Selective breeding programs for farmed Atlantic salmon have dramatically increased growth rates but created welfare challenges. The relationship between genetics and salmon wellbeing requires careful consideration.
The salmon farming industry's success in dramatically accelerating fish growth has created unforeseen welfare costs. Domesticated salmon grow so rapidly that their cardiovascular and skeletal systems struggle to keep pace, leading to heart muscle disease, spinal deformities, and joint problems. Cataracts are so prevalent in some populations that they represent a major source of pain and impaired feeding. The welfare of billions of farmed fish depends on breeding programs that balance productivity with health and welfare traits. Progress is being made, but the scale of the problem - hundreds of millions of fish per year - means even small improvements in genetic welfare traits have enormous aggregate impact.