Abundance, composition and distribution of microplastics on Korean Beaches

Abstract

Spatial Microplastics are widespread and ubiquitous in the marine environment. Especially, beach is the most important location of microplastics accumulation. Spatial distribution within a beach is not well addressed yet. In addition, major factors influencing on pollution levels and spatiotemporal distribution of microplastics on beach are still unclear. Multiple lines across a beach (backshore B, strandline S, middle M, and water-edge W) and two seasons (before and after rainy seasons) were investigated to evaluate spatiotemporal distribution in twenty beaches along the coast of Korea in 2016. The relationship of microplastic abundance with environmental and potential source related factors influencing their spatial distribution were evaluated. The median value of microplastic abundances at each sampling line was in order of B > M > S > W. The mean abundance was significantly higher in B line than M and W lines. The mean abundance of L-MP in after rainy season was 10 times significantly higher than that in before rainy season. L-MP distribution demonstrated significant positive correlation with S-MP, beach width, population, and proximity to the city among the factors tested, on the other hand none of significant correlations were obtained between S-MP and all the factors other than L-MP. In this study, significant increase of L-MP abundance after rainy season and correlation with the land-based sources imply t factors influencing on pollution levels and spatiotemporal distribution of microplastics on beach are still unclear. Multiple lines across a beach (backshore B, strandline S, middle M, and water-edge W) and two seasons (before and after rainy seasons) were investigated to evaluate spatiotemporal distribution in twenty beaches along the coast of Korea in 2016. The relationship of microplastic abundance with environmental and potential source related factors influencing their spatial distribution were evaluated. The median value of microplastic abundances at each sampling line was in order of B > M > S > W. The mean abundance was significantly higher in B line than M and W lines. The mean abundance of L-MP in after rainy season was 10 times significantly higher than that in before rainy season. L-MP distribution demonstrated significant positive correlation with S-MP, beach width, population, and proximity to the city among the factors tested, on the other hand none of significant correlations were obtained between S-MP and all the factors other than L-MP. In this study, significant increase of L-MP abundance after rainy season and correlation with the land-based sources imply t