长岛北四岛海洋牧场海域环境适宜性分析

Suitability Analysis on Marine Environment in Beisidao Marine Ranch Area of Changdao Islands

对长岛北四岛海洋牧场海域101个表层沉积物和102个表层海水样进行取样调查,开展表层沉积物类型、粒度、表层沉积物和海水重金属等指标分析测试,采用单因子污染指数法、富集系数法和潜在生态危害指数法评价该区表层沉积物潜在生态风险,采用海水水质分类和单因子污染指数法评价表层海水污染情况。表层沉积物结果表明:沉积物为泥质砂质砾、砾质泥质砂、砾质泥、含砾泥质砂、砂、粉砂质砂和砂质粉砂,平均粒径介于2.44~5.44Ф;Hg、Cu、Zn、Pb、Cd、As、Cr、硫化物和石油类都符合第一类标准,属于清洁沉积物;Cr、Cu、Pb、Zn、Cd、Hg和As富集系数均<1,处于低度污染水平;Cr、Cu、Pb、Zn、Cd、Hg和As单项潜在生态危害系数E_(r)^(i)介于0.56~30.71之间,RI均值为66.27,远低于低度生态危害的划分标准值。表层海水结果表明:21个站位受到Hg污染,略高于第一类标准,满足第二类标准,主要位于研究区西北部、西中部和东北部海域,其余指标均符合规定第一类标准;Hg、Cu和Zn含量处于较清洁环境范围内,As、COD、石油类、Pb、Cr和Cd含量处于自然本底环境。根据海底沉积物和海水分析结果得出,长岛北四岛海域海洋牧场规划区底质和水质环境适宜建设海洋牧场。

101 surface sediments and 102 surface seawater samples from the sea area of Beisidao marine ranch in Changdao island have been investigated,and the indicators,such as surface sediment type,particle size,surface sediment and seawater heavy metals have been analyzed and tested.The potential ecological risks of surface sediments in this area have been evaluated by single factor pollution index method,enrichment coefficient method and potential ecological hazard index method,The surface seawater pollution has been evaluated by seawater quality classification and single factor pollution index method.As showed by the results of surface sediments,the sediments are argillaceous sandy gravel,gravelly argillaceous sand,gravelly mud,gravelly argillaceous sand,sand,silty sand and sandy silt,with an average particle size of 2.44~5.44Ф;Hg,Cu,Zn,Pb,Cd,As,Cr,sulfide and petroleum all meet the classⅠstandard and belong to clean sediments.The enrichment coefficients of Cr,Cu,Pb,Zn,Cd,Hg and As are less than 1,which is at the low pollution level.The single potential ecological hazard coefficient E_(r)^(i) of Cr,Cu,Pb,Zn,Cd,Hg and As is 0.56~30.71,and the average value of RI is 66.27,which is far lower than the standard value of low level ecological hazard.As showed by the results of surface seawater,21 stations are polluted by Hg,which is slightly higher than the first standard and meets the second standard.They are mainly located in the northwest part,west and central part and northeast part of the study area,and the other indexes meet the first standard.The contents of Hg,Cu and Zn are in a relatively clean environment,and the contents of As,COD,petroleum,Pb,Cr and Cd are in a natural background environment.According to the analysis results of seabed sediments and seawater,it is concluded that the sediment and water quality environment of the marine pasture planning area in Beisidao marine ranch of Changdao Island is suitable for the construction of marine ranch.