The Central Valley Constant Fractional Marking/Tagging Program (CFM) was initiated in the spring of 2007 to estimate the relative contribution of hatchery production to fishery harvest and spawner escapement, and to evaluate various release strategies employed in the Central Valley. The program is implemented at the Coleman National Fish Hatchery, Feather River Fish Hatchery, Nimbus Fish Hatchery, Mokelumne River Fish Hatchery, and the Merced River Hatchery.
Each year, approximately 32 million fall-run Chinook salmon are produced across the five Central Valley hatcheries. Under CFM, the Marking/Tagging Program ensures that at least 25% of all hatchery production fish are marked with an adipose fin clip and tagged with a uniquely numbered coded wire tag (CWT), which is inserted in the snout of juvenile salmon. Hatchery fish are then released in-river or trucked out to bays and estuaries where they can migrate to the ocean and grow. Correspondingly, the Recovery Program is a robust sampling program which recovers CWTs from adipose fin clipped salmon observed in commercial and recreational ocean harvest, inland harvest, and in spawner escapement to hatcheries and natural areas.
Objectives of the CFM program:
To evaluate the contribution rates of hatchery fish to Central Valley Chinook salmon populations;
To evaluate the recovery and contribution rates of hatchery fish to ocean and inland harvests;
To evaluate recovery and stray rates of hatchery fish under various release strategies;
To evaluate the Central Valley propagation program’s genetic and ecological effects on natural Chinook populations;
To estimate exploitation rates of hatchery and natural Central Valley Chinook salmon in ocean and inland fisheries;
To evaluate the success of restoration actions designed to increase natural production of Central Valley Chinook salmon;
To evaluate the relative impacts of water project operations on hatchery and naturally-produced Chinook salmon;
To evaluate the status and recovery of listed stocks of Chinook salmon.