Flow cytometry, 16S rRNA gene amplicons, chlorophyll a, and surface seawater measurements taken between August 2017 to June 2019 Kāneʻohe Bay, Oʻahu, Hawaiʻi

These data include temperature, pH, salinity, chlorophyll a concentrations, cellular abundances of Prochlorococcus, Synechococcus, photosynthetic picoeukaryotes, and heterotrophic bacteria, and 16S ribosomal RNA gene amplicon libraries from 200 surface seawater samples collected as part of the Kāneʻohe Bay Time-series (KByT). Near-monthly sampling of surface seawater was conducted between August 2017 to June 2019 at 10 sites within coastal waters of Kāneʻohe Bay, Oʻahu, Hawaiʻi and in the adjacent offshore. Instruments used were a YSI 6,600 sonde, a Turner 10AU fluorometer, an EPICS ALTRA flow cytometer, and an Illumina MiSeq v2 platform.

These data characterize the partitioning of microbial communities across sharp physiochemical gradients in surface seawaters connecting nearshore and offshore waters in the tropical Pacific. This study provides evidence for the ecological differentiation of SAR11 marine bacteria across nearshore to offshore waters in the tropical Pacific and further increases our understanding of how SAR11 genetic diversity partitions into distinct ecological units. Data were collected by Sarah J. Tucker, Kelle C. Freel, Elizabeth A. Monaghan, Clarisse E. S. Sullivan, Oscar Ramfelt, Yoshimi M. Rii, and Michael S. Rappé.