SWFSC Fisheries Ecology Division scientists provided results of genetic analyses of an unprecedented reintroduction experiment in Sonoma County. Managed by multiple agencies including California DFG and NMFS Southwest Region, this reintroduction involved the release of adult fish that have never been to sea into Salmon Creek as they were reaching reproductive maturity. Salmon Creek is geographically between Lagunitas Creek and the Russian River, and has been without salmon for several decades. Program staff followed FED recommendations and, in December 2008, released equal numbers of adult fish originating from these two proximate streams.
This summer, numerous juvenile coho salmon were present, but two of the streams where they were oversummering were drying up and a fish rescue was undertaken. Genetic analysis of 210 fish sampled during that rescue confirmed that they were progeny of experimentally released fish and demonstrated that the majority of mating events in Salmon Creek were due to outbred (Lagunitas by Russian) crosses, bolstering the programmatic decision to incorporate outbred crosses into the captive broodstock program.
(November 30, 2009)