Stunning fish before slaughter is essential for welfare but is inconsistently practiced in global aquaculture. Different methods have very different welfare profiles, and establishing minimum standards is a priority.
Fish stunning is perhaps the most tractable high-impact welfare intervention available in aquaculture. The scale of fish production — tens of billions of individuals annually — means that improving slaughter welfare for even a fraction of farmed fish produces enormous total welfare benefit. Current practices in much of the global industry involve killing methods (CO2, ice slurry, air asphyxiation) that are associated with minutes of conscious distress before death. The evidence that fish are sentient and can experience suffering makes this a serious welfare concern. Percussive stunning and electrical stunning, properly applied, provide rapid unconsciousness. Consumer demand for certified humane slaughter and retailer commitments to require stunning are the primary drivers of industry change.