Photo Credits: John McMillan
We study how salmon adapt to hatcheries. Early work using pedigree reconstruction in a population of steelhead (Oncorhynchus mykiss) from the Hood River showed that even first generation hatchery fish have lower fitness (production of returning adult offspring) than wild fish when both spawn in the same river. Furthermore, this appears to be a genetically based change and owing to adaptation to the hatchery environment. More recently we have been attempting to determine what traits are under selection in hatcheries, and what changes to the hatchery environment one might make to reduce those selection pressures.
Selected papers (for comprehensive list, see Publications link above):
Blouin, MS, MC Wrey, SR Bollmann, JC Skaar, R Twibell and C Fuentes. 2021. Offspring of first-generation hatchery steelhead trout (Oncorhynchus mykiss) grow faster in the hatchery than offspring of wild fish, but survive worse in the wild: possible mechanisms for inadvertent domestication and fitness loss in hatchery salmon. PLOS ONE https://doi.org/10.1371/journal.pone.0257407
Christie, MR, GG McNickle, RA French and MS Blouin. 2018 Life history variation is maintained by fitness trade-offs and negative frequency dependent selection. Proceedings of the National Academy of Sciences USA 115(17):4441-4446
Thompson NF, Blouin MS.2016. Family dominance level measured during the fry stage weakly influences family length at smolting in hatchery reared steelhead (Oncorhynchus mykiss). Transactions of the American Fisheries Society 145: 1282-1289.
Thompson, NF and MS Blouin 2015 The effects of high rearing density on the potential for domestication selection in hatchery culture of steelhead (Oncorhynchus mykiss). Canadian Journal of Fisheries and Aquatic Sciences. 72:1-6.
Christie, M., M. Ford and M.S. Blouin. 2014. On the reproductive success of first-generation hatchery fish in the wild. Evolutionary Applications, 7:883-896.
Christie MR, ML Marine, RA French, RS Waples, MS. Blouin. 2012. Genetic adaptation to captivity can occur in a single generation. Proceedings of the National Academy of Sciences USA 109:238-242
Christie MR, RA French, ML Marine and MS. Blouin. 2012 Genetic drift, inbreeding, and the fitness of hatchery fish in the wild. Heredity, 109, 254–260
Christie, M.R., M.L. Marine and M.S. Blouin. 2011. Who are the missing parents? Grandparentage analysis identifies multiple sources of gene flow into a wild population. Molecular Ecology, 20:1263-1276.
Araki, H., B. Cooper and M.S. Blouin. 2009. Carry-over effect of captive breeding reduces reproductive fitness of wild-born descendants in the wild. Biology Letters 5: 621-624
Araki, H., B. Berejikian, M. Ford, and M.S. Blouin. 2008 Fitness of hatchery-reared salmonids in the wild. Evolutionary Applications 1:342-355.
Araki, H., B. Cooper and M.S. Blouin. 2007. Genetic effects of captive breeding cause a rapid, cumulative fitness decline in the wild. Science, 318: 100-103.
