| 引用本文: | 郑天昊,袁华茂,宋金明,贺志鹏,段丽琴,李学刚.氨基糖对中国东部边缘海表层沉积物中有机质来源和降解的指示作用[J].海洋科学,2024,48(11):3-. |
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| 氨基糖对中国东部边缘海表层沉积物中有机质来源和降解的指示作用 |
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郑天昊1,2,3, 袁华茂1,2,3,4, 宋金明1,2,3,4, 贺志鹏5, 段丽琴1,2,3,4, 李学刚1,2,3,4
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1.中国科学院海洋研究所, 中国科学院海洋生态与环境科学重点实验室, 山东 青岛 266404;2.青岛海洋科技中心海洋生态与环境科学功能实验室, 山东 青岛 266404;3.中国科学院大学, 北京, 100049;4.中国科学院海洋大科学中心, 山东 青岛 266404;5.山东省淡水渔业研究院, 山东 济南 250013
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| 摘要: |
| 边缘海是全球有机质埋藏的热点区域,以不足10%的面积承载了全球约80%的有机碳埋藏,而表层沉积物中有机质的活性直接决定了有机质的埋藏效率。中国东部边缘海存在复杂的水动力过程和人为干扰,导致有机质埋藏的不确定性。本文研究了南黄海与长江口及其邻近海域表层沉积物中总有机碳(TOC)、总氮(TN)、稳定碳、氮同位素(δ13C、δ15N)以及氨基糖(AS)的含量和组成,评估了两个海域沉积物中有机质的来源与活性。结果显示,海源自生有机质约占研究海域沉积物总有机质的70%,且随离岸距离增加而增加。研究海域表层沉积物中葡萄糖胺与半乳糖胺之比(GlcN/GalN)小于3,表明其中的有机质经历了深度的异养改造,活性相对较低。相较于长江口及其邻近海域表层沉积物中的GlcN/GalN (1.76±0.72),南黄海表层沉积物中的GlcN/GalN更高(1.83±0.66),表明其有机质降解程度相对较低且活性较高。利用细菌特有的氨基糖生物标志物胞壁酸(MurA)估算了沉积物中有机质的细菌贡献,发现南黄海表层沉积物中有机质的细菌贡献(20.24%±7.45%)略高于长江口及其邻近海域(14.95%±5.22%),表明南黄海在中国东部边缘海细菌有机碳长期封存中可能发挥更重要的作用。相较于长江口及其邻近海域,南黄海泥质区等远端泥质区受人类活动干扰程度更小,将成为有机碳长期埋藏的热点区域。 |
| 关键词: 氨基糖 南黄海 长江口及邻近海域 有机碳来源 有机碳降解 |
| DOI：10.11759/hykx20240425001 |
| 分类号:P736.4 |
| 基金项目:崂山实验室科技创新项目(LSKJ202205002,LSKJ202204001) |
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| Amino sugars as indicators of source and degradation of sedimentary organic matter in the Eastern China Marginal Sea |
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ZHENG Tianhao1,2,3, YUAN Huamao1,2,3,4, SONG Jinming1,2,3,4, HE Zhipeng5, DUAN Liqin1,2,3,4, LI Xuegang1,2,3,4
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1.Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology Chinese Academy of Sciences, Qingdao 266404, China;2.Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266237, China;3.University of Chinese Academy of Sciences, Beijing 100049, China;4.Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China;5.Shandong Freshwater Fisheries Research Institute, Jinan 250117, China
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| Abstract: |
| Marginal seas are global hotspots for organic matter burial, accounting for approximately 80% of global organic carbon burial in less than 10% of ocean areas. The activity of organic matter in surface sediments is crucial for determining burial efficiency. In the Eastern China Marginal Sea, complex hydrodynamic processes and human disturbances create uncertainty regarding organic matter burial. This study analyzed total organic carbon (TOC), total nitrogen (TN), stable carbon and nitrogen isotopes (δ13C, δ15N), and amino sugars (AS) in surface sediments from the South Yellow Sea and the Yangtze River estuary and adjacent seas to assess the sources and activity of organic matter. The results indicated that marine-derived organic matter comprised approximately 70% of the total organic matter in the sediments, increasing with distance from the shore. The glucosamine-to-galactosamine (GlcN/GalN) ratio in the surface sediments was less than 3, indicating deep heterotrophic modification and relatively low organic matter activity. In the South Yellow Sea, the GlcN/GalN (1.83 ±0.66) was slightly higher than that in the Yangtze River estuary and adjacent areas (1.76 ±0.72), suggesting lower degradation and higher activity. The bacterial contribution to organic matter, estimated using the bacterial biomarker muramic acid (MurA), was higher in the South Yellow Sea (20.24% ±7.45%) than in the Yangtze River estuary and its neighboring seas (14.95% ±5.22%). This suggests that the South Yellow Sea may play a more significant role in the long-term sequestration of bacterial organic carbon. The organic matter in the Yangtze River Estuary is more susceptible to degradation due to human activities, whereas distal areas, such as the South Yellow Sea, are less disturbed and may serve as potential hotspots for long-term organic carbon sequestration. |
| Key words: amino sugar South Yellow Sea Yangtze River Estuary and adjacent seas organic carbon sources organic carbon degradation |
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