Assessing the distribution and influx of microplastics into the east sea of korea

Marine microplastic pollution is a globally recognized environmental issue, with microplastics being detected throughout the water column from the ocean's surface to the seafloor. Buoyant microplastics are prevalent in the water column due to various biological and physical factors. This study aimed to ascertain the distribution and characteristics of microplastics entering the East Sea and to estimate their input levels. The study was conducted in September 2022 and April 2023 at three stations situated in the southeastern region of Korea. Seawater samples, ranging from 100 to 200 liters, were collected from six water layers, and microplastics were analyzed using μFT-IR. The average concentration of microplastics in seawater collected in September 2022 and April 2023 ranged from 247 to 757 n/m³ and 308 to 737 n/m³, respectively. Microplastic concentrations exhibited an overall decreasing trend with distance from the coast. No discernible vertical pattern in the concentration distribution of microplastics along the water column was observed. Polymer compositions varied, with samples from September 2023 containing polypropylene (PP), polyethylene vinyl acetate (PEVA), polyethylene (PE), Alkyd, and polyester (PES)/polyethylene terephthalate (PET). In April 2023, Alkyd, PP, PEVA, PES/PET, and PE predominated. PP emerged as the dominant polymer detected in the water column, despite its positive buoyancy due to its low density compared to seawater. Alkyd polymer, prominently detected in April 2023, predominantly exhibited small sizes ranging from 20 to 200 μm, with red and green colors being predominant (¿90 Also see: https://micro2024.sciencesconf.org/559398/document