Data from: Reproductive success of captively bred and naturally spawned Chinook salmon colonizing newly accessible habitat

Captively reared animals can provide an immediate demographic boost in reintroduction programs but may also reduce the fitness of colonizing populations. Construction of a fish passage facility at Landsburg Diversion Dam on the Cedar River, WA, USA, provided a unique opportunity to explore this trade-off. We thoroughly sampled adult Chinook salmon (Oncorhynchus tshawytscha) at the onset of colonization (2003 – 2009), constructed a pedigree from genotypes at 10 microsatellite loci, and calculated reproductive success (RS) as the total number of returning adult offspring. Hatchery males were consistently but not significantly less productive than naturally spawned males (range in relative RS: 0.70 – 0.90), but the pattern for females varied between years. The sex ratio was heavily biased towards males, so inclusion of the hatchery males increased the risk of a genetic fitness cost with little demographic benefit. Measurements of natural selection indicated that larger salmon had higher RS than smaller fish. Fish that arrived early to the spawning grounds tended to be more productive than later fish, although in some years, RS was maximized at intermediate dates. Our results underscore the importance of natural and sexual selection in promoting adaptation during reintroductions.GenotypesThis file contains genotypes at 10 microsatellite loci for Chinook salmon collected in the fish passage facility at Landsburg Diversion Dam, Cedar River, WA, USA. Values of "0" indicated no observation at the given locus for that individual.PhenotypesThis file contains the non-genetic data on each individual in the study. "Adipose" refers to the presence or absence of the adipose fin; salmon hatcheries in this region generally remove this fin prior to release. Thus "Absent" indicates hatchery origin