Modeling coho salmon (Oncorhynchus kisutch) population response to streamflow and water temperature extremes

Models that assess the vulnerability of freshwater species to shifting environmental conditions do not always account for short-duration extremes, which are increasingly common. Life cycle models for Pacific salmon (Oncorhynchus spp.) generally focus on average conditions that fish experience during...

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Bibliographic Details
Main Authors: Bellmore, J. Ryan, Sergeant, Christopher, Bellmore, Rebecca, Falke, Jeffery, Fellman, Jason
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2023
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Online Access:http://hdl.handle.net/11122/14923
Description
Summary:Models that assess the vulnerability of freshwater species to shifting environmental conditions do not always account for short-duration extremes, which are increasingly common. Life cycle models for Pacific salmon (Oncorhynchus spp.) generally focus on average conditions that fish experience during each life stage, yet many floods, low flows, and elevated water temperatures only last days to weeks. We developed a process-based life cycle model that links coho salmon (Oncorhynchus kisutch) abundance to daily streamflow and thermal regimes to assess: (1) “How does salmon abundance respond to short-duration floods, low flows, and high temperatures in glacier-, snow-, and rain-fed streams?” and (2) “How does the temporal resolution of flow and temperature data influence these responses?”. Our simulations indicate that short-duration extremes can reduce salmon abundance in some contexts. However, after daily flow and temperature data were aggregated into weekly and monthly averages, the impact of extreme events on populations declined. Our analysis demonstrates that novel modeling frameworks that capture daily variability in flow and temperature are needed to examine impacts of extreme events on Pacific salmon. Alaska Sea Grant. Abstract -- Key words -- Introduction -- Methods -- Results -- Discussion -- Conclusions -- Acknowledgements -- Article information -- Copyright -- Data availability statement -- Author information -- Supplementary material -- References. Yes