嵊泗绿华岛养殖海域环境质量综合评价

The comprehensive evaluation of sea area environmental quality for breeding in Shengsi Lvhua Island

根据2011年嵊泗绿华岛养殖区春、夏、秋3个季度的水质和沉积物监测结果,分析评价表明:养殖区水温、盐度、pH、化学需氧量(COD)、溶解氧(DO)、无机氮(DIN)和叶绿素a(Chl.a)呈季节性变化,养殖区海水富营养化严重,且富营养化水平春季﹥夏季﹥秋季;夏季海水有机污染水平(A值)最轻,春季和秋季达轻度污染水平。该海域海水环境主要受长江径流、养殖污染等影响,而无机氮含量较高是富营养化和有机污染的主要原因,也是该海域赤潮高发的原因之一。沉积物中汞(Hg)、砷(As)、铜(Cu)、铅(Pb)、镉(Cd)、铬(Cr)6种重金属元素含量均符合一类海洋沉积物质量标准;根据Hakanson评价法,潜在生态风险为低水平,但铬(Cr)含量已呈中等污染水平,应加强监测。

Based on the seawater and sediment monitoring results of Shengsi Lvhua Island＇ s maricuhure zone in spring, summer, autumn of 2011, the results showed that, maricuhure zone＇ s water temperature, salinity, pH, chemical oxygen demand （COD）, dissolved oxygen （DO） , dissolved inorganic nitrogen （DIN） and chlorophyll a（ Chl. a） changed with the seasons, eutrophication of the mariculture zone was serious, and the eutrophication level was spring 〉 summer 〉 autumn ; the sea water＇ s organic pollution level （ A ） in summer was the lowest, but attained lightly polluted level in spring and autumn. The seawater environment was mainly affected by the Changjiang River, breeding pollution and so on, and the higher level of dissolved inorganic nitrogen was the main reason for eutrophication and organic pollution, and was also a reason of the area＇ s high incidence of the red tides. The content of mercury （Hg）, arsenic （As）, copper （Cu）, lead （Pb）, cadmium （Cd）, chromium （Cr） in sediments （6 kinds of heavy metal） accorded with the first class of the marine sediment quality of National Standards. According to the Hakanson＇ s evaluation method, the potential ecological risk was low, but the content of chromium （Cr） reached medium pollution level, so monitoring should be strengthened.