Microplastics and other anthropogenic particles contamination and its potential trophic transfer in a tropical Andean reservoir, Colombia

Microplastics are a threat to ecosystem health, and their impacts and effects are increasingly serious and need to be studied. This study assessed anthropogenic contamination, with emphasis on microplastics, in the water, sediment, and biota (i.e., microcrustaceans, macroinvertebrates, and fish) compartments in a tropical Andean reservoir, Antioquia, Colombia. For this purpose, sampling was carried out at three hydrological periods between 2022 and 2023. The obtained samples were subjected to specific digestion for each environmental compartment and the identified particles were quantified and classified in size, shape, and color. Fourier transform spectrophotometry was used to analyze polymer composition. An ANOVA was used to evaluate statistical differences in particle size and quantity between sampling times for each compartment. Discriminant analysis was used to evaluate the relationship of fish feeding habits with the quantity of particles found in fish. Anthropogenic particles were found in all abiotic and biotic compartments. Blue fibers were predominant in all compartments, with omnivorous fish exhibiting the highest particle concentration. Microplastics comprised 12% of the particles, mainly polypropylene, polyester and polyethylene, the rest were rayon, cellulose and cotton. A conceptual model addressing the dynamics of pollution in Peñol-Guatapé reservoir is proposed, suggesting how anthropogenic particles transfer between environmental compartments and species.