Q: Why is acidification a problem?
A: Human activities – such as driving cars, generating electricity, and land use change – have increased the amount of carbon dioxide in the atmosphere, causing more carbon dioxide to be absorbed by the surface ocean and increasing ocean acidity.
Ocean acidification could have a big effect on things living in our ocean. Since pre-industrial times, the ocean’s acidity level has increased by about 25 per cent and conditions are not going to get better as CO2 emissions continue to rise.
Q: How does acidification affect the Great Barrier Reef?
A: Acidification could have a significant impact on the overall health of the Great Barrier Reef.
It can reduce coral growth, weaken reef structures and also affect the ability of some marine organisms – such as shelled plankton and molluscs – to create shells. And these changes can have knock-on impacts that weaken the Reef’s overall ecosystem.
Not all species are susceptible to the changes, but evidence suggests that as acidification increases, corals will take longer to build reefs, and structures may be more fragile and vulnerable to erosion and storm damage. As a result, ecosystems and biodiversity may change and coral’s ability to provide ecosystem habitats is likely to decline. With coral bleaching and other stresses adding to the problem, we are likely to see a shift away from healthy reefs towards more algal-dominated ecosystems.
Q: How do you monitor ocean acidification?
A: We’re partnering with the Great Barrier Reef Foundation and Rio Tinto to conduct the Future Reef 2.0 research project. As part of the project, we have fitted one of Rio Tinto’s bauxite carriers with a mobile laboratory and specially designed ocean sensor system.
The ship travels along the shipping channel between Weipa and Gladstone, providing water samples along the length of the Great Barrier Reef Marine Park. It is the only regular monitoring system of its kind that runs along the entire length of the Reef.
The sensors take measurements every one to two minutes along the entire route, providing important data on surface CO2, pH, temperature, salinity and dissolved oxygen levels.