南宁市南湖浮游动物生物多样性分析及水质评价

Biodiversity Analysis and Water Quality Evaluation of Zooplankton in Nanhu Lake of Nanning City

为了解南宁市南湖浮游动物群落现状及水质状况,于2017年1月至12月对南湖浮游动物多样性进行调查,并利用浮游动物Shannon-Wiener多样性指数和浮游动物生物量对南湖水质情况进行评价。结果表明:2017年南湖9个监测点共监测到浮游动物52种,其中,原生动物12属15种,占总种数的28.9%,轮虫11属25种,占总种数的48.1%,枝角类6属8种,占总种数的15.4%,桡足类4属4种,占总种数的7.7%。浮游动物中出现次数最高的是前节晶囊轮虫、裂足臂尾轮虫、角突臂尾轮虫及无节幼体。浮游动物生物量月均值为1.15604mg·L^-1;原生动物、轮虫、枝角类、桡足类月均值分别占比0.05%、35.59%、22.97%、41.39%;对南湖浮游动物生物量贡献最大的是桡足类,排在第2位的是轮虫,第3位是枝角类。浮游动物Shannon-Wiener多样性指数和浮游动物生物量数值表明南湖水体属于中度污染、中度富营养化水平。

In order to understand the status quo of zooplankton community and the water quality of Nanhu Lake in Nanning City,the diversity of zooplankton in Nanhu Lake was investigated from January to December in 2017,and the water quality of Nanhu Lake was evaluated by using the Shannon-Wiener diversity index and the biomass of zooplankton.The results showed that 52 species of zooplankton were detected in 9 monitoring sites in Nanhu Lake in 2017,among which protozoa were 15 species and 12 genera,accounting for 28.9%of the total species;rotifers were 25 species and 11 genera,accounting for 48.1%of the total species;cladocerans were 8 species and 6 genera,accounting for 15.4%of the total species;and copepods were 4 species and 4 genera,accounting for 7.7%of the total species.Among the zooplankton,the most frequent ones were Asplanchna priodonta,Brachionus diversicornis,Brachionus angularis and nauplius.The monthly mean biomass of zooplankton was 1.156 04 mg·L^-1,while the monthly mean values of protozoa,rotifers,cladocerans and copepods respectively accounted for 0.05%,35.59%,22.97%and 41.39%.And copepods contributed the most to the biomass of zooplankton in Nanhu Lake,rotifers ranked the second,and cladocerans ranked the third.Therefore,the Shannon-Wiener diversity index and the biomass of zooplankton indicated that the water body in Nanhu Lake belonged to the level of moderate pollution and eutrophication.