Land 7.75 percent of mainland Australia s environment is protected by legislation. Australia has some of the oldest land surface on earth and while rich in biodiversity its soils and seas are among the most nutrient poor and unproductive in the world, due mainly to the country s geological stability. Only six percent of the Australian landmass is arable, so large volumes of water are required from both surface and groundwater supplies. Both are being extracted at higher rates than they are being replaced. Extraction from groundwater supplies for dryland agriculture has resulted in the water table rising significantly, bringing salinity with it.
Australian soils are highly dependent upon vegetation cover to generate nutrients and for stability.
Land clearing, water extraction and poor soil conservation are all causes of a decline in the quality of Australia s soils. Water Australia is the driest inhabited continent on earth, with the least amount of water in rivers, the lowest run-off and the smallest area of permanent wetlands of all the continents. The pressure caused by human activity continues to mount on marine environments. Pollution is the most serious problem, and the vast majority of marine pollution is caused by land based activities-soil erosion, fertiliser use, intensive animal production, sewage and other urban industrial discharges. Australia currently has 53 Ramsar listed wetlands and more listings are being prepared.