Australia is the driest inhabited continent on earth. While rich in biodiversity, Australia’s soils and seas are among the most nutrient-poor and unproductive in the world. Only 6 per cent of the Australian landmass is arable, so large volumes of water are required from both surface and groundwater supplies. Extraction from groundwater supplies for dry-land agriculture has resulted in a rising water table and salinity. 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. At least 18 introduced mammals have established feral populations in Australia, with cats and foxes responsible for the decline and extinction of several native animals. Introduced plants also cause substantial damage to native vegetation and habitats. The pressure caused by human activity continues to take its toll on marine environments. Pollution is the most serious problem; the vast majority of marine pollution is caused by land-based activities, including soil erosion, fertiliser use, intensive animal production, sewage and other urban industrial discharges. The natural beauty of Australia make it a most popular destination for people who move in to Australia for retirement.