Marine Subsurface Microbial Community Shifts Across a Hydrothermal Gradient in Okinawa Trough Sediments

Figure 1

Relative sequence abundance, listed as % across the -axis, of 16S rRNA gene amplicons from Site C0014 sediment samples classified at the domain level: Archaea, Bacteria, Eukaryota, and not classified. IODP sample names are listed along the -axis by increasing depth (meters) below seafloor, depth in parentheses. Site C0015, 600 m northwest and upslope of the hydrothermal vent (shown separately as the topmost sample), showed no current hydrothermal activity and is being compared to represent nonhydrothermal conditions within the Iheya North Field. The remainders of the horizontal bars represent the relative abundance of sequences in that sample consistent with those found in the drilling fluid [1] and/or extraction blanks and are excluded here, as they are less likely to represent indigenous taxa. See Supplemental Table S1 for sequence information. The red shaded region corresponds to horizons composed of a hydrothermally altered clay lithology.