The past two decades have transformed scientific understanding of fish cognition, revealing intelligence and social complexity that demands a corresponding reassessment of how fish welfare is approached.
The emerging picture of fish cognition — self-awareness, tool use, social complexity, individual recognition, problem solving — is reshaping the ethical calculus around fish welfare. Each of these cognitive abilities is associated in other animals with a richer inner life and greater capacity for suffering. The implications for commercial fishing, aquaculture, the ornamental trade and recreational angling are profound. A fish that recognises individuals, uses tools and may be self-aware deserves welfare consideration that goes far beyond what is currently provided in any of these contexts.