Can late stage marine mortality explain observed shifts in age structure of Chinook salmon?
Chinook salmon (Oncorhynchus tshawytscha) populations have experienced widespread declines in abundance and abrupt shifts toward younger and smaller adults returning to spawn in rivers. The causal agents underpinning these shifts are largely unknown. Here we investigate the potential role of late-st...
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ftdoajarticles:oai:doaj.org/article:4e14b5e9b6b946c7aea56bf5372456f7 2023-05-15T17:53:52+02:00 Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? Kaitlyn A Manishin Curry J Cunningham Peter A H Westley Andrew C Seitz 2021-01-01T00:00:00Z https://doi.org/10.1371/journal.pone.0247370 https://doaj.org/article/4e14b5e9b6b946c7aea56bf5372456f7 EN eng Public Library of Science (PLoS) https://doi.org/10.1371/journal.pone.0247370 https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0247370 https://doaj.org/article/4e14b5e9b6b946c7aea56bf5372456f7 PLoS ONE, Vol 16, Iss 2, p e0247370 (2021) Medicine R Science Q article 2021 ftdoajarticles https://doi.org/10.1371/journal.pone.0247370 2022-12-31T10:10:27Z Chinook salmon (Oncorhynchus tshawytscha) populations have experienced widespread declines in abundance and abrupt shifts toward younger and smaller adults returning to spawn in rivers. The causal agents underpinning these shifts are largely unknown. Here we investigate the potential role of late-stage marine mortality, defined as occurring after the first winter at sea, in driving this species' changing age structure. Simulations using a stage-based life cycle model that included additional mortality during after the first winter at sea better reflected observed changes in the age structure of a well-studied and representative population of Chinook salmon from the Yukon River drainage, compared with a model estimating environmentally-driven variation in age-specific survival alone. Although the specific agents of late-stage mortality are not known, our finding is consistent with work reporting predation by salmon sharks (Lamna ditropis) and marine mammals including killer whales (Orcinus orca). Taken as a whole, this work suggests that Pacific salmon mortality after the first winter at sea is likely to be higher than previously thought and highlights the need to investigate selective sources of mortality, such as predation, as major contributors to rapidly changing age structure of spawning adult Chinook salmon. Article in Journal/Newspaper Orca Orcinus orca Yukon river Yukon Directory of Open Access Journals: DOAJ Articles Yukon Pacific PLOS ONE 16 2 e0247370 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
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English |
topic |
Medicine R Science Q |
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Medicine R Science Q Kaitlyn A Manishin Curry J Cunningham Peter A H Westley Andrew C Seitz Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? |
topic_facet |
Medicine R Science Q |
description |
Chinook salmon (Oncorhynchus tshawytscha) populations have experienced widespread declines in abundance and abrupt shifts toward younger and smaller adults returning to spawn in rivers. The causal agents underpinning these shifts are largely unknown. Here we investigate the potential role of late-stage marine mortality, defined as occurring after the first winter at sea, in driving this species' changing age structure. Simulations using a stage-based life cycle model that included additional mortality during after the first winter at sea better reflected observed changes in the age structure of a well-studied and representative population of Chinook salmon from the Yukon River drainage, compared with a model estimating environmentally-driven variation in age-specific survival alone. Although the specific agents of late-stage mortality are not known, our finding is consistent with work reporting predation by salmon sharks (Lamna ditropis) and marine mammals including killer whales (Orcinus orca). Taken as a whole, this work suggests that Pacific salmon mortality after the first winter at sea is likely to be higher than previously thought and highlights the need to investigate selective sources of mortality, such as predation, as major contributors to rapidly changing age structure of spawning adult Chinook salmon. |
format |
Article in Journal/Newspaper |
author |
Kaitlyn A Manishin Curry J Cunningham Peter A H Westley Andrew C Seitz |
author_facet |
Kaitlyn A Manishin Curry J Cunningham Peter A H Westley Andrew C Seitz |
author_sort |
Kaitlyn A Manishin |
title |
Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? |
title_short |
Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? |
title_full |
Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? |
title_fullStr |
Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? |
title_full_unstemmed |
Can late stage marine mortality explain observed shifts in age structure of Chinook salmon? |
title_sort |
can late stage marine mortality explain observed shifts in age structure of chinook salmon? |
publisher |
Public Library of Science (PLoS) |
publishDate |
2021 |
url |
https://doi.org/10.1371/journal.pone.0247370 https://doaj.org/article/4e14b5e9b6b946c7aea56bf5372456f7 |
geographic |
Yukon Pacific |
geographic_facet |
Yukon Pacific |
genre |
Orca Orcinus orca Yukon river Yukon |
genre_facet |
Orca Orcinus orca Yukon river Yukon |
op_source |
PLoS ONE, Vol 16, Iss 2, p e0247370 (2021) |
op_relation |
https://doi.org/10.1371/journal.pone.0247370 https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0247370 https://doaj.org/article/4e14b5e9b6b946c7aea56bf5372456f7 |
op_doi |
https://doi.org/10.1371/journal.pone.0247370 |
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PLOS ONE |
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16 |
container_issue |
2 |
container_start_page |
e0247370 |
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1766161566883905536 |