中文摘要：

海洋区域环境背景值是多种环境因素的共同作用的结果，往往具有很强的地域性特点。在评价区域元素的累积、人为污染强度时，使用全球页岩或其他大范围的元素地球化学背景作为衡量依据，会使得判断结果出现较大的偏差。位于广东省东部的柘林湾是一个具有典型热带与亚热带特色和鲜明地质特点的小型河口湾，也是粤东地区最大规模的增养殖区。2003年9月、12月在柘林湾进行了两个航次的沉积物背景值调查，对取得的3个沉积物柱状样分层并测定了各层沉积物的重金属含量，在分析重金属垂直分布特征的基础上，结合已知的沉积速率，确定了柱状样下部未受人类活动影响的背景段，并根据数据的分布类型确定重金属的环境背景值。结果表明，柘林湾重金属元素Cd、Cr、Cu、Ni、Pb、Zn的背景值分别为0．150mg·kg^-1、28．6mg·kg^-1、15．8mg·kg^-1、14．8mg·kg^-1、32．2mg·kg^-1，57．8mg·kg^-1。与其他区域比较，柘林湾Pb的背景值最高，而Cd、Cr、Cu、Ni、Zn的背景值与其邻近的粤东外海和南海北部陆坡区及广东沿海的相近，但与南海陆坡和南海海盆的相比则明显偏低。

英文摘要：

The Zhelin Bay is a small bay with typical tropical and subtropical characteristics and distinctive geological features; it is also the largest marine culture area in eastern Guangdong Province. Three sediment columnar samples were collected in the bay during two cruises in September and December of 2003 in order to investigate heavy metal background values, and the heavy metal contents of the samples were measured. Based on analysis of the vertical distribution characteristics of heavy metals and the known sedimentation rate, the non contaminated segments of the sediment columnar samples were determined, and the background values of heavy metals were assessed according to the distribution pattern of the data. The results show that the background values of the sediments in the Zhelin Bay are 0. 150 mg·kg^-1 for Cd, 28.6 mg·kg^-1 for Cr, 15.8 mg·kg^-1 for Cu, 14.8 mg·kg^-1 for Ni, 32.2 mg·kg^-1 for Pb, and 57.8 mg·kg^-1 for Zn. Compared with the contents of heavy metals in other areas, the background value of Pb in the bay is the highest, while those of Cd, Cr, Cu, Ni, Zn have no obvious difference from those in the open sea of eastern Guangdong Province, the northern continental slope of the South China Sea and nearshore area of Guangdong Province, though they are lower than those in the basin and continental slope of the South China Sea.