上海市淀山湖水质富营养化状况及常见水生生物体内微囊藻毒素水平

Eutrophication of Lake Water and Microcystins in Common Aquatic Animals in Dianshan Lake,Shanghai

[目的]对上海市青浦区2013年淀山湖水质富营养化状况和微囊藻毒素(MC)污染进行评估。[方法]于2013年3—9月间在环淀山湖周边依据地理位置和功能区分布特点设立5个水质监测点,进行水质和生物采样检测,每月监测1次,涵盖丰水期、平水期和枯水期。依据GB 3838—2002《地表水环境质量标准》中地表水Ⅲ类标准对结果进行评价。[结果]质浊度监测均值为10.73 NTU。p H和化学耗氧量、氨氮的监测均值分别为8.38和4.98、0.82 mg/L,达到标准;总氮、总磷监测均值分别为2.98、0.17 mg/L,超过标准限值;各指标最大值均超过标准限值。不同月份间水质差异均有统计学意义。湖区水生生物体内MC-LR、MC-RR监测期均值为7.02、10.14μg/kg;3—7月以MC-RR为主,8—9月以MC-LR为主;河蚌和螺蛳检出频率较高,鲢鱼和鲫鱼蓄积毒素浓度最高,分别为25.1、21.4μg/kg。[结论]淀山湖水质为中度富营养化,湖区生物体内有一定藻类毒素蓄积。

[ Objective ] To evaluate the eutrophication status and microcystins （MCs） pollution in 2013 in the Dianshan Lake in Qingpu District of Shanghai. [ Methods ] From March to September of 2013, we set five monitoring sites around the Dianshan Lake based on its geographical and functional characteristics and collected water samples and aquatic animal samples once a month, covering wet, normal, and dry seasons. The samples were evaluated according to quality of surface water category Ⅲ stipulated by Environmental Quality Standards for Surface Water （GB 3838-2002）. [ Results ] The average turbidity was 10.73 NTU. The average pH was 8.42, the average CODMn, was 4.98 mg/L, and the average ammonia nitrogen was 0.82 mg/L, respectively, meeting the corresponding requirements of the national standard for surface water category Ⅲ. The total nitrogen and total phosphorus were 2.98 mg/L and 0.17 mg/L respectively, beyond the limits of category m. No max values of the detected indicators exceeded the limits. The quality of water showed a distinct monthly variation. The average MC-LR and MC-RR during the monitoring periods were 7.02 gg/kg and 10.14 μg/kg respectively; MC-RR was dominant between March and July, and MC-LR was dominant between August and September. MCs were mostly detected in mussels and spiral shells, highest in Hypophthalmichthys molitrix （25.1 μg/kg） and Carassius （21.4 μg/kg）. [ Conclusion ] The Dianshan Lake is mid-eutrophic. MCs are cumulated in the aquatic animals in the lake.