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Corals living in more acidic bays around Palau's Rock Islands are surprisingly healthy. Credit: Palau International Coral Reef Center
The coral reefs off one of the islands of Palau are marine acidheads. They thrive in waters that are more acidic than those yet measured for any other healthy reef. That’s of interest because the world’s oceans are becoming more acidic as a result of our changing climate. In 2011 and 2012, researchers studied the chemistry of the waters near Palau, a chain of islands in the western Pacific Ocean, from the open ocean to the bays and inlets of one of the larger islands. As they got closer to shore, the water got more acidic.
In fact, all the oceans are getting more acidic. They absorb some of the carbon dioxide that we humans pump into the atmosphere. The CO2 reacts with sea water to make the water more acidic. That also depletes some of the raw materials that corals and other animals need to make their shells.
The researchers found that the bays and inlets of Palau are as acidic today as the rest of the ocean is expected to be at the end of the century. That’s not a result of global warming, though — it’s caused by the corals and other creatures, which make the water more acidic as they build their shells.
Despite the high levels of acidity, though, the researchers found that the coral reefs were thriving, with many species of coral spread across a large area. The Palau reef system may simply be the result of a unique set of factors. Or the corals may have genetically adapted to living in a more acidic environment — which could have implications for other coral reefs in the decades ahead.
