Effects of intraspecific hybridisation between two hatchery‐reared strains of Atlantic salmon, Salmo salar, on juvenile survival and fitness‐related traits

• Published in: Fisheries Management and Ecology
• Main Authors: Audet, C. L., Wilson, C. C., Pitcher, T. E.
• Other Authors: Natural Sciences and Engineering Research Council of Canada, Ontario Ministry of Economic Development and Innovation, Ministry of Natural Resources and Forestry
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/fme.12195; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Ffme.12195; https://onlinelibrary.wiley.com/doi/pdf/10.1111/fme.12195

Abstract Intraspecific hybridisation may result in hybrid offspring exhibiting superior (heterosis) or inferior (outbreeding depression) fitness relative to their parental populations. As both have been demonstrated in salmonids, consequences of interbreeding between divergent populations are relevant to their conservation. Atlantic salmon Salmo salar L. were extirpated from Lake Ontario by the late 19th Century due to anthropogenic causes. Multiple allopatric populations of hatchery‐reared Atlantic salmon are being stocked in an effort to re‐establish a self‐sustaining population. This study evaluated whether interbreeding between Sebago Lake (Maine) and LaHave River (Nova Scotia) individuals will result in heterosis or outbreeding depression in juveniles. This was accomplished through full‐factorial 2 × 2 mating crosses between the strains and comparing multiple fitness‐related traits between the cross types. Hybrid juveniles displayed no signs of outbreeding depression nor heterosis. Further studies on comparative fitness of backcross and F 2 hybrids are recommended to assess potential consequences for this and similar restoration efforts.