Genetic selection in farmed Atlantic salmon has created rapid growth improvements but also introduced welfare tradeoffs including increased susceptibility to cardiac problems, spinal deformities, and developmental abnormalities.
Genetic selection for rapid growth in farmed salmon has created unintended welfare consequences through the physiological demands of accelerated development. Cardiac abnormalities, spinal deformities, and cataract prevalence are all elevated in fast-growing strains. The welfare cost of these conditions is borne by individual fish in the form of pain, impaired function, and reduced capacity to cope with environmental challenges. Future genetic programs incorporating welfare traits alongside production performance could reduce these welfare costs while maintaining economic viability.