金塘岛海域表层沉积物重金属分布特征与潜在生态风险研究

Research on the Distribution Characteristic and Potential Ecological Risks of Heavy Metal Pollution in the Surface Sediments of Jintang Islands

利用波动系数、富集系数、潜在生态危害指数法结合我国的海洋沉积物标准对浙江省舟山市金塘岛海域春、秋季的表层沉积物进行了详细评价。研究结果表明:(1)金塘海域春季不同种类的重金属的分布离散性差异明显,春季Cu和Hg的空间分布最不均匀,而As和Zn的离散性较小,秋季各重金属元素则分布较为均一;(2)春季富集系数分析,最高为Pb,属中度污染,其余种类属低污染;秋季的值,均属低污染范围,总体来看,该区重金属离子的富集度季节性变化不大,其主要的污染因子为Pb;(3)金塘海域春季潜在生态风险因子和总的潜在生态风险程度均属为低度。秋季两项指标较春季更小,且各站位的指标相差不大,且有明显下降,其可能是较高的水温和流场(暖流)共同作用的结果。

The research including Cu/Pb/Zn/Cd /Hg/Cr/As of heavy metals in the surface sediments from the sea region of Jintang Is. of Zhoushan Islands. Moreover, the degree in spatial fluctuation and accumulation of heavy metals was analyzed by using the method of variation coefficients and accumulation coefficients. The method of potential ecological risk indices presented by Lar Hakanson was used to assess the potential ecological risk of heavy metals. The Cu and Hg spatial fluctuation is highest in spring, on the contrary As and Zn was appears to be the lowest; all of the heavy metals is general uniformity in autumn. The degrees accumulation of heavy metals show the Pb is the main source of pollution, reach to moderate degree in spring and the abundant is the highest in autumn, but decline to light pollution. The assessment of potential ecological risk revealed that the potential ecological risk of these heavy metals to the ocean ecology system is very light, which belongs to light potential ecological risk level, with the order of light potential. Obviously, the risky in autumn is lower than the one in spring, that hint the combined action of the water temperature and flow field（warm current）.