How farmed fish are slaughtered significantly affects their welfare at the end of life. Understanding the evidence on different methods informs consumer choices and regulatory advocacy.
Fish slaughter welfare has historically received minimal attention despite fish representing by far the largest number of animals killed for food. Ice slurry killing, where fish are placed into ice water and die slowly from asphyxiation and cold shock over minutes, is the most widely used commercial method and causes prolonged stress and likely suffering. The contrast with mammalian slaughter standards that require effective stunning before bleeding is stark. Percussive stunning and electrical stunning both render fish insensible rapidly and humanely when correctly applied. Ikejime — the Japanese practice of brain spiking immediately after stunning — ensures irreversible insensibility. Consumer and retailer demand for humanely slaughtered fish is the primary market driver of welfare improvement, as regulatory requirements remain minimal in most jurisdictions.