Estuary water quality assessment
Estuaries are dynamic water bodies, influenced both by the marine environment and by freshwater from the catchment. The conditions within estuaries vary both seasonally and diurnally (a result of tide, temperature and sunlight).
The Department of Water coordinates water quality monitoring programs in estuaries throughout the state. Parameters which are typically measured include salinity, temperature, light, dissolved oxygen, nutrients and chlorophyll a. These parameters help monitor natural phenomena such as stratification and tidal flushing, as well as impacts caused by human activities and from the catchment. The sites and the frequency that these measurements are taken vary depending on the estuary (location and pressures) and current reporting requirements. A particular problem, such as a phytoplankton bloom for example, may require water quality in the estuary to be monitored more regularly over the duration of the bloom.
Water quality data is a critical component of estuary management and has contributed to outputs and achievements by the Department of Water which include:
- estuary condition reports, e.g. the Hardy Inlet Estuary condition report 1999 to 2010
- estuary water quality improvement plans
- estuary management plans
- the development of a water quality indicators and a water quality index
- monitoring and reporting on the effectiveness of intervention technologies e.g. oxygenation plants