Compositional Differences in Dissolved Organic Matter Between Arctic Cold Seeps Versus Non-Seep Sites at the Svalbard Continental Margin and the Barents Sea
Compositional Differences in Dissolved Organic Matter Between Arctic Cold Seeps Versus Non-Seep Sites at the Svalbard Continental Margin and the Barents Sea
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斯瓦尔巴群岛大陆边缘和巴伦支海北极冷渗点与非冷渗点溶解有机质的组成差异
DOI：
10.3389/feart.2020.552731
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
Muhammed Fatih Sert;J. D’Andrilli;Friederike Gründger;H. Niemann;M. Granskog;A. Pavlov;B. Ferré;A. Silyakova
中科院分区：
文献类型：
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作者：
Muhammed Fatih Sert;J. D’Andrilli;Friederike Gründger;H. Niemann;M. Granskog;A. Pavlov;B. Ferré;A. Silyakova
分离的天然气水合物、被淹没的永久冻土和含气沉积物将甲烷从北冰洋的大量渗漏中释放到水柱中。渗流甲烷溶解并支持好氧甲烷氧化菌（MOB）的生长，但渗流和与渗流相关的生物地球化学过程对水柱溶解有机质（DOM）动力学的影响尚未得到很好的约束。2017年5月和6月，我们比较了斯瓦尔巴群岛和巴伦支海大陆边缘先前描述的渗漏和非渗漏区域的溶解甲烷、营养物质、叶绿素、颗粒物浓度和甲烷氧化（MOx）率。采用电喷雾电离傅里叶变换离子回旋共振质谱（FT-ICR MS）测定DOM的分子组成。我们发现，与非渗漏区相比，甲烷渗漏区DOM的化学多样性高出3 - 5%，并且构成了更多的蛋白质和脂质样成分。然而，营养物、叶绿素和颗粒物的分布基本上受水柱水文特征和初级生产的支配。我们推测，直接来自渗漏或间接来自与渗漏相关的生物地球化学过程的有机中间体，如MOx，改变了DOM的组成，导致冷渗漏时水柱中DOM的分子水平特征明显。
Dissociating gas hydrates, submerged permafrost, and gas bearing sediments release methane to the water column from a multitude of seeps in the Arctic Ocean. The seeping methane dissolves and supports the growth of aerobic methane oxidizing bacteria (MOB), but the effect of seepage and seep related biogeochemical processes on water column dissolved organic matter (DOM) dynamics is not well constrained. We compared dissolved methane, nutrients, chlorophyll, and particulate matter concentrations and methane oxidation (MOx) rates from previously characterized seep and non-seep areas at the continental margin of Svalbard and the Barents Sea in May and June 2017. DOM molecular composition was determined by Electrospray Ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We found that the chemical diversity of DOM was 3 to 5% higher and constituted more protein- and lipid-like composition near methane seeps when compared to non-seep areas. Distributions of nutrients, chlorophyll, and particulate matter however, were essentially governed by the water column hydrography and primary production. We surmise that the organic intermediates directly derived from seepage or indirectly from seep-related biogeochemical processes, e.g., MOx, modifies the composition of DOM leading to distinct DOM molecular-level signatures in the water column at cold seeps.