渤海中部海域表层沉积物生源要素分布特征及其环境评价分析

于2015年5月在渤海中部海域采集30个表层沉积物样品，对总有机碳（TOC）、总氮（TN）、总磷（TP）、生物硅（BSi）、有机质（OM）、含水率（MC）进行了分析测定，通过分析渤海中部海域表层沉积物生源要素的分布特征，进一步揭示有机质物源的贡献以及海域生物地球化学等过程。渤海中部海域表层沉积物生源要素含量分别为TOC（0.21%~1.43%）、TN（0.01%~0.12%）、TP（0.01%~0.04%）、BSi（0.08%~0.46%）、OM（1.43%~9.42%）、MC（18.24%~47.70%），TOC、TN、TP、OM和MC分布特征相近，总体呈现东低西高的分布特征，BSi则在渤海中部含量较高。TOC、TN摩尔比值显示渤海中部表层沉积物中有机质来自陆源和海源混合输入，以陆源输入为主；而TOC/BSi说明硅藻对渤海中东部海域总初级生产力贡献较大。沉积物质量评价显示渤海中部海域表层沉积物受到一定程度的污染，部分海域沉积物中TOC和TN含量超过加拿大安大略省环境和能源部沉积物质量评价标准的Ⅱ类标准。

Distribution characteristics and environmental assessment of biogenic elements in surface sediments from the central Bohai Sea

Thirty surface sediment samples were collected from the central Bohai Sea in May 2015.Total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), biosilicon (BSi), organic matter (OM) and moisture content (MC) were analyzed to understand distribution characteristics of biogenic elements of the surface sediments from the central Bohai sea and further reveals the contribution of organic matter sources and marine biogeochemical processes.The contents of biogenic elements were 0.21%~1.43% for TOC, 0.01%~0.12% for TN, 0.01%~0.04% for TP, 0.08%~0.46% for BSi, 1.43%~9.42% for OM and 18.24%~47.70% for MC, respectively.The distribution patterns of TOC, TN, TP, OM, and OM were similar, reflected by lower in the east and higher in the west.However BSi was higher in the middle of the central Bohai Sea.Organic matters were originated from mixed inputs of terrestrial and marine sources and mainly form the terrestrial sources based on the molar ratios of TOC/TN.Diatoms contributed a lot to the total primary productivity based on TOC/BSi ratios.Results from the sediment quality evaluation showed that the surface sediments were contaminated to some extent, and TOC and TN were over class Ⅱ standards in some sea areas of the central Bohai Sea based on sediment quality assessment criteria of the Department of Environment and Energy of Ontario, Canada.