Linking navigation behaviors of coral larvae to microbial cues and microbe-mediated mortality

Many aquatic animals produce larvae that use complex swimming behaviors to locate settlement habitats. Microbes (Bacteria and Archaea) in the water column and on settlement surfaces may provide navigational information for animal larvae, however the role of microbes in each stage of the coral settlement process is not well understood. This project will use larvae from six Caribbean coral species to test a novel hypothesis about coral behavior, that coral larvae use waterborne microbial communities as navigational information and that they avoid adults of the same species. The study will: (1) determine how coral larvae navigate different reef microbial environments by quantifying their swimming behaviors using videoanalysis, (2) characterize microbial communities from part 1 using high-throughput DNA sequencing, (3) test for behavior, survivorship, and settlement effects in larvae exposed to individual bacterial species, and (4) observe whether patterns of coral settlement in the field are consistent with laboratory results.

Intellectual merit: Coral reefs create food, economic revenue, shoreline protection, and cultural pride, yet they are massively threatened by human activity. Meanwhile, coral recruitment rates continue to decline on Caribbean reefs. This project will advance knowledge of: the microbial cues key to successful coral recruitment, the conditions under which coral larvae can identify lower-mortality habitats, and the best approaches for helping threatened corals survive their most crucial life history stage.

Broader impacts: At a research site in Curaçao, we will continue to communicate our findings through the CARMABI Foundation nature education program and through CARMABI's broader outreach channels (news coverage, public lectures). We will continue to communicate with local scuba divers, nature resource managers, and government officials on Curaçao, and broadly through publications, presentations, photography exhibits, blogging, and podcasts. The project will support the training of one female postdoctoral researcher and two students.