Anaesthesia and Welfare in Fish Handling

Anaesthetic agents can significantly reduce stress and pain in fish during handling, vaccination, and transport, but their use remains inconsistent.

Key Facts

MS-222 (tricaine methanesulfonate) is the most widely used fish anaesthetic in research and aquaculture
Clove oil (eugenol) is a widely used natural anaesthetic with good safety profiles in many species
Anaesthesia significantly reduces cortisol stress responses during salmon vaccination
Recovery from anaesthesia causes physiological stress and requires careful management
Cost and logistics are cited as barriers to routine anaesthetic use in commercial aquaculture

Welfare Considerations

Fish handling without anaesthesia causes significant physiological stress responses including elevated cortisol, compromised immune function, and altered behaviour. Anaesthesia during vaccination, grading, and transport significantly reduces these stress responses and improves subsequent welfare and productivity. The argument that anaesthetic use is impractical at commercial scale is undermined by successful implementation in progressive aquaculture operations. Regulatory requirements for anaesthetic use during specific procedures would drive welfare improvement across the industry.

What You Can Do

Support aquaculture welfare standards requiring anaesthetic use during major handling procedures
Choose seafood certified by schemes with anaesthesia requirements
Advocate for regulatory guidance on fish anaesthesia in your country
Support research into practical, low-cost anaesthesia systems for commercial aquaculture