Approved Abstracts

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

[back]



Confirmed
Speakers


Venue
HOTEL HIMMELBLAU

Hotel Himmelblau has a family tradition of over 40 years, operating and offering the very best in hospitality. Located in the central region of the city, we are close to the main attractions of Blumenau, next to Shopping Neumarkt and at a distance of 2km from Vila Germanica Park.

Rua 7 de Setembro - 1415 - Centro
Blumenau - Santa Catarina - Brasil
CEP: 89010-203


Any questions?

Please send a message to us!