Sources,distribution and preservation of size-fractionated particulate organic carbon in the turbidity maximum zone of the Changjiang Estuary based on water elutriation
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摘要: 从分粒级的角度研究大河河口颗粒有机碳的输送特征是深刻理解河口淡咸水混合过程中有机碳的生物地球化学过程的关键.于2011年6月采集了长江口最大浑浊带附近盐度梯度下的表层悬浮颗粒物,采用水淘选方法对其按照水动力直径大小进行了分级分离,分析了这些颗粒物的有机碳含量、稳定碳同位素组成及颗粒物比表面积等参数,讨论了不同粒级颗粒物上有机碳的来源、分布和保存随盐度的变化特点及其影响因素.结果表明,随着盐度的增加和粒径的增大,长江口最大浑浊带附近分级颗粒有机碳逐渐降低,颗粒有机碳含量主要集中在小于32 μm的粒级.相对于长江干流,长江口颗粒有机碳含量偏低,可能归因于河口最大浑浊带附近特殊的生物地球化学作用,如细颗粒物絮凝-沉降、微生物分解等.基于蒙特卡洛模拟的三端元混合模型的计算表明长江口分级颗粒有机碳主要来源于河流和三角洲输入,海洋来源贡献较小,三者的平均贡献比例分别为40%、35%和25%.在河口盐度梯度的淡水端,不同粒级颗粒物上三角洲来源的有机碳比例均随着盐度升高而增加,而在咸水端,海源有机碳的贡献比例升高,尤其是在16~32 μm粒级,最高达39%.32~63 μm粒级的颗粒物单位比表面积有机碳含量均大于1.0 mg/m2,小于32 μm的颗粒物单位比表面积有机碳含量均在0.4~1.0 mg/m2的范围之内,符合河流颗粒物的一般特点,同时也说明细颗粒物上的有机碳可能已经发生了一定程度的分解,不过相对于长江口表层沉积物,颗粒物单位比表面积有机碳含量普遍较高,表明这些颗粒有机碳在沉降过程中或沉积之后还要经历进一步的再矿化分解,初步的估算表明,长江所输送的陆源有机碳约71%会在沉积过程中损失掉.本研究有助于深入了解大河河口不同粒级颗粒物在有机碳迁移转化过程中的作用,深化对高浊度河口有机碳生物地球化学过程的认识.Abstract: Knowledge of the transport of particulate organic carbon in large-river estuaries from the perspective of size-fractionation is key to better understand the biogeochemical processes of organic carbon during the mixing of freshwater and seawater. Suspended particulate matters (SPM) in surface water were collected along a salinity gradient in the turbidity maximum zone of the Changjiang Estuary in June 2011,and then were separated into different size fractions using the water elutriation method. Organic carbon (OC) and nitrogen,stable carbon isotopic composition and specific surface area (SSA) of these size-fractionated particles were analyzed to discuss the variation of sources,distribution and preservation of OC with the increasing salinity and their impact factors. The results showed that with the increase of salinity and particle size,the size-fractionated particulate OC (POC) gradually reduced and mainly concentrated in less than 32 μm fractions. The POC in the estuary was lower than those in the main stream,perhaps due to the special biogeochemical processes around the maximum turbidity zone,such as flocculating and settling of fine particles,microbial decomposition,etc. The results of the three end-member mixing model based on Monte-Carlo simulation indicated that the POC was mainly from riverine and deltaic sources,whereas the contribution from marine end-member was relatively small,and the average fractions of these three end-members were 40%,35% and 25%,respectively. In the freshwater end,deltaic OC of the size fractions increased with the increase of salinity,but in the seawater end,the contribution of marine OC increased,especially in the 16-32 μm fractions,with the maximum value of 39%. The SSA normalized OC contents of the 32—63μm fractions were all larger than 1.0 mg/m2,while the OC/SSA ratios of less than 32 μm fractions were in the range of 0.4 to 1.0 mg/m2,consistent with the typical characteristics of river suspended particulates. Furthermore,the OC/SSA ratios also indicated that OC in fine particulates could have been decomposed in a certain degree. However,these ratios were generally higher than those of the surface sediments in the Changjiang Estuary,which indicated that particulate OC may go through further remineralization during or after sedimentation. Preliminary estimate showed that 71% of the terrigenous OC delivered by the Changjiang was lost during sedimentation. This study helps to deeply understand the role of particulate matters with different sizes in the transport and transformation of OC in large-river estuaries,and deepen the knowledge of biogeochemical processes of OC in high turbidity estuary.
