Slaughter is the most acute welfare risk in aquaculture. Evidence-based stunning methods that rapidly induce insensibility are available but inconsistently applied across the industry.
Fish slaughter welfare is the most visible and tractable welfare improvement available in aquaculture — the methods are available, the evidence is clear, and the cost differential is modest. Yet most farmed fish globally are still killed by methods including live chilling and asphyxiation that cause prolonged suffering before death. The gap between scientific knowledge of fish sentience and pain and industry practice at slaughter is one of the largest in animal welfare. Regulatory mandates for pre-slaughter stunning — already in place for salmon in Norway and required by welfare certification schemes — demonstrate that enforcement drives improvement where voluntary uptake has been insufficient.