大亚湾内、外海域重金属分布对比及其潜在生态风险评价

Comparison of Heavy Metal Distribution and Potential Ecological Risk Assessment in the Inner and Outer Seas of Daya Bay

为促进大亚湾区的海洋生态环境保护和可持续发展,文章以铜等9种重金属为指标,根据相关规范和标准,分别调查大亚湾内、外海域的海水、表层沉积物和生物质量,并采用单因子污染指数和内梅罗综合污染指数,对比重金属的污染程度,具有创新性;同时,以表层沉积物为代表,采用潜在生态风险指数,评价大亚湾海域的潜在生态风险。研究结果表明:大亚湾海域海水、表层沉积物和生物中的重金属含量大部分符合相关一类或推荐的标准;海水中的主要重金属为铅,综合污染指数湾外低于湾内,可能与人类活动和海水交换有关;表层沉积物中的主要重金属为钒,综合污染指数湾内低于湾外,可能与钒的最大值超标有关;生物体内重金属的综合污染指数,甲壳类和头足类湾外低于湾内,而鱼类和贝类湾内低于湾外,但差距均不明显;大亚湾海域多种重金属的潜在生态风险等级为很高,其中汞为首要潜在生态风险因子,须引起高度关注。

In order to promote the marine ecological environment protection and sustainable development in Daya Bay,the paper evaluated the pollution level of heavy metals of Daya Bay,by the single factor index and Nemero comprehensive pollution index,using 9 heavy metals such as copper as indicators to investigate the seawater,surface sediments and organism of the inner and outer sea of Daya Bay,according to relevant norms and standards,which is innovative.The paper also evaluated the potential ecological risk in the Daya Bay,based on surface sediments,and the potential ecological risk index.Research indicated: Most of the heavy metals in seawater,surface sediments and organism of Daya Bay meet the first level standard or recommended standards.The main heavy metal in seawater is lead,and the comprehensive pollution index is lower than the bay outside the bay,which may be related to human activities and seawater exchange.The main heavy metal in the surface sediment is vanadium,and the comprehensive pollution index is lower than the bay in the bay,which may be related to the maximum value of vanadium exceeding the standard.The comprehensive pollution index of heavy metals in the crustaceans and cephalopods which are outside the bay are lower than that inner the bay,while the comprehensive pollution index of heavy metals in the fish and shellfish which are inside the bay are lower than that outside the bay,but the gap is not obvious.The potential ecological risk level of most heavy metals in Daya Bay is very high,and mercury is the primary potential ecological risk factor,which must be highly concerned.