title: Recurrent blooms of Heterosigma akashiwo (Raphidophyceae) in the Piraquê Channel, Rodrigo de Freitas Lagoon, southeast Brazil.
abstract: Six blooms of Heterosigma akashiwo (Raphidophyceae) were observed from March 2007 through March 2008 in the Rodrigo de Freitas Lagoon, a semi-confined eutrophic system located in Rio de Janeiro state, southeast Brazil. Vegetative cells of H. akashiwo analysed by optical and electron microscopy showed morphology as described in the literature. The blooms (2.8 × 10(4) to 4 × 10(8) cell.L(-1)) were restricted to the middle section of the Piraquê Channel, which is situated in the northeastern part of the lagoon and receives freshwater inflow. The salinity of subsurface water and the channel depth showed significant negative correlations with H. akashiwo abundances, and appeared to restrict the blooms to this compartment of the lagoon. No fish mortality was associated with the H. akashiwo blooms, nor were brevetoxins detected in a cell extract obtained from the bloom observed on 19 March 2007.
authors.affiliation: Museu Nacional, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Branco
authors.affiliation: Museu Nacional, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Menezes
authors.affiliation: Museu Nacional, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Alves-de-Souza
authors.affiliation: Instituto de Biologia Roberto A. Gomes - IBRAG, Universidade Estadual do Rio de Janeiro - UERJ, Rio de Janeiro, RJ, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: Domingos
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia de Santa Catarina, Itajaí, SC, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Schramm
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia de Santa Catarina, Itajaí, SC, Brazil.
authors.forename: L A O
authors.initials: LA
authors.lastname: Proença
mesh_terms: D001938:Brazil; D004784:Environmental Monitoring; D056890:Eukaryota / Q000254:growth & development*; D060106:Lakes; D011156:Population Density; D012621:Seasons