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

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.