Farmed Fish Slaughter Welfare | Animal Welfare Hub

Slaughter is the final welfare event in farmed fish lives, yet most farmed fish are killed without stunning — dying from suffocation, CO2 exposure, or live chilling that causes prolonged conscious suffering.

Key Facts

The majority of farmed fish globally are killed by suffocation in air, CO2 narcosis, or live chilling — all methods that cause prolonged conscious distress
Percussive stunning followed by spiking (ikejime) or gill cutting is considered best practice for salmonids — it renders fish unconscious immediately
The European Food Safety Authority (EFSA) has consistently concluded that fish killed by common commercial methods experience significant pain and suffering before death
Electrical stunning systems for salmon and trout are commercially available and used by some producers — they render fish unconscious in less than one second
Live chilling — immersing fish in ice slurry while conscious — can take 9–15 minutes to achieve insensibility in salmonids
CO2 narcosis is aversive at effective concentrations — fish show violent escape behaviour before losing consciousness
Slaughter welfare is included in some welfare certification schemes but is rarely independently audited at commercial scale

Welfare Considerations

Fish slaughter welfare is perhaps the most acute and immediate welfare problem in aquaculture — fish die badly in enormous numbers. The methods used for most farmed fish globally — suffocation, CO2 narcosis, live chilling — impose minutes of acute distress in conscious animals that have well-evidenced pain systems. The technology for humane slaughter exists: electrical stunning, percussion stunning, and rapid spiking all achieve rapid loss of consciousness at reasonable cost. The barrier is not technological but economic and regulatory: without mandatory standards, producers have no incentive to invest in welfare improvements at slaughter. Consumer demand for welfare-certified products and advocacy for mandatory pre-slaughter stunning represent the most tractable paths to change.

What You Can Do

Choose farmed fish certified under standards that include mandatory pre-slaughter stunning requirements
Ask retailers and restaurants about the slaughter method used by their fish suppliers
Support advocacy for mandatory pre-slaughter stunning to be extended to all farmed fish species in law
Donate to fish welfare organisations including the Fish Welfare Initiative working on scalable slaughter improvements
Reduce farmed fish consumption and prioritise welfare-certified sources when you do eat farmed fish