The Atlantic cod is by many considered ‘the new salmon’ in aquaculture. A lot of effort in many countries is currently aimed at producing market size cod of good quality for human consumption. To improve production traits and quality, breeding programmes have been established. However, relatively little emphasis is given to the origin of fish for the initial establishment of ‘broodstocks’. This is despite the fact that the Atlantic cod is known to be separated into a number of genetically isolated wild stocks, which displays trait differences shaped by their genetic adaptation to the local environment (e.g. temperature and salinity). Accordingly, different stocks can potentially possess different traits beneficial for aquaculture.
Investigating trait differences among fish from numerous stocks simultaneously under controlled environmental conditions is, however, a formidable task. Alternatively, a ‘genome scan’ is a newly developed and fast method for generating insights into genetically based adaptive trait variation among stocks. Here a high number of genes are screened to identify those displaying divergent patterns of variation in different stocks, thus likely reflecting differences in adaptive traits.
