
geographic_facet |
Bering Sea |
genre |
Bering Sea harbor seal Aleutian Islands |
genre_facet |
Bering Sea harbor seal Aleutian Islands |
op_source |
Publications, Agencies and Staff of the U.S. Department of Commerce |
op_relation |
https://digitalcommons.unl.edu/usdeptcommercepub/144 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1152/viewcontent/Boveng_MMS_2008_Harbor_seal_population_decline.pdf |
_version_ |
1782332642381791232 |