The California Department of Fish and Wildlife (CDFW) is working to keep hundreds of thousands of trout alive at the American River Hatchery after warm water temperatures killed approximately 155,000 trout Tuesday.
A chiller that cools water at the hatchery about 18 miles east of Sacramento unexpectedly failed Tuesday, and warm temperatures killed most of the Eagle Lake species of trout being raised at the hatchery. Failure of the hatchery equipment may be related to work by the U.S. Bureau of Reclamation, which owns the hatchery, but the exact cause is not clear and is under investigation. Hatchery staff is working to get a least one chiller working again, which could drop the water temperature – now approximately 70 degrees Fahrenheit – by five degrees, enough to help sustain the remaining trout in the hatchery.
Additional losses are expected because of stress to the fish and continuing elevated water temperatures.
Loss estimates as of Sept. 9, by species:
155,000 of the 199,313 (78%) of Eagle Lake trout
300 of the 61,839 (0.5%) of Shasta trout
Five of the 230,000 Lahontan cutthroat trout
Though this fish kill means that CDFW likely will not be able to stock streams and lakes at an ideal level in the Sacramento region next year, all trout at the American River Hatchery were not lost. CDFW will seek ways to supplement the trout produced at its hatcheries to increase angling opportunities next year.