Restoring Atlantic Salmon to Lake Ontario: Genetic Considerations and Approaches

The effort to re-establish Atlantic salmon in Lake Ontario is a large-scale, multifaceted experiment aiming to build self-sustaining populations in historical habitats.  Genetic tracking is a key component being used to assess the comparative performance of the different strains being stocked, as well as optimal life stages to stock for juvenile survival and adult returns.  Genetic markers are being used to track Atlantic salmon at population, family, and individual levels, and evaluate the relative fitness of different strains and life stages. Three allopatric populations with contrasting ecological characteristics have been used to establish broodstocks for experimental stocking.  Genetic monitoring of these broodstocks is providing baseline data for identifying proportional contributions to fish in Lake Ontario and its tributaries, and genetic tracking of families stocked at different juvenile life stages is being used to assess their relative survival, growth, and ecological performance.  Combined analyses are being used to identify the source strain(s), families and stocked life stages of Atlantic salmon captured in Lake Ontario and as returning adults in stocked rivers.  These results are helping to inform restoration efforts, and will provide ongoing assessment and feedback to help ensure their success.