淀山湖夏季微囊藻毒素分布状况及其影响因素

为了解淀山湖夏季微囊藻毒素的昼夜、区域、垂直分布状况及其影响因素，在淀山湖上选择11个采样点，每个采样点设4个采样深度，进行24h的4次采样．测定水样中总氮（TN），总磷（TP），微囊藻毒素（MC）浓度，同时记录采样时的水温（TEM）、pH值、可见度（VDWB）、风向、风速．结果表明，MC分布具有明显的昼夜、区域差异，早晨和下午最高，西南水域明显低于其他区域，体现了光照、空气流动对MC分布的影响，同时MC的分布与总磷、pH值、可见度呈正相关（P＜0.05），多因素分析显示，除光照、空气流动外，影响湖水MC分布的最主要因素为湖水可见度和水中总磷的含量．表明光照、空气流动、水体总磷含量是影响夏季淀山湖水体MC分布的主要原因．

The distribution of microcystin and its influence factors in Dianshan Lake in summer.

In order to understand the distribution of Microcystin (MC) within day and night and at different locations and depths, and their influence factors in Dianshan Lake in summer, 11 different locations for sampling were selected. Each location included 4 different depths; and water samples were taken for 4 times in 24 hours. Total nitrogen (TN), total phosphorous (TP) and MC contents in the water samples were determined. At the same time, water temperature(TEM), pH value, visual degree of water body (VDWB) and direction and velocity of wind were recorded. The results showed that the distributions of MC were markedly different within day and night and among sampling locations. MC content was the highest in morning and afternoon, and markedly lower in the southwest part of the lake than that in other parts reflecting the effect of light and wind and the positive correlation with TP content pH and VDWB(P<0.05). Multiple factors analysis showed that distribution of MC in water was mainly affected by VDWB and TP content besides light and wind. Thus, it indicated that the most important factors affecting the distribution of MC in water body of Dianshan Lake in summer were light, wind and TP content.