Science activity

The Mokelumne River supports Central Valley fall-run Chinook salmon (Oncorhynchus tshawytscha) (fall-run), which is the only salmon run known to naturally occur in this waterway (Clark 1929). Fall-run are listed as a Species of Concern under the federal Endangered Species Act (NMFS 2004). Camanche Dam, which impounds Camanche Reservoir is the upper limit of anadromous fish migration in the Mokelumne River. East Bay Municipal Utility District (EBMUD) initiated construction of Camanche Reservoir in 1963. As mitigation for blocking access to spawning grounds for salmonids, EBMUD provided funding for the original construction of the MOK in 1964.The MOK is located on the south bank of the Mokelumne River at the base of Camanche Dam. While EBMUD provides funding for fall-run production, the California Department of Fish and Wildlife (CDFW) administers and operates the hatchery. The Commercial Salmon Stamp Fund provided funding for an additional MOK building built in 2002 and continues to financially support the MOK. On an annual basis the MOK produces fall-run for mitigation (Mitigation Element) and for ocean salmon enhancement (Ocean Enhancement Element). The annual MOK production goal is 6,400,000 fall-run smolts (3,400,000 for Mitigation Element and 3,000,000 for Ocean Enhancement Element). The hatchery operations are involved with tagging and monitoring fish to assess the success of the hatchery program.