World's coral reefs unable to acclimatise to ocean acidification - study

A new study has warned that the world's coral reefs are under threat from ocean acidification with many corals unable to adapt to the conditions. The study, published in the journal Nature Climate Change, determined the capacity of coral reefs to acclimatise to ocean acidification by investigating the chemistry in the corals' calcifying fluid.

The researchers at the University of Western Australia (UWA) and colleagues examined four species of coral and two types of calcifying algae in a year-long test. "We found that corals and coralline algae weren't able to acclimatise to ocean acidification," said Professor Malcolm McCulloch from UWA. "The effects of ocean acidification on the calcifying fluid were rapid and persisted after one year in the experimental conditions," McCulloch said. Researchers found that two coral species that were resistant to ocean acidification were resistant from the start while the two sensitive ones were affected from the start and were not able to acclimatise.

"The two species resistant to ocean acidification used different mechanisms to alleviate the effects of ocean acidification," McCulloch said. The results validated previous research that found coral reefs were under threat from ocean acidification, said Steeve Comeau, from the Sorbonne University in France. "The results also confirm that ocean acidification could have repercussions on the competition between species which could, in turn, affect the ecological function of reefs," Comeau said.