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Dagg M,Benner R,Lohrenz S,et al. Transformation of dissolved and particulate materials on continental shelves influenced by large rivers: plume processes[J]. Continental Shelf Research,2004,24(7): 833-858. Bianchi T S,Allison M A. Large-river delta-front estuaries as natural "recorders" of global environmental change[J]. Proceedings of the National Academy of Sciences,2009,106(20): 8085-8092. Meybeck M. Riverine transport of atmospheric carbon: sources,global typology and budget[J]. Water,Air,and Soil Pollution,1993,70(1/4): 443-463. Ludwig W,Probst J L,Kempe S. Predicting the oceanic input of organic carbon by continental erosion[J]. Global Biogeochemical Cycles,1996,10(1): 23-41. Walling D E,Woodward J C. Use of a field-based water elutriation system for monitoring the in situ particle size characteristics of fluvial suspended sediment[J]. Water Research,1993,27(9): 1413-1421. Harvey H R,Mannino A. The chemical composition and cycling of particulate and macromolecular dissolved organic matter in temperate estuaries as revealed by molecular organic tracers[J]. Organic Geochemistry,2001,32(4): 527-542. Meyers P A. Preservation of elemental and isotopic source identification of sedimentary organic matter[J]. Chemical Geology,1994,114(3/4): 289-302. Hedges J I,Keil R G. Sedimentary organic matter preservation: an assessment and speculative synthesis[J]. Marine Chemistry,1995,49(2): 81-115. Bergamaschi B A,Tsamakis E,Keil R G,et al. The effect of grain size and surface area on organic matter,lignin and carbohydrate concentration,and molecular compositions in Peru margin sediments[J]. Geochimica Cosmochimica Acta,1997,61(6): 1247-1260. Keil R G,Mayer L M,Quay P D,et al. Loss of organic matter from riverine particles in deltas[J]. Geochimica Cosmaochimica Acta,1997,61(7): 1507-1511. 何会军,于志刚,陈洪涛,等. 水淘选颗粒物分级的研究与应用[J]. 中国海洋大学学报,2010,40(2): 68-72. He Huijun,Yu Zhigang,Chen Hongtao,et al. The water elutriator method for particle size separation and its application[J]. Periodical of Ocean University of China,2010,40(2): 68-72. 张龙军,刘立芳,张向上. 应用多元线性回归法测定黄河口不同粒径悬浮物中的有机碳含量[J]. 分析化学,2008,36(5): 567-571. Zhang Longjun,Liu Lifang,Zhang Xiangshang. Application of multiple linear regression in studying particulate organic carbon content in size-fractioned total suspended solids in Huanghe Esuary[J]. Chinese Journal of Analytical Chemistry,2008,36(5): 567-571. Zhang L J,Zhang J,Gong M N. Size distributions of hydrocarbons in suspended particles from the Yellow River[J]. Applied Geochemistry,2009,24: 1168-1174. Zhang L J,Wang L,Cai W J,et al. Impact of human activities on organic carbon transport in the Yellow River[J]. Biogeosciences,2013,10: 2513-2524. He H J,Chen H T,Yao Q Z,et al. Behavior of Different Phosphorus Species in Suspended Particulate Matter in the Changjiang Estuary[J]. Chinese Journal of Oceanology and Limnology,2009: 859-868. He H J,Yu Z G,Yao Q Z,et al. The hydrological regime and particulate size control phosphorus form in the suspended solid fraction in the dammed Huanghe (Yellow River) [J]. Hydrobiologia,2010,638: 203-211. Milliman J D,Farnsworth K L. River discharge to the coastal ocean: a global synthesis[M]. New York: Cambridge University Press,2011. Zhou J L,Wu Y,Zhang J,et al. Carbon and nitrogen composition and stable isotope as potential indicators of source and fate of organic matter in the salt marsh of the Changjiang Estuary,China[J]. Chemosphere,2006,65: 