Fig. 4: Microbial picoplankton communities associated to rhodopsin dynamics in surface water at SPOT.

A Relative abundance of prokaryotic picoplankton (0.2–3.0 µm size-fraction) at 5 m and Deep Chlorophyll Maximum (DCM) depths based on 16S rDNA gene. Rhodopsin and cell concentrations are shown for reference. DCM depths are noted with grey italic letters under the sampling month. Relevant known rhodopsin-containing bacteria (Flavobacteriales and SAR11 clade) and their estimated total abundances are noted in boldface. Taxa abbreviations: Other CFB (Other Bacteroidota), Other Proteob. (Other Proteobacteria), Other bact. (other bacteria). Asterisks under the columns denote the samples subsequently used for metagenome analyses. B Linear model of surface rhodopsin concentrations in picoplankton (0.2–3.0 µm) against the estimated Flavobacteriales concentrations n = 12, with 95% confidence intervals (grey shading). Green filling on the datapoints indicates total chlorophyll-a concentrations as a visual measure of the water’s productivity. The datapoints chosen for metagenomic analysis (with asterisks) and two additional ones outside the confidence range are labeled with date and depth. Source data are provided as a Source Data file.