Salmon slaughter methods vary dramatically in humaneness. Evidence-based improvements to slaughter welfare represent one of the most achievable near-term improvements in aquaculture.
Salmon slaughter welfare is an achievable improvement that the industry has been slow to implement fully. Traditional methods - CO2 exposure, live chilling in ice water - cause prolonged periods where salmon appear calm but physiological evidence suggests ongoing stress response and possible pain experience. Percussive or electrical stunning that causes immediate insensibility eliminates this period of potential suffering before killing. The welfare case for improved slaughter methods does not require certainty about fish pain - the precautionary principle is sufficient justification, and the practical implementation is feasible with existing technology. Norwegian regulations have led the way in requiring pre-slaughter stunning, providing proof of concept that industry-wide adoption is achievable. Certification programs that require and verify slaughter welfare standards help drive improvement.