sentences:  Mangroves have been converted to small shrimp aqua-cultural ponds, while intertidal mudflats have been afforested with mangrove or intensely fished by lines of stack nets, which severely impacts their value as feeding habitat for migratory waterbirds and other species.Moreover, sand dune ecosystems are severely threatened by afforestation, for instance, with the Australian exotic Casuarina equisetifolia.Overfishing and the increasing use of destructive fishing techniques diminishes the fish population in both coastal and offshore marine ecosystems.