The Variation Characteristic Of Phytoplankton And Water Quality In Weilv Area Of The Poyang Lake During The Fall And Winter

The Poyang Lake Weilv area is located in South-east of Poyang Lake, Poyang County, a body of water close to the shore, is vulnerable to human activities and algal bloom, so that monitoring of the area is extremely important and helpful in providing some background information for water conservancy project.This research, from Sept. to Nov.2012determined four sampling points, investigated the physical and chemical indicators such as total nitrogen, total phosphorus, transparency, dissolved oxygen every three days, besides, counted and analysed algae species composition and cell density, and did ecological.Assessment of water quality conditions:(1) During autumn and winter, total nitrogen concentration ranged from0.773to5.534mg/L while total phosphorus from0.0561to0.4651mg/L.There is.the relationship between Algal density and ammonia nitrogen, total nitrogen,temperature. The water quality was poor due to excessive total nitrogen and total phosphorus.(2) Phytoplankton consisted of54genera belonging to8phyla, mainly Chlorophyta, Bacillariophyta and Cyanophyta.28of54generabelonged to Chlorophyta, accounting for52%of the total number of phytoplankton,11genera belonged to Cyanophyta, accounting for19%and9genera belonged to Bacillariophyta, accounting for16%.(3) Algae ecological evaluation showed that the Poyang Lake Weilv area was going through a moderate eutrophication period.(4) Based on the laboratory results, the suspended particles could adsorp and settle Microcystis aeruginosa and Scenedesmus obliquus, optimum conditions for pH7,1.5h static period, the concentration of20mg/L.