Sampling locations were accessed via day-trips aboard a University of the Virgin Islands powerboat in the U.S. Virgin Islands in April 2022. At each sampling location, reef seawater was collected to characterize water quality metrics, including microbial community composition, inorganic nutrient concentrations, total organic carbon (TOC), total nitrogen (TN), and microbial cell abundances.
Water samples were collected by SCUBA divers approximately 2 meters above the reef. Temperature, salinity, dissolved oxygen, pH, and turbidity were measured from the boat using an EXO2 multiparameter sonde. Sample processing and analytical procedures will follow previously published methods (Becker et al., 2020; Weber et al., 2020). Each site was sampled in replicate on two separate days.