Analysis On The Dynamic Variation Characteristics Of The Plankton Community And Water Quality Evaluation In Harbin Section Of Songhua River

An investigation on plankton was carried out in the Harbin section of Songhua River, During June(wet season),August(normal season) and October (dry season) in2011by setting up seven systematically placed sample station. Main results for this study are as follows:A total of125phytoplankton species were identified, among which55were Bacillariophyta,51Chlorophyta,11Cyanophyta and11other species. The changes of phytoplankton abundance significantly in different hydrological period.The dry season (6951.6×104ind/L)>normal season (3556.8×104ind/L)>wet season (2059.2×104ind/L). Canonical correspondence analysis (CCA) was applied to explore the relationship between phytoplankton composition, distribution and environmental factors, biodiversity index was used to evaluate water quality. The result showed that Shannon-weaver index, Pielou index and Margalef index in dry season were lower than wet season and normal season, so water quality is relatively poor, S2right, S4right, S6middle were polluted in serious levels in dry season. CCA showed that water temperature and turbidity were main factors affecting the distribution of phytoplankton community, biochemical oxygen demand and total phosphorus were also significantly positively correlated with the phytoplankton species distribution.The zooplankton community in Harbin section of Songhua River was investigated and analyzed. A total of53zooplankton were identified, consisting of41species of Rotifera,9species of Protozoa,2species of Cladocera,1species of Copepoda. The abundance ranged from180-12030ind./L, the biomass varied from0.14-3.6mg/L. According to the saprobic indices, all of sample sites belong to mesosaprobic water, and water quality was the worst in autumn. S4saprobic indices were higher than the other sample sites, so water quality is relatively poor. Canonical Correspondence Analysis (CCA) showed that water temperature, pH, dissolved oxygen saturation and turbidity were important factors influencing the distribution of the zooplankton community.