Conservation Genetics

, Volume 11, Issue 3, pp 785–794 | Cite as

Reduced anti-predator responses in multi-generational hybrids of farmed and wild Atlantic salmon (Salmo salar L.)

  • Aimee Lee S. Houde
  • Dylan J. Fraser
  • Jeffrey A. Hutchings
Research Article


Cultured organisms undergo genetically-based behavioural changes that may reduce their ability to survive in the wild. This has raised concerns that interbreeding between escaped cultured and wild organisms will generate hybrids exhibiting maladaptive behaviours which may ultimately reduce the fitness of the wild counterpart. We compared anti-predator responses in Atlantic salmon (Salmo salar) from two wild North American populations, the major farmed strain used in regional aquaculture, and their wild-farmed hybrids (F1, F2, and wild backcross). Anti-predator responses of fry (age 0+ parr) were measured under common environmental conditions, using a model of a natural predator (belted kingfisher, Ceryle alcyon). Farmed fry exhibited significantly reduced anti-predator responses relative to fry from both wild populations. The anti-predator responses of wild-farmed hybrid fry were intermediate to those of the parental populations (pure farmed or wild). The magnitude by which wild-farmed hybrids differed in anti-predator responses from pure wild fish also depended on the wild population. These results suggest that: (1) the observed behavioural differences have a genetic basis; (2) wild-farmed hybrids have, on average, reduced anti-predator responses relative to wild fish; and that (3) the effects of wild-farmed interbreeding on anti-predator responses will differ between wild populations. Our study is consistent with the general hypothesis that continual farmed-wild interbreeding may have detrimental effects on the fitness of wild organisms.


Aquaculture F1 F2 Backcross Escape Risk assessment Outbreeding depression 



The work was supported by the Natural Sciences and Engineering Research Council (Canada) through an undergraduate student research award to ASH, a post-doctoral fellowship to DJF, and a Strategic Grant to JAH. ASH was also supported by an Atlantic Salmon Federation Olin Fellowship. We thank at Dalhousie University J. Eddington (Aquatron facility), M. Merrimen, R. Myers, K. Tae, L. Weir, and P. Debes. We also thank P. Amiro (Department of Fisheries and Oceans Nova Scotia Region), J.-G. Godin (Carleton University, Ottawa), A. Hebda (Natural History Museum of Nova Scotia), A. D-S. Houde (Saint Mary’s University, Halifax), the constructive comments of two anonymous reviewers, and E. Anderson. Petrie the belted kingfisher.


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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Aimee Lee S. Houde
    • 1
  • Dylan J. Fraser
    • 1
  • Jeffrey A. Hutchings
    • 1
  1. 1.Department of BiologyDalhousie UniversityHalifaxCanada

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