Award: OCE-1105201

RAPID funding was requested to assess the integrated impact of the 2010 Caribbean bleaching event on coral reef communities, coral gene expression, immune function and microbial communities. 2010 was the warmest year on record, and created a large thermal anomaly in the Caribbean basin and in the southeastern Caribbean, exceeding in the south-east the previous record-breaking warm temperature period of 2005. The study integrated ecological surveys that documented high coral mortality in the most impacted region of the southeastern Caribbean, with remote sensed temperature data, with coral health and immune function, and bacterial assemblages. The ecological impact was highly significant, with a 25-36% reduction in live coral cover in some of the previously healthier coral reefs in the southern Caribbean, significant increases in coral disease, and changes in coral microbial communities. Results from the reefs affected indicate that (1) fifty two species of hard corals, 12 octocorals and many other species from other important reef animals showed bleaching signs; (2) the proportion of coral colonies showing bleaching signs (prevalence) associated with the high thermal stress varied between 28 and 39% across the four localities; (3) similarly to the 2005 event in the northeastern Caribbean, an outbreak of a white plague-like disease (WPD) impacted several localities in the southern Caribbean and produced fast and significant coral mortality; (4) Caribbean yellow band disease (CYBD), a chronic problem in most Caribbean coral reefs since the late 1990Æs, increased in all reefs surveyed (Curacao, Grenada and Grand Cayman), except in Puerto Rico, where this disease was declining by the time of the thermal event; (5) the combined impact of bleaching and infectious diseases produced an average coral mortality of 25% in less than 3 months in Curacao, a significant and fast loss of live coral tissue, reproductive output, and productivity for these communities. For the surviving corals, we detected large-scale changes in immune function and composition of associated bacteria. Both Orbicella spp. and G. ventalina immune responses (measured by biochemical assays) were depressed during the bleaching event. Orbicella spp. gene expression indicates short-term changes during the bleaching event. In addition, the bleached hard corals exhibited changes in algal symbionts during and after the bleaching event. Contrary to our original hypothesis that seafans would not be significantly affected, G. ventalina immune gene expression was highly down-regulated during the bleaching event as compared to pre- and post-event sampling. Although sampled from the same locations and time periods, Orbicella spp. and G. ventalina bacterial communities are significantly different from one another. G. ventalina bacteria moved towards a disparate, less diverse community from pre- to post- event and did not rapidly recover following the event. This project has generated 10 new scientific publications to date and will produce at least 4 more. This study resulted in significant broader impacts at three levels: 1) training of future science leaders, 2) educating the general public about massive climate impacts to coral reefs through a large new museum exhibit, and 3) conveying information from this study into national climate strategy documents. This project provided unique training to post-docs (1 female postdoc), graduate students (4 female PhD students, 3 male PhD student), and undergraduates (3 minority undergraduates, 6 other undergraduates) that was outside of their previous areas of expertise and knowledge. Because this project is utilizing new emerging approaches, these young scientists are gaining valuable skills that will be transferable to future research projects and positions. This project also contributes fundamentally to human resources and development by training minority and female undergraduates and through near-peer mentoring amo...