The slaughter of farmed Atlantic salmon involves millions of fish daily. Improving pre-slaughter stunning and welfare practices can significantly reduce the suffering of one of the world's most intensively farmed species.
Pre-slaughter welfare for Atlantic salmon is an area where evidence-based improvements are achievable and increasingly required by regulations and certification standards. The use of CO2 narcosis - which causes visible distress responses including leaping, rapid gill movement, and loss of equilibrium over several minutes - is incompatible with humane slaughter under evolving scientific understanding of fish sentience. Crowding and pumping before slaughter imposes acute stress that adds to any suffering during the killing process itself. Better welfare at slaughter requires effective stunning immediately before killing, minimal pre-slaughter handling and crowding, and monitoring systems to ensure stunning efficacy. The scale of salmon slaughter makes marginal improvements enormously significant in aggregate welfare terms.