Microplastics, pesticides, and entomofauna of aquatic ecosystems: toxicological effects at different functional levels over the life cycle of Chironomus sancticaroli

• Grant number: 24/15151-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Evaldo Luiz Gaeta Espindola
• Grantee: Gleyson Borges Castro
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/12104-4 - Fate and impacts of microplastics and pesticides in aquatic and terrestrial matrices in agricultural contexts, AP.TEM

Abstract

The occurrence of microplastics and pesticides in agricultural areas has been recorded worldwide, however, knowledge about its on populations of aquatic invertebrates from Brazil remains scarce. This project aims to investigate, on a multilevel scale, the toxicological effects of the polyethylene microplastics (MP), tebuconazole (TB), and imidacloprid (ID), in isolated and combined exposures, for the invertebrate widely occurring in the tropical zone Chironomus sancticaroli (Diptera: Chironomidae). The species will be exposed to a range of environmentally relevant concentrations of MP, TB, and ID in water and sediments, considering different exposure times, ages, and generations of the animals. In this context, key endpoints were chosen: a) assessment of the change in the species' sensitivity status after exposure to contaminants; b) biomechanical impact of MPs over ingestion and recovery scenarios; c) escape capacity and consequent habitat selection; d) locomotion dynamics (distance covered, speed, and frequency of body curvature); e) effects on growth, mentum, and biomass; f) changes in the composition, diversity, and richness of the microbiome; g) transgenerational effects of emergence and reproduction (emergence times and rates, sex ratio, fecundity, fertility, hatching rates); h) effects on wing morphometry (centroid, asymmetries and allometry); i) neurotransmitter activity (dopamine and acetylcholinesterase) of winged individuals; j) egg oviposition preferences; and k) changes in metabolic profiles. Predicting potential damage caused at the different functional levels of this bioindicator species living in the sediment-water-air interface will contribute to forming a solid framework to evaluate, prevent, and limit MPs and pesticides in aquatic ecosystems.