Dinoflagellates in tropical estuarine waters from the Maraú River, Camamu Bay, northeastern Brazil

Dinoflagellates display great diversity in tropical regions and play an important role in the complex microbial food webs of marine and brackish environments. The goal of this study is to identify planktonic dinoflagellates and their distribution in the estuary of the Maraú River, Camamu Bay, state of Bahia, in a region with increasing use of shellfish farming. Samples were carried out monthly from August 2006 to July 2007 at four stations along the estuary. Plankton was sampled with a 20 μm mesh net. We identified 20 dinoflagellate species. The greatest species richness was observed in the genera Protoperidinium (five spp.), Tripos (four spp.), and Prorocentrum (three spp.). Based on literature, six species were classified as potentially harmful: Akashiwo sanguinea, Dinophysis caudata, Gonyaulax spinifera, Prorocentrum micans, Scrippsiella cf. acuminata, and Tripos furca. Protoperidinium venustum was recorded for the first time in coastal waters of Bahia.