Comprehensive biological assessment of Asuncion Bay (Paraguay): evaluating environmental health through zebrafish, Tradescantia, and macroinvertebrates biomarkers

This study presents, to our knowledge, the first ecotoxicological assessment in Paraguay combining multiple biomarkers from distinct biological levels (individual and community), including fish, plants, and macroinvertebrates. These findings revealed genotoxic effects in Tradescantia (Commelinacea, commonly known as spiderwort), as evidenced by significant micronucleus formation, suggesting potential genetic damage from sediment contaminants. Conversely, micronucleus tests in zebrafish did not indicate genotoxicity, likely due to the limited bioavailability or short exposure duration. Sediment analysis did not detect polycyclic aromatic hydrocarbons (PAH). The macroinvertebrate community exhibited disturbances, with limited diversity of taxa associated with high organic matter content and low oxygen levels. While acute embryotoxicity was not observed, sublethal effects on aquatic biota cannot be ruled out. This study established crucial baseline data for future ecotoxicological studies, considering the ecological importance of Asuncion Bay and ongoing anthropogenic changes.