Atmospheric and sea surface CO2 concentrations are expected to continue to increase substantially over the coming decades resulting in warmer and more acidic oceans, which will greatly stress the health of coral reefs. In addition, ocean margins where most corals live will also see continued increases in human-produced nutrient inputs. While there has recently been a considerable focus on how ocean acidification (due to higher CO2 alone) could negatively impact the growth of reef-building corals due to the projected loss in calcification, the combined impacts of CO2, temperature, and nutrients on coral physiology and calcification are poorly understood. This project will investigate the possible synergistic and antagonistic effects of elevated temperature, CO2, and nutrients on the physiology and internal calcifying chemistry of several species of corals in a laboratory setting. Research tools will include the assessment of coral energy reserves and metabolic demand, symbiotic algal physiology and molecular diversity, coral calcification, and direct measurement of the internal coral pH and carbonate concentration via microprobes. The results from this project have the potential to supply broad scientific impacts regarding how (or if) reef-building corals will survive future climate change scenarios, and will help establish several parameter ranges that could be used to strengthen ocean acidification and coral reef growth models. Likewise, broader impacts toward further education will include the professional development of two postdoctoral scholars, two PhD graduate students, and several undergraduate students. This project will also enhance scientific and technological understanding by several public outreach efforts, including participation and research education in the Young Ocean Explorers program at the Batelle Discovery Center in Ohio, the annual Coast Day public open house at the University of Delaware, as well as advisement in the National Ocean Science Bowl in Georgia.
