Rising carbon dioxide levels— and oh boy, do we haz them—lead to lower pH in our oceans. The lower the pH, the more acidic the water. Coral reefs, underwater structures notoriously unwilling to relocate, are stuck dealing with the result. A new paper shows that coral reefs that have been exposed to acidic waters are less dense and more fragile.
Marine scientist and paper co-author Adina Paytan points out that it could’ve been worse. “The good news is that they don't just die,” she says, in what one can only imagine to be a hollowly perky tone of voice. “They are able to grow and calcify, but they are not producing robust structures.”
Fortunately, what she’s not saying is that the whole wide world of coral has gone rickety. Scientists, being scientists, work hard to gather data that lets them make predictions about what will happen. In this case, the study focused on coral located near underwater springs off of Mexico’s Yucatan Peninsula, where the ocean water becomes naturally more acidic.
Because, though they can simulate conditions in a laboratory, scientists can’t be deliberately acidifying coral environments in the wild, now can they? By looking at a place where coral is already surviving in conditions of higher acidity, the paper’s authors found a site “where nature is already doing the experiments for us,” explains Don Rice, program director in the National Science Foundation's (NSF) Division of Ocean Sciences.
For Paytan, the results mix not-terrible news with a concise course of action. "We need to protect corals from other stressors, such as pollution and overfishing. If we can control those, the impact of ocean acidification might not be as bad."