Within hydrothermal plumes, chemosynthetic processes and microbe-mineral interactions drive primary productivity in deep-ocean food webs and may influence transport of elements such as iron. However, the source of microorganisms in plumes and the factors governing how these communities assemble are poorly understood, in part due to lack of data from early stages of plume formation. In this study, we examined microbial community composition of rising hydrothermal plumes from five vent fields along the Eastern Lau Spreading Center. Seafloor and plume microbial communities were significantly dissimilar and shared few phylotypes. Plume communities were highly similar to each other with significant differences in community membership only between Kilo Moana and Mariner, two vents that are separated by extremes in depth, latitude and geochemistry. Systematic sampling of waters surrounding the vents revealed that species richness and phylogenetic diversity was typically highest near the vent orifice, implying mixing of microbial communities from the surrounding habitats. Above-plume background communities were primarily dominated by SAR11, SAR324 and MG-I Archaea, while SUP05, Sulfurovum, Sulfurimonas, SAR324 and Alteromonas were abundant in plume and near-bottom background communities. These results show that the ubiquitous water-column microorganisms populate plume communities, and that the composition of background seawater exerts primary influence on plume community composition, with secondary influence from geochemical and/or physical properties of vents. Many of these pervasive deep-ocean organisms are capable of lithotrophy, suggesting that they are poised to use inorganic electron donors encountered in hydrothermal plumes.
|Original language||English (US)|
|Number of pages||12|
|State||Published - Jun 23 2015|
Bibliographical noteFunding Information:
We thank the Capitan and crew of the R/V Thomas G Thompson as well as the crew of the remotely operated vehicle Jason II. We also thank Drs AL Reysenbach, M Tivey, C Fisher, P Girguis, G Luther and the Eastern Lau Spreading Center 2009 scientific parties for allowing us to participate in their cruises (National Science Foundation Grants: OCE-0424953, OCE-02040985, OCE-0728391, OCE-0752469 and OCE-0751839). We are grateful to Dr AL Reysenbach for providing access to seafloor sequences and Dr Sheri White for assistance with sampling. This work was funded by National Science Foundation Grants (OCE-1038006, OCE-1029242 and OCE-1038055) and the Gordon and Betty Moore Foundation (GBMF 2609). JAB was supported by Grant OCE-1038055, and the Frank and Lisina Hock Endowed fund was provided in support of the Scientific Staff. We gratefully acknowledge the constructive comments of two anonymous reviewers, which greatly improved the manuscript.
© 2015 International Society for Microbial Ecology. All rights reserved.