Investigation of microplastic pollution in beach areas on Mersin shore

In this study, sand samples were collected from five beaches representing four seasons in Mersin in November 2021, February 2022, April 2022 and August 2022. The samples were collected at three different depths, and the analysis focused on the microplastic count, color distribution, and size analysis based on the particle size. The highest microplastic count was found at the Viranşehir Taşkıran beach (2071 MP/kg dry sand.year). Adonis Beach, Müftü Stream, Marina Beach, and Viranşehir Stream had microplastic counts of 1686, 1570, 1504, and 1510 MP/kg dry sand.year, respectively. The analysis was conducted on the surface, 0-20 cm depth, and 20-40 cm depth. According to the depth-based analysis, the annual total microplastic counts were 3830 particles at the surface, 2563 particles at 0-20 cm depth, and 1948 particles at 20-40 cm depth, per kg of dry sand per year. When evaluated seasonally, it was observed that the total microplastic count decreased with depth at Marina and Adonis beaches. However, fluctuations in microplastic counts were observed in relation to seasons at other depths. The analysis based on particle size revealed the presence of microplastics in all studied sizes and depths. In the color analysis conducted across all areas, black-colored microplastics were observed in the range of 72-100%. The size analysis indicated that microplastics ranged from 20 to 500 μm with a percentage of 58%, 500 to 1000 μm with 23%, 1000 to 1500 μm with 10%, 1500 to 2000 μm with 4%, 2000 to 2500 μm with 2%, 2500 to 4000 μm with 2%, and 4000 to 9000 μm with 1%. In conclusion, this study found that microplastics can reach depths of up to 40 cm in the coastal areas of Mersin. The total microplastic count decreases with depth, and microplastics ranging from 20 to 500 μm are predominant. Additionally, black-colored microplastics account for 72-100% of the observed particles.