Salinity

Impacts from salinity have been identified as one of Australia's most serious environmental issues. In areas already affected, salinity has devastated ecosystems resulting in massive loss of habitat, biodiversity, native vegetation and water resource value (Land and Water Australia, 2002). An estimated 48 000 ha of land in Queensland is seriously affected by induced salinity and an assessment undertaken for the Land and Water Resources Audit found that 3.1 million ha of land could be affected by salinity by 2050 (Department of Natural Resources and Mines, 2002). Soluble salts occur naturally in aquatic ecosystems and are a vital component of the normal functioning of freshwater biota. They are ubiquitous in Australia's soils and are a remnant of geological history. Salts are also an integral part of the biochemistry of life in terrestrial and aquatic environments though for many freshwater aquatic animals exposure to high concentrations of salt can have toxic effects. Similarly, a lack of salt can also act as a toxicant in saline and estuarine environments for freshwater species.

Summary of factors contributing to the salinity variability of streams