Water Quality Tolerences of Aquatic Biota of the Murray-Darling Basin

"November 2009".

Project Number: Evaluation of Local Biological Effects (Water Quality) – M/BUS/327.

MDFRC item.

The purpose of this report is to inform target setting for key water quality parameters for the Basin Plan, being developed by the Murray-Darling Basin Authority. This report examines the thresholds of biota found in the Murray-Darling Basin to water quality parameters. It is based on an exhaustive review of both the peer-reviewed and non-peer reviewed literature. In developing this report we have focused only on studies which specifically report on species found in the Basin. Frequently water quality thresholds reported in the Australian literature are based on North American or European species. It is inferred that Australian species should respond in an analogous manner to their northern-hemisphere relatives. Compared to North America and Europe, there are relatively few studies on chemical thresholds of MDB endemic species. (The notable exception is salinity tolerances; however, as salinity thresholds are covered under a separate study, we have limited our discussion on salinity to a brief overview of thresholds). Unfortunately the paucity of data leads to uncertainty in the risk assessment process.