Freshwater mollusks as proxies for assessing agrochemicals hazards in Volta Grande Reservoir, Brazil

  • Andressa Mendes Sene Instituto de Ciências Naturais. Departamento de Ecologia e Conservação. Universidade Federal de Lavras (UFLA), Avenida Doutor Sílvio Menicucci, s/n, CEP: 37200-900, Lavras, MG, Brazil.
  • Daniel Melo Rosa Programa de Pós-graduação em Ciências (FIMAT). Departamento de Física. Universidade Federal de Ouro Preto (UFOP), Rua Cinco, n° 2, CEP: 35400-000, Ouro Preto, MG, Brazil. Centro de Bioengenharia de Espécies Invasoras de Hidrelétricas (CBEIH), Avenida José Cândido da Silveira, n° 21000, CEP: 31035-536, Belo Horizonte, MG, Brazil.
  • Silvia Maria Millan Gutierre Instituto de Ciências Naturais. Departamento de Ecologia e Conservação. Universidade Federal de Lavras (UFLA), Avenida Doutor Sílvio Menicucci, s/n, CEP: 37200-900, Lavras, MG, Brazil.
  • Paulo Santos Pompeu Instituto de Ciências Naturais. Departamento de Ecologia e Conservação. Universidade Federal de Lavras (UFLA), Avenida Doutor Sílvio Menicucci, s/n, CEP: 37200-900, Lavras, MG, Brazil.
Keywords: bivalve, gastropoda, high contamination-risk, organic agrochemicals, pesticides

Abstract

Brazil has experienced a rise in the use of agrochemicals in recent years, representing a potential threat to nearby ecosystems. The Volta Grande Reservoir (Minas Gerais/São Paulo, Brazil) has about 87% of its area surrounded by agricultural systems, and many compounds used in agriculture end up being carried into nearby water bodies. Given the potential ecological risk, our purpose was to assess pesticides in the reservoir. We collected specimens of two bivalves and three gastropods using bottom dredging and visual investigation in three different sites within the reservoir. The sampling sites were classified according to their distance from the dam, and all were close to agricultural lands. The samples were processed and frozen for qualitative toxicological analysis using mass spectrophotometry. Eight pesticides were identified, including four organochlorines (Aldrin, p,p’-DDE, Heptachlor epoxide, and Endrin) and organophosphates (Disulfoton, Malathion, Parathion- methyl, and Parathion-ethyl). All five studied species (Limnoperna fortunei, Corbicula fluminea, Melanoides tuberculata, Aylacostoma tenuilabris, and Pomacea aff. canaliculata) presented traces of pesticides in their bodies. Of the eight pesticides found in our analysis, six are illegal in Brazil, raising awareness about the continuous use of forbidden pesticides, and also the ecological risk in the Volta Grande Reservoir area. Our results suggest stricter control by environmental agencies regarding the use and commercialization of these illegal toxic compounds.


Published
17/05/2021
Section
Papers