Fig. 5: Ecological mechanisms shaping biogeographic patterns and environmental variables affecting the structure of epipelagic microbial communities as captured by different β-diversity metrics between the subantarctic and subarctic Pacific.

A Relative contribution of homogeneous and heterogeneous selection, homogenizing dispersal and dispersal limitation and stochastic drift on community assembly of the 0.2–3 µm, 3–8 µm and >8 µm prokaryotic and 18S eukaryotic communities in the epipelagic (20, 40, 60, 100 m) and mesopelagic (200, 300 or 500 m). 300 m was sampled from 52°S to 10°N and 500 m from 15° to 59°N. B Community variance individually explained by single environmental variables for different dissimilarity indices (Bray–Curtis, UniFrac, TINA and PINA) for 0.2–3 µm, 3–8 µm and >8 µm prokaryotic communities in epipelagic depths. Explained variance was inferred from PERMANOVA and only significant results with Benjamini-Hochberg adjusted p values < 0.05 are displayed.