A unique subseafloor microbiosphere in the Mariana Trench driven by episodic sedimentation

• DOI: 10.1007/s42995-023-00212-y
• Publication Date: 2024-01-23T11:02:06Z
• Authors: Jiwen Liu; Da-Wei Li; Xinxin He; Ronghua Liu; Haojin Cheng; Chenglong Su; Mengna Chen; Yonghong Wang; Zhongsheng Zhao; Hanyue Xu; Zhangyu Cheng; Zicheng Wang; Nikolai Pedentchouk; David J. Lea-Smith; Jonathan D. Todd; Xiaoshou Liu; Meixun Zhao; Xiao-Hua Zhang
• Keywords: Sedimentation; Deposition

Abstract Hadal trenches are characterized by enhanced and infrequent high-rate episodic sedimentation events that likely introduce not only labile organic carbon key nutrients but also new microbes significantly alter the subseafloor microbiosphere. Currently, role of in controlling composition hadal microbiosphere is unknown. Here, analyses isotope a ~ 750 cm long sediment core from Challenger Deep revealed noncontinuous deposition, with anomalous 14 C ages caused seismically driven mass transport funneling effect trench geomorphology. Microbial community diverse enzyme activities upper 27 differed those at lower depths, probably due to sudden deposition differences redox condition matter availability. At microbial population numbers, remained relatively constant, except some discrete depths altered activity phyla abundance, possibly additional different magnitude. Evidence provided unique for subsurface Earth’s deepest ocean floor highlight need perform thorough analysis over large depth range characterize benthic populations. Such depositional processes crucial shaping deep-water geochemical environments thereby deep biosphere.