Most farmed fish are killed without stunning, despite evidence of fish sentience. Improving fish slaughter welfare through stunning represents one of the most scalable welfare improvements available in animal agriculture.
Fish slaughter welfare represents perhaps the largest single opportunity for improving animal welfare by total number of individuals affected. The 73-180 billion farmed fish killed annually vastly exceeds all other livestock combined. Standard killing methods including asphyxiation, live chilling in ice slurry, and bleeding without prior stunning cause death while fish remain conscious, experiencing prolonged distress. Validated stunning methods including percussion, electrical stunning, and anaesthetic immersion can render fish insensible before killing is completed, preventing conscious dying. The Norwegian regulatory requirement for salmon stunning demonstrates that the transition is technically and economically feasible at commercial scale. The welfare gain from extending stunning requirements to all farmed fish globally would represent an extraordinary reduction in the number of individual animals experiencing conscious slaughter.