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Review article - Peer-reviewed, 2020

Beyond hybridization: the genetic impacts of non-reproductive ecological interactions of salmon aquaculture on wild populations

Bradbury, I. R.; Burgetz, I; Coulson, M. W.; Verspoor, E.; Gilbey, J.; Lehnert, S. J.; Kess, T.; Cross, T. F.; Vasemägi, Anti; Solberg, M. F.; Fleming, I. A.; McGinnity, P.


Cultured Atlantic salmon Salmo salar are of international socioeconomic value, and the process of domestication has resulted in significant behavioural, morphological, and allelic differences from wild populations. Substantial evidence indicates that direct genetic interactions or interbreeding between wild and escaped farmed Atlantic salmon occurs, genetically altering wild salmon and reducing population viability. However, genetic interactions may also occur through ecological mechanisms (e.g. disease, parasites, predation, competition), both in conjunction with and in the absence of interbreeding. Here we examine existing evidence for ecological and non-reproductive genetic interactions between domestic Atlantic salmon and wild populations and the potential use of genetic and genomic tools to resolve these impacts. Our review identified examples of genetic changes resulting from ecological processes, predominately through pathogen or parasite transmission. In addition, many examples were identified where aquaculture activities have either altered the selective landscape experienced by wild populations or resulted in reductions in population abundance, both of which are consistent with the widespread occurrence of indirect genetic changes. We further identify opportunities for genetic or genomic methods to quantify these impacts, though careful experimental design and pre-impact comparisons are often needed to accurately attribute genetic change to aquaculture activities. Our review indicates that ecological and non-reproductive genetic interactions are important, and further study is urgently needed to support an integrated understanding of aquaculture-ecosystem interactions, their implications for ecosystem stability, and the development of potential mitigation and management strategies.


Atlantic salmon; Aquaculture; Management; Genetic

Published in

Aquaculture environment interactions
2020, volume: 12, pages: 429-445

Authors' information

Bradbury, I. R.
Fisheries and Oceans Canada
Burgetz, I
Fisheries and Oceans Canada
Coulson, M. W.
Fisheries and Oceans Canada
Verspoor, E.
University of the Highlands and Islands (UHI)
Gilbey, J.
Marine Science Scotland
Lehnert, S. J.
Fisheries and Oceans Canada
Kess, T.
Fisheries and Oceans Canada
Cross, T. F.
University College Cork
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Estonian University of Life Sciences
Solberg, M. F.
Institute of Marine Research - Norway
Fleming, I. A.
Memorial University of Newfoundland
McGinnity, P.
University College Cork

UKÄ Subject classification

Evolutionary Biology

Publication Identifiers


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