Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis
The article of record as published may be found at http://dx.doi.org/10.1111/j.1365-2419.2006.00408.x Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976-77 climate...
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2007
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ftnavalpschool:oai:calhoun.nps.edu:10945/48244 2024-06-09T07:50:11+00:00 Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis Trites, Andrew W. Miller, Arthur J. Maschner, Herbert D.G. Alexander, Michael A. Bograd, Steven J. Calder, John A. Capotondi, Antonietta Coyle, Kenneth O. DiLorenzo, Emanuele Finney, Bruce P. Gregr, Edward J. Grosch, Chester E. Hare, Steven R. Hunt, George L. Jr. Jahncke, Jaime Kachel, Nancy B. Kim, Hey-Jin Ladd, Carol Mantua, Nathan J. Marzban, Caren Maslowski, Wieslaw Mendelssohn, Roy Neilson, Douglas J. Okkonen, Stephen R. Overland, James F. Reedy-Maschner, Katherine L. Royer, Thomas C. Schwing, Franklin B. Wang, Julian X.L. Winship, Arliss J. Naval Postgraduate School (U.S.) Oceanography 2007 22 p. application/pdf https://hdl.handle.net/10945/48244 unknown Blackwell Publishing Ltd. Fisheries Oceanography, v. 16, no. 1, pp.46-67, 2007 https://hdl.handle.net/10945/48244 Aleutian Islands Climate regime shift Gulf of Alaska Stellar sea lion Article 2007 ftnavalpschool 2024-05-15T00:31:03Z The article of record as published may be found at http://dx.doi.org/10.1111/j.1365-2419.2006.00408.x Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976-77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon by Steller sea lions at mid-trophic levels. The east–west asymmetry of the oceanic response to climate forcing after 1976-77 is consistent with both the temporal aspect (populations decreased after the late 1970s) and the spatial aspect of the decline (western, but not eastern, sea lion populations decreased). These broad-scale climate variations appear to be modulated by regionally sensitive biogeographic structures along the Aleutian Islands and Gulf of Alaska, which include a transition point from coastal to open-ocean conditions at Samalga Pass westward along the Aleutian Islands. These transition points delineate distinct clusterings of different combinations of prey species, which are in turn correlated with differential population sizes and trajectories of Steller sea lions. Archaeological records spanning 4000 yr further indicate that sea lion populations have experienced major shifts in abundance in the past. Shifts in ocean climate are the most parsimonious underlying explanation for the broad suite of ecosystem changes that have been observed in the North Pacific Ocean in recent decades. Article in Journal/Newspaper Alaska Aleutian Islands Naval Postgraduate School: Calhoun Gulf of Alaska Pacific |
institution |
Open Polar |
collection |
Naval Postgraduate School: Calhoun |
op_collection_id |
ftnavalpschool |
language |
unknown |
topic |
Aleutian Islands Climate regime shift Gulf of Alaska Stellar sea lion |
spellingShingle |
Aleutian Islands Climate regime shift Gulf of Alaska Stellar sea lion Trites, Andrew W. Miller, Arthur J. Maschner, Herbert D.G. Alexander, Michael A. Bograd, Steven J. Calder, John A. Capotondi, Antonietta Coyle, Kenneth O. DiLorenzo, Emanuele Finney, Bruce P. Gregr, Edward J. Grosch, Chester E. Hare, Steven R. Hunt, George L. Jr. Jahncke, Jaime Kachel, Nancy B. Kim, Hey-Jin Ladd, Carol Mantua, Nathan J. Marzban, Caren Maslowski, Wieslaw Mendelssohn, Roy Neilson, Douglas J. Okkonen, Stephen R. Overland, James F. Reedy-Maschner, Katherine L. Royer, Thomas C. Schwing, Franklin B. Wang, Julian X.L. Winship, Arliss J. Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis |
topic_facet |
Aleutian Islands Climate regime shift Gulf of Alaska Stellar sea lion |
description |
The article of record as published may be found at http://dx.doi.org/10.1111/j.1365-2419.2006.00408.x Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976-77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon by Steller sea lions at mid-trophic levels. The east–west asymmetry of the oceanic response to climate forcing after 1976-77 is consistent with both the temporal aspect (populations decreased after the late 1970s) and the spatial aspect of the decline (western, but not eastern, sea lion populations decreased). These broad-scale climate variations appear to be modulated by regionally sensitive biogeographic structures along the Aleutian Islands and Gulf of Alaska, which include a transition point from coastal to open-ocean conditions at Samalga Pass westward along the Aleutian Islands. These transition points delineate distinct clusterings of different combinations of prey species, which are in turn correlated with differential population sizes and trajectories of Steller sea lions. Archaeological records spanning 4000 yr further indicate that sea lion populations have experienced major shifts in abundance in the past. Shifts in ocean climate are the most parsimonious underlying explanation for the broad suite of ecosystem changes that have been observed in the North Pacific Ocean in recent decades. |
author2 |
Naval Postgraduate School (U.S.) Oceanography |
format |
Article in Journal/Newspaper |
author |
Trites, Andrew W. Miller, Arthur J. Maschner, Herbert D.G. Alexander, Michael A. Bograd, Steven J. Calder, John A. Capotondi, Antonietta Coyle, Kenneth O. DiLorenzo, Emanuele Finney, Bruce P. Gregr, Edward J. Grosch, Chester E. Hare, Steven R. Hunt, George L. Jr. Jahncke, Jaime Kachel, Nancy B. Kim, Hey-Jin Ladd, Carol Mantua, Nathan J. Marzban, Caren Maslowski, Wieslaw Mendelssohn, Roy Neilson, Douglas J. Okkonen, Stephen R. Overland, James F. Reedy-Maschner, Katherine L. Royer, Thomas C. Schwing, Franklin B. Wang, Julian X.L. Winship, Arliss J. |
author_facet |
Trites, Andrew W. Miller, Arthur J. Maschner, Herbert D.G. Alexander, Michael A. Bograd, Steven J. Calder, John A. Capotondi, Antonietta Coyle, Kenneth O. DiLorenzo, Emanuele Finney, Bruce P. Gregr, Edward J. Grosch, Chester E. Hare, Steven R. Hunt, George L. Jr. Jahncke, Jaime Kachel, Nancy B. Kim, Hey-Jin Ladd, Carol Mantua, Nathan J. Marzban, Caren Maslowski, Wieslaw Mendelssohn, Roy Neilson, Douglas J. Okkonen, Stephen R. Overland, James F. Reedy-Maschner, Katherine L. Royer, Thomas C. Schwing, Franklin B. Wang, Julian X.L. Winship, Arliss J. |
author_sort |
Trites, Andrew W. |
title |
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis |
title_short |
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis |
title_full |
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis |
title_fullStr |
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis |
title_full_unstemmed |
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis |
title_sort |
bottom-up forcing and the decline of steller sea lions (eumetopias jubatus) in alaska: assessing the ocean climate hypothesis |
publisher |
Blackwell Publishing Ltd. |
publishDate |
2007 |
url |
https://hdl.handle.net/10945/48244 |
geographic |
Gulf of Alaska Pacific |
geographic_facet |
Gulf of Alaska Pacific |
genre |
Alaska Aleutian Islands |
genre_facet |
Alaska Aleutian Islands |
op_relation |
Fisheries Oceanography, v. 16, no. 1, pp.46-67, 2007 https://hdl.handle.net/10945/48244 |
_version_ |
1801383417207586816 |