Planktonic Cyanobacteria forming blooms in reservoirs of northeastern Brazil

Abstract

This paper contributes to the inventory of cyanobacteria in freshwater environments in Northeastern Brazil. Forty-two samples were collected from 19 reservoirs between February 2009 and January 2010. Twenty-three species of cyanobacteria distributed among the orders Chroococcales (10), Oscillatoriales (8) and Nostocales (5) were identified, 12 of which constitute new records for the state of Pernambuco. The greatest degrees of species richness were recorded in three ecosystems (Alagoinha, Carpina and Ingazeira reservoirs). Microcystis was the most representative genus, with the greatest number of species (Microcystis novacekii (Komárek) Compère, Microcystis panniformis J. Komárek, J. Komárková-Legnerová, C.L. Sant’Anna, M.T.P. Azevedo & P.A.C, Senna, Microcystis protocystis W.B. Crow and Microcystis sp.). Cylindrospermopsis raciborskii (Woloszynska) Seenaya and Subba Raju (straight morphotype) had the greatest distribution (considered very frequent) and was present in 16 reservoirs (84.25%). Only four of the 42 samples did not have cyanobacteria.