Less than two centuries ago, it did not seem silly for Byron to write “Man marks the earth with ruin, his control stops with the shore.” Today, as this volume makes clear, the situation is grimly different.

Byron's observation about human impacts on terrestrial species and ecosystems was brought into sharp scientific focus by Vitousek et al's (1986) analysis, suggesting that roughly 35–40% of the products of photosynthesis on land were taken, directly or indirectly, for our use. The corresponding careful analysis for fisheries came 10 years later, finding that although the overall fraction of aquatic primary production required to support all fisheries was around 8%, this did not really capture the essentials. Essentially all the fish we eat comes from fresh water or from oceanic upwelling or shelf systems, and here we took 24–35% of primary production in the years just before 1995 (Pauly and Christensen, 1995); significantly more is taken today.

Even more important was Pauly's emphatic recognition that most fisheries are managed – if you can call it that – on a single stock basis. The present volume is largely devoted to the many and varied developments in fisheries science, subsequent to the recognition that single species management is ultimately nonsense. To take just one example, if you sought to maximize sustainable yield of krill in the Southern Ocean, you would eliminate krill-eating whales, and conversely if you wished to maximize sustainable yield of whales you would not harvest krill at all (the first draft of the Treaty of the Southern Ocean entirely failed to realize this!).