Elevation mediates juvenile steelhead demographic response to stream temperature and flow

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

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Abstract

Climate change alters streams by modifying flow dynamics, temperature, and biotic communities, changing the habitat where stream dwelling fish have evolved. We used snorkel survey data spanning four decades to investigate how juvenile steelhead (anadromous Oncorhynchus mykiss) counts and size structure were influenced by stream temperature and flow. Warmer temperatures were associated with lower abundance and larger fish at low elevations and with higher abundance and smaller fish at higher elevations. Low flows were related to increased abundance and smaller fish at low elevations but to decreased abundance at high elevations, suggesting that lower elevation streams, which tend to be larger, provided additional habitat during low flows. High flows were negatively related to abundance and positively related to average size, suggesting emigration of fish in younger age-classes. Overall, steelhead exhibited greater resilience to warm temperatures at high elevations and, conversely, greater resilience to low and high flows at lower elevations. Understanding how streamflow and temperature affect juvenile steelhead abundance and size structure provides insight into how climate change can affect juvenile steelhead production.

Suggested Citation

Vosbigian, R., Ballinger, A., Link, T.E., Copeland, T., Falcy, M.R., 2025, Elevation mediates juvenile steelhead demographic response to stream temperature and flow: Canadian Journal of Fisheries and Aquatic Sciences, v. 82, 16 p., https://doi.org/10.1139/cjfas-2025-0057.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Elevation mediates juvenile steelhead demographic response to stream temperature and flow
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/cjfas-2025-0057
Volume 82
Year Published 2025
Language English
Publisher Canadian Science Publishing
Contributing office(s) Coop Res Unit Seattle
Description 16 p.
Country United States
State Idaho
Other Geospatial Clearwater River basin, Salmon River basin
Additional publication details