Aquaculture Slaughter Welfare: Improving Fish End-of-Life Practices

Slaughter practices for farmed fish are among the least regulated and most welfare-significant moments in aquaculture; humane methods are available but unevenly adopted.

Key Facts

Most farmed fish are slaughtered by asphyxiation in air or ice slurry — both methods cause prolonged distress
Percussive stunning followed by immediate killing is the most humane slaughter method for many species
Electrical stunning is effective for salmon, trout, and some other species when correctly applied
CO2 stunning causes documented aversion responses in fish before unconsciousness is achieved
The EU Slaughter Regulation (1099/2009) includes fish but enforcement and species coverage are incomplete
RSPCA Assured and some ASC-certified farms require improved slaughter methods for farmed fish

Welfare Considerations

Fish slaughter welfare represents one of the largest welfare deficits in food production. Billions of farmed fish are killed each year using methods that cause minutes of conscious distress — suffocation in air, cold water shock, or CO2 exposure. Proven humane alternatives exist: percussive stunning for large fish, electrical stunning for salmonids, and species-specific methods validated by welfare research. Regulatory reform to mandate pre-slaughter stunning for all farmed fish species is among the highest-impact welfare interventions available in the food system.

What You Can Do

Choose fish certified by RSPCA Assured or ASC schemes that require humane slaughter methods
Ask fishmongers and retailers about slaughter welfare standards in their aquaculture supply chains
Support Fish Welfare Initiative and other organizations working to improve fish slaughter regulation
Advocate for mandatory pre-slaughter stunning in aquaculture legislation in your jurisdiction