Intensive selective breeding of farmed Atlantic salmon has improved production traits but may have inadvertently affected disease resistance and stress tolerance. Understanding genetic diversity implications guides better aquaculture genetics.
Salmon aquaculture genetics has an opportunity to explicitly incorporate welfare traits in selection programs that have historically focused almost entirely on production. The available tools now exist: genomic selection allows identification of genetic markers associated with cortisol stress response, immune function, and disease resistance, enabling selection of fish who are physiologically better adapted to tolerate aquaculture conditions. This does not mean selecting fish who mask stress — cortisol suppression is not the same as reduced stress — but rather selecting for genuine resilience and calm disposition under routine aquaculture stressors. Programs that incorporate these traits alongside production objectives are beginning to demonstrate that welfare and production are not competing priorities but can be positively correlated when selection is designed thoughtfully.