Microplastics in the sediment of intertidal areas of Lamongan, Indonesia

Microplastics are small plastic pieces which pose a great threat to marine ecosystems. Indonesia is among the world's largest contributors to microplastics pollution. This research aimed to identify and measure the abundance of microplastics in the intertidal areas of Lamongan, Indonesia. The sediment characteristics in the study areas were also examined for correlation between soil type and microplastics abundance. Microplastics characterization of the sediments were carried out using a modified flotation method. Sediment types were determined using sieve shaker analysis and hydrometer analysis. On average, there were 206 items kg-1 dry weight of microplastics in which fibers shared more than 85% of all microplastics found in the research areas, with an average abundance of 178 items kg-1 dry weight. Fragments constituted 12%, with an average concentration of 25 items kg-1 dry weight. There was no significant difference between microplastics abundance at depths of 0-5 cm and 5-10 cm. However, the sediment texture may contribute to a higher concentration of microplastics. On average, clayey silts held significantly higher concentrations of microplastics than sand and gravelly sand. The high concentration of microplastics in the intertidal areas of Lamongan could have a negative impact on intertidal organisms and therefore may affect humans through the food chain.