9 October: Inshore reefs of the GBR especially vulnerable to ocean acidification

October 9, 2014

The Australian Institute of Marine Scientist (AIMS) has revealed in a peer-reviewed journal, PLoS One today that inshore reefs are particularly vulnerable to Ocean Acidification (OA)* on the Great Barrier Reef (GBR).

“We found that inshore reefs were particularly vulnerable to ocean acidification (OA) during the wet season. This is due to the cumulative impacts of both increased soil runoff from rivers because of storms and cyclones as well as OA. OA is caused by elevated carbon dioxide levels in the atmosphere and oceans as a result of humans continuing to burn fossil fuels,” said AIMS scientist Dr Sven Uthicke.

The team found that the rates of increase of the levels of carbon dioxide in the waters surrounding inshore reefs were almost twice as high as in the waters of outer reefs of the Great Barrier Reef (GBR).

Uthicke explained that although increased carbon levels can benefit some organisms such as benthic algae, seagrasses and phytoplankton, it also decreases coral calcification and therefore the health of reefs.

The AIMS team used carbon chemistry data from the GBR collected six times over two years as part of the Reef Rescue Marine Monitoring Program covering a wide latitudinal range.

More research is being conducted into the inshore reefs close to the coast that are under the greatest threat from increases in runoff sediment, nutrients and pesticides. AIMS is also conducting research into OA in the naturally-occurring volcanic seeps in eastern Papua New Guinea.

Funding was provided through the Australian Government’s National Environmental Research Program.

PLoS One is a journal of the Public Library of Science.

*What is ocean acidification?

When carbon dioxide from the atmosphere dissolves in water, it causes ocean acidification, slightly lowering the pH of the water and changing its carbonate chemistry. This in turn makes it harder for a range of marine animals to form their carbonate shells and skeletons.

Journal: PloS One

Article title: Coral Reefs on the Edge: Carbon chemistry of inshore reefs of the Great Barrier Reef

Authors: Sven Uthicke, Miles Furnas, Christian Lonborg

Weblink: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0109092