Mariana Trench Targeted Locus (Loci)

The Mariana Trench lies at the boundary between the eastern edge of the Philippine Sea plate and the subducting Pacific plate. This system is a nonaccretionary convergent plate margin, in which the basement of the overriding plate is in direct contact with the subducting plate at the trench axis and no material is accreted from the subducting plate. The southern part of the trench from south of Guam to the intersection with the Caroline Ridge is deeper than the rest of the trench axis farther north and includes both the Challenger Deep and the Sirena Deep. We propose to utilize the sequence data and the VAMPS tool collections to look for trends in richness, microbial distribution, and PCA comparisons of community structure across fractions and locations (ours and those of others). Our previous studies of microbial life at depth in the Puerto Rico Trench indicated the presence of particles enriched with members of the Rhodobacterales, unclassified Myxococcales, Bacteroidetes, Planctomycetes and free-living communities containing more Caulobacterales, Xanthomonadales and Burkholderiales, Marine Group A and Gemmatimonadetes. The Sirena Deep water samples were recovered in an environment with exposed peridotite country rock overlain with microbial mats. Dr. Kevin Hand from the JPL is characterizing the mineralogy of the Sirena Deep sediments collected in detail. We expect to see a greater reliance on chemoautotrophic microbes in this setting.