Distribution of coastal freshwater wetlands and riparian forests in the Herbert River catchment and implications for management of catchments adjacent the Great Barrier Reef Marine Park

Because coral reefs are sensitive to land derived inputs of nutrient and se diment, there is concern worldwide for the effects of anthropogenic change in river catchments on reefs. Thirty-one river catchments drain directly in to the waters of the Great Barrier Reef; NE Australia. This case study was undertaken on the floodplain of the Herbert River catchment in north Queens land, utilizing remote sensing and GIS to assess both spatial and temporal changes in freshwater wetlands and riparian forests. We demonstrate that th ere has been a very large reduction in the area of these ecosystems since E uropean settlement in the mid nineteenth century, with an 80% decline in th eir extent since 1943. We provide a range of quantitative measures to show that the landscape diversity of these ecosystems has also declined. These c hanges are of importance in terms of regional, national and international t rends. We argue that policy, planning and management reform is required if the remaining ecological, economic and social values of these systems and t he adjacent Great Barrier Reef Marine Park are to be maintained.