Department of Civil and Environmental Engineering, University of Brasília, Brasília 70910-900, Brazil.
Environ Monit Assess. 2012 Aug;184(8):4635-45. doi: 10.1007/s10661-011-2291-4. Epub 2011 Sep 3.
The water reservoir of Vargem das Flores, Brazil, has been subject to eutrophication problems. The occurrence of cyanobacterial blooms in this water body has raised concerns regarding the presence of toxic metabolites. In order to understand the factors that promote the proliferation and distribution of cyanobacteria in the reservoir, physicochemical parameters, species composition, and toxicity of the reservoir water column were analyzed at monthly intervals over a 3-year period (2004-2007) using a range of analytical techniques. The results showed that cyanobacteria were absent in the dry period, returning after the onset of stratification. A succession pattern was observed within this group. The Aphanocapsa genus was dominant in the last rainy period of the study (October 2006 to March 2007). However toxicity was only detected when the genera Microcystis and Sphaerocavum were present (October 2005). The principal components analysis showed negative correlation between cyanobacteria and orthophosphate. The change of dominant cyanobacteria along the 3 years of study and the final prevalence of nontoxic genera in the reservoir is an evidence of water quality improvement in response to the management techniques implemented in the reservoir basin.
巴西瓦尔加姆·达·弗洛雷斯水库一直存在富营养化问题。该水体中蓝藻水华的出现引起了人们对有毒代谢物存在的担忧。为了了解促进水库中蓝藻增殖和分布的因素，在 3 年期间（2004-2007 年）每月使用一系列分析技术对水库水柱的理化参数、物种组成和毒性进行了分析。结果表明，在干旱期蓝藻不存在，在分层开始后返回。在这个群体中观察到一个演替模式。在研究的最后一个雨季（2006 年 10 月至 2007 年 3 月），Aphanocapsa 属占主导地位。然而，只有当微囊藻属和球腔菌属存在时才检测到毒性（2005 年 10 月）。主成分分析显示蓝藻与正磷酸盐呈负相关。3 年来优势蓝藻的变化以及水库中非毒性属的最终流行是对水库流域实施管理技术导致水质改善的证据。
