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Published on: November 18, 2022
Differences in thermal tolerance among sockeye salmon populations
Erika J Eliason1, Timothy D Clark, Merran J Hague
1Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4. eliason@zoology.ubc.ca
Science (New York, N.Y.)
|April 2, 2011
Summary
Rising river temperatures due to climate change impact sockeye salmon (Oncorhynchus nerka) migration. Local adaptations in fish physiology, particularly cardiorespiratory function, influence their survival in historically warmer waters.
Area of Science:
- Environmental Science
- Zoology
- Physiology
Background:
- Climate change is increasing river temperatures, leading to higher mortality in migrating adult sockeye salmon (Oncorhynchus nerka).
- Sockeye salmon populations exhibit variations in their physiological responses to environmental stressors during migration.
Purpose of the Study:
- To investigate population-level variations in cardiorespiratory physiology among Fraser River sockeye salmon.
- To determine if these physiological differences correlate with historical environmental conditions and thermal tolerance.
Main Methods:
- Comparative analysis of cardiorespiratory physiology (aerobic scope, heart size, coronary supply) across different sockeye salmon populations.
- Correlation of physiological traits with historical river temperature data.
Main Results:
- Sockeye salmon populations from more challenging, warmer historical environments displayed superior aerobic scope, larger hearts, and enhanced coronary supply.
- Thermal optima for physiological scopes aligned with the historical temperature ranges experienced by each population.
- Evidence suggests local-scale physiological adaptation in sockeye salmon populations.
Conclusions:
- Sockeye salmon exhibit population-specific physiological adaptations to local thermal conditions, indicating adaptation at a fine geographic scale.
- Physiological limitations, potentially cardiac collapse at high temperatures, may define population-specific thermal tolerance limits.
- Understanding these adaptations is crucial for predicting sockeye salmon resilience to climate change.
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