Monitoring ocean acidification on the Great Barrier Reef

The challenge

Ocean acidification

As the ocean absorbs greater amounts of carbon dioxide from the atmosphere, ocean acidity increases. Ocean acidification has the potential to reduce coral growth and weaken reef structures, threatening the diverse marine life that make up reef ecosystems. This may have serious implications for Australia’s iconic Great Barrier Reef. 

To protect the Reef we need to understand how factors like water chemistry, including ocean acidity levels, can influence the growth of corals and other organisms across its many different habitats.

Our response

Landmark monitoring program

From 2016 we commence Future Reef 2.0, a landmark three-year, A$1 million extension of our research collaboration with Rio Tinto and the Great Barrier Reef Foundation.

The project will take water samples along the length of the Great Barrier Reef, collecting important data on the Reef’s chemistry. Future Reef 2.0 continues work undertaken in the Future Reef MAP (2013-2016).

This research is the first of its kind to provide large-scale assessment of ocean acidification in the region and gather data essential to better understand the threat of acidification to the Great Barrier Reef.

We fitted one of Rio Tinto's vessels – the RTM Wakmatha –with an on-board laboratory and ocean sensor system. Samples are being collected along more than 2000 kilometres of the Queensland coast as the RTM Wakmatha travels between the company's Weipa bauxite mine and Gladstone alumina refineries.

These data will provide valuable and detailed information on the current conditions along the Great Barrier Reef, and allow a better understanding of potential impacts of ocean acidification on the region.

The results

Working together to protect the Reef

Understanding changes in water chemistry is essential to protect the Reef, and this collaboration will provide a consistent and sustained approach to measuring vital signs of reef health that will help Reef managers understand where and how acidification is having the most impact.

So far the project has shown that:

• Ocean chemistry across the Great Barrier Reef remains positive for the growth of coral, providing an environment in which it can recover from events such as bleaching and cyclones.
• Ocean chemistry, and therefore the conditions for coral growth, differs greatly between seasons with the best growing conditions due to ocean chemistry in the summer.
• Inflow from the Coral Sea is a much stronger influence on the chemistry of Reef waters than outflow from coastal rivers.