厦门海域贝类养殖生态环境质量评价和类别划分研究

Study on assessment of the environmental quality and grading of shellfish-culture areas in Xiamen Bay

根据2005年4月和10月同步进行厦门海域贝类养殖区海水、表层沉积物和养殖贝类体中有毒有害物质(Cu、Pb、Zn、Cd、Hg、As、石油类、六六六、滴滴涕、多氯联苯、大肠菌群、腹泻性贝毒和麻痹性贝毒)的调查资料,采用海水质量评价指数(Swj)、表层沉积物质量评价指数(Ssj)和养殖贝类质量评价指数(Soj)以及贝类养殖生态环境质量综合评价指数(SI)对厦门海域贝类养殖生态环境质量进行了综合评价和类别划分。结果表明,海水质量、表层沉积物质量和养殖贝类质量水平范围均为2～7级,平均值分别为3级、5级和4级。贝类养殖生态环境质量水平范围为2～7级,平均值为4级。总体上,贝类养殖区海水质量处于较好水平,表层沉积物质量处于较差水平,养殖贝类质量处于一般水平。贝类养殖生态环境质量处于一般水平。其主要污染物为大肠菌群、石油类。厦门贝类养殖区1类区两个,属清洁区,占贝类养殖区总数的8%。2类区共18个,占贝类养殖区总数的72%。其中2a类区9个,属较清洁区,占贝类养殖区总数的36%,2b类区6个,属轻度污染区,占贝类养殖区总数的24%;2c类区3个,属中度污染区,占贝类养殖区总数的12%。3类区5个,属重度的污染区,占贝类养殖区总数的20%。厦门贝类产地环境质量的评价和类别划分的结果与厦门贝类养殖区环境污染现状相吻合。

According to the data of environmental survey on harmful substances （such as Cu, Pb, Zn, Cd, Hg, As, petroleum, HCH,DDT, PCBs, coliforms, DSP, PSP） in seawater, surface sediments and cultured organisms from shellfish-culture areas of Xiamen Bay in April and October 2005, eco-environmental quality of shellfish-culture areas was assessed and classified by seawater quality index method, surface sediment quality index method, culture shellfish quality index method and the shellfish culture eco-environmental quality synthesis assessment index method. The results showed that the quality grades of seawater, surface sediment and cultured shellfish ranged between Grade 2 and Grade 7, and averaged Grade 3, Grade 5 and Grade 4, respectively. The shellfish-culture eco-environmental quality ranged between Grade 2 and Grade 7, at a mean of Grade 4. Overall, the eco-environmental quality of shellfish-culture areas of Xiamen Bay was at a regular level; speeifically, the seawaters were of relatively good quality, surface sediments were of relatively poor quality, and the cultured shellfish were of ordinary quality. The major contaminants were coliforms and petroleum. In the shellfish-culture areas of Xiamen, two areas belonged to the first class, occupying 8% of all areas; 18 areas be- longed to the second class, occupying 72% of all areas. In addition, there were 9 areas belonged to 2a class, which were relatively clean and occupied 36% of all areas, six areas belonged to 2b class which were lightly polluted and occupied 24% of all areas, three areas belonged to 2c class which were medially polluted and occupied 12% of all areas. There were 5 seriously polluted areas belonging to the third class and occupying 2000 of all areas. The results of environmental quality assessment and grading of Xiamen shellfish habitat correlates well with the present situation of environmental pollution in Xiamen shellfish-culture areas.