The vast majority of farmed fish globally are slaughtered without prior stunning. Improving pre-slaughter stunning is one of the most scalable welfare reforms available in aquaculture.
Fish slaughter welfare represents the largest single-species welfare challenge in animal agriculture by sheer numbers. While uncertainty remains about the subjective experience of fish, the evidence of nociceptive capacity and stress responses during prolonged slaughter is sufficient to motivate precautionary welfare action. The welfare calculus is simple: stunning before slaughter adds small costs and guarantees that if fish experience something during slaughter, it lasts seconds rather than minutes. Regulatory requirements for stunning in Norway have been followed by industry adaptation and compliance, demonstrating feasibility at scale. Certification schemes requiring stunning provide a market mechanism for welfare improvement ahead of regulation.