State and federal biologists have begun moving endangered adult winter-run Chinook salmon to the upper reaches of Battle Creek and threatened spring-run Chinook salmon to Clear Creek in northern California, where colder water temperatures will better support spawning and help their eggs survive the continuing drought.
Teams from the California Department of Fish and Wildlife (CDFW) and the U.S. Fish and Wildlife Service (USFWS) are relocating the fish. Together, they will return about 300 adult winter-run Chinook salmon to native habitat above Eagle Canyon Dam on North Fork Battle Creek, about 20 miles east of Cottonwood, in Shasta and Tehama counties for the first time in more than 110 years.
Pacific Gas and Electric (PG&E), which operates hydroelectric facilities on Battle Creek, coordinated operations to make the move possible. It is one of a series of urgent actions to help the native fish survive another year of the lasting drought and high temperatures, thiamine deficiency, predators and other stressors that devastated the population the last two years in the Sacramento River below Shasta and Keswick dams.
Agencies Join Forces
CDFW, USFWS, NOAA Fisheries, Bureau of Reclamation, the California Department of Water Resources and water users are coordinating efforts to save the state and federally protected species. The agencies are working closely with the Winnemem Wintu Tribe, whose culture is intertwined with salmon in the area. Other actions include:
- Managing releases of limited water stored in Shasta Reservoir into the Sacramento River, where additional spawning gravel has been placed, to improve the odds that the released water is cool enough to allow some Chinook salmon eggs in the river to survive.
- Expanding production of juvenile winter-run Chinook salmon at Livingston Stone National Fish Hatchery operated by the USFWS at the base of Shasta Dam. Offspring produced at the hatchery in recent years have helped save the species as most of their eggs in the wild have died. Juvenile fish will be released into the river in stages when conditions are more hospitable in the late fall and winter.
- Moving adult spring-run Chinook salmon that return up the Sacramento River to the upper reaches of Clear Creek in Shasta and Siskiyou counties to cooler water and increased chances of egg survival.
- Boosting the resilience of transported adult salmon with injections of thiamine (Vitamin B) to counter a deficiency that researchers believe has depressed survival of their offspring in recent years. The deficiency has been tied to shifting ocean conditions and salmon feeding primarily on anchovies compared to a more diverse diet of forage fish, krill and other species.
- Tracking the survival and reproduction of the transported fish as part of a science plan to learn from these actions to promote climate resilience of Chinook salmon. Research includes field studies to understand the productivity of historic habitat where winter-run Chinook salmon will be reintroduced.