Once lost, seagrass does not readily recover and attempts to replant seagrasses in temperate Australia have been unsuccessful. The loss of seagrass can have serious implications. Australia has the world's third largest mangrove area including a high diversity of 39 different species. The greatest diversity of mangroves occurs in the wet tropics. Mangroves are tree and shrub species that are adapted to the periodically inundated and salty conditions within the tidal zone.
Mangrove forests are very productive ecosystems and of major ecological and economic importance.
Clearing and development continue to be a major threat while only 8 per cent of mangroves are in protected areas. A threat to saltmarshes in developed areas is land reclamation. Extensive areas have been filled for ports, marinas, canal estates and urban and industrial sites. The total loss of saltmarshes in Australia is highly significant as habitat although it has not been great in area, with most loss concentrated in the south-east where the initial area was small. Coral reefs are among the most productive, diverse and complex ecosystems in the world.