Study of the phytoplankton community with emphasis on Cyanobacteria, in Carpina-PE reservoir

Abstract

The blooms of Cyanobacteria are frequently found in reservoir used to supply public, because of eutrophication process. In this study, there were eight samples of water from July to November 2006, with the goal of studying the dynamic of the phytoplankton community with emphasis on Cyano bacteriain Carpina-PE reservoir. To floristic survey, they were collected living samples and samples preserved with in 2% formalin, using plankton net with mesh opening of 25μm. While, for the quantitative analysis, the samples were collected with bottles of wide mouth, preserved with formalin (2%), and examined in Utermöhl chambers of 5mL. The Analyses phytoplanktonic were performed on inverted microscopy. Were identified 21 taxa distributed from the following divisions: Cyanobacteria (10spp.), Chlorophyta (6spp.), Chrysophyta (4spp.) e Euglenophyta (1spp). Amongst these 71.43% showed with a large frequence, where Cyanobacteria appeared the most conspicuous along study. As for the density, every samples presented values over 100.000 cel.mL-1. According with OMS, the environment find out in alert level 2, indicating a high risk to human health.