Salmon Anaesthesia in Aquaculture: Protocols

The use of anaesthesia for salmon during handling, vaccination and other procedures is an important welfare intervention that is increasingly standard in well-managed aquaculture operations.

Key Facts

Atlantic salmon are handled multiple times throughout their lives for vaccination, grading, treatment and transport
Without anaesthesia, handling causes acute stress responses including elevated cortisol and physiological disruption
MS-222 (tricaine methanesulfonate) and AQUI-S are the most commonly used salmon anaesthetics in aquaculture
Effective anaesthesia depth must be carefully monitored to avoid under- or over-anaesthetising fish
Recovery from anaesthesia should occur in clean, oxygenated water with monitoring for full normal behaviour

Welfare Considerations

Salmon handling without anaesthesia causes measurable acute and potentially chronic welfare harm. Fish show escape behaviour, elevated stress hormones and immune suppression following unanaesthetised handling events. The investment in anaesthetic agents and induction/recovery equipment is justified by the welfare improvements it provides, and is increasingly standard in Norwegian and Scottish premium salmon production. Welfare standards should require anaesthesia for all non-emergency salmon handling procedures.

What You Can Do

Choose salmon certified to welfare standards that require anaesthesia for handling procedures
Advocate for anaesthesia requirements to be included in national aquaculture welfare regulations
Support research into newer, faster-acting and safer anaesthetic agents for salmon
Engage with salmon producers about their anaesthesia protocols at different life stages
Support inspection systems that verify anaesthesia use in certified aquaculture facilities