Challenges for Diadromous Fishes in a Dynamic Global Environment

<em>Abstract</em>.-The general acceptance that individual fisheries should be managed in the context of the ecosystem of which the target species are a part has led to the paradigm of ecosystem- based fisheries management (EBFM). Such management may be particularly suitable for diadromous fishes, which spend time in rivers, estuaries, and the sea, because their sustainability would benefit from a holistic approach. The extent to which this is possible and has been successful depends on a wide variety of biological, socioeconomic, and political factors. Fishing in all its forms is only one of a broad array of human activities in rivers, estuaries, and the coastal zone; hence, diadromous fisheries management requires not only integration across ecosystems, but also its inclusion in overall planning processes. Tropical diadromous fisheries in developing countries suffer from overfishing, lack of adequate human resources to manage the fisheries, insufficient scientific data for sound management and decision making, lack of monitoring capabilities, poor enforcement of laws, inefficient administration, and increasing conflicts between different types of users. Even in developed countries, many of these issues also have not been addressed. The extent to which an EBFM approach has been successful for tropical diadromous species is discussed using the various barramundi <em>Lates calcarifer</em>, mullet (Mugilidae), and tropical shad (<em>Tenualosa</em>) fisheries of Asia and Australia, taking into account issues of food security and the role of community-based management.