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 (C_12:0~C_20:0) 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.