The question of whether fish experience pain has been intensively studied. Evidence increasingly supports fish sentience, with significant implications for how we treat billions of farmed and wild fish.
The scientific question of fish pain is substantially resolved in the direction of sentience. The behavioural, neurological and pharmacological evidence that fish experience something functionally equivalent to pain in mammals is now extensive. Academic debate continues on the precise nature of fish subjective experience, but the precautionary principle strongly supports treating fish as sentient in welfare-relevant contexts. The welfare implications are profound given the billions of fish killed annually in aquaculture and wild capture fisheries, mostly without any welfare consideration. Regulatory recognition of fish sentience — as in the UK Animal Welfare (Sentience) Act 2022 — translates this scientific understanding into policy obligation.