东海近岸表层沉积物中脂肪酸与脂肪醇的组成以及分布与来源

选取了19个东海近岸表层沉积物样品,通过GC-MS分析获得脂肪酸和脂肪醇的特征信息,并结合统计学方法,探讨了调查海区的有机碳来源。结果表明,东海近岸沉积物中脂肪酸的含量为11.58~31.58 μg/g,由正构饱和脂肪酸(SFAs)、一元不饱和脂肪酸(MUFAs)、多元不饱和脂肪酸(PUFAs)及支链脂肪酸(BrFAs)组成。高含量的C12:0-C20:0短链脂肪酸和较丰富的异构脂肪酸以及其他细菌标志脂肪酸的出现表明,海洋微藻-细菌源是脂肪酸的主要贡献者,而陆源脂肪酸的贡献仅占次要位置。脂肪酸的主成分分析结果表明,东海沉积物脂肪酸的全部信息可由海洋微藻-细菌源(PC1)和陆源(PC2)来反映。PC1的贡献率为75.4%,PC2的贡献率为11.9%。表层沉积物中烷基醇主要来源于陆地高等植物,各断面显示离岸越远陆源输入的烷基醇越少。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丰富的营养盐有关。

COMPOSITION,DISTRIBUTION AND SOURCE OF FATTY ACIDS AND FATTY ALCOHOLS IN MARINE SURFACE SEDIMENTS OF THE EAST CHINA SEA

The compositions of fatty acids and fatty alcohols in the surface sediment at 19 sites of the East China Sea (ESC) were examined with GC-MS. Statistical method is applied to seek for the source of organic matters. The results show that the fatty acids, which range from 11.58 to 31.58 μg/g, consist of normal saturated fatty acids (SFAs), mono-unsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs) and branch fatty acids (BrFAs). The high contents of short chain fatty acids (C12:0~C20:0) and bacteria biomarker acids indicate that plankton and bacteria might be the major source of the fatty acids in the East China Sea surface sediments while fatty acids from terrestrial are rare. Fatty acids of principal component analysis (PCA) results show that the fatty acids information in the East China Sea can be reflected by plankton-bacterial (PC1) and terrestrial (PC2). The contribution ratios of PC1 and PC2 are 75.4% and 11.9%, respectively. Alkyl alcohols in the surface sediments are mainly from terrestrial higher plant, and decrease offshore from the Changjiang River mouth. The proportion of brassicasterol and dinoflagellatesterol displays that dinoflagellates in research area dominate, and the brassicasterol content increases away from the coast, owing to the rich nutrient from the Taiwan warm current and upwelling current.