Plastic pellet pathways: Understanding transport patterns to Santa Catarina Island, Southwestern Atlantic Ocean

Among the various types of plastics present in the marine environment, pellets stand out due to their wide dispersion. This study aims to assess the trajectory of plastic pellets reaching Santa Catarina Island (southern Brazil) from nearby port regions, and to investigate their distribution and fate. Using a Lagrangian particle tracking model and outputs from a hydrodynamic model, we evaluated particle transport and sources. The results indicate a predominant southward flow from Itajaí harbor, suggesting this port region as the most likely source of microplastics. From this source, particles reach the island in only 2 days, with their pathways following seasonal oceanographic conditions in the region. These findings highlight the persistent threat of plastic pollution and underscore the need for improvements in port management. •Itajaí Harbor is the main source of pellets to Santa Catarina Island, Brazil.•Pellets from Itajaí Harbor reached Santa Catarina Island in just two days.•Santa Catarina Island faces pellet contamination, especially in summer and spring.