Floating microplastics in a hypersaline Mediterranean coastal lagoon: Abundance, chemical composition, and influence of environmental parameters

Coastal lagoons are marine environments with high economic importance due to their great role in seafood production. However, only a small fraction of coastal lagoons has been investigated for microplastic pollution, and considering hypersaline lagoons, the percentage drops even further. This study investigated microplastics (MPs) pollution for the first time in a Mediterranean hypersaline coastal lagoon. Our work reports an average abundance of 60 MPs/L with a statistically significant positive correlation to salinity. The microplastic particles identified in this study were primarily fragments of semi-synthetic fibers of cellulose acetate. A small amount was determined as polyester polyethylene terephthalate (PET), originating from fishing and touristic activities that occur in the area and potentially transported by the surface circulation of the NE Ionian Sea. Finally, this study shows that the mechanisms controlling the hypersaline conditions in the lagoon (atmospheric forcing and seawater intrusions) are also responsible for the higher concentration of MPs compared to other lagoons. • Korissia lagoon’s first evaluation of MPs pollution. • MPs abundance in the lagoon was 60 MPs/L. • MPs were mostly semi-synthetic fibers of cellulose acetate and PET.