Microplastic pollution in the sediment of Jagir Estuary, Surabaya City, Indonesia

This study was aimed to investigate the abundance and characteristics of microplastics (MP) in the sediment of Jagir estuary and Wonorejo coast, Surabaya, Indonesia. Sediment samples from 5 sites in the estuary and the adjacent coast were collected in replicates using Ekman dredge sampler. The MP particles were extracted using density separation method. Then the MP particles were counted and categorized according to shape, size, and color under a Zeiss Discovery V.12 stereomicroscope. Identification was done using Thermo Scientific Nicolet iS10 FIR Spectrometer. The MP shapes comprised fiber (57%), film (36%), and fragment (7%). Abundance of the MP was highest in the Wonorejo coast sediment (590 particles/kg dry weight). The MP particles consisted of 68% large and 25% small sizes and comprised 56.7% polyester, 24.6% low-density polyethylene, and 18.8% polypropylene. The MP colors were 43% transparent, 21% black, 14% blue, 10% white, 8% red, and 4% yellow.