Effects of salinity on river, stream and wetland ecosystems in Victoria, Australia

• Published in: Water research (Oxford) 1990, Vol.24 (9), p.1103-1117
• Main Authors: Hart, Barry T., Bailey, Paul, Edwards, Rick, Hortle, Kent, James, Kim, McMahon, Andrew, Meredith, Charles, Swadling, Kerrie
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; aquatic ecosystems; Biological and medical sciences; biological assessment; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; rivers; salinity; Synecology; wetlands
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/0043-1354(90)90173-4

Salinity is a growing problem in many parts of the world. In Australia both dryland salinity and salinity in irrigation regions are serious problems. Options being considered to control the latter involve pumping the groundwater to lower the watertable; however, this leaves a saline wastewater to be disposed, probably into local streams or wetlands. A previous review by the authors covered the lethal and sub-lethal effects of salinity on individual species within the following groups of aquatic organisms: microbes (mainly bacteria), macrophytes and micro-algae, riparian vegetation, invertebrates, fish, amphibians, reptiles and mammals and water birds. That review concentrated on Australian information, information it is argued that will be more typical of the effects occurring over a large part of the world than data from the better watered areas of North America and Europe. This paper uses these data on individual species to determine the possible adverse effects of saline wastewater discharges on aquatic ecosystems, in particular lowland rivers and streams and wetlands. In these freshwater systems, the macroinvertebrates and plants (riparian vegetation, macrophytes and micro-algae) were assessed to be the most salt sensitive biological communities, with direct adverse biological effects likely to occur when salinity is increased to around 1000 mg l −1. More subtle sub-lethal and indirect effects possibly occur at salinities below this, however the scientific data are not presently available to assess the extent that this might occur. A set of guidelines for assessing the possible biological effects in particular salt-affected rivers, streams or wetlands is developed.