Fig. 2

Viral communities and macrodiversity among CB, SB, and SW. A–C Comparison of microbial communities between CB17 and CB18, two cryopeg brine samples from successive years (2017 and 2018). A Venn and pie plots illustrate all the shared and unique vOTUs and their accounted relative abundances in the two samples. B Venn plot illustrates the shared and unique vOTUs based on the top 100 abundant vOTUs in the two samples. C Relative abundances of the top 100 abundant vOTUs in the two samples. D–E Comparison of viral communities in sea ice brine (SB) and seawater (SW). D Venn and pie plots illustrate all the shared and unique vOTUs and their accounted relative abundances in the two samples SB and SW. E Rank abundance curve shows the relative abundances of SB and SW vOTUs. The vOTUs were ordered according to their relative abundances in SW, with the addition of the exclusive vOTUs in SB based on their relative abundances. The shared and unique vOTUs are indicated by colors. F Viral macrodiversity (by vOTU-level Shannon diversity; the error bar indicates a standard error of the mean for the Shannon diversity of the two CB samples, i.e., CB17 and CB18) and G the number of shared and unique vOTUs among CB, SB, and SW ecosystems