Composition and spatial distribution of floating plastic debris along the estuarine ecocline of a subtropical coastal lagoon in the Western Atlantic.

With the objective of characterizing the composition and spatial distribution of plastic fragments in a subtropical lagoon system, five sample areas affected by various anthropogenic impacts were chosen in the southern part of the Estuarine Lagoon System in Laguna, Santa Catarina, Brazil. The total density of the floating meso- and microplastics encountered was 7.32/m3, with the greatest density in the access channel and external area of the lagoon. Plastic filament was the most abundant and mainly comprised polyester (PET), polypropylene (PP) and polyethylene (PE) from 0.05 to 0.71 mm2. Fishing and urbanization were the main sources of the meso- and microplastics in the environment. This is the first study to evaluate contamination by meso- and microplastics in the southern part of the Estuarine Lagoon System and provides information about the nature and extent of contamination by plastics in this estuarine ecosystem.

Spatio-seasonal microplastics distribution along a shallow coastal lagoon ecocline within a marine conservation unit.

The aim of our study is to estimate the abundance and sources of floating microplastics (MPs) along a coastal lagoon ecocline in a marine conservation unit (MCU) for implementing effective prevention and mitigation actions in South Brazil. MPs were sampled monthly, and the abundance and size were determined for hard solids, soft plastic, plastic filaments, and paint fragments. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis was performed, and the MPs were classified as polyethylene, polyester, polypropylene, polybutadiene, and polystyrene. Downstream areas (outside of the MCU) showed high levels of MPs, during the winter, due to low precipitation and the predominance of S/SE winds. During summer, precipitation increases, and MPs are exported with surface runoff, resulting in lower level of MPs. Outside MCU areas, a high concentration of tourism houses, commercials, and artisanal fisheries were observed, which could contribute to all types of plastic debris found in our study.