Spatial and temporal variation of microplastic in mussels from intertidal and subtidal banks in the Southwestern Atlantic Ocean.

The objective of this study was to identify the presence of MPs in M. platensis tissues and evaluate the spatial and temporal variation of MPs in this species between different zones (Intertidal and Subtidal) and years (2012 and 2019) in Buenos Aires province Villa Gesell, Southwestern Atlantic Ocean. Our hypothesis is that the Intertidal zone will have a greater number of MPs than the Subtidal zone, and this trend will also be observed in 2019 compared to 2012. Specimens of M. platensis from the intertidal zone were hand-collected during low tide on the pier pilings in August 2012 and 2019, and the subtidal specimens were obtained by bottom trawling from a campaign with the Oceanographic ship ARA Puerto Deseado in August 2012. In general, the number of MPs varied between zones, indicating a greater number of this contaminant in the intertidal zone, whereas the same was not observed for the years. Furthermore, among the analyzed specimens, 90 % contained MPs, all of which were in the form of fibers, with blue fibers being the predominant type, and polystyrene being the most prevalent polymer. This group of organisms has significant ecological roles and commercial value. Assessing their contamination status and MPs characteristics is important to understand the potential risks to marine ecosystems and human health.