Abstract:
In an effort to combat rising groundwater tables and expanding saline lakes, saline water has been disposed of into the aquatic environment, despite there being little information as to the environmental effects. Monitoring of the effect of saline lake water disposal on aquatic macroinvertebrates and water quality was conducted in the Barwon River, south west Victoria, Australia, in association with toxicity tests. The disposal of saline lake water was associated with changes in macroinvertebrate community structure. Contrary to expectations, increases in electrical conductivity (a measure of salinity) was not the only water quality parameter associated with saline water disposal. An experiment was conducted where the toxicity of saline lake water was compared to that of a prepared solution of the same electrical conductivity. Toxicity was greater in the saline lake water than the prepared solution. The results suggest that saline water disposal is impacting on macroinvertebrate fauna but electrical conductivity is not the only factor responsible. These results have consequences for both management of aquatic resources and for monitoring programs which are discussed.
