Fig. 2

Diversity as assessed by 16S rRNA gene amplicon data. A Shannon index of the sampled bacterial communities over time. Colors correspond to sample fractions (FL, 0.2–3 µm; PA3, 3–10 µm; PA10, > 10 µm). B Shannon index of the FL fraction over time. C Non-metric multidimensional scaling (NMDS) analysis of the bacterial community of all three fractions. Colors correspond to sample fractions and shapes to bloom phases