Fig. 4

Effect of site and sample type on present and active bacterial community structures. a Number of bacterial Orders shared between the water 16S rRNA gene amplicons, oyster gut 16S rRNA gene amplicons, and oyster gut metatranscriptomes (vertical bars). The total number of Orders found in each group is shown in the horizonal bar graph on the left. b Relative percent abundances (square root rescaled) of top 30 bacterial Orders associated with seawater samples (n = 2) or oyster gut tissue (n = 10 or 5), per site. The most abundant bacteria (16S rRNA gene amplicons, middle, n = 10) and the most transcriptionally active bacteria (metatranscriptomes, right, n = 5) in the oyster gut are shown