Current and historical roles of apex predators in the Bering Sea ecosystem
Large population declines (>50%) since the early-1970s of some eastern Bering Sea and Aleutian Island apex predator populations (Steller sea lions, murres, and kittiwakes) suggest that major changes have occurred in the structure of the Bering Sea ecosystem. One cause of the decline in mammalian...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.585.7516 2023-05-15T13:14:44+02:00 Current and historical roles of apex predators in the Bering Sea ecosystem Richard L. Merrick The Pennsylvania State University CiteSeerX Archives 1997 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.585.7516 http://journal.nafo.int/J22/Merrick.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.585.7516 http://journal.nafo.int/J22/Merrick.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://journal.nafo.int/J22/Merrick.pdf Key words Bering Sea ecosystem groundfish predators marine mammals seabirds text 1997 ftciteseerx 2016-01-08T13:15:17Z Large population declines (>50%) since the early-1970s of some eastern Bering Sea and Aleutian Island apex predator populations (Steller sea lions, murres, and kittiwakes) suggest that major changes have occurred in the structure of the Bering Sea ecosystem. One cause of the decline in mammalian and avian predator populations may be a decrease in availability or abundance of preferred prey (e.g. capelin, juvenile walleye pollock). However, adult groundfish biomass has generally been at high levels, and periods of high adult groundfish biomass coincide with periods of decline of sea lion and seabird populations. Adult groundfish may, therefore, be out-competing other predators for their common prey (i.e. small schooling fish). Three factors may have led to increases in adult groundfish biomass in the southeastern Bering Sea, changes in environmental conditions, present commercial fishing practices, and predator release resulting from overharvesting of marine mammals and some fishes during 1955–75. If the decline in whale and fur seal populations during 1955–75 contributed to the current high biomass of groundfish, then marine mammals once (but no longer) exerted a structuring effect on the Bering Sea eco-system. The current high abundance of piscivorous adult groundfish in the eastern Bering Sea may, therefore, impede the recovery of marine mammal and bird populations to his-torical levels. Text Aleutian Island Bering Sea Unknown Bering Sea |
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English |
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Key words Bering Sea ecosystem groundfish predators marine mammals seabirds |
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Key words Bering Sea ecosystem groundfish predators marine mammals seabirds Richard L. Merrick Current and historical roles of apex predators in the Bering Sea ecosystem |
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Key words Bering Sea ecosystem groundfish predators marine mammals seabirds |
description |
Large population declines (>50%) since the early-1970s of some eastern Bering Sea and Aleutian Island apex predator populations (Steller sea lions, murres, and kittiwakes) suggest that major changes have occurred in the structure of the Bering Sea ecosystem. One cause of the decline in mammalian and avian predator populations may be a decrease in availability or abundance of preferred prey (e.g. capelin, juvenile walleye pollock). However, adult groundfish biomass has generally been at high levels, and periods of high adult groundfish biomass coincide with periods of decline of sea lion and seabird populations. Adult groundfish may, therefore, be out-competing other predators for their common prey (i.e. small schooling fish). Three factors may have led to increases in adult groundfish biomass in the southeastern Bering Sea, changes in environmental conditions, present commercial fishing practices, and predator release resulting from overharvesting of marine mammals and some fishes during 1955–75. If the decline in whale and fur seal populations during 1955–75 contributed to the current high biomass of groundfish, then marine mammals once (but no longer) exerted a structuring effect on the Bering Sea eco-system. The current high abundance of piscivorous adult groundfish in the eastern Bering Sea may, therefore, impede the recovery of marine mammal and bird populations to his-torical levels. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Richard L. Merrick |
author_facet |
Richard L. Merrick |
author_sort |
Richard L. Merrick |
title |
Current and historical roles of apex predators in the Bering Sea ecosystem |
title_short |
Current and historical roles of apex predators in the Bering Sea ecosystem |
title_full |
Current and historical roles of apex predators in the Bering Sea ecosystem |
title_fullStr |
Current and historical roles of apex predators in the Bering Sea ecosystem |
title_full_unstemmed |
Current and historical roles of apex predators in the Bering Sea ecosystem |
title_sort |
current and historical roles of apex predators in the bering sea ecosystem |
publishDate |
1997 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.585.7516 http://journal.nafo.int/J22/Merrick.pdf |
geographic |
Bering Sea |
geographic_facet |
Bering Sea |
genre |
Aleutian Island Bering Sea |
genre_facet |
Aleutian Island Bering Sea |
op_source |
http://journal.nafo.int/J22/Merrick.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.585.7516 http://journal.nafo.int/J22/Merrick.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766265185020936192 |