The EPA has conducted water quality monitoring in Macquarie Harbour since 1993. The monitoring increased the understanding of water quality within Macquarie Harbour and the Gordon and King Rivers. Monitoring was formalised under the Mount Lyell Remediation Research and Demonstration Project (MLRRDP) that was established in 1995 and later expanded to include the World Heritage Monitoring (WHA) Project. Monitoring under these projects was undertaken on a seasonal basis until February 2023.
As of September 2023 a single monitoring program was instigated for the entire Harbour.
Water Quality Monitoring Program
The purpose of the current program is to provide water quality information
to increase the understanding of water quality in Macquarie Harbour.
to increase the understanding of the Gordon and King Rivers and oceanic exchanges to the overall water quality of Macquarie Harbour.
to build upon the understanding of water quality in Macquarie Harbour gained under the Mt Lyell Remediation Research and Demonstration Project (MLRRDP).
to increase the understanding of water quality within the World Heritage Area (WHA) area of Macquarie Harbour and the influence of riverine flows from the Gordon River on the WHA.
for comparison with interim Default Guideline Values (DGVs) for aquatic ecosystems of Macquarie Harbour.
for Dissolved Oxygen at key locations across the harbour through deployment of in situ loggers.
to assist nutrient dispersion modelling and biogeochemical model development and validation.
Water Quality Monitoring
The EPA undertakes quarterly monitoring of physico-chemical, nutrient and metal data at 15 sites throughout Macquarie Harbour. The EPA data will allow for the characterisation of waters within Macquarie Harbour and entering from the Gordon and King Rivers and entering/exiting to the oceanic environment. The EPA monitoring sites are additional to the 17 sites monitored by the salmon industry on a monthly basis under the Broadscale Environmental Monitoring Program (BEMP) requirements of the environmental licences.
In situ Dissolved Oxygen Loggers
In September 2023, the EPA reinstated data logging equipment on the World Heritage Area boundary of Macquarie Harbour. Data logging equipment had been deployed at this location from 2013 until December 2022. The data logger string records dissolved oxygen at 10, 25 and 35 metres from the surface and is sited in an area of approximately 50 metres of depth.
In September 2023 an additional logger string was deployed within the deep central channel of the harbour with dissolved oxygen loggers at 10, 25 and 35 metres from the surface. Further logger instrumentation was deployed near the mouth of the Gordon and King Rivers and within Kelly Channel. The dissolved oxygen loggers at these locations will aid in characterising oxygen levels for the confluence of the Gordon and King Rivers with Macquarie Harbour and the oxygen levels at the harbour mouth.
In January 2024, the EPA deployed additional logger instrumentation within the WHA area. The instrumentation is sited south of Gould Point and extends data coverage along the deepest part of Macquarie Harbour. The data logger string records dissolved oxygen at 10, 15, 20 and 25 metres from the surface and is sited in an area of approximately 30 metres of depth.
Also in January 2024, the EPA deployed eight additional sets of logger instrumentation within areas known to be preferred habitat for Maugean Skate. The dissolved oxygen loggers at these locations will aid in characterising changes in oxygen levels within these shallow areas of the harbour.
For further information on the Maugean Skate refer to Maugean Skate | Department of Natural Resources and Environment Tasmania (nre.tas.gov.au).
Interim Default Guideline Values (DGVs) for aquatic ecosystems
Interim Default Guideline Values (DGVs) for aquatic ecosystems have been derived for Macquarie Harbour. The available data from May 1993 to October 2009 has allowed for the derivation of annual and seasonal interim DGVs of surface, halocline (interface between surface layer and marine water dominated bottom layer) and bottom waters for key indicators. Annual interim DGVs have also been derived based on depth ranges for field based indicators and on a seasonal basis for dissolved oxygen. For dissolved oxygen, temperature, and pH the 20th percentile represents the lower interim DGV and the 80th percentile the upper interim DGV, whilst for all other indicators the 80th percentile represents the interim DGV. The interim DGVs are for three segments within Macquarie Harbour and provide a level of refinement over the
Default guideline values for estuarine waters.
Monitoring Results
Macquarie Harbour Dissolved Oxygen Report February 2023 (PDF 1Mb)
Reports and Web Resources
The following section provides links to a range of reports and web resources available for Macquarie Harbour: