This book examines pre-existing management systems in fishing communities in Indonesia, Laos, the Philippines, Thailand and Vietnam. Besides the erroneous assumption that tropical fisheries are ‘open access’, the cases demonstrate that pre-existing systems (1) are concerned with the community of fishers and ensuring community harmony and continuity; (2) involve flexible, multiple and overlapping rights adapted to changing needs and circumstances; (3) that fisheries are just one component of a community resource assemblage and depend on both the good management of linked upstream ecosystems and risk management to ensure balanced nutritional resources of the community; and (4) pre-existing systems are greatly affected by a constellation of interacting external pressures.The cases presented in “Managing Coastal and Inland Waters” demonstrate that good management systems must account for such cultural, ecological, economic, political and social context factors to achieve their goals.