310-317. Zhang J,Wu Y,Jennerjahn T C,et al. Distribution of organic matter in the Changjiang (Yangtze River) Estuary and their stable carbon and nitrogen isotopic ratios: implications for source discrimination and sedimentary dynamics[J]. Marine Chemistry,2007,106(1/2): 111-126. Wang X,Ma H,Li R,et al. Seasonal fluxes and source variation of organic carbon transported by two major Chinese Rivers: The Yellow River and Changjiang (Yangtze) River[J]. Global Biogeochemical Cycles,2012,26,doi: 10.1029/2011GB004130. Gao L,Li D J,Zhang Y W. Nutrients and particulate organic matter discharged by the Changjiang (Yangtze River): Seasonal variations and temporal trends[J]. Journal of Geophysical Research: Biogeosciences,2012,117,G4001. Hu J F,Peng P A,Jia G D,et al. Distribution and sources of organic carbon,nitrogen and their isotopes in sediments of the subtropical Pearl River estuary and adjacent shelf,Southern China[J]. Marine Chemistry,2006,98: 274-285. Waterson E J,Canuel E A. Sources of sedimentary organic matter in the Mississippi River and adjacent Gulf of Mexico as revealed by lipid biomarker[J]. Organic Geochemistry,2008,39(4): 422-439. Andersson A. A systematic examination of a random sampling strategy for source apportionment calculations[J]. Science of the Total Environment,2011,412: 232-238. Vonk J E,Sanchez-Garcia L,Semiletov I P,et al. Molecular and radiocarbon constraints on sources and degradation of terrestrial organic carbon along the Kolyma paleoriver transect,East Siberian Sea[J]. Biogeosciences Discussions,2010,7(4): 3153-3166. Karlsson E S,Charkin A,Dudarev O,et al. Carbon isotopes and lipid biomarker investigation of sources,transport and degradation of terrestrial organic matter in the Buor-Khaya Bay,SE Laptev Sea[J]. Biogeosciences,2011,8(2): 1865-1879. Li X X,Bianchi T S,Allison M A,et al. Composition,abundance and age of total organic carbon in surface sediments from the inner shelf of the East China Sea[J]. Marine chemistry,2012,145: 37-52. 沈焕庭,贺松林,潘定安,等. 长江河口最大浑浊带研究[J]. 地理学报,1992,47(5): 472-479. Shen Huanting,He Songlin,Pan Ding'an,et al. A study of turbidity maximum in the Changjiang Estuary[J]. Acta Geographica Sinice,1992,47(5): 472-479. Wakeham S G,Canuel E A,Lerberg E J,et al. Partitioning of organic matter in continental margin sediments among density fractions[J]. Marine Chemistry,2009,115(3): 211-225. 林晶,吴莹,张经,等. 最大浑浊带对长江口有机碳分布的影响初探[J]. 海峡科学,2009,30(6): 150-159. Lin Jing,Wu Ying,Zhang Jing,et al. The influence of maximum turbidity zone of Yangtze estuary in organic carbon distribution[J]. Straits Science,2009,30(6): 150-159. 张龙军,徐雪梅,何会军. 黄河不同粒径悬浮颗粒物中POC含量及输运特征研究[J]. 环境科学,2009,30(2): 342-347. Zhang Longjun,Xu Xuemei,He Huijun. POC content in size-fractioned TSS and transportation character in the Yellow River[J]. Environmental Science,2009,30(2): 342-347. Wang L,Fan D,Li W,et al. Grain-size effect of biogenic silica in the surface sediments of the East China Sea[J]. Continental Shelf Research,2014,81(4):29-37. 林以安,唐仁友,李炎,等. 长江口生源要素的生物地球化学特征与絮凝沉降的关系[J]. 海洋学报,1995,17(5): 65-72. Lin Yi'an,Tang Renyou,Li Yan,et al. The relationship of biogeochemical characteristics of elements and flocculating sedimentation in Yangtze Estuary[J]. Haiyang Xuebao,1995,17(5): 65-72. 李道季. 长江河口悬浮体的有机特性及其动力沉积生物地球化学行为. 上海: 华东师范大学,1998. Li Daoji. Organic characteristics and dynamic sedimentation of suspended matter and its biogeochemical behavior in the Changjiang Estuary. Shang Hai: East China Normal University,1988. 