Genotoxicity in field studies: what do we know today about DNA damage in fish and aquatic macrophytes from contaminated sites?

MENONE, ML; LOMBARDERO, LUCAS RODRIGO; PÉREZ, D.J

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

SETAC LA

ecosystems are affected by several anthropic activities. However, most of the knowledge about itseffects in non- target organisms come from bioassays. Particularly the use of aquatic plants as sentinel species of pollution in field studies is scarce. Indeed, a recent review highlighted that most of the studies on effects on macrophytes were carried out under controlled laboratory conditions (93%), 5% in controlled field, and only 2% in natural field. The fragmentation of DNA through the “Comet” assay has been used in Lemna minor exposed to polluted surface water contaminated by a fertilizer factory effluent rich in fluorides, metals, and polycyclic aromatic hydrocarbons. Importantly, the authors found comparable responses in L. minor and fish regarding DNA damage and oxidative stress. The genotoxicity observed from in situ exposure was the result of numerous interactions between contaminants themselves and environmental factors, an area of research also scarcely addressed. Other sensitive techniques like the chromosomal abnormalities in roots of aquatic plants are common in bioassays. However, in Elodea canadensis this cytogenetic analysishas been used as a tool for testing genotoxicity of bottom sediments in the field, concluding that it can be used as a relevant and sensitive genotoxicity endpoint. On the other hand, in fish several field studies in Latin America have been carried out. The fish species commonly used are Jenynsia lineata, Olygosarcus jenynsii, Prochilodus lacustris and several species of the genera Astyanax (A. lacustris, A. jacuhiensis, A. bifasciatus) from freshwater ecosystems and Plagioscion squamosissimus from estuaries. The in situ biomonitoring of the water quality conducted with these species allowed to associate DNA damage to areas subjected to petrochemical influence, and exposure to metals and pesticides. Most of the results have shown the sensitivity of the techniques applied and the species used, making genotoxicity a suitable effect to be studied in pollution research.