HERE鈥橲 a surprising twist. More acidic water may actually be a sign of healthy corals, says a new study, muddying the waters still further on our understanding of how coral reefs might react to climate change.
of the Scripps Institution of Oceanography in San Diego, California, and his colleagues carefully monitored a coral reef in Bermuda for five years, and found that spikes in acidity were linked to increased reef growth (PNAS, ). 鈥淚t鈥檚 completely the opposite to what we would expect in an ocean-acidification scenario,鈥� says Andersson.
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The team discovered that the coral growth itself drove up this local acidity. To build their skeletons, it seems the corals sucked alkaline carbonate out of the water, leaving it more acidic.
The results complicate the question of how coral reefs will respond to climate change, which is thought to be raising the acidity of the oceans. 鈥淒o corals care about ocean pH if they have plenty of food and light? At this point, we don鈥檛 fully know the answer to that question,鈥� says Andersson.
These corals didn鈥檛 seem to mind the fluctuations in local acidity that they created, which were much bigger than those we expect to see from climate change. This may mean that corals are well equipped to deal with the lower pH levels.
(Image: Georgette Douwma/Getty)
This article appeared in print under the headline 鈥淕rowing corals bathe in acid, confounding expectations鈥�
Article amended on 13 November 2015
Correction: Since this article was first published, the title and some of the text has been changed to clarify that although the water the corals聽live聽in is more acidic than it was, it isn鈥檛 actually acidic.