Tidal and diurnal succession of microbial communities at three tropical biomes: mangroves, seagrasses, and coral reefs

To investigate the influence of tide on microbial community composition in these three important coastal biomes, we sampled for microbial (bacteria and archaea) community composition and environmental condition (temperature, salinity, and inorganic nutrients) at nine sites on the southern shore of St. John, U.S. Virgin Islands over 48 hours. Despite the close proximity (within 4 km) of all biomes, the mangrove sites exhibited tidally-influenced shifts in environmental parameters and microbial community structure, while seagrass and reef sites exhibited relatively consistent environmental conditions and community structure, but were dominated by diurnal shifts in picocyanobacteria.