Phyo Zaw OoSuwanna Kitpati BoontanonNarin BoontanonShuhei TanakaShigeo FujiiGraduate School of Global Environmental StudiesFaculty of Environment and Resource Studies, Mahidol UniversityMahidol University2022-08-042022-08-042021-12-01Marine Pollution Bulletin. Vol.173, (2021)187933630025326X2-s2.0-85114790073https://repository.li.mahidol.ac.th/handle/20.500.14594/75527Microplastic (MP) pollution in estuarine environments is poorly characterized globally, although they are extensive buffer regions between terrestrial, freshwater and seawater environments. This research aims to investigate MP pollution levels and variations of MPs abundance with tidal fluctuation. Fourteen samples were collected from the surface water of the Chao Phraya River Estuary, Thailand using the Manta net at flood and ebb tides. The average abundance of microplastics at flood tide was 5.16 × 105 particles/km2 and at ebb tide was 3.11 × 105 particles/km2. The abundance of microplastics in the estuary was directly related to the tidal fluctuation, creating an accumulation of microplastics in the study area. Polypropylene, polyethylene, and polystyrene were the most common polymers. The findings provide important information on the pollution status of microplastics in the Chao Phraya River Estuary and the variation of suspended microplastics with tidal fluctuation should be considered in future estuarine microplastic studies.Mahidol UniversityAgricultural and Biological SciencesEarth and Planetary SciencesEnvironmental ScienceArticleSCOPUS10.1016/j.marpolbul.2021.112933