Russian River Coho Salmon Captive Broodstock Program
Salmon all along the west coast have faced tremendous adversity for many years. Since the gold rush, salmon populations have been steadily declining due to a number of factors that have impaired their habitat, including stream diversion, damming, mining, logging, and urban and agricultural development--in addition to overfishing, natural predation, drought, and climate change. Coho salmon have had a particularly difficult time and are currently estimated to be no more than 15% of their 1940's abundance throughout California. The Central California Evolutionarily Significant Unit of coho is on the State and Federal Endangered Species Lists. The only remaining viable wild population is in Lagunitas Creek, in western Marin County, and even there the annual return is but a small fraction of historic runs. In the Russian River watershed, which spans Sonoma and Mendocino counties, the return has been so small that restoration efforts have expanded to include the artificial stocking of juvenile coho salmon from wild, local genetic stocks.
The Russian River Coho Salmon Captive Broodstock Program is working to supplement the wild Russian River coho population in the hope of restoring it to a sustainable size. Since 2001, a collaborative partnership including the US Army Corps of Engineers, the National Oceanic and Atmospheric Administration Fisheries Service, the California Department of Fish and Wildlife, the Sonoma County Water Agency, and the University of California Cooperative Extension/California Sea Grant Extension Program, have been breeding coho salmon from local genetic stock at the Don Clausen Fish Hatchery at Lake Sonoma and releasing them as juveniles into historic coho streams in the Russian River watershed.
Sea Grant's role in the Broodstock Program is to monitor wild and broodstock salmon in the stream environment to evaluate the efficacy of the program, and to work with program partners to apply advances in scientific knowledge to its management. Monitoring activities include downstream migrant smolt trapping in the spring, snorkel surveys in the summer, and spawner surveys in the winter. Biologists also use innovative PIT-tag technology to track program fish with Passively-Integrated Transponder tags at all life stages through the use of channel-spanning antennas and handheld transceivers.