Phytoplankton Community And Water Quality Assessment Of Main Landcape Waters In Shanghai

With the growth of the water landscape in Shanghai and the improvement of living standards and economy, residence requires a better and beetter living environment. In this condition,the quality of landscape water has become the object of concern and attention.Phytoplankton are extremely sensitive to pollution. The characteristics of phytoplankton community can reflect water quality. Phytoplankton is an important bioindicator. According to the investigation on the characteristics of phytoplankton community(including Cyanophyta, Chrysophyta, Xanthophyta,Cryptophyta,Pyrrophyta,Bacillariophyta,Euglenophyta and Chlorophyta) in 31 parks or landscapes in Shanghai, we analyzed the correlation ship between community structure of phytoplankton and environmental factors and combined the evaluation of water quality.The main results show as follows:1. 206 taxa species of phytoplankton belonging to 72 genera 7 decisions were identified, of which the most abundant are Chlorophyta(100 species of 40 genera) which took 47% of the total species,followed by Bacillariophyta(42 species of 21 genera), Cyanophyta(25 species of 16 genera), Euglenophyta(20 species of 6 genera), Chrysophyta(10 species of 6 genera), Cryptophyta(6 species of 2 genera), and Xanthophyta(3 species of 2 genera).Species composition of phytoplankton followed seasonal variation, Summer> Spring > Autumn > Winter.2. The annual density of phytoplankton ranged from 162 to 31988 ind./L.Cyanophyta accounted for the largest proportion.The average density of zooplankton has an obvious change from season to season. The annual density of phytoplankton ranged from 1.08 to 67.79 mg/L. The annual biomass of phytoplankton has an obvious change from season to season.3. The dominant species of phytoplankton were Microcystis spp.、Merismopedia minima,Pseudanabaena sp.、Chromulina sp.、SynuraCuvella、Chroomonas acuta、Cryptomonas erosa, Cyclotella vmeneghiniana 、 Pediastrum simplex and Scenedesmus quadricauda.The dominant species composition of four quarters differs from each others, but most of which indicates currently the water faces the problem of pollution.4.According to Pearson correlation analysis, the characteristics of zooplankton community were related to water temperature(WT), dissolved oxygen(DO), chemical oxygen demand(COD), total phosphorus(TP) and total nitrogen(TN).To explore the effects of pollution and eutrophication of water bodies on zooplankton,the landscape waters were clustered into four groups through cluster analysis,based on COD, TN, TP.Found that as water pollution and eutrophication increases, the density and biomass of phytoplankton increased in turn. The density and biomass of phytoplankton wereclosely related to the quality of landscape waters.5. The annual Shannon-Wiener index(H?) ranged from 3.52 to 4.76,the Margalef index(D) ranged from 16.90 to 19.24, and the Pielou index(J) ranged from 0.27 to 0.42. The average Shannon-Wiener index(H?) was that Spring > Winter > Autumn >Summer, the average Margalef index(D) was that Summer > Winter > Spring > Autumn, the average Pielou index(J) was that Winter > Spring > Autumn > Summer. Physical and chemical index, phytoplankton dominant species and the diversity index were used to value landscape waters quality in Shanghai. In the view of Shannon-Wiener index, the water quality of landscape waters in Shanghai was in lightly to heavily polluted state.In the view of Margalef index, the water quality of landscape waters in Shanghai was in clean to heavily polluted state.In the view of Margalef index, the water quality of landscape waters in Shanghai was in clean to heavily polluted state.Taken together, the landscape waters in Shanghai were in middle to heavily polluted state.