Can late stage marine mortality explain observed shifts in age structure of Chinook salmon?
| Autor: | Peter A. H. Westley, Andrew C. Seitz, Curry J. Cunningham, Kaitlyn A. Manishin |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Male
Sexual Reproduction 0106 biological sciences Chinook wind Marine and Aquatic Sciences Predation 01 natural sciences Salmon Abundance (ecology) Oceans Marine Fish education.field_of_study Multidisciplinary Ecology Simulation and Modeling Mortality rate Eukaryota Spawn (biology) Trophic Interactions Community Ecology Osteichthyes Vertebrates Oncorhynchus Medicine Female Research Article Spawning Death Rates Oceans and Seas Science Population Modes of Reproduction Zoology Marine Biology Biology Research and Analysis Methods 010603 evolutionary biology Population Metrics Animals Mortality Population Growth education Life Cycle Stages Population Biology 010604 marine biology & hydrobiology Ecology and Environmental Sciences Organisms Biology and Life Sciences Aquatic Environments Bodies of Water biology.organism_classification Lamna Marine Environments Fish Predatory Behavior Sharks Earth Sciences Whale Killer Developmental Biology |
| Zdroj: | PLoS ONE, Vol 16, Iss 2, p e0247370 (2021) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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