Desert Springs of the Australian Great Artesian Basin

The Great Artesian Basin (GAB) underlies about one fifth of mainland Australia. Much of this area is arid or semiarid and often artesian water is the only reliable source of potable water, historically via springs. Prior to the 1870s, there were around 3,000 flowing springs ringing the GAB. The springs were a vital source of water for Aborigines as well as early explorers, workers and pastoralists. The drilling of thousands of bores led to the extinction of about a third of the springs and reduced flows for the remainder. Extant springs are clustered in 13 major spring "supergroups,” mostly in South Australia and Queensland. Biological studies commenced late; fishes not being properly sampled in South Australian springs until the 1970s and in Queensland as late as the 1990s. The first report on aquatic invertebrates in South Australian springs was in the 1970s and the first report of an invertebrate group (hydrobiid snails) from Queensland springs was in 1990. The GAB springs are home to many indigenous aquatic invertebrates and fishes, most with restricted distributions and several rare or indigenous plants. Some higher taxa are unique to certain springs and each major group has a distinct fauna. While South Australian springs are relatively well studied, with some significant springs protected, these habitats in Queensland remain poorly known and mostly unprotected. The most immediate conservation issue is to reduce drawdown in the GAB. About 88 percent of current usage is by pastoralists and much is wasted through evaporation and soakage. Government-sponsored bore capping and control programs are reducing wastage, but major mining ventures increasingly use large amounts of GAB water, resulting in problems with local drawdown. Other significant threats include spring modification, trampling by stock and feral animals, and the introduction of exotic plants and animals. In the last decade, GAB water usage and spring conservation have become increasingly significant issues, providing hope for the future of at least some of these unique habitats.