The welfare of farmed fish at slaughter is one of the most significant and most neglected animal welfare issues globally, affecting billions of animals annually. Effective stunning methods exist but are rarely used.
Fish slaughter welfare represents the largest single welfare improvement opportunity in animal agriculture by sheer numbers. The assumption that fish do not experience pain or distress has been scientifically refuted, yet slaughter practices for most farmed fish remain incompatible with what we know about fish sentience. Asphyxiation in air causes fish to thrash violently for minutes — behaviour consistent with acute distress. Ice slurry slows metabolism and may reduce the speed of death, but fish remain conscious for minutes to over an hour in some studies. Electrical and percussive stunning are commercially viable, cost-effective alternatives that achieve immediate unconsciousness. The gap between available technology and actual practice is primarily driven by cost calculation and regulatory absence, not technical impossibility.