Darrah Springs Hatchery, operated by the California Department of Fish and Wildlife (DFW), was partially released from quarantine on October 9, 2015 after being in quarantine since May because of whirling disease.
Extensive DNA testing of the fish by a commercial sciences lab have determined that all the trout in the hatchery building and the lower rearing ponds are free of the disease, and the hatchery is resuming normal operations for that portion of the facility. Part of the hatchery is still infected, and the DFW will have to destroy some fish. The fish rearing areas still infected will be dried up and not utilized until the water supply can be either disinfected through a water treatment system or pathology testing verifies that the water supply no longer is infected. Approximately 160,000 fish will be euthanized.
Darrah Springs Hatchery supplies catchable trout for waters in Lassen, Modoc, Shasta, Siskiyou, and Trinity counties, and is one of 21 state-run hatcheries that provide millions of fish for California anglers.