乌梁素海浮游动物与底栖动物调查及水质评价

于2004年4，8和10月及2005年1月分别对乌梁素海浮游动物进行了监测，共检出浮游动物34属62种. 其中，原生动物11属16种；轮虫17属33种；枝角类4属4种；桡足类5属9种. 大型浮游动物的年均丰度为687 L-1，年均生物量为3.498 5 mg/L；原生动物年均丰度为2.508×104 L-1，年均生物量为0.125 4 mg/L. 于2004年8和10月进行了2次调查，共获底栖动物4科11种，底栖动物平均丰度为3 031.4 m-2，平均生物量为71.672 g/m2. 调查结果显示，随着季节的变化，浮游动物的丰度及生物量变化幅度很大，夏季最高，春季次之，秋、冬两季极低. 利用浮游动物和底栖动物的生物量作为水体状况评价指标，对乌梁素海营养状况进行的初步评价表明，乌梁素海水体处于富营养化状态. 

Zooplankton and Zoobenthos Investigation in Lake Wuliangsuhai and the Estimationof Nutrition Status

A monitoring of zooplankton was conducted in Lake Wuliangsuhai in April, August, October 2004 and January 2005. A total of 34 genera and 62 species ofzooplankton were detected in Lake Wuliangsuhai. These include 11 genera and 16 species of Protozoa, 17 genera and 33 species of Rotifera, 4 genera and 4 species of Cladocera, and 5 genera and 9 species of Copepodo. The annually averaged abundance and biomass of macrozooplankton were 687 L-1 and 3.498 5　mg/L respectively, while those of Protozoa were 2.508×104 L-1 and 0.125　4 mg/L respectively. Zoobenthos were investigated in August and October, 2004. A total of 4 families and 11 species of zoobenthos were found. The average abundance and biomass of zoobenthos were 3　031.4 m-2 and 71.672 g/m2 respectively. The results showed thatthe abundance and biomass of zooplankton changed significantly following the seasonal variation. The abundance and biomass in Spring and Summer were dramatically higher than in Autumn and Winter. The biomass of zooplankton and zoobenthos was used as water body status estimating indicators to evaluate the nutritional status and the results showed that the lake was in the status of eutrophication.