For coral reefs to persist, rates of reef construction must exceed reef breakdown. Prior research has largely focused on the negative impacts of ocean acidification on reef growth, but new research demonstrates that lower ocean pH also enhances reef breakdown: a double-whammy for coral reefs in a changing climate. To measure bioerosion, researchers deployed small blocks of calcium carbonate (dead coral skeleton) onto the reef for one year. Traditionally, these blocks are weighed before and after deployment on the reef; however, HIMB scientists used microCT (a high-resolution CT scan) to create before and after 3-D images of each block. Current models from the International Panel on Climate Change (IPCC) predict changes in pH for the open ocean, but these predictions are problematic for coral reefs, which are embedded in highly variable coastal ecosystems.