环北部湾典型港湾表层沉积物中生源要素分布特征

为了解环北部湾典型港湾沉积物生源要素分布及污染状况，于2015~2016年采集了广东西部、海南省西北部以及广西沿海7个港湾的48个表层沉积物样品，分析了沉积物中总有机碳（TOC）、总氮（TN）、总磷（TP）和生物硅（BSi）的含量。TOC、TN、TP和BSi含量分别为0.27%~1.64%、0.09%~0.25%、0.02%~0.05%和0.55%~2.28%，湛江港生源要素含量较高，其次为北海港，海南沿海的4个港湾TOC、TN和TP含量相近，但BSi含量则在北部的海口港和新海港明显高于中西部的洋浦港和八所港。各生源要素之间显著正相关，说明它们来源相近；大部分站位TOC/TN小于10，说明沉积物中TOC主要源于海洋浮游植物，特别是海洋硅藻。生源要素潜在生态危害评价表明，而所有港湾的TN均受到一定程度的污染，而湛江港、北海港与八所港的TOC也已受到污染。

Distribution contamination of biogenic elements in surface sediments from typical sea areas of Beibu Gulf Rim in China

Forty-eight surface sediment samples were collected from typical sea areas of Beibu Gulf Rim between April 2015 and May 2016. Biogenic elements including total organic carbon (TOC), total nitrogen (TN), total phosphate (TP) and biogenic silica (BSi) were analyzed. The concentrations of TOC, TN, TP and BSi were in the range of 0.27%~1.64%, 0.09%~0.25%, 0.02%~0.05% and 0.55%~2.28%, respectively. Biogenic elements were higher in Zhanjiang port, and followed by Beihai port. Concentrations of TOC, TN, and TP were comparable in four ports of Hainan coast, however BSi levels were significantly higher in Haikou port and Xinhai port in the northern coast than those in Yangpu port and Basuo port in the mid-western coast. The significant coefficients among biogenic elements indicated their similar origin. TOC mainly originated from marine phytoplankton especially from diatoms based on the molar ratios of TOC/TN. Contamination assessment of biogenic elements indicated TN was contaminated in all ports, and TOC in Zhanjing port, Beihai port and Baosuo port has been polluted as well.