Variação espacial e temporal do fitoplâncton no trecho do rio Tocantins sob influência da UHE de estreito

Abstract

The study of the dynamics of phytoplankton communities associated with tropical water bodies is a complex task because the wide range of factors and environmental aspects of natural or anthropogenic origin, influencing environmental processes. The changes in these communities are promoted by human intervention, with the construction of dams, are still underestimated, especially in the middle course of the Tocantins River. In order to try to fill this knowledge gap that has carried out the study of the phytoplankton community structure in the area of direct influence of the Strait of hydroelectric power plants in the middle reaches of the Tocantinsriver, seeking to obtain data from both the river environment and the lake environment, over the two typical seasonal periods of the region (dry and wet). Throughout the study were identified 237 species of phytoplankton algae, being Conjugatophyceae (40.1%), Chlorophyceae (16.5%) and cyanobacteria (12.7%) of the more representative sampling along the classes. Separation was observed between the seasonal periods (dry and wet) and relative to the environment (lakes and rivers), this latter mainly related to the number unique to the species in each of these environments.