海州湾人工鱼礁海域沉积物中重金属生态风险的分析

The ecological risk evaluation of heavy metals in surface sediments in artificial reefs sea area in Haizhou Bay

于2008年春季(5月)、夏季(8月)、秋季(11月)对海州湾人工鱼礁投放海域表层沉积物中重金属取样调查,分析了该海域沉积物中主要重金属的时空分布特征,并采用综合污染指数法和潜在生态危害指数法对重金属潜在生态危害进行了研究。结果表明:海州湾人工鱼礁投放海域表层沉积物中Pb、Cd、Cu、Zn、Hg和As重金属含量存在较为明显的季节变化,秋季高于夏季和春季;在空间分布上总体上呈现对照区2>鱼礁区2>鱼礁区1>对照区1这一近岸高、远岸低的变化趋势。生态风险分析显示:Hg和Pb的单个污染系数较大,其中Hg的污染程度和潜在生态危害在秋季(11月)处于中等程度(Ⅱ),其他5种重金属均处于轻微污染程度和较低生态危害;总体污染程度低,潜在生态危害均属轻微生态危害。

The spatio-temporal profiles of heavy metals in surface sediments of artificial reefs deployed sea area in Haizhou Bay were investigated in spring（May）,summer（August）and autumn（November）of 2008,and the potential ecological risk of the heavy metals were analyzed and assessed by the method of potential ecological risk index and coefficient of contamination.The results showed that the contents of Pb,Cd,Cu,Zn,Hg and As were found to be varied significantly with the seasons.There were significantly higher contents of the heavy metals in autumn than those in spring and summer,and higher near shore and lower offshore,and the maximum in control 2 in the four sampling stations,followed by in the reef 2,the next in the reef 1 and the minimum in the control 1.The coefficients of contamination of Hg and Pb were found bigger than those of other heavy metals.The level of contamination and potential ecological risk of Hg were in middle level（Ⅱ）in autumn（Nov.）,while the other five heavy metals were in weak level.It was found that the artificial reef sea area in Haizhou Bay was weak pollution level according to the index of contamination and potential ecological risk.