Aquatic Animals

Fish Anaesthesia in Aquaculture

Anaesthesia is increasingly used in aquaculture to reduce stress and pain during handling procedures.

Key Facts

MS-222 (tricaine methanesulfonate) is the most widely approved fish anaesthetic
Fish anaesthesia reduces cortisol release during handling by up to 90%
Proper anaesthesia requires precise dosing to avoid overdose or under-anaesthesia
Recovery time varies by species, temperature, and concentration used
Fish anaesthesia is mandatory for some procedures in Norway and Switzerland

Welfare Considerations

Routine aquaculture procedures like vaccination, marking, grading, and transport cause significant stress in fish. Properly applied anaesthesia dramatically reduces this stress response and improves fish welfare. Under-anaesthesia leaves fish responsive to pain while appearing immobilised. The adoption of anaesthesia protocols represents a meaningful welfare improvement for the billions of fish in aquaculture systems worldwide.

What You Can Do

Support regulations requiring anaesthesia for invasive fish procedures
Choose farmed fish from producers with documented welfare protocols
Advocate for mandatory anaesthesia training in aquaculture certification
Learn about the evidence for fish pain and nociception
Support research into alternative anaesthetic agents appropriate for different species