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Industrial laundries have water as one of their main inputs and they release effluents in large amounts, with a high polluting load, which are usually discarded into the environment, or they are insufficiently treated for release into the neighboring water bodies. The aim of this study was to evaluate the efficiencies of the biological treatments in an industrial textile laundry and their environmental impact on the surface waters of the stream where the dump is usually made, by using cytotoxicity tests on the meristematic root cells of Allium cepa L. The results have shown, for the most part, that the treated effluents over a period of 24 h showed reductions in their mitotic index. The treatments on the raw effluents showed cytotoxic effects when compared to control, with cell division recoveries after 24 h in the waters. Cytotoxic effects were additionally observed in the stream waters, at a point before the dump, indicating that they received a pollutant load, before the effluent disposal site of the evaluated industrial laundry. Notably, the treatments that were being applied by the industrial laundry were effective throughout the processing, reducing the concentrations of the toxic substances. When considering the data presented, it is now understood that there is a constant need for the evaluation of industrial effluents, as well as for the waters of the streams and the rivers that receive these disposals, in order to preserve and maintain the quality of the waters, the organisms, and consequently, the ecosystems.

Environmental characteristics of an invaded environment can predict the invasion success of a species, depending on its habits and life strategies. Cichla kelberi is a visual and voracious predator introduced in the upper Paraná River floodplain, an area that suffers with several upstream dams that caused many environmental changes over the years (e.g. increased water transparency). As this species is a pre-adapted species to environments that presents high water transparency, our main goal was to test the hypothesis that variables related to the underwater visibility would be important drivers of the successful invasion of C. kelberi in the upper Paraná River floodplain. We predict that turbidity (proxy of water transparency) is one of the major limnological determinants of occurrence and abundance of C. kelberi. Individuals of the invasive species and seven limnological variables were sampled quarterly between February 2000 and November 2018. This long-term data is part of the sixth site of the Brazilian Long Term Ecological Program (PELD). We fitted two regression models to all occurrence and abundance data (response variables) against the limnological variables (explanatory variables). For occurrence data, we fitted a Generalized Linear Mixed Model and for abundance data, we fitted a Linear Mixed Effects Model. The occurrence data of C. kelberi showed that turbidity and dissolved oxygen were the variables that most influenced the presence of this species, negatively and positively, respectively. The abundance data showed that dissolved oxygen and concentration of chlorophyll-a were the ones that most influenced the abundance of this species, negatively and positively, respectively. Our findings showed that besides turbidity, other limnological variables were also determinants for the occurrence and abundance of C. kelberi. Therefore, our results provided important

Foi proposto um debate para alunos do 9º ano de um colégio público do Estado do Paraná. Neste debate, os alunos foram divididos em dois grupos antagônicos, sendo que um deles foi responsável por defender que o aquecimento global é causado pelos humanos e o outro por argumentar que ele possui causas naturais. O debate mostrou uma grande deficiência dos alunos em criar argumentos e contra-argumentos, e destacou a importância de exercitar esse tipo de ação. Porém, essa ferramenta se mostrou efetiva na discussão do tema, visto que os alunos tiveram contato com os dois lados e no fim formularam suas próprias conclusões acerca do tema e ainda foram capazes de propor medidas para a diminuição do aquecimento global.

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