show Abstracthide AbstractThis projects explores the functional diversity and activity of rocky subseafloor microbial communities in hydrothermal vent systems. Samples were collected in 2014 from three low temperature diffuse fluid vents at Axial seamount, located in the northeast Pacific Ocean. We also collected a sample using a CTD within the Axial Caldera, at 1200m depth. Shotgun metagenomics and metatranscriptomics were performed on four diffuse vent samples. This study helps to determine the genetic potential and expression patterns of the largely uncharacterized subseafloor microbial community and shows how these patterns change across the complicated biogeochemical gradients of hydrothermal vent systems.