Assessing pain in fish requires understanding behavioral and physiological indicators specific to fish. This knowledge enables welfare-positive management decisions.
Fish pain assessment is scientifically complex but increasingly important for aquaculture welfare decisions. The question of whether fish experience subjective suffering remains genuinely uncertain, but behavioral and physiological indicators show that fish nociceptive systems are functional. Fish show aversive learning, avoid noxious stimuli, and show physiological stress responses to painful events. The precautionary principle — acting on the possibility of suffering even under uncertainty — argues for implementing welfare protections without waiting for definitive consciousness evidence. Validated behavioral pain indicators are increasingly used in research and are being developed for practical farm-level assessment.