东海赤潮高发区与舟山群岛沉积物中脂类物质的生物地球化学研究

发布时间：2018-12-14 18:13

【摘要】：东海是典型的大河影响下的边缘海（RiOMar），，是有机质沉降、埋藏和转化的场所，其生物地球化学过程非常复杂。脂类物质是大河影响下的边缘海系统中有效的生物标志物，不仅能重建过去种群结构和初级生产力的变化，还可以指示有机质来源与归宿等。本文以东海赤潮高发区沉积柱状样和舟山群岛表层沉积物样品为研究对象，分析了TOC、TN、C/N、δ13C以及脂类生物标志物等地球化学参数，并使用统计学方法综合阐明了调查海区有机质的来源和浮游植物种群结果的变化。主要得到以下结果：（1）柱状样和表层样δ13C的双端元模型表明，研究站位均为陆-海混合来源，且以海源输入为主。由于有机质降解和微生物活动等因素的影响，C/N没有很好的反映有机质来源，但具有变化趋势的指示意义。柱状样现代沉积物中有机质来源海洋自生源的比例增加。样品年龄超过100年，大约从1905年~2011年。各站位表层沉积物TOC、TN含量相差不大，空间分布基本呈现近岸高远岸低的特点。（2）对于柱状样中的脂类生物标志物而言，正构烷烃呈双峰型分布、高碳数占优势、明显的奇偶优势，指示了陆-海混合来源。正构烷烃的特征指数（CPI、TAR、Pmar-aq等）反映了陆源正构烷烃的输入占优势，且以草本植物为主。Pr/Ph值反映出采样站位沉积各层段环境以还原环境为主，而56~64cm层段中却显示强氧化环境。脂肪酸碳数在C11~C31之间，典型的双峰型分布显示陆-海混合来源，且以海源为主。主成分分析（PCA）结果显示脂肪酸89%的信息受2个主要因子的控制，其中海源（藻类、细菌）为主要来源。正构烷烃和脂肪酸对比发现，高碳数正构烷烃部分来源于气溶胶。直链烷基醇由陆源高等植物、海洋藻类和细菌共同控制，但以海洋藻类为主。甲藻甾醇与菜子甾醇之间的比值说明了过去一段时期内甲藻比例逐渐增加。反演ZC13站位100多年来浮游植物种群结构变化发现甲藻总体趋势不断增加，与上世纪八九十年代东海水体富营养化程度增加，导致赤潮由硅藻赤潮向硅-甲藻赤潮转变是一致的。（3）对于表层沉积物中的脂类物质而言，各站位正构烷烃均成双峰群分布，且以高碳数烷烃为主，有明显的奇碳数优势。∑C15-21和∑C25-35含量分布趋势比较相近，呈现近岸高远岸低的特点，这可能与沉积物的粒度有关，粒度越小越易吸附有机质，造成了海源和陆源都出现高值。CPI、Pmar-aq、 ACL、AI等特征指数反映了陆源输入的正构烷烃占优势，且以草本植物为主。OEP值指示研究区域没有发现石油污染。各站位脂肪酸的分布均为前峰群明显高于后峰群，反映了海洋自生源大于陆源有机质的输入。主成分分析结果表明，沉积物脂肪酸的全部信息3个主成分来反映，其累计贡献率为91.7%，且以海源自生源为主。由于细菌的降解作用，导致TOC和脂肪酸的相关性差，脂肪酸特征参数未能很好的反映陆源有机质的输入。菜子甾醇-甲藻甾醇的比例显示甲藻在研究海区为优势种，离岸越远菜子甾醇的比例越高，这可能与上升流和台湾暖流带来了丰富的营养盐有关。
[Abstract]:The East China Sea is an edge sea (Riopmar) under the influence of a typical great river, which is the site of the sedimentation, burial and transformation of organic matter, and its biogeochemical process is very complicated. The lipid material is an effective biological marker in the edge-sea system under the influence of the great river, not only can the change of the structure of the past population and the primary productivity be reconstructed, but also the source and the destination of the organic matter can be indicated. In this paper, we study the geochemical parameters such as TOC, TN, C/ N, B13C and lipid biomarkers in the sediments of the sediments of the high-hair area of the East China Sea and the samples of the surface sediments of the Zhoushan Islands. The source of organic matter and the change of the population of phytoplankton in the survey area were elucidated by using the statistical method. The following knot is mainly obtained Fruit: (1) The double-end meta-model of columnar sample and surface-like element 13C shows that the study station is the source of land-sea mixing and is lost by sea source. As a result of the influence of organic matter degradation and microbial activity, C/ N did not reflect the source of organic matter well, but it has the changing tendency. The value of the source of organic matter in the column-like modern sediment from the source of the marine origin The sample age is increased. The sample age is over 100 years, from 1905 to 20 11 years. The content of TOC and TN in the surface sediments of each station is not large, and the spatial distribution is basically in the near-shore and high-distant land. and (2) for the lipid biomarkers in the columnar sample, the normal paraffin is in a bimodal distribution, the high-carbon number is dominant, the obvious parity advantage is obvious, and the land-The characteristics of n-alkanes (CPI, TAR, Pmar-aq, etc.) reflect that the input of the n-alkanes in the land is dominant, and the characteristic index of n-alkanes (CPI, TAR, Pmar-aq, etc.) reflects the dominance of the input of the n-alkanes in the land. This plant is the main plant. The Pr/ Ph value reflects the environment of each layer section deposited in the sampling station to restore the environment, while the 56-64cm layer section shows Strong oxidizing environment. The carbon number of fatty acid is between C11 and C31, and the typical bimodal distribution shows the source of land-sea mixing. The principal component analysis (PCA) shows that 89% of the information of the fatty acid is controlled by two main factors, including the sea source (algae, fine). A comparative study of n-alkanes and fatty acids found that high carbon number n-alkanes the linear alkyl alcohol is co-controlled by land-derived higher plants, marine algae and bacteria, but in that past, the ratio of the ratio of the alcohol to the vegetable oil and the alcohol indicate that in the past a period of time, The proportion of the algae is gradually increased. The change of the phytoplankton population structure over the past 100 years of the inversion of the ZC13 station shows that the overall trend of the algae has been increasing, and the eutrophication of the water body in the East China Sea in the 1980s and the 1990s has increased, leading to the red tide being caused by the diatom red tide to the silicon-methadone. and (3) in the case of the lipid material in the surface layer sediment, the normal paraffin of each station is in a bimodal group distribution, and the high-carbon number alkane is mainly used as the main, There is a significant number of odd carbon numbers. The distribution trend of the content distribution of the CC15-21 and the C25-35 is similar, and the characteristics of the near-shore high-shore and low-shore are presented. This may be related to the grain size of the sediment. The smaller the particle size, the more the organic matter can be adsorbed, resulting in the sea. High values appear in both the source and the source. The PI, Pmar-aq, ACL, and AI feature indices reflect the predominance of n-alkanes input by the land source. and is dominated by herbs. The OEP value indicates the study area No oil pollution is found in the domain. The distribution of fatty acid in each station is obviously higher than that of the back peak group, which reflects the great ocean self-source. The results of the principal component analysis show that the total information of the sediment fatty acid is reflected by the three principal components, and the cumulative contribution rate is 91.7%. Because of the degradation of bacteria, the correlation between TOC and fatty acid is poor, and the characteristic parameters of fatty acid are not very good. The ratio of the origin of the organic matter to the source of terrestrial sources is that of the dominant species in the study area, the higher the proportion of the offshoring and the lower, which may be associated with the upflow and the warm flow of Taiwan.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P736.4

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