Microplastics in the Biota of Andean Rivers

In recent years, microplastics pollution in freshwater systems has triggered a series of environmental impacts difficult to manage. These polymers of different sizes and shapes, which are also a source and transfer vector for toxic components and substances, can be ingested by aquatic biota and enter the trophic networks of the ecosystems. Among the adverse effects caused by microplastics are, for example, the decrease in feeding due to intestinal damage, alterations in metabolism, reproduction, growth, survival, etc. So far, at the Latin American level, studies on the ingestion of microplastics and their effects on the organisms involved remain scarce. For this reason, this study analyzes the presence, type and size of microplastics in the stomach contents of nine freshwater macroinvertebrate taxa. The study was performed along a gradient of environmental stress that includes four Andean rivers in the upper basin of the Guayllabamba river. Where, in addition, the susceptibility of ingestion by the macroinvertebrates taxa and the trophic groups to which they belong is determined. The microplastics are present in all sampled sites reference, moderately altered and altered, with values per individual and per mg of tissue higher than those reported in other river studies. The functional feeding group with the highest ingestion of microplastics are predator and collector gatherer, which contains the most exposed taxa, Planariidae, Psychodidae, Chironomidae, Oligochaeta and Baetidae. Fibers are the most common type of microplastic found, which sizes are larger compared to the other types of microparticles studied. Abundance of microplastics and their potential risk of reaching higher trophic levels, warns us about the importance of establishing protective measures for these ecosystems.