Levels of metals and toxicity in sediments from a Ramsar site influenced by former mining activities.

This study aimed to evaluate the sediment quality in a Ramsar site located in the Southeast Brazil, by using several lines of evidence (LOEs). Chemical and sedimentological analyses, ecotoxicological tests, and whole-sediment Toxicity Identification Evaluation (TIE) were performed. The sediments were predominantly composed of fine sands and muds. Higher concentrations of metals in the sediments collected close to Iguape were observed; however according to the SEM/AVS analyses, most sediments should not be toxic and the potentially toxic samples could occur along the whole channel. In fact, sediments of most stations were toxic in at least one survey. The PCA revealed associations between mud, metals and toxicity. Acutely toxic sediments presented Pb concentrations above the threshold effect levels, while chronic toxicity seemed to be influenced also by SEM. The most contaminated and toxic areas are not necessarily those located close to the primary sources, but are actually those with finer sediments. Toxicity Identification and Evaluation (TIE) showed that metals and ammonia were responsible for the toxicity. The results suggest that metals from former mining areas located at the upper Ribeira de Iguape River are transported to the Cananéia Iguape Peruíbe Protected Area and accumulate in the sediments at potentially toxic levels. The location of muddy and more contaminated sediments appears to move along the estuary, accompanying the displacement of the maximum turbidity zone, which, in turn, depends on seasonal freshwater inputs. The results also showed that using several lines of evidences to asses contamination in a protected area provides reliable information to subsidise further actions to control the sources of contaminants.

Assessing genotoxic effects in fish from a marine protected area influenced by former mining activities and other stressors.

The goal of the current study was to evaluate different genotoxicity tools in order to assess a marine protected area (MPA) affected by former mining activities and urban settlements. A catfish (Cathorops spixii) was analyzed for genotoxic effects at the (i) molecular and at the (ii) chromosomal levels. Through factor analysis, genotoxicity was found to be linked to levels of metals bioaccumulated and PAH metabolites in the bile. Micronucleus and nuclear alteration were less vulnerable to the effects of confounding factors in mildly contaminated areas since they were more frequently associated with bioaccumulated metals than the DNA analysis. The different genotoxicity responses allowed for the identification of sources of pollution in the MPA. This approach was important for detecting environmental risks related to genotoxic contaminants in a mildly contaminated MPA.

Assessing pollution in marine protected areas: the role of a multi-biomarker and multi-organ approach.

Marine protected areas (MPAs) are vulnerable to many pressures, including pollution. However, environmental quality monitoring in these areas traditionally relies on only water chemistry and microbiological parameters. The goal of the current study was to investigate the role of a set of biomarkers in different target organs (liver, kidney, and gills) of fish in order to assess the environmental quality of an MPA (MTs, GPx, GST, GSH, DNA damage, LPO, AChE, and condition index). Chemical analyses were also performed on liver and muscle tissues to evaluate metal body burdens, and PAHs were identified in bile. A demersal fish (Cathorops spixii) that is widely consumed by the local population was used as bioindicator species, and the results were integrated using multivariate analysis. The use of the biomarker approach allowed for the identification of both seasonal and spatial variations in pollution sources around the Environmental Protected Area of Cananéia-Iguape-Peruíbe (APA-CIP). Higher metal body burdens associated with biological responses were found in the sites under the influence of urban areas during the dry season, and they were found in the sites under the influence of the Ribeira de Iguape River (RIR) during the rainy season. The liver was found to be more responsive in terms of its antioxidant responses, whereas gills were found to be more responsive to biomarkers of effect. These results show that this set of biomarker analyses in different organs of fish is a useful tool for assessing chemical pollution in an MPA.

Percepção ambiental / Environmental Awareness

O Núcleo Pedro de Toledo faz parte do Parque Estadual da Serra do Mar, uma categoria de Unidade de Conservação que não permite a presença de moradores e o uso direto de seus recursos naturais. No entanto, o Núcleo é ocupado por diversas famílias distribuídas em bairros relativamente bem definidos. Neste trabalho, foi realizado um perfil sócio-econômico dos moradores do núcleo, sendo investigada também a forma como usam e ocupam o solo e identificados os potenciais impactos ambientais decorrentes desse uso. Para tal, foram conduzidas visitas ao local, tendo sido aplicados questionários semi-estruturados aos moradores do interior e entorno do Núcleo. As comunidades são bastante homogêneas, sendo formadas basicamente por agricultores, muitos originados de fora do parque, não constituindo uma população tradicional. Embora tenham afirmado conhecer as restrições legais e conviver relativamente bem com elas, o uso e ocupação do solo foram considerados incompatíveis com a conservação dos recursos naturais destinando-se principalmente à produção agrícola, piscicultura e lazer. Com base nas informações levantadas, evidenciou-se a necessidade da incorporação de práticas agrícolas menos impactantes, além da introdução de alternativas econômicas que não envolvem o uso direto dos recursos do parque, como o ecoturismo, de modo a garantir a preservação do ambiente e a melhoria da qualidade de vida dos moradores, até que a situação fundiária do Núcleo seja resolvida.

Avaliação ecotoxicológica da água do rio Pirajussara (SP, Brasil) / Ecotoxicological Assessment of Water from the Pirajussara River (SP, Brazil)

Neste estudo, foi avaliada a qualidade de amostras de água coletadas em quatro pontos do rio Pirajussara, por meio de análise de parâmetros físico-químicos e testes de toxicidade. Foram realizadas quatro campanhas de coleta, e em todas elas as águas do rio apresentaram baixos teores de oxigênio dissolvido e altas concentrações de amônia. Foram observados efeitos tóxicos sobre Daphinia similis em todos os experimentos realizados. Nas duas primeiras campanhas todas as amostras causaram efeitos tóxicos. Já na terceira campanha, as amostras dos pontos 2 e 4 apresentaram toxicidade, enquanto na quarta foram tóxicas amostras 3 e 4. Os resultados indicam que as águas do rio Pirajussara não apresentam qualidade satisfatória para a vida aquática, e mostram que há a necessidade da continuação dos estudos físico-químicos e ecotoxicológicos.