Project: Coevolution of scleractinian corals and their associated microorganisms

Description from NSF award abstract:
Coral reefs are among the most biologically diverse marine ecosystems on the planet, and provide substantial economic and ecological benefits to coastal communities. Corals are composed of both the Cnidarian animal host and complex communities of unique and underexplored microbial organisms. Today these natural wonders are in global decline, threatened by the intersecting effects of multiple stressors including overfishing, pollution, and climate change. These stressors can alter coral microbial communities in ways that may contribute to the susceptibility of corals to disease or overgrowth by algae. Therefore, understanding the relationships between corals and their microbiota may be useful for efforts to understand coral disease and preserve reef ecosystems. The microbial diversity of coral species in many diverse and ancient groups of corals remains unexplored, but understanding these communities will help to extend the knowledge gained in well-studied corals to diverse reefs worldwide. This project aims to describe microbial diversity across all major groups of reef-building corals in each of several distinct ecosystems across the globe, to determine the genome sequences and metabolic capabilities of key coral bacteria, and to test whether the composition of coral microbial communities helps to explain the overall vulnerability or resistance of different coral species to stress or disease. 

Coral species differ in their susceptibility to bleaching and disease, but these differences are only partially explained by coral phylogeny. Therefore this project will test the extent to which incorporating the microbiota (or their contributed genes) better predicts these and other traits. Recent technological advances have broadened understanding of how complex microbiomes shape the life history, physiology, and evolution of their multicellular hosts (e.g., the human microbiome). The use of newly developed DNA sequencing techniques will allow a more complete exploration of microbial diversity in corals than has previously been feasible, while advanced computational methods will help to maximize the value of sequenced bacterial genomes. Improved predictive models that incorporate both coral phylogeny and microbial function will help inform conservation strategies and yield predictive biomarkers for coral vulnerability to disease or bleaching. Relating the diversity of corals to the diversity of their microbes will also provide important insights into how intimate symbiotic associations with microorganisms arose and are maintained in diverse animals.