Liu Jiwen, Li Da-Wei, He Xinxin, Liu Ronghua, Cheng Haojin, Su Chenglong, Chen Mengna, Wang Yonghong, Zhao Zhongsheng, Xu Hanyue, Cheng Zhangyu, Wang Zicheng, Pedentchouk Nikolai, Lea-Smith David J, Todd Jonathan D, Liu Xiaoshou, Zhao Meixun, Zhang Xiao-Hua
Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China.
Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237 China.
Mar Life Sci Technol. 2024 Jan 23;6(1):168-181. doi: 10.1007/s42995-023-00212-y. eCollection 2024 Feb.
Hadal trenches are characterized by enhanced and infrequent high-rate episodic sedimentation events that likely introduce not only labile organic carbon and key nutrients but also new microbes that significantly alter the subseafloor microbiosphere. Currently, the role of high-rate episodic sedimentation in controlling the composition of the hadal subseafloor microbiosphere is unknown. Here, analyses of carbon isotope composition in a ~ 750 cm long sediment core from the Challenger Deep revealed noncontinuous deposition, with anomalous C ages likely caused by seismically driven mass transport and the funneling effect of trench geomorphology. Microbial community composition and diverse enzyme activities in the upper ~ 27 cm differed from those at lower depths, probably due to sudden sediment deposition and differences in redox condition and organic matter availability. At lower depths, microbial population numbers, and composition remained relatively constant, except at some discrete depths with altered enzyme activity and microbial phyla abundance, possibly due to additional sudden sedimentation events of different magnitude. Evidence is provided of a unique role for high-rate episodic sedimentation events in controlling the subsurface microbiosphere in Earth's deepest ocean floor and highlight the need to perform thorough analysis over a large depth range to characterize hadal benthic populations. Such depositional processes are likely crucial in shaping deep-water geochemical environments and thereby the deep subseafloor biosphere.
The online version contains supplementary material available at 10.1007/s42995-023-00212-y.
超深渊海沟的特征是存在增强且不频繁的高速间歇性沉积事件，这些事件可能不仅会引入不稳定的有机碳和关键营养物质，还会引入新的微生物，从而显著改变海底以下的微生物圈。目前，高速间歇性沉积在控制超深渊海底以下微生物圈组成方面的作用尚不清楚。在此，对取自挑战者深渊的一个约750厘米长的沉积物岩芯中的碳同位素组成进行分析，结果显示沉积并非连续，异常的碳年龄可能是由地震驱动的物质输运和海沟地貌的漏斗效应所致。在约27厘米以上深度的微生物群落组成和多种酶活性与较深深度的不同，这可能是由于沉积物的突然沉积以及氧化还原条件和有机质可用性的差异。在较深深度，微生物数量和组成保持相对恒定，但在一些离散深度处酶活性和微生物门类丰度有所改变，这可能是由于不同规模的额外突然沉积事件。有证据表明高速间歇性沉积事件在控制地球最深海底的地下微生物圈方面具有独特作用，并强调需要在大深度范围内进行全面分析以表征超深渊底栖生物种群。这种沉积过程可能对塑造深水地球化学环境进而对深海海底以下生物圈至关重要。
在线版本包含可在10.1007/s42995 - 023 - 00212 - y获取的补充材料。
