Selective breeding in salmon aquaculture has produced fish with high growth rates but also potential welfare tradeoffs that require careful management.
Selective breeding for extreme growth rates in farmed salmon has inadvertently created animals more prone to specific health problems - heart disease, cataracts, and spinal deformities that cause pain and reduced quality of life. The welfare of these health problems is real: cataracts impair vision and feeding, vertebral compression causes pain with movement, and heart disease limits the fish's ability to maintain normal activity. Including welfare traits in selective breeding programs - disease resistance, limb and organ integrity, behavioral normality - alongside production traits represents a more ethical approach to aquaculture genetics.