Genetic Evaluation of Sacramento River Winter-Run Chinook Salmon

Sacramento River Winter-run Chinook salmon were largely blocked from their historical freshwater habitat by an impassible dam and were listed as “endangered” under the Endangered Species Act in 1994.  A conservation hatchery program for this species was initiated in 1989 at an existing facility, and was subsequently moved to Livingston Stone National Fish Hatchery in 1998.  Since its inception, the Winter-run Chinook salmon program has operated under an integrated hatchery paradigm, and has incorporated several measures to minimize genetic risks of hatchery propagation to the population.  In order to prevent inadvertent hybridization with other populations of Chinook salmon, all fish collected as potential broodstock at Livingston Stone National Fish Hatchery were screened with either microsatellite or single nucleotide polymorphism markers.  The genetic samples and data collected during this screening process provide an opportunity for evaluating change in the population over time.  Here we present an overview of how the genetic profile of the population has changed over time as well as how the role of genetic data in hatchery operations has continued to evolve.