A regional Lagrangian model to evaluate the dispersion of floating macroplastics in the North Atlantic Ocean from land and river sources in the western coast of Spain

Marine plastic litter is an emerging global problem with serious environmental and economic consequences. Once deposited in the ocean, it is transported by currents for long periods of time, making it a transboundary problem. The variety of plastic items makes the study of their transport in the ocean system a challenge. Identifying the sources and analyzing the extent of their dispersion/accumulation can help solve the problem on a global scale. In this study, using modeling tools, the dispersion of particles from land-based sources located on the Spanish Atlantic coast was analyzed over a seven-year period. The results show that the highest concentrations of plastic are found near the coast. The particle dispersion is consistent with the oceanic dynamics of each region studied. The seasonal behavior of plastics arriving in neighboring countries was also analyzed. The time-varying patterns are consistent with local hydrodynamics and the general circulation of the ocean.