李道季,张经,张利华,等. 长江口悬浮颗粒表面特性的初步研究[J]. 泥沙研究,2001(5): 37-41. Li Daoji,Zhang Jing,Zhang Lihua,et al. Primary study on surface properties of suspended particles in the Changjiang Estuary[J]. Journal of Sediment Research,2001(5): 37-41. Gram L,Grossart H P,Schlingloff A,et al. Possible quorum sensing in marine snow bacteria: production of acylated homoserine lactones by Roseobacter strains isolated from marine snow[J]. Applied and Environmental Microbiology,2002,68(8): 4111-4116. Grossart H P,Tang K W,KiØrboe T,et al. Comparison of cell-specific activity between free-living and attached bacteria using isolates and natural assemblages[J]. FEMS microbiology letters,2007,266(2): 194-200. Bianchi T S. The role of terrestrially derived organic carbon in the coastal ocean: A changing paradigm and the priming effect[J]. Proceedings of the National Academy of Sciences,2011,108(49): 19473-19481. Hmelo L R,Mincer T J,Van Mooy B A S. Possible influence of bacterial quorum sensing on the hydrolysis of sinking particulate organic carbon in marine environments[J]. Environmental Microbiology Reports,2011,3(6): 682-688. Hedges J I,Clark W A,Quay P D,et al. Compositions and fluxes of particulate organic material in the Amazon River[J]. Limnology and Oceanography,1986,31(4): 717-738. Prahl F G,Ertel J R,Goni M A,et al. Terrestrial organic carbon contributions to sediments on the Washington margin[J]. Geochimica et Cosmochimica Acta,1994,58(14): 3035-3048. Jaffé R,Mead R,Hernandez M E,et al. Origin and transport of sedimentary organic matter in two subtropical estuaries: a comparative,biomarker-based study[J]. Organic Geochemistry,2001,32(4): 507-526. Sikes E L,Uhle M E,Nodder S D,et al. Sources of organic matter in a coastal marine environment: Evidence from n-alkanes and their δ13C distributions in the Hauraki Gulf,New Zealand[J]. Marine Chemistry,2009,113(3): 149-163. Fry B,Sherr E B. δ13C measurements as indicators of carbon flow in marine and freshwater ecosystems[J]. Contributions in Marine Science,1984,27: 13-47. Redfield A C,Ketchum B H,Richards F A. The influence of organisms on the composition of seawater[M]// Hill M N. The Sea. New York: Interscience,1963: 26-87. O'Leary M H. Carbon isotopes in photosynthesis[J]. Bioscience,1988,38: 328-336. Meyers P A. Organic geochemical proxies of paleoceanographic,paleolimnologic,and paleoclimatic processes[J]. Organic Geochemistry,1997,27(5/6): 213-250. Schmidt F,Hinrichs K U,Elvert M. Sources,transport,and partitioning of organic matter at a highly dynamic continental margin[J]. Marine Chemistry,2010,118(1/2): 37-55. Pancost R D,Boot C S. The palaeoclimatic utility of terrestrial biomarkers in marine sediments[J]. Marine Chemistry,2004,92(1): 239-261. Cloern J E. Turbidity as a control on phytoplankton biomass and productivity in estuaries[J]. Continental Shelf Research,1987,7: 1367-1381. Andrea E A,Cloern J E. Trophic interaction and direct physical effects control phytoplankton biomass and production in an estuary[J]. Limnology and Oceanography,1992,37: 946-955. 姚鹏,郭志刚,于志刚. 大河影响下的陆架边缘海沉积有机碳的再矿化作用[J]. 海洋学报,2014 ,36(2): 23-32. Yao Peng,Guo Zhigang,Yu Zhigang. Remineralization of sedimentary organic carbon in river dominated ocean margins[J].Haiyang Xuebao,2014,36(2): 23-32. Blair N E,Aller R C. The fate of terrestrial organic carbon in the marine environment[J]. Annual Review of Marine Science,2012,4: 401-423.
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