Assessment of the sublethal toxicity of organochlorine pesticide endosulfan in juvenile common carp (Cyprinus carpio).

This study is aimed at evaluating the sublethal effects of endosulfan (EDS) in juvenile common carp (Cyprinus carpio). For this purpose, fish were exposed for 15 days to the technical EDS (95% pure) diluted in dimethyl sulfoxide (DMSO) 0.1% of the total volume in water solution in a semi-static system at sublethal concentration (1 µg/L). Subsequently, the liver somatic index (LSI) and factor condition (K) were determined. The total cytocrome P450 (CYP), CYP1A isoform, and the ethoxyresorufin-O-deethylase (EROD) activity were determined from the hepatic microsomal fraction as well as the activity of the oxidative stress enzyme system such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GP(X)), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH). Among the parameters assessed, EDS at the sublethal concentration in subchronic exposure caused significant changes in liver somatic indices as well as induction of the phase I biotransformation system and oxidative stress in juvenile common carp (Cyprinus carpio). Thus, it is seen that the use of biochemical biomarkers of environmental contamination in this study proved to be an extremely important tool for detecting the adverse effects of xenobiotics in the aquatic environment, even at low concentration.

The value of hydrologic information for watershed management programs: The case of Camboriú, Brazil.

Investments in watershed services programs hold the promise to protect and restore ecosystems and water resources. The design and implementation of such programs is often accompanied by hydrologic modeling and monitoring, although the role of hydrologic information in meeting the needs of program managers remains unclear. In the Camboriú watershed, Brazil, we explored the value of hydrologic modeling and monitoring with respect to two dimensions: scientific credibility and use of generated knowledge in the design, implementation, and evaluation of the watershed management program. We used a combination of semi-structured interviews, focus groups, and hydrologic modeling under various levels of data availability to examine when improved models and data availability might build credibility and provide more useful information for decision makers. We found that hydrologic information was not actually used for the detailed design, but rather contributed to broad-scale support of the program by increasing scientific credibility. Model sophistication and data availability improved the credibility of hydrologic information but did not affect actual decisions related to program design. Hydrologic monitoring data were critical for model calibration, and high-resolution land use and land cover data, obtained via remote sensing, affected some model outputs which were not used to design the program. Our study suggests that identifying how hydrologic data will inform decision making should guide the level of effort used in hydrologic modeling and monitoring.

Returns on investment in watershed conservation: Application of a best practices analytical framework to the Rio Camboriú Water Producer program, Santa Catarina, Brazil.

Watershed management may have widespread potential to cost-effectively deliver hydrologic services. Mobilizing the needed investments requires credible assessments of how watershed conservation compares to conventional solutions on cost and effectiveness, utilizing an integrated analytical framework that links the bio-, litho-, hydro- and economic spheres and uses counterfactuals. We apply such a framework to a payment for watershed services (PWS) program in Camboriú, Santa Catarina State, Brazil. Using 1 m resolution satellite imagery, we assess recent land use and land cover (LULC) change and apply the Land Change Modeler tool to predict future LULC without the PWS program. We use current and predicted counterfactual LULC, site costs and a Soil and Water Assessment Tool model calibrated to the watershed to both target watershed interventions for sediment reduction and predict program impact on total suspended solids (TSS) concentrations at the municipal water intake-the principal program objective. Using local water treatment and PWS program costs, we estimate the return on investment (ROI; benefit/costs) of the program. Program ROI exceeds 1 for the municipal water utility in year 44, well within common drinking water infrastructure planning horizons. Because some program costs are borne by third parties, over that same period, for overall (social) program ROI to exceed 1 requires delivery of very modest flood and supply risk reduction and biodiversity co-benefits, making co-benefits crucial for social program justification. Transaction costs account for half of total program costs, a result of large investments in efficient targeting and program sustainability. Co-benefits justify increased cost sharing with other beneficiaries, which would increase ROI for the utility, demonstrating the sensitivity of the business case for watershed conservation to its broader social-economic case and the ability to forge institutional arrangements to internalize third-party benefits.

Cytochrome P450 detection in liver of the catfish Ancistrus multispinis (Osteichthyes, Loricariidae)

Sensitive biological responses to environmental contaminants are useful as early warning signals to predict the damages by long-term exposure. Protocols standardization to quantify biochemical parameters in different fish species is required to validate its use as biomarkers. Comparative studies from different fish species and its interpretation are a challenge for the validation of its use as general biomarkers, representative of environmental impact. In this study, the protocol for liver cytochrome P450 (CYP) analysis from the native Brazilian fish Ancistrus multispinis was established. The microsome contamination by hemoglobin during the analysis of CYP in liver was detected, leading to misinterpretation of the results. The spectrophotometric method for CYP analysis was adapted in order to diminish the hemoglobin interference. Additionally, the western blotting method for CYP1A analysis was tested with success for this fish species.

Respostas biológicas sensíveis aos contaminantes ambientais são úteis para prever efeitos prejudiciais devido a exposições crônicas. Padronização de protocolos para quantificar parâmetros bioquímicos em diferentes espécies de peixes é necessária para validar o uso como biomarcador. Estudos comparativos de diferentes espécies de peixe e sua interpretação são um avanço para a validação do uso de biomarcadores gerais, representativos do impacto ambiental. Neste estudo o protocolo para a análise do citocromo P450 (CYP) do peixe nativo brasileiro Ancistrus multispinis foi estabelecido. Cyp é um biomarcador de exposição principalmente de hidrocarbonetos policíclicos aromáticos (HAP), bifenilas policloradas (PCB) e dioxinas. A contaminação do microssomo pela hemoglobina durante as análises do CYP no fígado foi detectada, levando a uma interpretação errônea dos resultados. O método espectrofotométrico para análise do CYP foi adaptado para diminuir a interferência da hemoglobina. Além disso, o método de western blotting para análise de CYP1A foi testado com sucesso para essa espécie de peixe.

