Farmed Salmon Genetic Welfare: How Selective Breeding Affects Fish Wellbeing

Selective breeding programs for farmed Atlantic salmon have significant welfare implications alongside their production benefits.

Key Facts

Decades of selective breeding have increased farmed salmon growth rates by 10-15% per generation
Fast-growing genetic lines can show cataracts at higher rates than slower-growing strains — a significant welfare concern
Spinal deformities are associated with rapid growth and are more prevalent in some high-growth genetic lines
Broodstock selection programs are increasingly including disease resistance and health traits alongside growth criteria
Wild salmon that escape from farms and interbreed with wild populations reduce wild population fitness
Domesticated salmon show reduced fear responses to predators — a welfare advantage in farm settings but a survival disadvantage if escaped
Genetic selection for welfare-relevant traits such as robustness, disease resistance, and skeletal integrity is possible
Norwegian breeding programs (AquaGen, SalmoBreed) are at the forefront of integrating health criteria into selection

Welfare Considerations

The genetics of farmed salmon are a welfare determinant that operates upstream of all on-farm management decisions. A genetic line predisposed to cataracts, spinal deformities, or immune dysfunction will produce animals with welfare problems regardless of how well they are managed. Progressive salmon breeding programs are beginning to recognize this and integrate health and welfare criteria into their selection objectives alongside growth and feed conversion. The welfare case for this shift is strong: animals bred for robustness and disease resistance require less medical intervention, experience fewer welfare-impacting conditions, and have lower mortality rates. Including welfare as a core breeding objective is one of the highest-leverage interventions available to the salmon aquaculture industry.

What You Can Do

Support salmon aquaculture certification schemes that require producers to use genetic lines with documented health traits
Advocate for welfare criteria including skeletal integrity and disease resistance to be mandatory in broodstock selection
Support research into salmon genetics and the welfare implications of different selective breeding approaches
Engage with salmon breeding companies about their welfare-related selection criteria
Follow Nofima and Norwegian Institute of Marine Research for salmon genetics and welfare research updates
Choose salmon from producers who disclose their genetic line sourcing and associated health performance data
Support international standards for farmed fish genetics that include welfare as a core selection criterion