Fish welfare at slaughter is a critical and often neglected issue in aquaculture. Research has identified several methods that minimise suffering and others that cause prolonged, severe distress.
Many commonly used aquaculture slaughter methods cause prolonged distress. Live chilling in ice or CO2 narcosis does not render fish unconscious before death — fish remain aware and responsive for several minutes. Research shows fish have nociceptors, show protective behaviours in response to pain, and experience physiological stress responses. Percussive stunning followed by immediate brain destruction provides near-instant insensibility. The aquaculture industry has been slow to adopt humane methods compared to mammalian livestock production.