Presence of oxygen and aerobic communities from sea floor to basement in deep-sea sediments
Presence of oxygen and aerobic communities from sea floor to basement in deep-sea sediments
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DOI：
10.1038/ngeo2387
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发表时间：
2015-04-01
影响因子：
18.3
通讯作者：
Ziebis, Wiebke
中科院分区：
文献类型：
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作者：
D'Hondt, Steven;Inagaki, Fumio;Ziebis, Wiebke
氧气渗透到海洋沉积物中的深度因地区而异1，2。在微生物呼吸率高的地区，O-2只能渗透到沉积物中几毫米到几厘米（3），但活跃的厌氧微生物群落存在于海底以下几百米或更深的沉积物中（4-7）。在沉积物呼吸作用较低的地区，O-2渗透更深（8-12），但微生物群落持续存在的深度以前是未知的（9，10，13）。南太平洋环流下的沉积物显示出极低的呼吸面积率（9）。在这里，我们表明，在这一地区，微生物细胞和有氧呼吸持续通过整个沉积序列的深度至少75米以下的海底。基于Redfield化学计量溶解O-2和硝酸盐，我们建议，在这些沉积物中的净好氧呼吸耦合到海洋有机质的氧化。我们确定了O-2渗透深度与沉积速率和沉积物厚度的关系。外推这种关系，我们认为，氧气和有氧社区可能发生在整个沉积物序列中的15-44%的太平洋和9-37%的全球海底。来自这些地区的沉积物和玄武岩的俯冲是地幔氧化物质的来源。
The depth of oxygen penetration into marine sediments differs considerably from one region to another1,2. In areas with high rates of microbial respiration, O-2 penetrates only millimetres to centimetres into the sediments(3), but active anaerobic microbial communities are present in sediments hundreds of metres or more below the sea floor(4-7). In areas with low sedimentary respiration, O-2 penetratesmuchdeeper(8-12) but the depth to which microbial communities persist was previously unknown(9,10,13). The sediments underlying the South Pacific Gyre exhibit extremely low areal rates of respiration(9). Here we show that, in this region, microbial cells and aerobic respiration persist through the entire sediment sequence to depths of at least 75 metres below sea floor. Based on the Redfield stoichiometry of dissolved O-2 and nitrate, we suggest that net aerobic respiration in these sediments is coupled to oxidation of marine organic matter. We identify a relationship of O-2 penetration depth to sedimentation rate and sediment thickness. Extrapolating this relationship, we suggest that oxygen and aerobic communities may occur throughout the entire sediment sequence in 15-44% of the Pacific and 9-37% of the global sea floor. Subduction of the sediment and basalt from these regions is a source of oxidized material to the mantle.