Coral reefs are showing evidence of decline on local, regional and global scales. Historical overfishing, nutrient loading and terrestrial discharge, combined with more recent threats of global warming, coral bleaching, ocean acidification and disease have resulted in long-term losses of abundance, diversity and habitat structure. Since European settlement of the Queensland coastline in the mid-19th century, extensive land use changes in the GBR catchment region have occurred resulting from grazing, agriculture and land clearance.
