中文摘要：

对2010年12月与2011年7月赣江中下游各监测断面中浮游动物类群的结构组成、优势类群进行调查,结果表明：赣江中下游浮游动物有4类41种;种类最多的是轮虫类,共计7科15属25种,占总数的60.98%;枝角类5科6属7种,占17.07%;桡足类与原生动物占21.95%。时间分布上浮游动物丰度丰水期大于枯水期,密度变动范围为100~522个/L,其中丰水期轮虫、枝角类、桡足类与原生动物密度分别占浮游动物密度的61.7%,11.4%,18.9%与7.8%;枯水期轮虫、枝角类、桡足类与原生动物密度分别占浮游动物密度的65.3%,9.5%,16.0%与9.1%。浮游动物密度空间分布上呈现中间大、两端小的特点,最大值出现在4号监测点新干,最小值出现在10号监测点赣州。赣江中下游浮游动物数量结构主要由轮虫和桡足类组成,生物量结构则主要由桡足类和枝角类组成。生物多样性及水质综合评价为轻度污染至中度污染。

英文摘要：

The population structure and dominant groups of zooplankton in the monitoring sections in the middle and lower reaches of the Ganjiang River were investigated in December of 2010 and July of 2011. The results show that there were 41 species of zooplankton, in which rotifers （seven families, 15 genera, and 25 species）, cladocerans （five families, six genera, and seven species ）, and copepods and protozoa were predominant, respectively accounting for 60.98%, 17.07%, and 21.95% of the total number. In regards to temporal distribution, the zooplankton abundance was greater in the wet season than in the dry season. The density of zooplankton ranged from 100 ind/L to 522 ind/L. The densities of rotifers, cladocerans, copepods, and protozoa respectively accounted for 61.7%, 11.4%, 18.9%, and 7.8% of the zooplankton density in the wet season, and 65.3%, 9.5%, 16.0%, and 9.1% of the zooplankton density in the dry season. It was found that the density of zooplankton was high in the middle section and low in the upper and lower sections, with the maximum value in the Xingan section （monitoring point No. 4） and the minimum value in the Ganzhou section （monitoring point No. 10）. The quantity structure of zooplankton consisted of rotifers and copepods, and the biomass structure consisted of copepods and cladocerans in the middle and lower reaches of the Ganjiang River. Biodiversity and water quality assessment showed that the Ganjiang River was slightly to moderately polluted.