Skip to main content
U.S. flag

An official website of the United States government

Differential heat shock protein responses in two species of Pacific salmon and their utility in identifying heat stress

December 7, 2023

Rapid and accelerating warming of salmon habitat has the potential to lower productivity of Pacific salmon (Oncorhynchus species) populations. Heat stress biomarkers can indicate where warming is most likely affecting fish populations; however, we often lack clear classifications that separate individuals with and without heat stress needed to make these tools operational. We conducted a heat exposure experiment with trials lasting 12 or 36 h using juvenile Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) to validate heat stress biomarkers in white muscle. Following habituation to 13°C, individuals were exposed to water temperatures that increased to 15°C, 17°C, 19°C, 21°C or 23°C. Heat shock protein 70 abundance (HSP70 measured by ELISA) and transcription of 13 genes (mRNA measured by qPCR) including three heat shock protein genes (hsp70, hsp90, hsp27) were measured. A distinct heat stress response was apparent by 21°C in juvenile Chinook salmon and 23°C in juvenile coho salmon using HSP70. A threshold for heat stress classification in Chinook salmon of > 2 ng HSP70 mg.1 total protein identified heat stress in 100% of 21 and 23°C treated individuals compared to 4% in cooler treatments. For coho salmon, > 3 ng HSP70 mg.1 total protein identified heat stress in 100% of 23°C treated individuals compared to 4% in cooler treatments. Transcription from a panel of genes separated individuals between cooler and stressful temperature experiences (≥21°C for Chinook salmon and ≥23°C for coho salmon) with ~ 85% correct classification. Our findings indicate that juvenile Chinook salmon were more temperature-sensitive than juvenile coho salmon and support the use of a HSP70 threshold sampled from muscle for assessing heat stress in individual wild Pacific salmon with an option for non-lethal biopsies for spawning adults.

Publication Year 2023
Title Differential heat shock protein responses in two species of Pacific salmon and their utility in identifying heat stress
DOI 10.1093/conphys/coad092
Authors Vanessa R. von Biela, Amy M. Regish, Lizabeth Bowen, Ashley E. Stanek, Shannon C. Waters, Michael P. Carey, Christian E. Zimmerman, Jonathon Gerken, Daniel Rinella, Stephen D. McCormick
Publication Type Article
Publication Subtype Journal Article
Series Title Conservation Physiology
Index ID 70250461
Record Source USGS Publications Warehouse
USGS Organization Leetown Science Center; Western Ecological Research Center; Alaska Science Center Ecosystems
Was this page helpful?