Farmed Fish Slaughter: A Review of Methods and Welfare Outcomes

Fish slaughter methods vary enormously in their welfare outcomes. Understanding which approaches render fish insensible before death guides welfare-positive purchasing decisions.

Key Facts

Common fish slaughter methods include live chilling, CO2 exposure, spiking, and percussion stunning
Live chilling — placing fish in ice slurry — does not render fish insensible quickly
Percussive stunning followed by spiking (killing the brain) is considered most welfare-positive
Electrical stunning followed by bleeding is increasingly adopted in salmon processing
RSPCA and other welfare bodies have published species-specific fish slaughter guidelines

Welfare Considerations

Fish slaughter welfare spans a wide spectrum from methods causing prolonged suffering to those providing rapid insensibility. Live chilling — common for many species — slows metabolic processes but does not immediately eliminate consciousness, meaning fish may experience distress for many minutes. Effective percussion or electrical stunning renders fish insensible immediately, followed by rapid bleeding. For salmon, several processors have adopted electrical stunning as standard practice. The choice of slaughter method is one of the most impactful welfare decisions in fish farming, affecting billions of animals annually.

What You Can Do

Choose fish products from processors using electrical or percussive stunning
Ask retailers about slaughter welfare standards for farmed fish they stock
Support RSPCA Assured or equivalent welfare standards for farmed fish
Advocate for mandatory humane slaughter requirements for fish in your country