Climate change threatens populations because an organism’s physical characteristics, or phenotype, may be ill-suited to new conditions. Ultimately, whether organisms persist or go extinct will depend on their ability to shift their phenotypes in an adaptive direction. For long-lived, broadly dispersing organisms that experience predictable environmental fluctuations, like coral, plasticity, or phenotypic changes produced within an individual’s lifetime, is predicted to play a significant role in the response to climate change. This project aims to address key questions on the causes and consequences of phenotypic plasticity in a foundational Caribbean coral species, Acropora cervicornis. Knowledge of the role of phenotypic plasticity in driving the success of coral transplants is also essential information for reef practitioners and managers working to conserve and restore reefs. This is because the restoration of reef ecosystems in US jurisdictional waters and the broader Caribbean relies heavily on clonal or “vegetative” propagation of select coral genotypes, or genetically unique individuals, which are then transplanted to new environments. Through direct collaboration with one of the leading reef restoration organizations in the world, Mote Marine Laboratory, results of this work will be applied to ongoing restoration of reefs in the Florida Keys, USA. Findings will also be communicated to the broader stakeholder community through the PIs' roles in various advisory groups. Finally, the project will directly involve high school students, undergraduates and graduate students in primary data collection and translation of this work, providing opportunities for education, training and broader community engagement with coral science and conservation.<br/><br/>This project aims to generate quantitative empirical data on the role of morphological plasticity in the eco-evolutionary dynamics of a foundation species in nature. Clonal replicates of A. cervicornis genotypes that are known to exhibit variation in their capacity for plasticity will be used to: (1) Investigate the mechanistic basis of adaptive morphological plasticity through a lab-based water flow manipulation experiment to test the hypothesis that variation in morphological plasticity is driven by underlying changes in calcification and fine-scale structural variation in skeletal deposition; (2) Quantify costs and/or trade-offs that may limit the evolution of morphological plasticity through a combination of field and lab-based experiments testing for context-dependent trade-offs in the response to climate stressors (temperature and acidification) and reproductive investment; and (3) Evaluate the ecological consequences of plasticity at the community and ecosystem levels by creating A. cervicornis reefs that differ in their capacity for morphological plasticity and quantifying changes in the resulting composition and diversity of fish and invertebrate communities, as well as the function of the reefs in terms of their production and calcification. Taken together, this work will fill an empirical gap in our understanding of plasticity and its role in climate adaptation through investigating the effects on environmental adaptation across levels of biological organization.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.