Scientific evidence for fish sentience and capacity for pain has grown substantially, transforming our understanding of fish welfare and the ethical obligations we have toward billions of farmed and wild-caught fish.
The scientific case for fish sentience is now strong enough to demand serious welfare consideration. Fish demonstrate all the behavioral and physiological markers scientists use to infer pain and suffering in other animals: nociception, analgesic efficacy, behavioral changes indicative of aversion, and stress responses proportional to noxious stimuli intensity. The "fish don't feel pain" position has been progressively undermined by decades of research. The welfare implications are enormous: fishing practices that cause prolonged suffering (suffocation, live chilling, CO2 narcosis), aquaculture conditions that cause chronic stress, and the sheer scale of fish use demand urgent policy attention. Accepting fish sentience does not require certainty about conscious experience — the precautionary principle alone justifies improved welfare standards.