State of the Environment 2011 (SoE 2011)

At a glance

The three drivers of environmental change—climate change, population growth and economic growth—result in a range of pressures on our coastal environment. Events associated with variations in climate have been major pressures on Australian coasts over the past decade, and concern about preparing for possible future impacts of climate change and variability has been a strong driver of adaptation responses. Concern about changes in the size and composition of coastal populations has also been growing for several decades. Urbanisation and coastal development for farming and industry are a major pressure on terrestrial and marine biodiversity and environmental quality, water resources, air quality, and cultural and natural heritage. The 2006 State of the environment report concluded that ‘most, if not all, of the issues identified and assessed in both the 1996 and the 2001 national state of the environment reports still remain to be resolved’.

Our coastal regions bring together many of the issues identified for other environmental themes.

For inland waters, issues relevant to coasts include coastal river and estuary pollution, desalination, seawater intrusion, and impacts of water abstraction (removal) on flora and fauna. Overall, the management of coastal waters has improved greatly in Australia in the past decade, including some high-profile programs to ensure river and estuary health in metropolitan areas (e.g. Hobart and Brisbane). Widespread drought has increased tensions over water use, including in coastal areas, and this is likely to be an important consideration for coastal management in the future.

For land, major trends in land use that have both negative and positive impacts on coastal Australia include urban expansion in capital cities and major regional coastal cities, changed flow in rivers that influences freshwater and nutrient flows to estuaries and coastal environments, expansion of conservation and Indigenous areas, declines in the extent of native forest managed for wood production and an increase in the extent managed for conservation, and improvements in land-management practices that have reduced the flows of sediments and chemicals to the coast during major rainfall events. Disturbance of acid sulfate soils remains a major consequence of coastal development, with significant environmental, economic and social costs to coastal communities.

For vegetation, impacts on the coastal strip are highly variable around Australia’s coastline. Native vegetation ranges from very heavily cleared, with less than 10% remaining, in parts of Victoria and South Australia, through 31–50% remaining in large parts of the south-western and north-eastern coastal areas, to 71–100% remaining for most of northern Australia. The greatest reductions in native vegetation extent have been in eastern, south-eastern and south-western Australia.

For biodiversity in general, many species of plants and animals are threatened by activities associated with Australia’s coast-based population. The introduction of weeds and pest species to our coasts has also contributed to national reductions in biodiversity, and to marine, estuarine and coastal productivity.

For the marine environment, issues relevant to coasts include modification of coastal habitats by processes such as coastal urban development, catchment development, marinas, breakwaters, island reclamation projects, coastal and nearshore mining and dredging, harbours and shipping channels; and a continued increase in impacts of invasive species, including threats from pathogens and viruses. A particular concern is the incremental nature of coastal development, which reduces the abundance of native vegetation and breaks down connectivity among remnant habitat patches. The cumulative effects of coastal development are rarely considered.

For natural and cultural heritage, our coastal areas include many important wetlands, places of importance in the traditional culture and practices of Indigenous people, buildings associated with areas of early European colonisation, historically important shipwrecks, threatened species and communities, and other places of natural heritage significance. Issues relevant to coasts include degrading conditions (e.g. wind, salt, inundation), low levels of recognition and understanding of what is significant, a decline in connections between Indigenous people and coastal places, the rapidly increasing number of invasive species and pathogens, progressive loss of habitat, tension between the potential economic value of land and its dedication for conservation purposes, and modest budgets for the management of reserved lands.