摘要：1 - Coastal lagoons show great fragility and vulnerability to the anthropogenic pressure. The understanding of physical, chemical, geological characteristics and ecological dynamics of lagoons is fundamental for planning the implementation of coastal management strategies in these ecosystems. The intrinsically high variability of phytoplankton communities in transitional environments should be taken into account not only because of phytoplankton ecological importance, but also because of the implications for environmental management. 2 - The aim of this study is a general description of the phytoplankton community in three coastal lagoons situated in the Rio Grande do Norte region, at the Northeast of Brazil. 3 - For the three lagoons, a total of 124 phytoplankton taxa were identified. In terms of species richness, diatoms were the largest group with 92 identified taxa belonging to 46 genera. At the class level, Bacillariophyceae recorded 39 taxa belonging to 18 genera; Coscinodiscophyceae recorded 39 taxa belonging to 21 genera and Fragilariophyceae recorded 14 taxa belonging to 7 genera. The group of the dinoflagellates recorded 15 taxa belonging to 6 genera and the Cyanophyceae was represented by 8 taxa belonging to 5 genera, including Trichodesmium erythraeum, a taxon related to toxic blooms.
关键词：phytoplankton;taxonomic composition;Brazilian coastal lagoons;Rio Grande do Norte
