Qualitative Study of the Transport of Microplastics in the Río de la Plata Estuary, Argentina, through Numerical Simulation

Information about the sources, sinks, dynamics, and how environmental variables affect the transport of microplastics (MPs) from continental deposits to marine systems is still limited. Most of the knowledge about the distribution of plastic in the oceans comes from the use of numerical models to understand the routes of MPs moving in aquatic systems. The Río de la Plata (RdP) is an estuary located on the eastern coast of South America and is one of the most anthropized watercourses in the region. In this study, the trajectory of MPs in the RdP was examined through the implementation, for the first time for the region, of numerical simulation models. The impact of the estuary’s hydrodynamic characteristics, winds, and MP morphological properties on their trajectory was investigated. The simulations produced demonstrated a high correlation between the hydrodynamics of the Río de la Plata and the trajectory of positively buoyant MPs. The wind was identified as a significant driving force in the simulation of MP motion dynamics. Modifications in the size of the MPs have more influence on the trajectory than their morphology. The results constitute an initial step toward understanding the dynamics of these emerging pollutants in one of South America’s most important basins.