Fish experience stress and pain during aquaculture handling procedures, and the use of anesthesia and sedation for routine procedures is becoming standard practice in welfare-leading operations.
Fish anesthesia for aquaculture procedures represents the application of welfare principles to species where sentience was long denied. We now have strong evidence that fish experience stress during unanaesthetized handling — cortisol spikes, physiological disruption, and behavioral indicators of aversion — and that anesthesia prevents this stress while improving operational outcomes. The cost of anesthesia for routine procedures is modest relative to fish welfare improvement and reduced handling injury. The barrier to adoption is often regulatory (inconsistent approval of fish anesthetics) and cultural (resistance to treating fish welfare as comparable to mammal welfare). Both barriers are changing.