Abstrakt
In the past 20 years, the exploration of deep ocean trenches has led to spectacular new insights. Even in the deepest canyons, an unusual variety of life and unexpectedly high benthic oxygen consumption rates have been detected while microbial processes below the surface of the hadal seafloor remains largely unknown. The information that exist comes from geophysical measurements, especially related to seismic research, and specific component analyses to estimate the carbon export. In contrast, no information is available on metabolic activities in deeper buried sediments of hadal environment. Here we present the first pore water profiles from 15 up to 11 m long sediment cores recovered during three expeditions to two hadal zones, the Japan Trench and the Atacama Trench. Despite low levels of organic debris, our data reveal that rates of microbial carbon turnover along the trench axes can be similar to those encountered in much shallower and more productive oceanic regions. The extreme sedimentation dynamics, characterized by frequent mass wasting of slope sediments into the trenches, result in effective burial of reactive, microbially available, organic material. Our results document the fueling of the deep hadal biosphere with bioavailable material and thus provide important understanding on the function of deep-sea trenches and the hadal carbon cycle.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | e2022GC010502 |
| Tidsskrift | Geochemistry, Geophysics, Geosystems |
| Vol/bind | 23 |
| Udgave nummer | 9 |
| ISSN | 1525-2027 |
| DOI | |
| Status | Udgivet - sep. 2022 |
Bibliografisk note
Funding Information:We acknowledge the captains and crews of the RV SONNE cruises SO219, SO251 and SO261 and the respective chief scientists G. Wefer (Univ. Bremen - MARUM), M. Strasser (Univ. of Innsbruck) and F. Wenzhöfer (Max Planck Inst. for Marine Microbiology, Bremen). Special thanks to S. Pape, N. Lübben, and J. Malnati (all Faculty of Geoscience, Univ. of Bremen) for their assistance in the labs. Last but not least, we thank two anonymous reviewers for their valuable comments on a first version of this paper. Financial support was provided by HADES-ERC Advanced grant “Benthic diagenesis and microbiology of hadal trenches” #669947, the Danish National Research Foundation grant DNRF145 (Danish Center for Hadal Research) and Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Initiative/Strategy through the Clusters of Excellence “The Ocean in the Earth System” (EXC 309–49926684). Open Access funding enabled and organized by Projekt DEAL.
Funding Information:
We acknowledge the captains and crews of the RV SONNE cruises SO219, SO251 and SO261 and the respective chief scientists G. Wefer (Univ. Bremen ‐ MARUM), M. Strasser (Univ. of Innsbruck) and F. Wenzhöfer (Max Planck Inst. for Marine Microbiology, Bremen). Special thanks to S. Pape, N. Lübben, and J. Malnati (all Faculty of Geoscience, Univ. of Bremen) for their assistance in the labs. Last but not least, we thank two anonymous reviewers for their valuable comments on a first version of this paper. Financial support was provided by HADES‐ERC Advanced grant “Benthic diagenesis and microbiology of hadal trenches” #669947, the Danish National Research Foundation grant DNRF145 (Danish Center for Hadal Research) and Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Initiative/Strategy through the Clusters of Excellence “The Ocean in the Earth System” (EXC 309–49926684). Open Access funding enabled and organized by Projekt DEAL.
Publisher Copyright:
© 2022. The Authors.