Egeria densa remediates the aquatic environment and reduces ¹⁴C-deltamethrin bioaccumulation in Danio rerio

Abstract

Deltamethrin is an insecticide with high toxicity to non-target aquatic organisms. Environment-friendly alternatives to removing insecticides from water bodies, like phytoremediation, require species to uptake and/or dissipate pesticides from water. Our research investigated the ability of Egeria densa plants to absorb and dissipate ¹⁴C-deltamethrin from water, and bioaccumulation in Danio rerio. The variables were four densities of E. densa (0, 234, 337, and 468 g dry weight m⁻³), in tanks with seven adults of D. rerio, with three replicates. Dissipation was evaluated at 0, 24, 48, 72, and 96 h after application (HAA). After 96 HAA, the uptake of ¹⁴C-deltamethrin by plants and accumulation in fish were assessed. The E. densa increased ¹⁴C-deltamethrin dissipation and reduced bioaccumulation in zebrafish. The DT₅₀ decreased 3-fold in treatments with 337 and 468 g m⁻³ of E. densa. The plants absorbed 32% of the ¹⁴C-deltamethrin applied, regardless of plant density. The bioaccumulation in fish was 8.21% without E. densa and only 1% in treatments with 468 g m⁻³ of plants. These results suggest phytoremediation using E. densa is a possible alternative to removing deltamethrin from water and reducing the accumulation in non-target organisms, reducing the environmental impact of insecticides in aquatic ecosystems.

Keywords:

• Phytoremediation
• insecticide
• macrophyte
• bioaccumulation
• zebrafish
• ecotoxicology
• aquatic environment

Disclosure statement

The authors declare that they have no conflicts of interest.

Data availability statement

Data supporting the findings of this study are available from the respective authors upon reasonable request.

Additional information

Funding

The authors thank the Center for Nuclear Energy in Agriculture (CENA/USP) for the structure and the São Paulo Research Foundation (FAPESP) for funding (Process: 2019/04758-1 and 2022/00718-8).