Abstract Summary
Reef habitat microbiomes play a vital role in coral reef ecosystem health and function. Characteristics of the physical habitat of a reef may help drive the evolution of the host organism, its algal symbionts, and associated microbiomes. In southern Florida in particular, reef marine microbiome communities may be influenced by fine-scale patchiness in sea temperature and available light, connectivity patterns in ocean circulation, microbial contaminants from wastewater, coastal inlet discharges, terrestrial runoff, and coastal tidal or storm flooding. We sequenced samples from coral tissue, water, and sediments at both near- and offshore reefs of the Florida reef tract. Sites included both near-urban southeast Florida shelf and more isolated reefs of the Florida Keys. We report on associations between the community structure and biodiversity of these microbiomes, and the observable characteristics of their environment, notably sea temperature variability and seafloor topography, tides, ocean currents, waves, and relative turbidity. The microbiomes were characterized by 16S rDNA amplicon Next-Generation-Sequencing (NGS) of total microbial metagenomic DNA extracts. We investigated connectivity using combined outputs of a quasi-operational ocean-circulation model with data on waves and surface winds. We estimated sea temperature variability from long-term in situ measurements and a reef ocean heat budget based on depth, slope, light, and waves. Relative turbidity change over time was estimated from a multiyear record of high-spatial-resolution satellite ocean-color.
