Distribution of Adult Chinook Salmon (Oncorhynchus tshawytscha) in Relation to Water Temperatures, Lake Scanewa, Cowlitz River, Washington, 2012

Open-File Report 2019-1055
Prepared in cooperation with Public Utility District Number 1 of Lewis County, Washington
By: , and 



A trap-and-haul program is operated to move anadromous Pacific salmon (Oncorhynchus spp.) around dams and reservoirs in the Cowlitz River basin, Washington. The primary release site for adult fish is in Lake Scanewa, a small reservoir created by Cowlitz Falls Dam, the uppermost dam in the basin. Releases in the reservoir are terminated when reservoir water temperature is 16 degrees Celsius (°C) or greater to reduce the risk of exposing adult salmon and steelhead (O. mykiss) to thermal conditions known to be stressful for these species. When the water temperature limit is reached, fish are released into the Cowlitz and Cispus Rivers upstream of the reservoir. Concerns have been raised about fish presence in the reservoir during warm conditions, so an empirical evaluation of water temperatures selected by spring Chinook salmon (O. tshawytscha) in Lake Scanewa was requested by resource managers. We conducted the evaluation during June–October 2012. Water temperature in the reservoir was measured using a series of thermographs combined with daily measurements at the Cowlitz Falls Fish Facility. Temperature-use data were collected from 50 adult hatchery-origin spring Chinook salmon tagged with temperature-sensing radio transmitters and released into the reservoir. This approach yielded a total of 930,056 individual temperature-use records in the reservoir during the study. Tagged fish occupied water temperatures less than 16 °C during most of the study period. Water temperatures ranged from 5 to 18.5 °C during the study, peaking in mid-August. Overall, about 25 percent of the detections of tagged fish were in water temperatures in the 16–20 °C range. In August, tagged fish detections in the 18–20 °C range comprised 13 percent of the total detections, and the remainder of the detections were in water less than or equal to 17 °C. Results from the study indicate that adult hatchery-origin spring Chinook salmon were able to locate and use water temperatures in the reservoir less than levels associated with stress. However, we also observed that thermal conditions in the reservoir were cool relative to most other years during 2008–16. Additional research may be warranted to better understand thermal exposure of adult spring Chinook salmon during warmer years.

Suggested Citation

Kock, T.J., Ekstrom, B.K., and Liedtke, T.L., 2018, Distribution of adult Chinook salmon (Oncorhynchus tshawytscha) in relation to water temperatures, Lake Scanewa, Cowlitz River, Washington, 2012: U.S. Geological Survey Open-File Report 2019-1055, 14 p., https://doi.org/10.3133/ofr20191055.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Methods
  • Results
  • Discussion
  • Acknowledgments
  • References
Publication type Report
Publication Subtype USGS Numbered Series
Title Distribution of adult Chinook salmon (Oncorhynchus tshawytscha) in relation to water temperatures, Lake Scanewa, Cowlitz River, Washington, 2012
Series title Open-File Report
Series number 2019-1055
DOI 10.3133/ofr20191055
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Western Fisheries Research Center
Description iv, 14 p.
Country United States
State Washington
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details