Postdoctoral Fellowship: OCE-PRF: Diving into the chemical signatures and spatial variability of Caribbean coral reef health

Coral reefs are one of the most diverse, productive, and threatened ecosystems on the planet. The rich biodiversity hosted by coral reefs has enhanced the economies of coastal countries and the livelihoods of people around the world. Unfortunately, coral populations have declined by 50% in the last 50 years due to both natural and human-caused stressors, including increasing rates of disease. New diseases are spreading quickly, affecting many coral species and causing downstream ecological consequences. To help protect these important ecosystems, it is necessary to develop better methods to detect and intervene early in the disease process. This project aims to identify small biomolecules called metabolites that are associated with a specific type of coral disease called Stony Coral Tissue Loss Disease (SCTLD), which is spreading rapidly throughout the Caribbean. By characterizing these metabolites, researchers can better understand the metabolic changes that occur during the onset and progression of SCTLD, and potentially identify early warning signs of the disease before visible symptoms appear. Current methods for detecting changes in metabolites are inefficient and lack spatial resolution. This project seeks to provide a more thorough investigation of the chemical changes associated with SCTLD and improve our understanding of how metabolites can serve as traceable signatures of coral disease. This will allow for earlier intervention and prevention efforts to protect these essential ecosystems. The Broader Impacts for this project include support for a first-generation female PI from an underrepresented group. The PI will work with groups that have been underrepresented in STEM through local (Woods Hole, MA) and global (United States Virgin Islands) activities. Additional broader impacts include participation in: (1) efforts aimed at improving science communication, (2) public outreach activities, and (3) undergraduate mentoring. Current studies of SCTLD have relied on bulk homogenates or slurries of coral tissue using untargeted metabolomic surveys and/or microbial measurements using RNA sequencing. The primary objective of the proposed research is to leverage targeted and untargeted metabolomics, ultrahigh-resolution mass spectrometry, and recent advances in the analysis of dissolved metabolites to characterize the metabolic profiles of SCTLD across a spatial gradient. The work will allow us to quantify the chemical composition of three individual coral microhabitats (i.e., tissue, mucus, and skeleton) in addition to the surrounding seawater and correlate these dynamic profiles with disease progression. Metabolites released or taken up by the coral holobiont serve as invisible signals that can improve our understanding of disease progression, provide diagnostic biomarkers, and allow for earlier intervention and prevention efforts. Using novel metabolomics methods and chemical derivatization, this project will allow us to capture and quantify ecologically relevant, labile polar metabolites with extraction efficiencies of less than 1% using traditional dissolved phase analyses. This project will establish a link between metabolome changes and disease susceptibility by studying the intra- and inter-species variability of coral microhabitats across six different coral species ranging in SCTLD susceptibility. The identification of chemical biomarkers of SCTLD and understanding the role different coral niches play in disease progression will supply coral reef conservationists with rapid detection methods, in addition to providing researchers with new information essential for elucidating pathogens and mechanisms of disease inception. Products of this research will be of broad interest to a diverse group of scientists, including chemists, ecologists, and coral reef disease experts, in addition to the broader public, especially those in coastal regions affected by the ecological and socio-economic impacts of SCTLD or other coral diseases. 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.