Aquaculture Welfare

Farmed Salmon Welfare: Crowding Stress at Harvest

Pre-harvest crowding concentrates salmon at extreme densities, causing acute stress, injury, and physiological disturbance before slaughter.

Key Facts

Crowding before slaughter elevates cortisol and reduces flesh quality
Pooling salmon from multiple pens increases competition and injury risk
Crowding duration should be minimised to reduce cumulative stress
Some welfare protocols now specify maximum crowding densities and durations
Water temperature during crowding affects oxygen availability and stress severity

Welfare Considerations

Pre-harvest crowding represents one of the most acute welfare challenges in salmon farming. Compressed space, social disruption, and oxygen depletion cause measurable suffering. Shorter crowding periods and better monitoring of fish behaviour during this phase are critical welfare improvements.

What You Can Do

Support salmon welfare standards requiring pre-harvest crowding time limits
Choose certified salmon products with harvest welfare protocols
Advocate for mandatory monitoring during pre-harvest operations