The hours before slaughter are among the highest-stress periods for farmed salmon — crowding, air exposure, and handling during harvest cause significant welfare compromise.
Pre-slaughter welfare for salmon is a concentrated welfare failure: large numbers of highly stressed fish crowded beyond normal capacity, then handled through air exposure before reaching stun equipment. Cortisol surges at this stage are extreme and measurable. Improvements to pre-slaughter welfare require reduced crowding time, water quality maintenance during harvest holding, and immediate, effective stunning upon exit from water. CO2 narcosis, still used in some facilities, causes aversion and is not considered humane. Percussive or electrical stunning produces immediate insensibility. Consumer demand for high-welfare salmon creates commercial incentives for adoption of better pre-slaughter protocols. Certification bodies should mandate stun-first protocols.