Most people encounter fish in simple ways. A fillet on a dinner plate, a fish and chips shop on a high street, a tuna sandwich, a sushi roll, or colourful species swimming in an aquarium. Yet behind this everyday familiarity lies a surprisingly vast system connecting oceans, coastal economies, international trade, conservation policy, aquaculture, tourism, and culture. Fish may appear to be a simple natural resource, but the systems surrounding them reveal a far more complex