Identifying the genomic basis of age at maturity in Atlantic salmon in Atlantic Canada: applications for fisheries and aquaculture management
Atlantic salmon can have differing ages at maturity, which is a central life history trait. Historically, one sea winter (1SW) and multi-sea winter (MSW) individuals occupy different regions of the North Atlantic (Reddin 1988). These different populations have been exploited by fisheries requiring different, independent management strategies. Due to significant declines of MSW individuals in recent decades, recreational harvest of large MSW salmon has been significantly restricted, although exploitation still occurs in fisheries in Greenland, Labrador, and Saint Pierre et Miquleon. In Atlantic salmon aquaculture, domestication selects for faster growth and larger size. Interbreeding between escaped farmed and wild salmon may affect the age at maturity of wild populations (Bolstad et al. 2017, Wringe et al. 2018). In both fisheries and aquaculture management, the ability to genetically identify individuals destined to mature early or late, and track changes in age at maturity in wild populations would dramatically improve management decisions and ultimately enhance salmon stock assessment, management, and conservation efforts. In the northeast Atlantic, the genomic basis of age at maturity in salmon has been identified and is associated with a region of chromosome 25 (i.e., involving the vestigial-like family member 3 gene, VGll3; Ayllon et al. 2015, Barson et al. 2015). The region has been used to track fishery induced changes in wild populations (i.e., fishery induced evolution) and accounts for most (>70%) of the variation in age at maturity observed in the wild. Interestingly, this gene does not appear to be involved in determining age at maturity in North American salmon populations (Boulding 2018, Kusche et al. 2017). The overarching goal of the PARR-2019-NL-05 is to identify the genes or gene regions associated with age at maturity in Atlantic salmon in the northwest Atlantic and use targeted genotyping to inform both fisheries and aquaculture management within Atlantic Canada.
Program for Aquaculture Regulatory Research (PARR)
Research scientist, Northwest Atlantic Fisheries Centre, St. John’s, N.L.
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