三峡水库支流拟多甲藻（Peridiniopsis sp.）

2009年和2010年对三峡水库支流童庄河回水区和长江干流水体理化和浮游植物进行了同步连续跟踪监测。结果表明，2010年童庄河回水区和长江干流氮磷含量较2009年有所升高，同一年份童庄河回水区和长江干流氮磷含量各有高低，但差别不大。2-3月，童庄河回水区拟多甲藻细胞密度呈逐步增加并达到高峰的变化，其优势地位可从2009年第十三位、2010年第九位逐步成为第一优势种类，并在2010年2月26日出现小范围水华。拟多甲藻水华最先出现在回水区尾端，随着时间推移，逐步向中下游发展，并形成大面积水华，在维持一段时间后消退。童庄河回水区拟多甲藻密度上游最高，从上游至下游，密度呈下降趋势。同期长江干流出现拟多甲藻的次数较少、密度较低，通常在回水区最低密度30.91%以下。分析认为，2-3月回水区更适合拟多甲藻生长，能否形成水华主要受水文因子影响。

Ecological monitoring and investigation of Peridiniopsis sp. of the main tributaries in the Three Gorges Reservoir

A consecutive investigation on the physicochemical property and phytoplankton was conducted in the main channel of the Yangtze River and Tong Zhuang River branch waterback area from 2009 to 2010. The monitoring results showed that the nitrogen and phosphorus contents in both the Yangtze River and Tong Zhuang River were higher in 2010 than in 2009,but no significant differences between the two rivers in the same year. The cell density of Peridiniopsis sp. in the waterback area of the Tong Zhuang River increased rapidly, respectively from the 13thand ninth up to the first in 2009 and 2010, and the algal water bloom occurred in February and March in 2010.The algal water bloom firstly occurred in the tail end of the waterback area, and gradually developed toward the middle and lower reaches and finally formed into a large-scale bloom, and withdrew after a period of time. The algal density was higher in the upper reach of the Tong Zhuang River with decreasing trend from the upper to lower reaches.In the same period, the occurrence frequency of the algal was less and the algal density was low in the mainstream of the Yangtze River, with the cell density in the branch waterback area lower than 30.91%. Our results indicated that the conditions in the branch waterback area are more suitable for the algal growth. Yet whether the algae water bloom occurs or not is up to hydrological factors.