Farmed Salmon Welfare at Slaughter: Stunning Methods and Standards

Salmon slaughter welfare has improved through the development of percussive stunning, but implementation remains inconsistent across global aquaculture.

Key Facts

Norway processes approximately 300 million salmon annually — the world's largest salmon slaughter volume
Traditional slaughter by CO2 immersion causes distress and potential consciousness during the killing process
Percussive stunning delivers a blow to the head, rendering fish immediately insensible when correctly applied
AQUI-S (isoeugenol) chemical stunning is effective but requires post-stun killing within a defined time window
Electrical stunning followed by cutting can also be effective when current density and frequency are calibrated correctly
Norwegian regulations now mandate effective stunning before killing in salmon aquaculture slaughter

Welfare Considerations

Salmon slaughter welfare has been the subject of sustained research and advocacy, producing genuine regulatory progress. The shift from CO2 immersion (which causes distress) to percussive or electrical stunning represents a meaningful welfare improvement for the hundreds of millions of salmon killed annually. However, percussive stunning quality varies with equipment maintenance, fish size, and operator training — inadequate blows leave fish partially conscious. Certification and auditing of stunning effectiveness using brain-based criteria (EEG, eye responses) is the direction of best practice. The salmon slaughter welfare story shows that industry-scale improvements are achievable when welfare standards are backed by research and regulation.

What You Can Do

Choose salmon certified by standards requiring effective pre-slaughter stunning
Support organizations that advocate for mandatory humane slaughter standards in global salmon aquaculture
Engage with the development of fish welfare regulations in your country
Reduce salmon consumption or shift to plant-based alternatives if welfare cannot be verified