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.

Potencial contribuição do lodo da estação de tratamento de água (ETA) para a poluição de rios

“…On the other hand, the decanter sludge showed to be highly toxic, with LOEC of 20% and 15% in collections 4 and 5, respectively (Figure 3). Studies in the Poxim estuarine region have already identified low environmental quality for both water and sediment samples [33], and WTP Poxim effluents may be contributing to the environmental degradation of this estuary.…”

Consumo de água em meios de hospedagem brasileiros

“…No entanto, não se pode desprezar as matrizes ambientais água e sedimento, pois estas trazem informações relevantes para entender o ambiente, através da detecção de marcadores moleculares. A cidade de Aracaju, por exemplo, apresenta uma significativa concentração populacional na zona costeira (Nilin et al, 2019). No entanto, pouco se sabe sobre as atuais condições de saúde de estuários localizados nesta cidade e, no sistema estuarino Sergipe-Poxim, a distribuição de marcadores moleculares é pouco conhecida.…”

“…Poxim é um bom exemplo para entender a relação entre as atividades humanas e suas influências no ecossistema. Localizado no Nordeste do Brasil, este ambiente aquático é um dos principais sistemas estuarinos do estado de Sergipe e uma importante fonte econômica para a cidade de Aracaju(Souza et al, 2018;Nilin et al, 2019). Não obstante, as atividades antropogênicas podem representar forte influência na dinâmica fluvial deste ambiente.…”

Acute and chronic toxicity of the benzodiazepine diazepam to the tropical crustacean Mysidopsis juniae

“…Some animals, especially invertebrates, are being used as experimental models to assess the effects of anthropogenic discharge on aquatic ecosystems (Silva et al 2017, Nilin et al 2019. Among them, marine crustaceans have been studied to assess the impact of chemicals in estuarine and marine environments (Figueirêdo et al 2015), as these compartments can become a final sink of effluents.…”

“…Mysidopsis juniae (Mysidacea) is a species of microcrustacean that is important in trophic chains as it feeds on phytoplankton and other microcrustaceans (Domingues & Bertoletti 2006) and is a food source for several fish species. This species has been used in ecotoxicological tests because of its ecological importance to the structure of the aquatic food web and its higher sensitivity to a wide range of xenobiotics than other test organisms (Verslycke et al 2004, Bif et al 2013, Gurgel et al 2016, Silva et al 2017, Nilin et al 2019. In Brazil, the Brazilian Association of Technical Standards has standardized an acute toxicity test for M. juniae (ABNT 2011) and other studies have indicated that this species is a good candidate for chronic toxicity testing (Figueirêdo et al 2016).…”