Aquaculture Welfare

Farmed Salmon Pre-Slaughter Welfare: Crowding and Stress

The pre-slaughter period for farmed salmon involves crowding, pumping and out-of-water exposure that cause significant stress and welfare harm if not properly managed.

Key Facts

Salmon are crowded into increasingly small volumes of water in the hours before slaughter
Crowding causes acute stress responses including elevated cortisol and adrenaline
Out-of-water time during transfer to slaughter causes hypoxia and intense stress
Electrical stunning prior to slaughter, when properly implemented, achieves immediate insensibility
Pre-slaughter fasting of 24-72 hours reduces gut contents but also causes stress and hunger

Welfare Considerations

The pre-slaughter phase is one of the highest welfare risk points in salmon farming. Crowding stress compounds prior to slaughter, with fish pumped through pipes and transferred between systems while experiencing acute hypoxia. Welfare-conscious processing uses careful crowding protocols, minimum handling time and effective electrical stunning to minimise suffering at end of life.

What You Can Do

Choose salmon products with welfare certification that includes pre-slaughter standards
Support research into low-stress harvest techniques for salmon
Advocate for mandatory stunning standards in salmon slaughter
Learn about the Aquaculture Stewardship Council (ASC) welfare provisions