The current scientific understanding of fish pain, including recent research that strengthens the case for treating fish as welfare-relevant beings.
Fish pain science has advanced substantially in the past decade, shifting the question from whether fish feel pain to what our obligations are given the evidence that they do. The neurobiological case is strong: nociceptors, opioid systems, behavioral pain responses that are blocked by analgesics, and motivational avoidance behavior all point toward genuine pain-relevant experience. The alternative interpretation — that all of this occurs without any subjective element — requires increasingly strained special pleading about the unique inability of fish to have any inner experience despite having the hardware that mediates it in other vertebrates. Acting precautionarily in the face of this evidence means improving fish welfare in fisheries and aquaculture.