Seawater Targeted Locus (Loci)

Sampling

We applied culture-independent, high throughput pyrosequencing to characterize the microbial communities associated with coastal seawater adjacent to populated Broward County, FL. These waters flow over adjacent coral reefs, which help compose the Florida reef tract, and also close to recreational beaches. In partnership with the NOAA FACE program to survey water quality, 38 total nearshore seawater samples were collected and characterized for bacterial populations from 6 distinct coastal locales - the Port Everglades and Hillsboro Inlets, Hollywood and Broward wastewater outfalls, and associated reef waters over the course of one year. More than 227,000 quality checked 16S rRNA V4 amplicon sequences were generated for longitudinal taxonomic profiles of marine bacteria and archaea. From these sequences, 4447 unique OTUs were found and there was a mean OTU count of 5986.816 across all site. Sequences were found to vary significantly due to seasonal effects and by site, but depth showed no significant correlation. Abundant microbial taxa across all samples included Synechococcus, Pelagibacteraceae, Bacteroidetes, and various Proteobacteria. Inlet-based communities significantly differed from outfall and reef communities, with a relative increase in Rhodobacteraceae and Cryomorphaceae, and depletion of SAR406 sequences. Unifrac analysis confirmed significant differences in the inlet populations relative to reef and outfall microbial communities. However, based on alpha diversity measurements, the outfalls sites showed the most diversity with the occurrence of Thiotrichales, Alteromonadales, and the archaean Thermoplasmata. This study also found increased levels of Firmicutes, Chloroflexi, and sludge associated bacterial OTUs such as SBR1093 at the outfall and reef sites.

Method steps

1. Pipeline used: https://www.ebi.ac.uk/metagenomics/pipelines/4.1