巢湖夏、秋季浮游植物叶绿素a及蓝藻水华影响因素分析

Analysis of phytoplankton chlorophyll-a concentration in summer and autumn in Chaohu Lake and the impact factors of cyanobacterial blooms

2007年6-11月份,对设置在巢湖全湖的23个样点水体的理化指标水温(WT)、pH值、溶解氧(DO)、总氮(TN)、总磷(TP)、活性磷(RP)以及浮游植物的种类组成和叶绿素a(Chl-a)浓度进行了调查分析。结果表明:在巢湖夏秋季温差变化不大的环境中,温度依然是影响藻类生物量的重要因素。夏、秋季蓝藻为最主要的藻类类群(其平均值占藻类总生物量的63.36%);藻类生物量与所测理化因子均有显著正相关。在夏、秋季各月份,蓝藻生物量呈前高后低状M型波动,其中7月份湖水中蓝藻浓度最低。夏、秋季湖水中叶绿素的浓度没有太大变化,维持在一个较高的水平(>10mg/m3),遇到合适的气象条件有形成大面积水华的可能。

From June to November 2007,23 points in Chaohu Lake were selected to investigate and analyze its physical and chemical indicators.Parameters contained water temperature,pH,dissolved oxygen,total nitrogen,total phosphorus,reactive phosphorus,and phytoplankton species composition and chlorophyll-a concentration.The results showed that little change in temperature environment.Cyanobacteria is the main algae taxa.Algae biomass and physical and chemical factors were significantly positively correlated.In the summer and autumn,Cyanobacteria′s biomass was M-type fluctuations,which in July is the lowest concentration of blue-green algae.There was not much change in the concentration of chlorophyll maintained at a high level.