The final stages of farmed salmon production - crowding, fasting, and slaughter - are critical welfare moments, and improvements in stunning and killing methods have significantly reduced suffering.
Salmon pre-slaughter welfare encompasses the hours and days before death. Crowding into progressively smaller spaces as harvest approaches causes chronic stress measurable in cortisol levels and behaviour changes. Fasting for gut clearance causes hunger discomfort. Water chilling used in some systems causes acute cold shock. The slaughter method itself is critical: effective percussive stunning followed by rapid bleeding can minimise suffering, while CO2 stunning is now recognised as aversive. The Norwegian and Scottish salmon industries have invested substantially in improving slaughter welfare, with automated systems achieving more consistent stunning quality than manual methods.