Captive broodstock gene rescue programs for Pacific salmon are a form of artificial propagation that differ from standard hatchery programs in one important respect: fish are cultured in captivity for their entire life cycle.
What are captive broodstocks, why are they important? Husbandry of animals in captivity to prevent extinction of wild populations and to amplify population numbers is a common gene maintenance technique popular worldwide. In the United States, captive husbandry has been a foundation that has aided ESA delisting of peregrine falcons and is providing critical population stability for many species including the black-footed ferret, red wolf, and California condor. The relatively short 2–7-year generation time and potential to produce a large number of offspring make Pacific salmon ideal candidates for these sort of gene rescue and population amplification efforts.
In all cases, the NOAA Fisheries' captive broodstock gene rescue programs at the NWFSC's Manchester Research Station are components of larger cooperatives by federal, state, tribal, and non-governmental organizations to address a multitude of issues for the populations and are functioning to help restore the populations in their native habitat.
Together with our partners, we have developed husbandry protocols that provide for an average of over 50% egg-to-adult survival, while maintaining over 90% of the original founding genetic variability of the population in long-term culture. For our programs, two eggs taken into gene rescue can reliably produce over one spawning adult. This survival advantage in culture can easily be over a thousand times what some of these depleted populations are currently experiencing in nature, and may provide them the difference between survival and extinction.
Our Pacific salmon captive broodstock projects include: