Key role of bacteria in the short‐term cycling of carbon at the abyssal seafloor in a low particulate organic carbon flux region of the eastern Pacific Ocean
Key role of bacteria in the short‐term cycling of carbon at the abyssal seafloor in a low particulate organic carbon flux region of the eastern Pacific Ocean
复制标题
东太平洋低颗粒有机碳通量区域深海海底碳短期循环中细菌的关键作用
DOI：
10.1002/lno.11069
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发表时间：
2018
影响因子：
4.5
通讯作者：
A. Gooday
中科院分区：
文献类型：
--
作者：
A. Sweetman;C. Smith;C. Shulse;Brianne M. Maillot;Markus V. Lindh;M. Church;K. Meyer;D. Oevelen;Tanja Stratmann;A. Gooday
底栖生物对碳(C)的循环是深海生态系统的一项重要功能。脉冲追逐实验旨在对这一过程进行量化，但使用深海(3500-6000 m)沉积物进行的研究很少，现场进行的研究也很少。我们在东部克拉里昂-克利珀顿断裂带相距数十至数百公里的三个深海地层(水深4050-4200 m)上进行了8次现场脉冲追逐实验。这些实验表明，在较短的时间尺度(~ 1.5d)内，底栖细菌对植物碎屑的消耗占主导地位，后生大型动物的作用较小。这些结果与其他唯一可比的原位深海研究形成对比，在富营养化的东北大西洋，大型动物在短时间尺度(2.5d)内对植物碎屑的同化占主导地位。我们还证明了底栖细菌能够将溶解的无机C转化为生物量，并表明这一过程可以以与藻类有机C的细菌同化一样高的速度发生。这表明了无机C吸收对该地区深海生态系统的潜在重要性。它还暗示了这样一种可能性，即在我们的藻类加成研究中，细菌对C的某些掺入可能是由于最初由其他未研究的生物呼吸的标记溶解无机碳的掺入。我们的发现揭示了底栖细菌在CCFZ东部深海生境中C的短期循环中的关键重要性，并提供了关于商业规模深海采矿活动区域海底生态系统功能的重要信息。
The cycling of carbon (C) by benthic organisms is a key ecosystem function in the deep sea. Pulse‐chase experiments are designed to quantify this process, yet few studies have been carried out using abyssal (3500–6000 m) sediments and only a handful of studies have been undertaken in situ. We undertook eight in situ pulse‐chase experiments in three abyssal strata (4050–4200 m water depth) separated by tens to hundreds of kilometers in the eastern Clarion‐Clipperton Fracture Zone (CCFZ). These experiments demonstrated that benthic bacteria dominated the consumption of phytodetritus over short (~ 1.5 d) time scales, with metazoan macrofauna playing a minor role. These results contrast with the only other comparable in situ abyssal study, where macrofauna dominated phytodetritus assimilation over short (2.5 d) time scales in the eutrophic NE Atlantic. We also demonstrated that benthic bacteria were capable of converting dissolved inorganic C into biomass and showed that this process can occur at rates that are as high as the bacterial assimilation of algal‐derived organic C. This demonstrates the potential importance of inorganic C uptake to abyssal ecosystems in this region. It also alludes to the possibility that some of the C incorporation by bacteria in our algal‐addition studies may have resulted from the incorporation of labeled dissolved inorganic carbon initially respired by other unstudied organisms. Our findings reveal the key importance of benthic bacteria in the short‐term cycling of C in abyssal habitats in the eastern CCFZ and provide important information on benthic ecosystem functioning in an area targeted for commercial‐scale, deep‐sea mining activities.