“…Microbial diversity surveys on the Juan de Fuca Ridge have focused at diffuse flow hydrothermal vents at Axial Seamount (e.g., Lynch, 2000; Alain et al, 2002;Pagé et al, 2004;Huber et al, 2006aHuber et al, , 2009Kaye et al, 2011;Meyer et al, 2013), high-temperature hydrothermal vents at Endeavor Segment (e.g., Wang et al, 2009aWang et al, , 2009bZhou et al, 2009;Anderson et al, 2013), a hydrothermal mound located at off-axis Cleft Segment (Davis et al, 2009), seafloor basalt (Mason et al, 2007(Mason et al, , 2009), sediment-buried basement fluid (Cowen et al, 2003;Huber et al, 2006b;Nakagawa et al, 2006;Jungbluth et al, 2013), and sediment-buried rock (Orcutt et al, 2011b;Smith et al, 2011;Lever et al, 2013). The limited number of microbiological studies focused on sediment of the Juan de Fuca Ridge have typically not incorporated phylogenetic marker-based surveys of community diversity such as small subunit ribosomal RNA (SSU rRNA) gene sequencing (e.g., Cragg et al, 2000;Mather and Parkes, 2000;Engelen et al, 2008); only studies focused on Cascadia margin methane hydrate-bearing sediment have incorporated such an approach (e.g., Bidle et al, 1999;Marchesi et al, 2001;Knittel et al, 2003;Inagaki et al, 2006;Nunoura et al, 2008;Briggs et al, 2012).…”