The detection of a disease-causing parasite has led the California Department of Fish and Wildlife (CDFW) to quarantine infected trout at two northern California hatcheries.
During routine hatchery and fish health checks, CDFW fisheries pathologists found that captive-raised fish at the Darrah Springs Trout Hatchery (located in the Battle Creek watershed east of Redding) tested positive for whirling disease. Prior to the discovery, trout were transferred from an infected raceway at Darrah Springs to Mt. Shasta Hatchery. While fish transferred to Mt. Shasta Hatchery from Darrah Springs Hatchery tested positive for the parasite, it is yet unknown if biological and environmental conditions allowed it to complete its lifecycle at that location. Approximately three million rainbow and brown trout at both hatcheries are now under quarantine and will undergo testing.