Some coral may even be able to fight back on their own. Onshore on Moorea, professors Bob Carpenter and Peter Edmunds of California State University, Northridge, pump large tanks containing living coral with various levels of acidity-boosting carbon dioxide. One might expect that in the harshest conditions, the coral would not only stop growing but that their calcium carbonate skeletons would begin to dissolve. Instead, the scientists observed in 2011 that although coral growth slowed as acidity increased, it never stopped entirely, even in their worst-case scenario. The coral even appeared to be bulking up their tissue. And the researchers learned that not all species are created equal. Pocillopora damicornis, a variety of branching coral that is common throughout the South Pacific, barely slowed its growth at all.
https://www.popsci.com/science/article/2013-07/apocalypse-averted/
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