Ecological patterns of Cladocera and Copepoda in natural oxbow lakes in the Upper Paranapanema River basin: the variations are regulated by the size, connection with the river and to the anthropic impacts

Abstract

The project consists of analyzing planktonic assemblages of Cladocera and Copepoda (Crustacea) microcrustaceans in natural lakes in the basin of the Upper Paranapanema River. These organisms perform indispensable ecological functions in aquatic ecosystems, forming the link between the primary producers and higher trophic levels and are still widely referenced as bioindicators, by sensitivity to anthropogenic environmental disturbances or not, especially as regards the trophic state. Due to its wide geographic distribution, there are several ecosystems that are still little studies in the country, such as meander-type natural lakes in the Upper Paranapanema River stretch. Ecological attributes of microcrustaceans will be analyzed under the influence of the size of the lakes, their connection with the river and the degree of anthropic impacts in a trophic gradient due to the extraction of sand, agriculture and livestock and the absence of impacts. Four lakes were selected and three collection points were sampled. Quantitative collections will be done by filtering a total of 400 liters of water through a graduated bucket of 10 liters, while the qualitative ones will be collected by vertical and horizontal trawls using a conical zooplankton net of 68 ¼m mesh. The material will be fixed with 4% formaldehyde buffered with calcium tetraborate and will be used stereoscope, binocular microscope and specialized bibliographies for identification. The data obtained will be analyzed through ecological indexes, descriptive statistical analyzes, univariate and multivariate analyzes, and bioindicator filters, using specific packages for the program R Can Project 3.3.1, in order to verify the occurrence of trends of data variation. Some limnological variables will be analyzed in situ and through laboratory analysis, such as water temperature, dissolved oxygen, turbidity, transparency, pH, electrical conductivity, total phosphorus, total nitrogen, total chlorophyll and total suspended matter. The modified Carlson trophic status index will be used for the characterization of lakes. The results of the project will be evaluated by the national and international scientific community through the presentation of in scientific events, as well as by the editorial committees of specialized journals. (AU)