Taxonomia, distribuição e quantificação de populações de cianobactérias em reservatórios do Estado de Pernambuco (Nordeste do Brasil)

• Autor(a) principal: ARAGÃO, Nísia Karine Cavalcanti Vasconcelos
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4904
• topic: Análise taxonômica; Biomassa; Densidade; Estudo populacional; Floração; Riqueza de espécie; Cianobactéria; Pernambuco (BR); Cyanobacteria; Taxonomic analysis; Biomass; Density; Flowering; CIENCIAS BIOLOGICAS::BOTANICA

Cyanobacteria occur in aquatic ecosystems in Brazil, especially in the semiarid region, are mostly responsible for the formation of blooms, and thus the increase of this phenomenon has been increasing concern because of its potential to release toxins. These organisms show a great morphological variability that reflect the taxonomic difficulties. This study aimed to perform a taxonomic study of cyanobacteria in 19 reservoirs of Pernambuco state, describing their morphological characteristics, with illustrations and geographical distribution, and quantify the population. Were 42 samples in the period between February 2009 and January 2010. The samples for qualitative and quantitative analysis of cyanobacteria were collected with a van Dorn bottle at a single point in the environment near the shore and in the subsurface. For the taxonomic study, samples were analyzed by optical microscope and was used identification keys in articles and specialized books. The quantitative analysis was performed using an inverted microscope by the method of Utermöhl. The count was performed on random fields, and the results expressed as densities (cel.mL-1), and from these, certain biomass of cyanobacteria. There were 23 taxa, distributed in Chroococcales, and Oscillatoriales Nostocales these, 11 were cited for the first time for the state of Pernambuco. In Alagoinha, Carpina Ingazeira were recorded and the highest species richness (10 spp.). Cylindrospermopsis raciborskii (Woloszynska) Seenaya & Subba Raju and Geitlerinema amphibium (Agardh ex Gomont) Anagnostidis were the only taxa with more occurrence (84.21% and 68.42%, respectively). The highest cell density was about 5x1010 cel.mL-1, registered in Venturosa. 14 reservoirs in the densities of cyanobacteria were above 106 cel.mL-1, while the reservoirs Bitury, Jazigo, Pastora, Saco I and Santo Antonio dos Palmares densities were between 104 and 105cel.mL-1. Two Unas fortunate and had the highest biomass recorded by Merismopedia tenuissima Lemmermann (74x103 mg.L-1) and Microcystis sp. (42x103 mg.L-1), respectively.