The welfare of fish at slaughter in aquaculture remains largely unregulated and highly variable. Applying existing slaughter science to practice could prevent enormous amounts of suffering.
The gap between what is known about humane fish slaughter and what is practiced in commercial aquaculture represents one of the largest preventable welfare failures in the food system. Methods proven to cause prolonged suffering — ice slurry immersion, air asphyxiation — remain in widespread use despite available alternatives. The barriers are cost, equipment availability, and the persistent assumption — now scientifically untenable — that fish do not experience significant suffering. The welfare solution requires a combination of regulatory requirements specifying approved stunning methods, industry investment in slaughter equipment, and certification schemes that verify welfare at the point of death. Given the billions of individuals involved, even modest improvements in slaughter practice translate to enormous reductions in aggregate suffering.