Assessment of aquatic plants in the reservoirs of AES-tietê and development of an integrated control model for the most important species

The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tietê as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promiss?o, and Nova-Avanhandava, located in the Tietê River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Gua?u reservoir, which belongs to the Mogi-Gua?u River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move coating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants.     

Endocrine and metabolic changes in Anguilla anguilla L. following exposure to beta-naphthoflavone--a microsomal enzyme inducer

Anguilla anguilla L. were exposed during 24 and 48 h to 2.7 muM beta-naphthoflavone (BNF), a known microsomal enzyme inducer. The BNF effects on thyroid-stimulating hormone (TSH), free triiodothyronine (T3), free thyroxine (T4) and cortisol plasma levels were investigated. Alterations on plasma glucose and lactate levels were also measured as an indication of energy-mobilizing hormones alterations. BNF showed to be able to decrease significantly A. anguilla plasma T4 levels, whereas TSH, T3 and cortisol plasma remained constant. However, plasma glucose levels were significantly increased, demonstrating that intermediary metabolism has been affected. These results demonstrate that BNF a PAH-like compound alters the normal functioning of the hypothalamo-pituitary-thyroid (HPT) axis in A. anguilla.     

Anguilla anguilla L. antioxidants responses to in situ bleached kraft pulp mill effluent outlet exposure

This study assesses the antioxidant enzymes activities viz., catalase, glutathione peroxidase, glutathione S-transferase and nonenzymatic antioxidant molecule such as glutathione in Anguilla anguilla L. gill, kidney and liver in response to 8- and 48-h exposure to bleached kraft pulp mill effluent (BKPME). A. anguilla were caged and plunged at three different sites-50 (Site 1), 100 (Site 2) and 2000 m (Site 3) away from the closed BKPME outlet. A significant gill (8 and 48 h) and kidney (48 h) catalase activity decrease was observed at site 2 exposure whereas liver showed a significant increase in catalase activity after 8 and 48 h to site 1 exposure. Glutathione peroxidase (GPX) activity was significantly decreased in gill after 8-h exposure to site 1 and 48-h exposures to sites 1 and 2, respectively. Concerning gill, kidney and liver glutathione S-transferase (GST) activity, a significant gill GST activity decrease after 8 h at site 2 and 48 h at sites 1 and 2 was observed; in kidney, a significant decrease in its activity was observed after 48 h at sites 1 and 2, respectively, whereas in liver, the decrease was significant only at site 2 after 48-h exposure. The in situ BKPME exposure caused a significant total gill and kidney reduced glutathione (GSH) decrease after 8 h at site 2 exposure and after 48 h at site 1 and 2 exposures, respectively. However, a biphasic response was observed in liver, i.e. initial significant increase after 8 h at site 2 followed by a significant decrease after 48 h to the same site exposure. The enzymatic and nonenzymatic antioxidants pattern in gill and kidney, as observed in this study, was different than liver, demonstrating that the liver was more resistant to oxidative damage than gill and kidney. In addition, A. anguilla gill, kidney and liver antioxidants adaptation potentials may serve as a surrogate biomarker to BKPME exposure.     

A knowledge network to promote the use and valorization of wild food plants in the Pantanal and Cerrado,Brazil

Regional Environmental Change - The conservation and use of wild food plants should include local people in the decision-making process, and many countries have done so. However, interacting with...     

Blood markers among residents from a coal mining area

Environmental Science and Pollution Research - Coal extraction and processing generate environmental contamination, which has several negative impacts on human health. Hematological and biochemical...     

LED irradiated photo-Fenton for the removal of estrogenic activity and endocrine disruptors from wastewater treatment plant effluent

Environmental Science and Pollution Research - The goal of this work was to evaluate the performance of the LED irradiated photo-Fenton process on the removal of (i) estrogenic activity and (ii)...     

Ecotoxicity of imidacloprid to soil invertebrates in two tropical soils with contrasting texture

Environmental Science and Pollution Research - Imidacloprid is one of the most commercialized insecticides in agriculture in the world, with a broad spectrum of action. However, little is known...