The current state of scientific evidence on fish pain and what it means for how we treat fish.
The scientific evidence for fish pain has strengthened substantially over the past two decades, shifting the burden of proof from demonstrating that fish feel pain to explaining why we continue to treat them as if they do not. Fish have the neurological hardware, behavioral responses, and learning capacity associated with pain experience in other vertebrates. The welfare implications extend from recreational fishing to industrial aquaculture affecting hundreds of billions of animals annually. The scale of fish use combined with their demonstrated capacity for suffering makes fish welfare one of the most consequential issues in animal ethics.