浯溪口水库蓄水对昌江流域浮游动物群落结构的影响

Effects of Wuxikou Reservoir Impoundment on Zooplankton Structure in Changjiang River Basin

2019年3月、4月和8月,即安徽省浯溪口水库蓄水前、蓄水初期和蓄水后期调查分析了昌江流域上9个监测断面水体理化因子和浮游动物群落结构,以掌握浯溪口水库蓄水对昌江水环境和流域内游动物群落结构的影响。结果表明,蓄水后库区水位、透明度、溶解氧以及N、P等营养盐含量增加;坝后河段N、P等营养盐含量下降;浮游动物群落以轮虫为主要门类,蓄水后优势种数量增加,浮游动物群落整体呈小型化趋势;坝前河段浮游动物丰度增加,而坝后则相反;昌江流域水质相对较好,整体处于轻污染状态,蓄水后水质有所改善;冗余分析表明:蓄水后显著影响浮游动物的因子在减少,但主要影响因子变化不大,基本以水温(WT)、溶解氧(DO)和N、P等营养盐含量为主,昌江流域水环境整体朝着有利于浮游动物的方向发展。

The water physical and chemical factors and zooplankton community structure were surveyed and analyzed in 9 monitoring sites in Wuxikou Hydro-Project reservoir in Changjiang River basin before,during and after the impoundment of the Wuxikou Reservoir in Anhui province in March,April,and August 2019 in order to understand the changes in water environment and zooplankton community structure before and after the impoundment of the Wuxikou Reservoir in Anhui Province.It was found that the water level,transparency,and levels of dissolved oxygen,N,P and other nutrients were increased in the reservoir area after reservoir impoundment.However,the contents of N,P and other nutrients decreased in the reach behind the dam.The zooplankton community was mainly composed of rotifers,with increase in the number of dominant species and miniaturization as a whole.There was increase in zooplankton abundance in the reach in front of the dam and decreased behind the dam.The water quality showed to be good in the Changjiang River basins,with a light pollution state,and better after reservoir impoundment.The redundancy analysis showed that the factors significantly affecting zooplankton decreased after reservoir impoundment,without change much in the main impact factors water temperature(WT),and contents of dissolved oxygen(DO),N,P and other nutrients.The water environment in the Changjiang River basin as a whole was developing in favor of zooplankton.