Spatial Distributions and Potential Sources of Long Chain (C30, C32 1,15-) Alkyl Diols in Surface Sediments from Eastern China Marginal Seas

Abstract

Long chain alkyl diols have shown important potential for the reconstruction of sea surface temperature, productivities and upwelling conditions in marine or lacustrine environments. However, little is known about the distribution and sources of the diols in eastern China marginal seas (CMS), which are areas of important organic carbon sink. Here the contents of C30 and C32 1,15-diols were analyzed in 181 surface sediments from eastern CMS. The similar distribution pattern and strong linear correlation between C30 and C32 diols indicated that they had similar biological source, with a dominance of C30 diol. Their contents ranged from 7–2726 ng g−1 for C30 diol and 5–669 ng g−1 for C32 diol, and both showed higher values mainly in the mud area of the Yellow Sea, while the TOC normalized contents showed a more obvious seaward increasing trend. The similar distribution pattern and significant positive correlation between diols and the other marine biomarkers (brassicasterol, dinosterol, C37 alkenones) indicated C30 and C32 diols in eastern CMS were mainly from marine algae. This conclusion was also supported by principal component analysis (PCA). Our results also showed that sediment diol contents were generally related to marine productivity, suggesting that diols could be applied for marine productivity reconstruction in eastern CMS.