东海赤潮高发区表层沉积物中部分脂类标记物的分布与来源

Source and distribution of lipid markers in surface sediments from the red tide-frequent-occurrence area in the East China Sea (ECS)

通过对2005年和2006年东海赤潮高发区表层沉积物部分脂类标记物(正构烷烃、脂肪酸等)的分析,初步探讨了表层沉积物有机物的来源。沉积物中正构烷烃的碳优势指数I_(CP)值及姥鲛烷/植烷的质量比(Pr/ Ph)普遍较低,而n-C_(16),n-C_(18)的质量分数较高。分析表明,石油烃是东海赤潮高发区表层沉积物脂肪烃的主要成分。来源于细菌、海洋微藻和陆生高等植物的脂肪酸如直链饱和脂肪酸、支链饱和脂肪酸、不(多不)饱和脂肪酸等在2005～2006年间的组成和分布比较稳定:直链脂肪酸含量普遍较高,其次为支链脂肪酸和单不饱和脂肪酸,多不饱和脂肪酸含量相对较少。利用生物标记物分析表明,海洋自生生物源(细菌、海洋微藻等)是沉积物中脂肪酸的主要来源,陆源脂肪酸对东海赤潮高发区表层沉积物的贡献较小。

A characterization study of lipid markers was undertaken to identify the provenance of organic matter in surface sediments from the red tide-frequent-occurrence area in the East China Sea（ECS） from April to May of 2005 and 2006. During both sampling periods, Petroleum Hydrocarbon revealed by the carbon preference index （CPI）, ratio of Pr/Ph and relative abundance of n-C16 （%） or n-C18 （G） was a predominant component of the aliphatic hydrocarbons. Linear, branched, mono and polyunsaturated fatty acids （FAs） from multiple organic matter sources, including microalgae, bacteria and vascular plant, were detected at all sites , which displayed no statistically significant difference between 2005 and 2006. The composition and distribution of FAs suggested that microalgae and bacteria of marine are the prominent contribution and terrigenous inputs are smaller.