Whether fish experience pain in a way that warrants moral concern is among the most significant debates in animal welfare science. Current evidence supports precautionary welfare protections for fish.
The fish pain debate has significant practical welfare implications given the trillions of fish affected by human activities annually in fishing, aquaculture, and research. The conservative position — that without a neocortex, fish cannot have conscious pain experience — has been increasingly challenged by neuroscience demonstrating that nociception and pain-related learning occur through multiple neural pathways not limited to neocortical structures. The precautionary principle argument holds that given the plausibility of fish pain and the enormous numbers involved, implementing welfare protections carries low cost and potentially very high benefit if fish do suffer. Progressive regulatory frameworks are incorporating fish welfare requirements. Research continues to develop; meanwhile, reducing unnecessary fish suffering through humane slaughter methods, anaesthesia in research, and catch-and-release best practice represents a meaningful welfare response.