Statement on the future of the Great Barrier Reef

Dr Selina Ward, Coral Researcher, UQ

The Great Barrier Reef is suffering with the effects of climate change and land use. In the five years between 2016 and 2021 we had three bleaching events which affected the entire Great Barrier Reef and resulted in substantial mortality of corals.

As climate change continues, if we do not reduce our emissions dramatically now, these bleaching events will continue and will be more frequent resulting in more mortality. Bleaching events globally have already become more frequent and this will continue unless we change the way we tackle climate change very quickly. Unfortunately climate change does not only bring the reef increased temperature, but also more intense cyclones causing broken and dislodged corals and sometimes movement of sediments onto reefs. It also brings sea level rise, which could see drowning of some reefs in the future and water quality problems as seawater and landuse interact more. Ocean acidification is also an enormous challenge for the reef as the water chemistry changes and corals will find it harder to build their skeletons and many reef animals may have changes in the way they reproduce and recruit. Shorter breaks between bleaching events makes recovery for reefs more difficult as corals have less time to resume their reproduction, regain strength to compete with algae and soft corals and fight coral disease.

At the same time we have not been able to improve the water quality in the Great Barrier Reef lagoon as much as we need to have optimal conditions for resilient reefs, particularly in the inshore reef areas. Although some great work has been done and funding has increased to improve water quality, this has not been enough. We need a greater investment to reduce sediment coming from the land along with chemical inputs such as fertilisers, herbicides and pesticides.

Unfortunately, the industrialisation of the Great Barrier Reef coastline continues and this brings further challenges to water quality. Expansions of existing ports and new port developments involve dredging seabed causing increased sedimentation. Coal ports hold large piles of coal, and dust from this coal is toxic to the adjacent marine environments. Toxic compounds from these coal ports have been detected across hundreds of kilometres of the Great Barrier Reef and in high levels at Abbot Point prior to the port expansion.

We have enough coral left to prevent the loss of the Great Barrier Reef if we can dramatically reduce emissions now. We need to work to improve the resilience of the reef with further improvements to water quality, protecting areas and managing fishing and other activities within the Great Barrier Reef Marine Park. But we must act now. We have no time to wait. We certainly have no time for new coal mines and new port expansions.