Resumen
Gene flow between wild and domestic populations has been repeatedly demonstrated across a diverse range of taxa. Ultimately, the genetic impacts of gene flow from domestic into wild populations depend both on the degree of domestication and the original source of the domesticated population. Atlantic salmon, Salmo salar, used in North American aquaculture are ostensibly of North American origin. However, evidence of European introgression into North American aquaculture salmon has accumulated in recent decades, even though the use of diploid European salmon has never been approved in Canada. The full extent of such introgression as well as the potential impacts on wild salmon in the Northwest Atlantic remains uncertain. Here, we extend previous work comparing North American and European wild salmon (n = 5799) using a 220 K SNP array to quantify levels of recent European introgression into samples of domestic salmon, aquaculture escapees, and wild salmon collected throughout Atlantic Canada. Analysis of North American farmed salmon (n = 403) and escapees (n = 289) displayed significantly elevated levels of European ancestry by comparison with wild individuals (p < 0.001). Of North American farmed salmon sampled between 2011 and 2018, ~17% had more than 10% European ancestry and several individuals exceeded 40% European ancestry. Samples of escaped farmed salmon similarly displayed elevated levels of European ancestry, with two individuals classified as 100% European. Analysis of juvenile salmon collected in rivers proximate to aquaculture locations also revealed evidence of elevated European ancestry and larger admixture tract in comparison to individuals collected at distance from aquaculture. Overall, our results demonstrate that even though diploid European salmon have never been approved for use in Canada, individuals of full and partial European ancestry have been in use over the last decade, and that some of these individuals have escaped and hybridized in the wild.
| Idioma original | English |
|---|---|
| Publicación | Evolutionary Applications |
| DOI | |
| Estado | Accepted/In press - 2022 |
Nota bibliográfica
Funding Information:The authors would like to thank staff of Fisheries and Oceans Newfoundland and Labrador Salmonids Section for assistance with sample collection. The acquisition of aquaculture salmon baseline samples was facilitated by G. Perry, C. Hendry, DFO Aquaculture Section Newfoundland Region, and by industry partners Cooke Aquaculture, and Northern Harvest Sea Farms. We thank the late Ove. T. Skilbrei for contribution toward collection of samples of Norwegian farmed salmon. We also thank M. Kent and S. Lien CIGENE, and the Aquatic Biotechnology Laboratory of the Bedford Institute of Oceanography for SNP genotyping, and Ian Paterson and Beth Watson at the Marine Gene Probe Lab, Dalhousie University assisted with laboratory analysis. Funding was provided through the Program for Aquaculture Regulatory Research of Fisheries and Oceans Canada, the Genomics Research and Development Initiative of Canada. Collection of Norwegian farmed samples was financed through the Research Council of Norway (RCN) INTERACT project grant number 200510, and the Norwegian Ministry for Trade, Industry and Fisheries.
Publisher Copyright:
© 2022 Her Majesty the Queen in Right of Canada and the Authors. Evolutionary Applications published by John Wiley & Sons Ltd. Reproduced with the permission of the Minister of Fisheries and Oceans Canada.
ASJC Scopus Subject Areas
- Ecology, Evolution, Behavior and Systematics
- Genetics
- General Agricultural and Biological Sciences
PubMed: MeSH publication types
- Journal Article