Quality evaluation of the estuary sediment of the river Ceara

A avaliaÃÃo da qualidade do sedimento tem sido vista como a extensÃo coerente e necessÃria de programas de avaliaÃÃo dos recursos aquÃticos. Os sedimentos apresentam-se como o mais preocupante dos compartimentos devido Ãs caracterÃsticas que favorecem a deposiÃÃo e acÃmulo de contaminantes. Estudos anteriores mostraram que o estuÃrio do rio Cearà vem sofrendo contaminaÃÃo por efluentes industriais e domÃsticos e que foi observada toxicidade a embriÃes de ouriÃo do mar expostos as Ãguas do estuÃrio. O objetivo do presente trabalho foi avaliar a qualidade ambiental de amostras de sedimento do estuÃrio do Rio CearÃ, atravÃs de anÃlises sedimentolÃgicas, quantificaÃÃo de metais e atravÃs de bioensaios em vÃrios compartimentos do sedimento. Foram realizadas trÃs Campanhas (Out/06, Jan/07 e Mai/07) em quatros estaÃÃes ao longo do estuÃrio. Como local de referÃncia foram amostrados sedimentos dos estuÃrios dos rios Malcozinhado e Pacoti. AnÃlises de granulometria, carbonatos, matÃria orgÃnica e ainda a anÃlise de Zn, Cu, Pb e Cr serviram para caracterizar as estaÃÃes. A toxicidade do sedimento integral foi avaliada em bioensaios com o anfÃpodo Tiburonella viscana e o copÃpodo Nitokra sp.; enquanto que embriÃes do ouriÃo do mar Lytechinus variegatus foram utilizados em testes na interface sedimento/Ãgua e com elutriatos. A caracterizaÃÃo da toxicidade de elutriatos foi realizada atravÃs de manipulaÃÃes fÃsicas e quÃmicas para AvaliaÃÃo e IdentificaÃÃo de Toxicidade (AIT). Foi observado um gradiente em relaÃÃo Ãs porcentagens de finos, matÃria orgÃnica e metais com valores decrescendo na direÃÃo da foz. De forma geral, as amostras coletadas no estuÃrio do rio Cearà foram tÃxicas em todas as rotas de exposiÃÃo. O teste com anfÃpodos mostrou boa reprodutibilidade, enquanto que a reproduÃÃo de copÃpodos teve grandes variaÃÃes no controle, entre as Campanhas. Para ambos os testes com embriÃes de ouriÃo do mar, a toxicidade foi elevada. A amÃnia parece ter contribuÃdo para toxicidade observada em amostras de elutriato, contudo manipulaÃÃes de adiÃÃo de EDTA, Tiossulfato de sÃdio, aeraÃÃo, filtraÃÃo e Ulva sp. reduziram a toxicidade das amostras sugerindo que alÃm da amÃnia, metais, compostos oxidÃveis, volÃteis e particulados contribuam para a toxicidade. A correlaÃÃo linear e a anÃlise dos componentes principais entre os parÃmetros abiÃticos, metais e toxicidade demonstraram que os parÃmetros pesquisados nÃo explicam totalmente a toxicidade observada nesse estudo. E apesar dos valores de metais encontrados no rio Cearà serem baixos em relaÃÃo a outros estuÃrios impactados, nÃveis elevados de toxicidade foram identificados em amostras de sedimento da regiÃo.The evaluation of sediment quality has been seen as a consistent and necessary extension of assessment programmes for water resources. Sediments are the most concerning of the compartments due characteristics that favour the deposition and accumulation of contaminants. Previous studies showed that the estuary of Cearà River is suffering contamination by industrial and domestic effluents, and that toxicity was observed in embryos of sea urchin exposed to water of the estuary. The objective of the present study was to evaluate the environmental quality of sediment samples from the estuary of Cearà River, through sediment characterization, quantification of metals and bioassays in several compartments of the sediment. Three Campaigns were conducted (Oct/06, Jan/07 and May/07) at four stations along the estuary. As reference, sediments of the estuaries of Malcozinhado and Pacoti rivers were sampled. Analysis of granulometry, carbonate, organic matter and of the metals Zn, Cu, Pb and Cr served to characterize the stations. Toxicity of the whole sediment was evaluated in bioassays with the amphipod Tiburonella viscana and the copepod Nitokra sp.; whilst embryos of the sea urchin Lytechinus variegatus were used in tests at the interface sediment/water and with aqueous elutriates. The characterization of the toxicity of elutriates was accomplished through chemical and physical manipulation for the Evaluation and Identification of Toxicity (TIE). We observed a gradient on percentages of mud, organic matter and metals with values decreasing toward the mouth. In general, the samples from the estuary of Cearà River were toxic on all routes of exposure. The test with amphipods showed good reproducibility, whilst the reproduction of copepods showed large variations in the control, amongst the campaigns. Toxicity was high for both tests with sea urchin embryos. Ammonia seems to have contributed to the toxicity observed in samples of elutriate, however, manipulation of addition of EDTA, Sodium thiosulfate, aeration, filtration and the macroalgae Ulva sp. reduced the toxicity. This suggests that apart from ammonia, other factors such as metals, and oxidizable volatile and particulated compounds contribute to the toxicity. Linear correlation and principal components analysis between abiotic parameters, metals and toxicity demonstrated that the parameters investigated do not fully explain the toxicity observed in this study. Despite the values of metals found in the Cearà River were low relative to other impacted estuaries, high levels of toxicity were identified in samples of sediment from the regio

