Recurrent blooms of Heterosigma akashiwo (Raphidophyceae) in the Piraquê Channel, Rodrigo de Freitas Lagoon, southeast Brazil

Brazilian Journal of Biology

S Branco¹  M Menezes¹  C Alves-de-souza¹  P Domingos¹  Ma Schramm¹  Lao Proença¹ 

关键词: morphology;    taxonomy;    blooms;    urban coastal lagoon;    Rio de Janeiro;    morfologia;    taxonomia;    florações;    lagoa costeira urbana;    Rio de Janeiro;   

DOI  :  10.1590/bjb.2014.0074

来源: SciELO

【 摘 要 】

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 × 104 to 4 × 108 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.

【 授权许可】

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