Biochemical biomarkers of exposure to deltamethrin in freshwater fish, Ancistrus multispinis

This study aimed to determine the effect of sublethal doses of deltamethrin, using biochemical biomarkers as activities of cholinesterase (ChE), ethoxyresorufin-O-deethylase (EROD) and the Na+K+- ATPase and levels of total cytochrome P450 (CYP450). Fishes received sublethal doses of deltamethrin and were sacrificed after 96 h of exposure. Samples of gills, heart, brain, liver and muscle were collected for enzymatic analyses. Deltamethrin inhibited the activity of the gills and heart Na+ K+-ATPase, induced the liver total CYP450, as well as the liver EROD activity. The activity of the ChE was not inhibited by deltamethrin. Deltamethrin altered the hepatic metabolism and the normal ionic flux in Ancistrus multispinis.

Deltametrina é um inseticida piretroide, usado in agricultura, na medicina veterinária a em saúde pública devido a sua baixa toxicidade para mamíferos. Contudo, para espécies não alvo como os peixes a deltametrina é extremamente tóxica. Esse estudo tem por objetivo determinar o efeito de doses subletais de deltametrina, usando biomarcadores bioquímicos como atividade da colinesterase (ChE), níveis totais de citocromo P450 (CYP450), atividade da ethoxyresorufin-O-deethylase (EROD) e da Na+K+-ATPase. Os peixes receberam doses subletais de deltametrina e após 96 horas de exposição foram sacrificados e o fígado, brânquias, coração e músculo foram coletados para as medidas enzimáticas. A atividade da Na+K+-ATPase em brânquias e coração foi inibida. A deltametrina aumentou os níveis de CYP450 total, bem como a atividade da EROD. A atividade da ChE não foi inibida. Deltametrina alterou a atividade da Na+K+-ATPase e desta forma o fluxo normal de ions em A. multispinnis, bem como seu metabolismo hepático. Os efeitos detectados através de biomarcadores tornam esse inseticida um importante contaminante para organismos aquáticos.

Effects of endosulfan sublethal concentrations oncarp (Cyprinus carpio, Linnaeus, 1758): Morphometric, hystologic, ultrastructural analysesand cholinesterase activity evaluation / Efeitos do endosulfano em concentrações subletais em carpas (Cyprinuscarpio, Linnaeus, 1758): Análises morfométricas, histológicas eultraestrutural e avaliação da atividade da colinesterase

Endosulfan, an organochlorine pesticide, has been banned by most developed countries, although it is still produced, sold and used in developing countries. Used for control in crops, as well as for insect control in public health programs in some countries, its effects on the environment and its toxicity are still in discussion. For some researchers, its bioaccumulation in terrestrial organisms is considered irrelevant but for aquatic life it should be considered carefully. The present research work was to carry out an study on the effects of sublethal concentrations of endosulfan on the fresh water fish carp (Cyprinus carpio, Linnaeus, 1758). The fishes were exposed during 15 days to 0.001 mg/L of endosulfan using dimethylsulfoxide 0.1% (DMSO) as solvent. The acetylcholinesterase activity on the brain and axial muscle, as well as liver morphometric, histopathologic and ultrastructural analysis were studied. The hepatic somatic index and the livers weight showed smaller values when compared with the control groups, besides being also observed histopathological and ultrastructural alterations. It has not been observed significant alterations in the cholinesterase activity of both brain and striated muscle. These results suggest that the organochloride endosulfan caused toxic effects in the hepatic metabolism of the fish exposed to it in sub lethal doses

Endosulfano, um pesticida organoclorado, tem sido banido pela maioria dos países desenvolvidos, embora seja ainda produzido e utilizado deliberadamente em países em desenvolvimento. Utilizado no controle de pragas, assim como no controle de insetos em Programas de Saúde Pública em alguns países, seus efeitos no meio ambiente e sua toxicidade continuam em discussão. Para alguns pesquisadores a bioacumulação nos organismos terrestres é considerada irrelevante, mas não para a vida aquática. O objetivo da presente pesquisa foi estudar os efeitos das concentrações subletais do endosulfano em peixes de água doce Cyprinus carpio, (Linnaeus, 1758). Os peixes foram expostos durante 15 dias, a uma concentração de 0,001mg/L de endosulfano utilizando o dimetilsulfóxido (DMSO) a 0,1% como solvente. A atividade da acetilcolinesterase do músculo axial e cerebral assim como a morfometria, histopatologia e a ultraestrutura do fígado desses peixes foram avaliadas. O índice somático hepático e o peso dos fígados mostraram valores menores quando comparados ao grupo controle, observando-se também, alterações histopatológicas e ultraestruturais. Nenhuma alteração significante na atividade da acetilcolinesterase muscular e cerebral foram observadas. Os resultados sugerem que o organoclorado endosulfano causou efeitos tóxicos no metabolismo hepático dos peixes expostos a doses subletais