Farmed fish are killed in enormous numbers annually, yet stunning and slaughter welfare standards for fish lag far behind those for mammals and birds despite growing evidence of fish pain capacity.
Fish slaughter welfare is where the scale of aquaculture meets the frontier of animal welfare science. The evidence that fish experience pain and distress has grown sufficiently for several scientific bodies to conclude that fish are sentient and that their welfare at slaughter matters morally. Yet the methods used to kill the vast majority of farmed fish — asphyxiation in air, CO2 immersion, ice slurry — are distressing rather than humane by the standards applied to land animals. Developing and implementing humane killing standards for fish at the scale of global aquaculture is one of the largest welfare challenges facing animal agriculture.