Pre-slaughter handling of farmed salmon involves crowding, pumping, and transportation that cause severe acute stress. Effective stunning before slaughter is achievable but inconsistently applied across the industry.
Pre-slaughter welfare is a critical endpoint in the welfare lifecycle of farmed salmon. The crowding events preceding harvest are among the most stressful experiences in a farmed salmon's life — physiological stress indicators spike dramatically during crowding, pumping, and crowding on the harvest vessel. Without effective stunning before slaughter, salmon may experience prolonged conscious suffering during killing. Ice slurry immersion is associated with gradual loss of consciousness over several minutes in a highly aversive environment. By contrast, effective electrical stunning renders fish immediately insensible. The technical solutions exist; the barrier is primarily economic and regulatory. Consumer pressure, certification requirements, and legislation requiring pre-slaughter stunning are the most effective levers for change.