How does fish welfare compare to that of land farm animals, and what does the evidence say?
Dismissing fish welfare because fish are different from mammals misunderstands the science of sentience. Fish show clear pain avoidance learning, cognitive abilities, and stress responses that indicate they experience suffering. The scale of aquaculture — trillions of fish — means that even small per-fish welfare improvements have massive total welfare impact. Fish welfare represents one of the highest-impact frontiers in animal welfare science.