Anaesthesia for fish during veterinary procedures, transport, and research is an important welfare tool. Understanding its applications improves fish welfare in aquaculture and scientific settings.
Fish anaesthesia is a practical welfare tool that remains underutilised in commercial aquaculture. The stress of handling, grading, and treatment causes measurable physiological harm that reduces immune function, growth, and survival. Brief anaesthesia before these procedures significantly reduces stress responses and physical injury from struggling. The welfare case for wider anaesthetic use is strong, and the barriers — cost, time, and unfamiliarity — are surmountable. In research settings, anaesthesia before any invasive procedure is now standard in most countries. Extending this norm to commercial aquaculture operations would represent a significant advance in the treatment of billions of fish globally.