Anaesthesia in fish is a rapidly advancing field that enables humane handling for veterinary procedures, research, and aquaculture operations. Proper use of fish anaesthetics significantly reduces stress and pain during necessary interventions.
Fish handling without anaesthesia causes acute stress responses including cortisol spikes, immune suppression, and altered behaviour that persist for hours to days. Procedures such as tagging, sampling, sexing, and transport are common in aquaculture and research but impose significant welfare costs without anaesthesia. Advances in fish anaesthesia have made chemical induction faster, safer, and more accessible. Key welfare considerations include achieving appropriate anaesthetic depth before any procedure, minimising anaesthetic duration, ensuring oxygen levels remain adequate during induction and recovery, and monitoring recovery to full consciousness. Training fish handlers in anaesthesia protocols significantly reduces animal suffering in research and production settings.