Editorial

In 2022, Ecotoxicology and Environmental Contamination - EEC, a scientific journal belonging to the Brazilian Society of  Ecotoxicology (ECOTOX-Brasil), originally called Journal of the Brazilian Society of Ecotoxicology (JBSE), celebrates its 17th anniversary. To continue promoting and expanding spaces for scientific dialogue, we initiated a new journal format with new sections and the opportunity to submit articles in both Portuguese and Spanish, in addition to English. The EEC editorial team greatly appreciates Dr. Charrid Resgalla’s dedication and effort as the head of the EEC in recent years. We are also grateful to the contribution of all associate editors in the editing of this volume. To remember EEC’s history, we have invited senior editor Gilberto Fillmann to inaugurate our editorial

Editorial

This editorial has the intention to highlight the role of the toxicological scientific societies in the Brazilian regulatory framework, reflecting on the importance of scientifically sound based protocols for the derivation of environmental standards, especially for the protection of the aquatic life. Some examples of initiatives organized by the scientists of Ecotox- Brasil and other toxicological societies are presented as well as the contribution of the EEC journal in the process. The involvement of the society, industry and academia in the regulatory process in a constructive dialogue in is key for the improvement of the Brazilian norms and consequently a better protection of our environment

Ecotoxicology assay for the evaluation of environmental water quality in a tropical urban estuary

Abstract Most studies evaluating the impacts of river pollution in the semi-arid region of Brazil have been geared towards physiochemical analyses, and investigations of the adverse effects of water pollution on associated organisms are scarce. This study aimed to evaluate the water quality in the Poxim river estuary in Aracaju, Sergipe throughout the dry and rainy season by evaluating the survival of the microcrustacean Mysidopsis juniae and physicochemical analyses. The evaluation of physiochemical parameters revealed a decrease in dissolved oxygen content in the rainy season. However, there was a significant reduction in microcrustacean survival in samples during the dry season, when the river flow is reduced and effluents become concentrated. These results suggest that pollutants received and carried by the waters of the Poxim River contribute to the reduction of environmental quality in the estuary, and this impact may vary according to dry and rainy patterns, that are uncertain considering the impacts of climate change on tropical regions

Bivalve esterases as biomarker: identification and characterization in European cockles (Cerastoderma edule)

This study characterized esterase activity in Cerastoderma edule tissues using different substrates and specific inhibitors and identified the tissue distribution of esterases in this species. Synthetic thiocholines and thioacetate esters and specific inhibitors (eserine, BW284C51 and iso-OMPA) were used to identify and quantify cholines and carboxyl esterases. The results demonstrated the presence of a non-specific propionyl thiocholine (PrSCh)-cleaving cholinesterase (ChE) and a large amount of carboxylesterases (CaE). For further studies using C. edule esterases as biomarkers, our results suggest that the adductor muscle, with PrSCh (5 mM) as substrate should be used to analyze ChE, and for CaE analyses, phenyl thioacetate should be used in digestive gland extracts (PSA, 5 mM).This study was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/Brazil) in international cooperation with Fundação de Ciência e Tecnologia (FCT/Portugal) (process 240/09) and the post-doctoral fellowship of M. S. Monteiro (SFRH/BPD/45911/2008). This publication has been partially financially supported by the Atlantic Area Operational Programme, through the European Regional Development Fund (ERDF), Project PORTONOVO (ref 2009-1/119). Technicians of Biology Department of University of Aveiro, Aldiro Pereira and Rui Marques assisted with organism collection. The English was edited by American Journal Experts (1875-CE76-75F9-2EAB-B015).publishe

Sediment quality assessment in a tropical estuary: The case of Ceará River, Northeastern Brazil

The present study aimed to assess the sediment quality in a tropical estuary located in the northeast of Brazil under semi-arid conditions and multiple sources of contamination, using both toxicity bioassays and metal distribution. The metal distribution followed a concentration gradient decreasing one order of magnitude from the inner station toward the outer estuary, with amounts in the following order: Fe > Al > Zn > Cr > Pb > Cu. The index of geoaccumulation indicated a metal enrichment in the Ceará river sediment, mainly at inner sites, considered from moderately to strongly contaminated by Al, Cu, Cr and Zn. Sediment samples were considered toxic by means of whole sediment tests with copepods (reproduction) and amphipods (survival), and also elutriate fraction and sediment-water interface with sea urchin embryos (development). Acute and chronic toxicity did not exhibit a significant correlation with metals, emphasizing the influence of other contaminants mainly related to the pollution sources installed in the mid-estuary. © 2013 Elsevier Ltd. All rights reserved