Fish Slaughter Welfare: Methods and Standards

Fish slaughter methods vary enormously in their welfare implications; percussive stunning, electrical stunning, and CO2 immersion differ substantially in the suffering they cause.

Key Facts

Asphyxia in air is one of the most common fish killing methods but takes minutes and is highly aversive
CO2 immersion is aversive and causes distress before insensibility in many species
Percussive stunning renders fish immediately insensible and is considered the most humane method
Electrical stunning can be effective but requires species-specific calibration to avoid partial stunning
The EU Slaughter Regulation does not include fish, leaving slaughter welfare largely unregulated

Welfare Considerations

The slaughter of fish is an area where welfare standards lag far behind those applied to mammals and birds. Asphyxia in air — simply removing fish from water and leaving them to die — takes several minutes during which fish show evidence of significant distress. CO2 immersion causes visible agitation before loss of consciousness. Percussive stunning, which renders fish immediately insensible through blunt trauma to the head, is the most humane method but requires skill and is not routinely used in commercial settings. The absence of fish in EU slaughter regulations reflects longstanding assumptions about fish sentience that are not supported by current science.

What You Can Do

Advocate for inclusion of fish in slaughter welfare regulations and standards
Choose fish products from certified producers using humane slaughter methods
Support research into optimal stunning methods for different fish species and sizes
Raise awareness about fish slaughter welfare as an overlooked aspect of food system ethics
Reduce consumption of fish from sources without welfare certification for slaughter methods