Oligosarcus jenynsii as biomonitor in La Brava Lagoon: A battery of biomarkers to study agricultural pollution.

LUCAS R. LOMBARDERO; DIANA M. VILLAGRAN; JULIETA R. MENDIETA; SANDRA MEDICI; PÉREZ, DÉBORA JESABEL; FERNANDO G. ITURBURU; ANDREA C. CRUPKIN; MIRTA L. MENONE

Congreso; 11th Young Environmental Scientists (YES) Meeting for SETAC. 7-9 March, On-demand. SETAC Asia-Pacific.; 2022

The chemical analysis alone does not reveal the impact of chemical contamination inaquatic ecosystems. Therefore potential effects on biota are necessary to study. Theaim of this study was to evaluate pollution by agriculture through oxidative stress andgenotoxicity effects in Oligosarcus jenynsii. La Brava lagoon (Buenos Aires province,Argentina) an eutrophic lentic body of water recently established as a protected area.Two samplings were carried out during one year; one in spring 2020, and another insummer 2021 during the maximum application of chemical compounds. Fish (n=20)and surface water (n=3) samples were collected in each sampling. Activity of theenzymes Catalase (CAT) and Glutathione-S-transferase (GST) were measured byspectrophotometry, as well as the levels of Malondialdehyde (MDA) in brain, liver andgills. Levels of hydrogen peroxide (H2O2) in liver and gills were also analyzed.Additionally, the frequencies of micronucleous (MN) and other nuclear abnormalitieswere quantified in erythrocytes using optical microscope. Current use pesticides wereanalyzed in water samples by UPLC-MS/MS. Student's t tests were performed todetermine statistically differences with a significance level of 0.05. The results showedthat CAT activity in liver and GST in the three organs studied was higher in summerthan in spring; while MDA in gills was lower in summer than in spring. There were nodifferences between seasons in H2O2 or MN. In spring, several pesticides were found(chlorpyrifos, glyphosate and AMPA) while summer only chlorpyrifos was detected, at amaximum concentration of 2.3 µg/L. The present study shows the utility of antioxidantenzymes as biomarkers associated to environmental levels of chlorpyrifos. Also, itallows including this type of research in a comprehensive management plan to becarried out in this protected area.