Water Quality In The Great Barrier Reef Catchment Set To Improve With New Research

A study conducted in Queensland, Australia, has successfully lead to the development of a tool that can be used to monitor and manage real-time water quality in river systems leading to the Great Barrier Reef lagoon, efficiently and effectively.

The research has been conducted by the Queensland University of Technology’s ARC Centre of Excellence for Mathematical and Statistical Frontiers, in partnership with the Queensland Department of Environment. Together, they have developed a model that can better monitor water quality data, specifically sediment and nutrient concentrations in rivers.

The Traditional Method

Traditionally, the water quality of rivers is measured using manual sampling techniques of sediment and nutrient levels across very few areas. It requires each sample to be taken manually and then transported and analysed at a laboratory offsite. 

The process as a whole is time consuming, costly, and offers little representative data due to the lack of coverage of sites across the catchment.

A New Tool

The study installed a series of low-cost sensors in two freshwater rivers and one estuarine environment near Mackay and Townsville in Queensland. The sensors measured turbidity, conductivity, and river level data which were found to act as an alternative proxy data representative of sediments and nutrient levels. Turbidity, and a threesome of turbidity, conductivity, and river level, were found to be useful surrogate data for both total suspended sediments (TSS) and nutrients respectively. 

This new tool, which can capture measurements more frequently than manually analysing sediment and nutrient samples, was then used alongside the manual sampling technique to corroborate and build a statistical model. It is this model that will be a tool to predict sediment, nutrient levels, and water quality information across the wider catchment.

Sediment and Nutrients: How They Impact Water Quality

Sediment and nutrient runoff is a major concern for water quality as they can cause eutrophication in rivers. More of an immediate local concern for the Great Barrier Reef Catchment area is the impact it can have on the health of coral reefs. 

Tropical areas like Queensland suffer from flashy, high magnitude and high volume rain events which result in high concentrations of sediment being carried in the river and overland flows. In these instances, manual sampling cannot be carried out fast enough to safely to monitor these changes through events.

How Will The New Tool Help?

The new model allows for real-time monitoring of the water quality of waterways in Queensland and beyond to better manage water quality and run-off to the Great Barrier Reef.

Eliminating the wait between sample collection and results, electronic communication of data could be used to immediately inform land managers and farmers of the current water quality. In future, apps could be used to alert them of any exceedance to agreed thresholds. 

The researchers are hopeful that the model can be rolled out to other catchments using the same concept. This will be increasingly useful as more environmental managers move towards remote monitoring using sensors.