Exposure to fipronil, 2,4-D and vinasse influences macroinvertebrate assemblage structure: An experimental mesocosm approach

• Published in: The Science of the total environment 2023-08, Vol.888, p.164259-164259, Article 164259
• Main Authors: Cotta, Carina P., Pinto, Thandy J.S., Yoshii, Maria Paula C., Silva, Laís C.M., Ogura, Allan P., Gabriel, Gabriele Verônica M., Schiesari, Luiz C., Carmo, Janaina B., Montagner, Cassiana C., Espíndola, Evaldo L.G., Moreira, Raquel A.
• Format: Article
• Language: English
• Subjects: 2,4-D; active ingredients; aquatic environment; Brazil; Chironomidae; dissolved oxygen; DMA® 806 BR; Ecological indices; Environmental contamination; Ephydridae; exposure duration; fertilizers; fipronil; freshwater; insecticides; macroinvertebrates; Mesocosms; Oligochaeta; Phoridae; pollution; Regent® 800 WG; regression analysis; Sciomyzidae; sugarcane; total nitrogen; Toxic mixtures; turbidity; vinasse
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.164259

Sugarcane is one of the main monocultures in Brazil and widely uses herbicide 2,4-D and fipronil insecticide. In addition, vinasse can be mentioned as it is widely used in this plantation. These compounds occurring simultaneously in the aquatic environment can potentiate the deleterious effects on organisms. Thus, this study aimed to evaluate the composition, abundance and ecological indices of the benthic macroinvertebrate community, as well as its ability to reestablish itself considering environmental contamination by the pesticides Regent® 800WG (active ingredient - a.i. fipronil) (F) and DMA® 806BR (a.i. 2,4-D) (D) and vinasse (V), alone and in mixtures: pesticides - M and the three contaminants - MV. The study was conducted using open-air mesocosms. The macroinvertebrate community was monitored by colonization structures, the physical-chemical parameters, metals and pesticides were determined and the effects of contaminants were evaluated over the exposure time in 1, 7, 14, 28, 75 to 150 days. A multiple regression was performed between the water parameters and significant relationships were found between parameters associated with vinasse contamination (pH, total nitrogen, turbidity, and dissolved oxygen) and concentration of fipronil and the ecological variables studied. Over time, changes were observed in the composition of the community. The dominance and richness increased in treatments V and MV. The family Chironomidae and subclass Oligochaeta were more sensitive to the treatment V and MV, while individuals from the families Phoridae, Ephydridae and Sciomyzidae were occasionally found (depending on the experimental time) in these treatments. The insects were sensitive to treatments F and M, disappearing in these mesocosms after contamination, reappearing only after 75 days. The results reveal that sugarcane management practices associated with the use of pesticides and vinasse as fertilizer pose risks to the macroinvertebrate community with consequences for the trophic chains, given its importance in freshwater ecosystems and adjacent terrestrial environments. [Display omitted] •Different physical-chemical variables were altered in the treatments V and MV.•Insects disappeared soon after contamination by the fipronil.•In treatments D, F and M, Pulmonata and Oligochaeta had the abundance increased.•In treatments V and MV there was a reduction and disappearance of the Oligochaeta.