The changing carbonate chemistry of coral reefs: ocean acidification, submarine groundwater discharge, and calcium carbonate (CaCO3) sediment dissolution

Uptake of atmospheric CO₂ is the dominant driver of ocean acidification (OA) in the open ocean, which is lowering the pH of seawater at an unprecedented rate. However, multiple processes can influence the CO₂ of coral reef ecosystems on diel and seasonal timescales, potentially masking or intensifying any effects of increasing atmospheric CO₂. Therefore, it is important to quantify any biogeochemical drivers of CO₂ variability in coral reefs that could act as feedbacks to OA. This thesis focuses on how permeable sediment metabolism and submarine groundwater discharge affect the carbonate system of coral reefs and, subsequently, the dissolution of sediments.