The period immediately before slaughter is among the most welfare-significant phases in farmed salmon production, involving crowding, handling, out-of-water exposure, and stunning methods of highly variable effectiveness.
Pre-slaughter handling in salmon farming concentrates multiple serious welfare insults in a short period. Crowding-induced hypoxia, out-of-water exposure, and ineffective stunning can cause suffering in fish that are increasingly understood to have nociceptive systems capable of registering and responding to painful stimuli. The scale of salmon farming — billions of individuals globally — makes even small improvements in pre-slaughter protocol highly impactful. Best practice involves minimising crowding duration, using well-maintained percussive or electrical stunning equipment with trained operators, and implementing post-stun checks. The industry is moving toward automated stunning systems that improve consistency, but uptake is uneven and regulatory requirements vary significantly between producing countries.