Kelvin Thomson (Wills, Australian Labor Party) Share this | Link to this | Hansard source

A couple of weeks ago in this place, during debate on the appropriation bills, I raised the issue of the state of the world’s coral reefs and in particular the threats that are being posed to them by global warming in the shape of increased warmer water temperatures and increased carbon dioxide. I have to report that a couple of studies produced by the Australian Institute of Marine Science in the last week or two draw attention to another very serious problem confronting the Great Barrier Reef and other coral reefs around the world in the shape of changes to the acid balance of oceans and acidification, which is also a consequence of increased carbon dioxide being absorbed by the world’s oceans.

The Australian Institute of Marine Science indicates that there are worrying signs that warmer sea water and a change in the acid balance of oceans are leading to a curtailing of the growth of important reef-building coral species. A paper published in the journal Global Change Biology points to a 21 per cent decline in the rate at which porites corals in two regions of the northern Great Barrier Reef have added to their calcium carbonate skeletons over the past 16 years. The researchers speculate that the results may be an early signal that the corals, as well as being subjected to warmer water, are being affected by the phenomenon known as ocean acidification. This is a predicted consequence of climate change in which large quantities of carbon dioxide from the atmosphere dissolve in the oceans, causing the alkaline-acid balance, or pH, to shift towards acidic.

The fact that they have been able to survey a number of different sites and get similar results is, they believe, strong evidence that something unusual is happening. Reef-building corals create their hard skeletons from materials dissolved in sea water, and when large amounts of carbon dioxide enter sea water the resulting chemical changes effectively reduce the ability of marine organisms to form those skeletons. There is also research by fish ecologists at the Australian Institute of Marine Science, James Cook University and the University of Edinburgh indicating that the development of fish is being affected as result of acidification and warmer sea water. This causes them to get lost during this crucial stage of their development.

These are very serious issues. I commend the work of the Australian Institute of Marine Science, the Great Barrier Reef Marine Park Authority and the Great Barrier Reef Foundation, who visited parliament this week. The important work that they are doing needs to be supported so that we can protect our coral reefs. (Time expired)