Acidification's Toll On Great Barrier Reef Substantially Worse Than Thought

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To study carbon mineral levels in the Great Barrier Reef, researchers simulated different factors that contribute to those levels. The map above shows changing phytoplankton blooms (green), deep ocean waters (dark blue) and sediments (browns). The team developed a modeling system that provides data on the state of a reef in close to real time.

The Great Barrier Reef is in worse shape than suspected thanks to ocean acidification, Mathieu Mongin of Australia’s CSIRO and colleagues estimate February 23 in Nature Communications.

Driven by rising atmospheric carbon dioxide, acidification lowers seawater levels of the mineral aragonite, which corals use to build their exoskeletons. The Great Barrier Reef actually contains 3,581 individual reefs, and a clear picture of aragonite levels across the reefs doesn't exist. Mongin’s team used a combination of carbon, salinity and temperature data at 22 coastal sites from 2010 to 2012 and models of ocean circulation and chemistry from 2010 to 2014 to determine the current state of aragonite levels across the reefs and to predict which reefs might be most at risk.

By their analysis, aragonite levels drop by an estimated 50 percent around individual reefs compared with the open ocean. Those saturation levels are also much more variable across the Great Barrier Reef than previous estimates projected. Northern reef corals probably drive this variability by using up all carbon resources, leaving reefs to the south at greater risk.

EDIT

https://www.sciencenews.org/blog/science-ticker/great-barrier-reef-acidification-predictions-get-worse