The growing acidity of the world's oceans is a worrying threat to coral reefs, which support an amazing array of marine life, and are generally harmed as ocean acidity rises. But a vibrant reef in the western Pacific Ocean is bucking this trend: Researchers have found that the coral there thrives, rather than suffers, in locally acidic conditions.
Coral reefs grow by extracting calcium and carbonate ions from seawater and combining them to form calcium carbonate, the same hard mineral found in clam and snail shells. Both calcium and carbonate are generally abundant in seawater; however, as water becomes more acidic, carbonate levels drop and organisms struggle to gather enough to form their outer skeletons.
Image: Despite living in waters that are more acidic than average seawater, the corals living in the bays around Palau’s Rock Islands are unexpectedly diverse and healthy. Credit: Palau International Coral Reef Center
