Coral Skeleton Crystals

Former MIT-WHOI Joint Program student Tom DeCarlo holds a vial containing aragonite, a crystal form of calcium carbonate, the mineral that reef-building corals use to build their skeletons. By manipulating the chemistry of seawater samples in the lab, DeCarlo and Michael Holcomb of the University of Western Australia investigated the mechanisms corals use to build aragonite skeletons and how they may be adversely affected by ocean acidification caused by rising carbon dioxide levels in the air and ocean. In the field, DeCarlo also showed how unusual weather conditions combined with warmer ocean temperatures to trigger massive coral bleaching. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)