Dinâmica espacial da comunidade fitoplanctônica de uma represa subtropical

Abstract

Phytoplankton comprises microscopic photosynthetic organisms that inhabit the water column of various continental and marine aquatic environments. These organisms have great environmental importance, since they are primary producers and are at the base of the food chain, and can be used as bioindicators of water quality. The present project aimed to evaluate the spatial variability of the phytoplankton community of a subtropical reservoir and to relate it to the abiotic physical and chemical variables of water and to the climatic variables. The area of study is the reservoir of the Federal Technological University of Paraná, Dois Vizinhos, Paraná. Water samples were collected at two different reservoir sites in the pelagic and littoral region in March 2019. The following climatic parameters were evaluated: temperature (ºC), rainfall (mm) and solar radiation, and physical and chemical parameters of the water: pH, transparency, temperature, dissolved oxygen, conductivity, orthophosphate, total phosphorus, nitrate, nitrite and ammonium. The structure of phytoplankton community were also evaluated using density of the taxa, richness (R), diversity (H'), dominance (D) and equitability (J). Nutrient concentrations are low and are not available in large quantities in the environment. Twenty five taxa were identified, distributed in 15 genera and 5 classes. The phytoplankton community presents low richness and diversity, and high species dominance. There were no significant differences in the physical, chemical and biological variables between the pelagic and littoral regions of the reservoir.