Fig. 3: Stacked bar chart showing relative abundance composition from a combination of sequencing run 1 and 2.

a Representation of the most abundant microbial eukaryotic groups classified by ‘Class’ division using PR2 V4 SSU rRNA database assignation (including all groups with relative abundance >5%) and b representation of the MAST and labyrinthulomycetes groups detected. Reads from Runs ‘1’ and ‘2’ were pooled by sediment core and normalised. All groups that appear in the colour coded key were detected in the study but some of them had a low relative quantity (<0.06%) so are not visible in the bar chart and so their colour code circle is removed. Asterisk symbol indicates OTUs affiliating with the wider taxonomic group but of uncertain Class designation. Taxon groups appended with _X (etc.) represent uncharacterised phylogenetic groups that branch with the assigned taxon in the PR2 database classification. c Schematic summary figure showing % active rRNA SSU amplicon contribution from putative phototrophic and osmotrophic–lysotrophic–saprotrophic eukaryotes. Holomycota is describes as one unit given that the initial classification of many of these amplicons was initially as fungi but later phylogenetic analysis indicates that they likely branch as fonticulida.