Heres one closer to home


http://www.fish.washington.edu/people/hauser/research.html

Evaluation of the Reproductive Success of Wild and Hatchery Steelhead in Natural and Hatchery Environments
Researchers: Todd Seamons (Staff Biologist), to be appointed (graduate student)
Collaborators: Tom Quinn, School of Fisheries and Aquatic Sciences, University of Washington, Kerry Naish, School of Fisheries and Aquatic Sciences, University of Washington
Funding: under consideration by the Bonneville Power Administration

Complex stochastic and deterministic processes related to breeding dynamics and survival of progeny result in differential reproductive success of adult salmonids with different phenotypic traits. These processes are essential to the long-term health of populations but are markedly different from patterns of mating and subsequent reproductive success in hatcheries. Hatchery populations are on evolutionary trajectories that may reduce their fitness, and their interactions with wild populations are a serious conservation concern. However, it is unclear to what extent hatchery fish can contribute to the stability or recovery of populations. To conserve wild salmonids and wisely manage hatchery populations, we propose to extend a unique study of reproductive success including wild steelhead, hatchery origin fish spawning naturally, and hatchery fish propagated in the hatchery. We have been sampling adults and smolts of the winter steelhead population in Forks Creek, a Willapa River tributary, since winter 1995-96. We are in a rare position – we are able to extend these data to the returning adult F2 within a year and to the F3 within the next four years. Our experiment will allow us to compare the genetic diversity from one generation to the next in natural and hatchery environments for males and females, estimate the reproductive success of the offspring of wild-hatchery matings in the wild, and determine the extent to which a wild population “resists” or “amalgamates” the genetic material from hatchery fish after cessation of hatchery releases over several generations. Specifically, we will document the phenotypic traits of fish used for breeding in the hatchery or migrating to spawn in the river, and will then use parentage analysis from DNA microsatellites to determine the reproductive success of individual fish, link these results to various fitness traits in spawning individuals, and examine the changes in gene frequency over three complete generations. Preliminary results from the returning adult F1 indicate markedly lower survival of hatchery compared to wild fish, with the differences largely in the freshwater rather than marine phases, and hybridization between wild and hatchery fish (despite significant differences in average spawning timing). We have also found great variation in realized reproductive success of hatchery-spawned adults, probably resulting from variation in fertilization success and low but variable marine survival among families. These results leave open the question of whether the population’s long-term health will be affected by the hatchery influence. Our study is poised to address this question within the next few years.