Humane slaughter of farmed salmon requires effective stunning before killing. Developing and mandating reliable stunning methods is a critical welfare frontier for the aquaculture industry.
Salmon slaughter is a significant welfare frontier. For much of the aquaculture industry's history, live chilling — lowering fish body temperature in ice slurry — was considered acceptable, but research demonstrates that salmon in ice slurry remain conscious and in distress for minutes to over an hour. Asphyxiation in air causes progressive oxygen deprivation while the fish remains conscious. Percussive stunning, when correctly applied, renders salmon immediately insensible and is considered the gold standard. Its adoption is constrained by cost, throughput speed at industrial slaughter lines, and lack of mandatory requirements in many jurisdictions. Every salmon slaughtered without effective prior stunning represents an individual welfare failure — multiplied by hundreds of millions annually. Regulatory mandates for effective stunning, backed by independent audit, are urgently needed globally.