From molecular endpoints to modeling longer-term effects in fish embryos exposed to the elutriate from Doce River
Author(s): FLÁVIA YOSHIE YAMAMOTO; ANGIE THAISA DA COSTA SOUZA; VINICIUS C.S. DE PAULA; JUAN RAMON ESQUIVEL GARCIA; DENIS MOLEDO DE SOUZA ABESSA;
Presenter: Flávia Yoshie Yamamoto
Sediments represent a major sink and also a main source of contaminants to aquatic environments. The environmental disaster of the Fundão dam collapse (MG) released about 43 million of m3 of tailing wastes into the Doce River Basin (DRB), resuspending the chemicals deposited in the sediment and spreading contaminants along with the whole extension of the River course. Despite many studies showed the presence of some chemicals in the river, their toxicological effects in aquatic organisms, such as fish, were poorly investigated. As a promising and widely used tool, the fish embryo toxicity test can be useful to access these effects. Therefore, the present study proposed to investigate survival rates, deformities, and biochemical endpoints in fish embryos of the native species Rhamdia quelen, exposed to the elutriate from different sites of the DRB to understand the potential effects of these chemicals during the initial stages of development. Despite no significant mortality was observed, our results showed that exposure to the elutriates from the Doce River, especially from the closest site (GUA) to the Fundão dam collapse disaster, caused deformities and DNA damage in the fish embryos. These sublethal effects may be related to the high levels of metals introduced by mining activities, compromising long-term survival and reproduction success. In addition, it was possible to observe the influence of other sources of pollutants along the river, then mining activities. According to our data, the mathematical model simulated a significant impact in the population density at longer-term exposure, for the sites that showed the most prominent toxicity responses. Thus, the survival rate per se was not a suitable endpoint to assess the toxicity of the pollutants present in the Doce River, as it may underestimate the potential toxicity of sediments to the native organisms. Different anthropogenic activities, such as mining, agriculture, domestic and industrial effluents, may represent significant sources of pollutants along the river pathway causing adverse effects in living organisms from this environment. The fish embryo toxicity test proved to be an effective assay to assess the toxicological effects of the sediment from the Doce River, despite further studies considering more sensitive responses are encouraged for ecological risk assessment.
Keywords: Sediment; pollutants; Fish embryo
Graduada em Ciências Biológicas pela Universidade Federal de São Carlos (1985) com mestrado em Ciências (Fisiologia Geral) pela Universidade de São Paulo (1990). Realizou o doutorado no Departamento de Fisiologia Geral do IBUSP e no Departamento de Zoologia da Universidade de Leicester, Inglaterra e...Saiba mais
2000-Present Professor Aquatic Ecotoxicology, University of California, Riverside, CA USA
1995-1999 Associate Professor Pharmacology and Environmental Toxicology, University of Mississippi, MS USA
1991-1995 Assistant professor Pharmacology and Toxicology, University of Arkansas for Medi...
Gisela de Aragão Umbuzeiro is a full professor at School of Technology – UNICAMP, Brazil and an adjunct professor at Wilson College of Textiles, NCSU, USA. She graduated in Biology at University of Campinas - UNICAMP (1979), Ph.D. in Genetics also at UNICAMP (1990). Worked for 22 years at the Enviro...Saiba mais
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