This project takes important first steps towards applying environmental metabolomics to the field of marine microbial ecology. It will provide important baseline information describing sediment community composition across environmental gradients and insight into the chemical landscape within which bacteria reside. Lab experiments will be used to determine the effects of sediment metabolomes on community structure and the growth of known coral pathogens. We will then use metagenomics and metatranscriptomics to assess BGC diversity and expression in marine sediments and establish links between gene clusters, the organisms in which they reside, and the metabolites whose production they encode. These results will be analyzed along with metadata associated with the Moorea LTER and linked to data obtained from ongoing studies to establish correlations between reef health and sediment bacterial community and metabolite composition. The fundamental objectives are to establish the role of natural products in structuring sediment microbial communities and to assess the potential role of these communities and the metabolites they produce in the maintenance of coral reef health.