Aquaculture

Farmed Salmon Pre-harvest Stress: Crowding and Handling

Pre-harvest handling of farmed salmon involves crowding, netting and pumping that causes significant stress. Welfare-conscious pre-harvest protocols reduce suffering significantly.

Key Facts

Crowding of salmon before harvest elevates cortisol to maximum levels within minutes
Starving fish for 3-5 days before slaughter causes hunger-related welfare impacts
Pumping fish from nets causes pressure injuries in some operations
Anaesthesia before slaughter is used in some systems to reduce pre-slaughter stress
Percussion stunning must be immediate and effective to prevent prolonged suffering
Water quality during crowding deteriorates rapidly worsening stress responses

Welfare Considerations

Pre-harvest handling represents a major welfare risk point for farmed salmon. The combination of crowding, starvation, unfamiliar handling and water quality deterioration creates cumulative stress that causes measurable physiological and behavioural distress. Minimising time between crowding and stunning, effective immediate stunning, and improving handling equipment design are the key welfare improvements for this stage.

What You Can Do

Support aquaculture welfare standards with specific pre-harvest handling requirements
Choose salmon certified under schemes with slaughter welfare criteria
Advocate for effective stunning monitoring requirements at salmon slaughter
Encourage research into reduced-stress pre-harvest protocols for farmed fish