Coral reefs around the world are in decline with much of the mortality attributed to coral bleaching - the loss of their photosynthetic microalgal symbionts - resulting from global warming. Recent projections of future global climate changes (GCC) have given rise to grave concerns about the future of the world's coral reefs, as the thermal consequences of GCC have been predicted to intensify in the next 30-50 years. To date, our ability to gauge the vulnerability of coral reefs to global warming has been limited by our lack of knowledge about the capacity for coral symbioses to acclimatize and/or adapt to thermal stress over ecological time frames. In order to be able to predict and model how corals will respond to increasing ocean temperature anomalies, we need to begin understanding the potential mechanisms of thermal tolerance in scleractinian coral symbioses. This project will identify the genetic response of coral species to global environmental changes by looking at the molecular mechanisms behind thermal tolerance and by identifying the genetic traits under global-change-induced selection. This area of research is crucial to a complete understanding of the potential of tropical corals to survive and adapt to the rapid global climate changes that our planet is facing. The use of gene expression profiling approaches, under simulated and controlled experimental settings, will allow the investigators to identify the molecular level effects that account for thermal tolerance ranges, and type of changes in gene expression is needed to achieve thermal acclimatization. This project will also use the identified candidate genes involved in the acclimatization process of thermal tolerance as genetic markers to monitor whether seawater temperature changes influence coral species at the level of DNA sequences. The nature of selection imposed by environmental changes and the potential of coral populations to respond to global climate change by evolutionary rapid adaptation will be assessed.Broader Impacts:Coral reef ecosystems provide for the livelihood of millions of people through the tropics but their future is uncertain as we still do not fully understand the capacity of corals to respond to the new global climate changes - thus the results of this project is relevant to society. The information to be generated in this project is vital for managing the current and future coral reefs in our planet, and the findings will be disseminated both through peer reviewed publications and through presentations at national and international scientific meetings. This project represents a collaborative effort between U.S. and Australian scientists with experience in the field of molecular biology and ecology of coral and Symbiodinium symbioses. In addition, the data and methodologies generated will be transferred to both national and international students during training workshops organized in collaboration with Australian scientists through the Global Coral Reef Targeted Research & Capacity Building Project, funded by the Global Environmental Fund from the World Bank. Moreover, this project will have an immediate and significant impact by training one or two graduate and several undergraduate students in a multicultural environment that includes minorities, national and foreign students. This setting will provide young scientists a chance to participate in the development of experiments that range from molecular ecology to physiology, including both lab and marine field experiments/procedures.Rodriguez-Lanetty has recently started a new position and new laboratory in the University of Louisiana at Lafayette, and part of his planned initiative is also to establish a relationship between his laboratory and the local community including teachers and students of several minority serving institutions in the region. The research in this project will be showcased in both interactions with the Louisiana schools and in guest lectures presented to community colleges and undergraduates at UL Lafayette. The effort of this initiative is aimed at transferring the details of our work to a diverse set of audiences which will promote awareness of the issues facing coral reefs worldwide.