b'The Presidents Commentary8Understanding and Protecting Coral Systems With the specter of climate change threatening our planets future, it is encouraging to review Carnegie scientists multifaceted approach to research on coral reefs and the response by these organisms to rising sea temperatures. Our ongoing research focus on coral reefs reflects the importance of these diverse ecosystems, both in terms of the thousands of species of fish and plant life that reefs support and in terms of the millions of human beings whose livelihoods depend on coral reef fishing and tourism. By documenting the dramatic changes inflicted on fragile coral ecosystems worldwide due to changing water temperatures and ocean acidification, our researchers are providing more compelling proof of our ongoing climate change challenges. At the same time, Carnegie scientists in our Plant Biology, Global Ecology, and Embryology departments are pursuing inventive strategies with the potential to mitigate the impacts of rising water temperatures and help restore some of these threatened coral communities. By combining fieldwork on the effects of ocean acidification with laboratory studies of the mechanisms of coral bleaching, our scientists are developing invaluable methods and models that can help us to better understand the underlying genomic and microbial mechanisms involved and perhaps to ultimately protect these vital ocean ecosystems.At right, researchers at Carnegies Department of Global Ecology, with colleagues, are studying the effects of climate change on coral reefs at One Tree Island in the Great Barrier Reef of Australia. Rising sea temperatures are a threat to coral communities worldwide. Bleached pillar coral, near Florida, is shown above. Corals have a symbiotic relationship with algae living in their polyps. Rising temperatures kill off the algae, resulting in bleaching. Images courtesy Aaron Takeo Ninokawa, U.C.-Davis and NOAA'