Australia's wetlands – learning from the past to manage for the future

Abstract

Australia has diverse wetlands with multiple threats. We reviewed knowledge about the extent of wetlands, representativeness, impacts and threats to integrity and options for effective conservation. Natural Australian wetlands cover an estimated 33 266 245 ha (4.4%), with 55% palustrine (floodplains and swamps), followed by 31% lakes, 10% estuarine systems, and 5% rivers and creeks. The Lake Eyre (1.1%), Murray–Darling (0.73%), Tanami–Timor Sea Coast (0.71%) and the Carpentaria Coast (0.55%) drainage divisions have more wetlands, also reflected in the distributions among states and territories. Ramsar sites and wetlands in protected areas were generally biased towards the southern continent. Overall representation of mapped wetlands was good for lacustrine (40.6%) and estuarine (34.4%), fair for riverine (16.8%), but inadequate for palustrine (10.8%) wetlands. Within drainage divisions, representation varied considerably, with shortfalls from the Aichi target of 17%. Agriculture, urbanisation, pollution and invasive species have degraded or destroyed wetlands, particularly in the developed south-east, south-west and north-east of the continent. Water resource developments, primarily the building of dams, diversion of water and development of floodplains, seriously threaten Australian wetlands, with all threats exacerbated by climate change impacts of rising sea levels and high temperatures. Management and policy for wetlands is dependent on data on distribution, type and extent of wetlands, a key national constraint. Some States are well advanced (e.g. Queensland) and others lack any comprehensive data on the distribution of wetlands. Mitigation of increasing development (e.g. northern Australia) will be critical for conservation, along with increased representativeness in protected areas and restoration, particularly with environmental flows.