Indicator: CO-72 Changes in sea acidity/alkalinity

Data

No continental data are available for Australia.

However, laboratory experiments have indicated that elevated carbon dioxide levels produce changes in the thickness and morphology of calcium carbonate tests of a key planktonic organism (Emiliania huxleyi) as a result of increasing the acidity of seawater (Cubillos 2005). Ocean acidification is also expected to have a major impact on populations of pteropods (small planktonic snails), an important prey in the Southern Ocean, and also plays an important role in the uptake of carbon dioxide (Royal Society 2005).

What the data mean

If increasing acidity decreases the thickness and integrity of the skeletal structures of plankton organisms that are key to the marine food web and are also responsible for the removal of carbon dioxide from the marine environment of the Southern Ocean, then the loss of these species will not only have a significant impact on the food chain but will also reduce the ocean’s ability to absorb carbon dioxide from the atmosphere.

Source: Royal Society 2005, Ocean acidification due to increasing atmospheric carbon dioxide, Royal Society, London, viewed 3 Oct 2006, http://www.royalsoc.ac.uk/.

Data Limitations

No data available.

Issues for which this is an indicator and why

Coasts and Oceans - Condition of the ocean and coastal waters - Climatic and carbon dioxide factors 

Changes in the acidity of the oceans may affect the ocean’s capacity to absorb carbon dioxide.

Other indicators for this issue:

Coasts and Oceans - Condition of the ocean and coastal waters - Water quality 

Changes in the acidity of the oceans may also affect water quality, with significant impacts on marine organisms.

Other indicators for this issue:

Coasts and Oceans - Contributions and pressures between the coasts and oceans and the atmosphere - Climate and carbon dioxide 

The acidity of the oceans may increase as a result of increased concentrations of carbon dioxide in the atmosphere, and the reduced capacity of the ocean to absorb carbon dioxide will increase greenhouse gas pressure on the atmosphere.

Other indicators for this issue: