Effects of Bifenthrin Application on Oxidative Stress and Neurotoxicity Biomarkers in Fish: A Cage Experiment.

CAZENAVE J., BACCHETTA C., MORA C., ROSSI A.

Montevideo

Congreso; Setac Latin America 15th Biennial Meeting; 2023

Integrated rice–fish farming implies the concomitant production of grain and animal protein on the same piece of land. However, the use of pesticides in an attempt to boost rice productivity could generate effects on fish. The present study aimed to assess the potential effects of the insecticide bifenthrin to fish (Piaractus mesopotamicus) using a caging experiment. Juveniles (n = 32; 44.5 ± 10.1 g; 14.2 ± 1.0 cm total length) were obtained from a local farm and were transported to a rice field (San Javier, Santa Fe, Argentina). Fish were divided into two sites: control (C) and bifenthrin-exposure (BF). These sites were irrigation canals next to paddy fields with a separate water supply but under similar environmental conditions. Two cages (n = 8 fish/cage) per site were placed separately at each irrigation canal. BF application (Seizer ®) was carried out with coastal spraying equipment, following the BF recommendation dose for rice culture (100 cm3/ha). After 72 h, fish were retrieved and rapidly transported to the laboratory for sample processing. Gills, liver, brain and muscle were dissected for biochemical analyses. The following oxidative stress biomarkers were measured: glutathione S-transferase (GST) and catalase activity (CAT), and lipid peroxidation levels (TBARS). Brain and muscle tissues were also investigated to assess acetylcholinesterase activity (AChE). The application of the insecticide caused an increase in the antioxidant enzymes CAT and GST activities in the liver and muscle tissues. Lipid oxidative damage was only observed in muscle. Furthermore, BF exposure significantly reduced AChE activity in fish muscles. Overall, our results demonstrate that the current use of bifenthrin in a rice field induces oxidative damage and neurotoxic effects in fish, which indicates potential risks to freshwater fish cultured in integrated rice–fish farming systems.