Farmed Salmon Welfare During Harvest Operations

Salmon harvesting involves a sequence of procedures - crowding, pump transfer, stunning, and killing - each carrying significant welfare implications. Well-designed harvest protocols minimise handling stress and ensure effective stunning before slaughter.

Key Facts

Pre-slaughter crowding to concentrate fish for harvest causes severe hypoxia and acute stress responses
Crowding duration should be minimised to reduce pre-slaughter suffering
Percussive stunning delivers a blow to the head causing immediate insensibility when correctly applied
Electrical stunning is used in some systems but effectiveness depends on current parameters and fish size
Carbon dioxide narcosis causes aversive sensations and distress before insensibility - considered poor practice
Two-phase systems combining electrical and percussive stunning improve reliability
Post-stunning gill cut is standard to allow rapid exsanguination before fish regain consciousness
Welfare standards require verification that fish are insensible throughout the killing process

Welfare Considerations

Harvest is one of the highest-risk stages for severe suffering in salmon production. Crowding induces oxygen depletion and physical injury. Ineffective stunning means fish may experience killing procedures while conscious. Robust harvest protocols with reliable stunning methods and confirmation checks can dramatically reduce end-of-life suffering. Industry-wide adoption of best practice remains uneven.

What You Can Do

Look for salmon certified under high-welfare standards such as RSPCA Assured or equivalent
Advocate for mandatory use of effective electrical or percussive stunning at salmon farms
Support research into improved pre-slaughter handling and stunning technologies
Reduce salmon consumption or choose certified alternatives as welfare standards improve