Figure 3.

Bacterial community composition based on 16S rRNA genes retrieved from seawater, bulk sediment, and fractions. (A) Non-metric multidimensional scaling (NMDS) plot at the ASV level showing dissimilarities between the samples. Numbers next to symbols indicate the grab number. SSW = surface seawater, OSW = overlying seawater, PW = porewater, LA = loosely attached cells, FA = firmly attached cells. (B) Shared and unique ASVs in the fractions, in raw numbers and percentages. An ASV was considered present if it was detected in 3 out of 5 replicates. (C) Most abundant families (>1% relative abundance) across all samples. The families are grouped and colored by taxonomic class. For taxa which are unclassified at the genus level, the higher taxonomic classification and rank are indicated. (D) Heatmap of ASVs with significant differential abundance (adjusted P value < 0.01) determined by DESeq2. Only the ASVs with the 10 highest and 10 lowest fold change in each comparison are shown. Columns are clustered according to sample similarity and rows are clustered according to ASV abundance values. All ASVs with significant differential abundance are enumerated in Table S8.