A fishery is an area with an associated fish or aquatic population which is harvested for its value (commercial, recreational, subsistence). It can be saltwater or freshwater, wild or farmed. Examples are the salmon fishery of Alaska, the cod fishery off the Lofoten islands or the tuna fishery of the Eastern Pacific. Most fisheries are marine, rather than freshwater; most marine fisheries are based near the coast. This is not only because harvesting from relatively shallow waters is easier than in the open ocean, but also because fish are much more abundant near the coastal shelf, due to coastal upwelling and the abundance of nutrients available there. However, productive wild fisheries also exist in open oceans, particularly by seamounts, and inland in lakes and rivers. Most fisheries are wild fisheries, but increasingly fisheries are farmed. Farming can occur in coastal areas, such as with oyster farms, but more typically occur inland, in lakes, ponds, tanks and other enclosures. This book is devoted to the management, economics and perspectives of fisheries.