Data Courtesy of U.S. Army Corps of Engineers, NWD and Grant County PUD and Chelan County PUD and Douglas County PUD

Mainstem Columbia

Snake Basin

Upper Columbia

Query Notes and Methods

• Figures show daily average water temperature data at Columbia River and Snake River forebay water quality monitor (WQM) sites with inseason forecast temperatures, highest observed (historical period) and historical mean with +/- 1 standard deviation (SD) for each location. Observed data is updated daily; inseason forecasts are updated weekly. Water temperature data can be noisy and difficult to QA/QC. For Rock Island, years 2000 and 2007 are excluded from historical data. For Wells, year 2001 is excluded from historical data.
  
• Visualizations inspired by the work presented at Fraser River environmental watch, Fisheries and Oceans Canada
• For additional information including individual year details for Water Temperature, please refer to the DART River Environment Graphics & Text query and DART River Environment Metadata & Glossary.
• Water Quality Forecasts based on Observed Water Quality Monitoring for Columbia and Snake River Dams and Temperature Forecasts Methods and Information
• For additional information including individual year details for Adult Passage, please refer to the DART Adult Passage Counts Graphics & Text query and DART Adult Passage Visual Counts Metadata & Glossary.
• Historical Run Timing average for 10 Years generated by DART Adult Passage Counts Historical Run Timing

Critical temperature thresholds for adult salmonids in the Columbia River

Apart from the impact of high temperatures that may lead to metabolic stress (Brett 1995) or disease (McCullough 1999), temperatures have an impact on travel rates (Bjornn and Reiser 1991). There are two components to this. First, bioenergetic efficiency allows fish to swim most rapidly in optimal temperature waters (Hinch and Rand 2000). E. g., Columbia River Chinook and Fraser River sockeye swim most rapidly near 16°C (Lee et al. 2003; Salinger and Anderson 2006). Second, sufficiently high temperatures delay migration, e.g. Chinook are known to slow their migration above 20°C (Goniea et al. 2006), and several species completely cease migration above 21°C including Chinook, steelhead and sockeye (McCullough 1999; Quinn et al. 1997) .

Although individual tolerances to temperature are determined partly on acclimation temperatures, diel variation, spatial variability and fish size, temperatures above 21°C are widely regarded as detrimental to migration. The U.S. Environmental Protection Agency recommends using a metric called the “7 day average of daily maximums” (a.k.a 7DADM) which “can be used to protect against acute effects, such as lethality and migration blockage conditions” (EPA 2003). This is 20°C for salmon/trout migration.

Finally, extreme temperatures lead directly to mortality. These thresholds are near 24°C and 25°C for steelhead and Chinook respectively.

References