Cassidy Cooper

UC Davis

“Exploring the Role of Feed and Temperature on Early Life Stage Chinook Salmon”

Understanding how environmental change affects impacted species is crucial for addressing the ecological effects of climate change. California contains 21 evolutionarily significant units (ESUs) of at-risk Pacific Salmonids, of which 11 federally-listed species are projected to be extinct within 50 years under current climate trends, including Chinook salmon. Chinook salmon is a species of anadromous fish, which migrates from freshwater to marine habitats and back during its lifecycle. Limitation in access to food or optimal rearing temperatures in wild populations may result in energetic tradeoffs between performance and growth, impacting the ability of Chinook salmon to reach critical juvenile sizes for outmigration. Our research takes a use-based approach to investigate these trends. Thermal tolerance data are used by state regulatory agencies to determine habitat management criteria. For this project, juvenile Chinook salmon were exposed to a broad spectrum of temperature and feeding conditions. Our results show both acute (“critical thermal maximum”) and chronic (“upper incipient lethal temperature”) thermal tolerance are influenced primarily by rearing temperature for fish in laboratory and field settings alike.


Rapidly changing environments have consequences for physiological performance and behavior of California native fish species like Chinook salmon. Cassidy’s work is designed to understand how environmental constraints (e.g., access to food) will influence a fish’s ability to adjust to changing temperatures in critical early life stages.

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