The concentrations, spatial distributions and sources of heavy metals in the surface sediments of the coastal wetland on the Leizhou Peninsular were analyzed through multiple statistics. The ecological risk assessments of heavy metals were conducted. The mean concentrations of Cu, Zn, Pb, Cr, As, Cd, and Hg were 10.29±7.80, 47.06±28.47, 24.74±10.78, 41.70±26.25, 7.98±4.73, 0.042±0.029, and 0.020±0.027 μg·g-1, respectively. High positive correlations were found in two groups among the seven metals. The metals including Cu, Zn and Cr in the first group were mainly originated naturally, whereas the second group consisting of Pb, Cd and Hg were originated from both human activities and natural sources. The high concentration areas of the metals were in the Liusha Bay, western Zhanjiang Bay, Hai’an Bay, and western Leizhou Bay. According to the biological effect criterion suggested by the NOAA, nearly no negative effects would occur for the metals in the study area except As. This is because its concentration is between the effect range low (ERL) and effect range median (ERM) level at about 50%of the sampling stations, which indicates the negative effects would occur occasionally. The degree of contamination and potential ecological risk index of the heavy metals were both low for the whole study area. However, the contaminations in some areas such as the western Zhangjiang Bay, Liusha Bay and Hai’an Bay need further investigation and monitoring to avoid inducing ecological risk to benthos under continued accumulation due to human activities.%采用多元统计方法分析了雷州半岛滨海湿地表层沉积物中重金属的含量、相关性、空间分布特征和来源，并对其生态风险进行了评价。研究区表层沉积物中的Cu、Zn、Pb、Cr、As、Cd和Hg的含量平均值分别为10.29±7.80、47.06±28.47、24.74±10.78、41.70±26.25、7.98±4.73、0.042±0.029和0.020±0.027μg·g-1。Cu、Zn和Cr以及Pb、Cd和Hg为2个强正相关群，第一个群中的重金属元素以自然来源为主，第二个群则兼有人为输入和自然2个来源。重金属含量的高值区主要分布在流沙港、湛江港西部、海安港和雷州湾西部海域。对照美国海洋与大气管理局(NOAA)的生物效应标准，研究区绝大部分海域内的表层沉积物中除As含量在约50%的站位的值在“效应范围低”(effect range low)和“效应范围中等”(effect range median)阈值之间，对底栖生物会偶尔发生负面效应外，其他重金属基本不发生负面效应。重金属总体为低污染程度和低潜在生态风险。应重视人类活动较强的区域如湛江港西部、流沙港、海安港等海区的重金属污染，以避免持续累积至能对生物造成危害的水平。
展开▼
