Farmed Salmon Slaughter Welfare: The Final Moment and Its Improvement

Salmon slaughter welfare is the final critical welfare event in a multi-year production cycle. Improving pre-slaughter stunning and processing reduces suffering at the most sensitive moment.

Key Facts

Atlantic salmon are slaughtered at approximately 4-6 kg after 14-24 months in sea cages
Crowding during harvest causes significant stress prior to slaughter
Electrical stunning in water bath provides rapid onset of unconsciousness in properly calibrated systems
Percussive stunning by spiking achieves rapid unconsciousness but is slower at commercial scale
CO2 immersion remains widely used despite clear evidence of aversion and stress before unconsciousness

Welfare Considerations

Salmon slaughter welfare represents the final welfare event for each individual fish - a moment where humane practice can prevent or minimise suffering during death. The harvest process begins with welfare-compromising crowding as fish are concentrated for pump-transfer to vessels. Pre-slaughter stress from crowding elevates cortisol and affects flesh quality. Stunning method determines whether fish lose consciousness rapidly and without aversion. Electrical stunning in appropriately calibrated systems provides the most welfare-positive rapid unconsciousness. Percussive stunning provides good welfare at lower throughput. CO2 immersion causes active aversion before unconsciousness and is the least welfare-positive method. Consumer and regulatory pressure is gradually shifting industry practice toward better methods.

What You Can Do

Choose salmon with RSPCA Assured or equivalent welfare certification covering slaughter methods
Support campaigns advocating for replacement of CO2 with electrical or percussive stunning
Advocate for regulatory requirements mandating humane salmon slaughter methods
Reduce salmon consumption or shift to certified welfare-conscious sources