Idaho Fish and Game Rescues Endangered Sockeye from Warming Rivers

For the second time in four years, the Idaho Department of Fish and Game (IDFG) has taken extraordinary measures to protect endangered sockeye salmon from dangerously warm river temperatures. More than 100 sockeye have been transported to the Eagle Hatchery near Boise after being trapped at the Lower Granite Dam near Lewiston.

 

"With warm water conditions this year and the extended heatwave that we're having, the river temperatures are starting to warm up, and we're expecting a lower survival than we'd like to see," said Dan Baker, hatchery manager at Eagle.

The water in the hatchery tanks is maintained at about 55 degrees Fahrenheit, over 10 degrees cooler than the Lower Snake River where the fish were rescued. This temperature difference can be crucial for the survival of sockeye, which are particularly sensitive to heat stress.

Ritchie Graves, Columbia River hydropower branch chief for the National Oceanic and Atmospheric Administration (NOAA), supports the IDFG's decision. "Not only are these fish important for their own sake, but they're also very important culturally and spiritually to our tribal co-managers," Graves explained. "We think it's a wise decision; a good thing to do for the species."

The rescued sockeye will remain at the Eagle Hatchery as part of the Captive Broodstock Program, aimed at rebuilding the population and eventually removing the species from the endangered list. Some fish may later be released into Redfish Lake, while others will be used for spawning at the hatchery.

This emergency measure was last employed in 2021, and before that in 2015. Baker hopes such interventions won't become more frequent. "I'd like to see some cool years with good snowpack and then migration conditions would really help all the salmon populations," he said.

As climate change continues to impact river ecosystems, such rescue operations may become increasingly necessary to protect vulnerable fish species. The IDFG's efforts highlight the ongoing challenges faced by Pacific Northwest salmon and the complex interplay between conservation, climate, and human intervention.