Salmon Genetics and Welfare: Selective Breeding Implications

Selective breeding of Atlantic salmon for aquaculture has produced fish with significantly different disease susceptibility and welfare outcomes, with genetics increasingly recognized as a welfare determinant.

Key Facts

Decades of selective breeding for growth rate and feed conversion have changed salmon physiology and disease susceptibility
Different broodstock lines show substantial variation in resistance to sea lice, amoebic gill disease, and viral diseases
Heart and skeletal muscle inflammation is more prevalent in fast-growing farmed salmon lines
Spinal deformities are more common in some genetic lines suggesting trade-offs between growth and structural health
Breeding programs are increasingly including disease resistance traits alongside production metrics
Genomic selection tools allow rapid genetic progress for welfare-relevant traits in salmon breeding
Some producers are using slower-growing genetics to improve animal welfare at some cost to feed efficiency

Welfare Considerations

The genetics of farmed salmon are a powerful determinant of lifetime welfare. Fish bred predominantly for growth rate may have cardiovascular pathology, structural deformities, and immune deficiencies that cause chronic welfare compromise throughout their lives. Including disease resistance and structural health traits in breeding goals can improve welfare for every fish produced from those genetics over many generations. The scale of salmon aquaculture means genetic welfare improvements have enormous cumulative impact. Retailer and regulatory pressure for welfare reporting creates incentives for producers to prioritize welfare-positive genetics, but progress requires industry-wide commitment.

What You Can Do

Support salmon producers that use genetics selected partly for disease resistance and structural health
Engage with salmon retailers about their requirements for welfare-positive genetics in their supply chains
Advocate for welfare trait inclusion as a requirement in aquaculture breeding program approvals
Support research into salmon welfare genomics identifying genes associated with health and disease resistance
Learn about the welfare implications of selective breeding in aquaculture to engage in informed advocacy
Engage with aquaculture certification schemes about genetics-based welfare requirements
Support transition to welfare-positive genetics through consumer and retailer purchasing decisions