中文摘要：

东平湖作为国家南水北调工程东线的调蓄湖和山东省西水东送的水源地，在国家水资源配置战略中起着重要的作用. 为了解其水生生物、水环境质量及湖泊富营养状态，在收集、整理和总结前人历年积累的东平湖水生生物等调查研究资料的基础上，并结合表层沉积硅藻和湖泊水质数据，分析东平湖目前的水环境状况及湖泊环境的潜在威胁. 2011-2012年东平湖表层沉积物硅藻属种鉴定显示优势属为Aulacoseira、Synedra、Cyclotella、Navicula和Fragilaria，营养型属种居多，表明湖泊整体营养水平较高. 由Shannon-Wiener多样性指数和Pielous种类均匀度指数分析得到东平湖硅藻门生物多样性指数为3.30和0.80，处于轻度污染水平. 因此，由水生生物群落所揭示的东平湖环境状况为营养状态从富营养化转变为中营养-轻度富营养化状态，水体由中度污染转变为轻度污染甚至部分区域水体良好，整体处于Ⅲ类水标准.

英文摘要：

Considering the lack of long-term studies of phytoplankton and water environment quality, the water quality and surface sediment diatoms of Dongping Lake were monitored and the results were combined with data on the aquatic communities in the lake. The aim of this study was to provide stakeholders with a scientific evaluation on the trends of lake development that could serve as a theoretical basis for the improvement of ecological environments, the restoration of biodiversity, and to assure water quality in North China. The dominant diatom taxa in Dongping Lake from 2011 to 2012 were Aulacoseira, Synedra, Cyclotella, Navicula, and Fragilaria. Species diversity analyses showed a Shannon-Wiener diversity index of 3.30 and a Pielou’s species evenness index of 0.80, indicating that the lake was slightly polluted. The spatial distribution of aquatic organisms can be affected by the lake environment, and at the same time, the aquatic organisms can reveal features of the lake environment. The changes in the aquatic community of Dongping Lake showed that the lake was in a transition state from eutrophication to meso-eutrophication and was slightly polluted.