BACKGROUND AND OBJECTIVES: Rapid development has increased the microplastics discharges into marine environments, including coastal waters at Jakarta Bay, Indonesia. This study is proposed to assess microplastics abundance and distribution in surface water and sediment from coastal water at Jakarta Bay.METHODS: The samples were collected from ۱۲ locations representing Ancol, Muara Baru, and Muara Angke - Muara Karang. Samples of water and sediment were extracted to obtain the microplastics. The microplastics were identified based on their morphology (shape) and numbered for their abundance. The polymer of microplastics was determined using Raman Spectrophotometer.FINDINGS: The results showed that microplastics were successfully identified and counted in water and sediment samples at all collection points. The number of microplastics was ۱۵۳۲ particles in the water sample and ۱۴۱۹ particles in the sediment sample. The shape of microplastics observed in the water and sediment samples were fibers, films, fragments, and pellets. Among those, fiber and film were the most dominant microplastic detected both in surface water and sediment in all locations. Three polymers, namely polyethylene, polypropylene, and polystyrene, were detected in the microplastic samples. These findings prove that microplastics with their various types are capable contaminate the aquatic environment.CONCLUSION: The most common microplastics shapes in sediment were fiber (۵۵.۷%) > film (۳۱.۱%) > fragment (۹.۹%) > pellet (۳.۲%) and for the surface water were film (۵۳.۵%) > fiber (۳۳.۹%) > fragment (۷.۸%) > pellet (۴.۷%). The abundance of microplastics in the sediment (۱۶۶.۸ particles/kg, ۹۵%CI: ۱۴۸.۰-۱۸۵.۰) was significantly higher (p < ۰.۰۵) than in surface water (۷۰.۹ particles/L, ۹۵%CI: ۵۵.۶-۸۶.۲). The abundance of microplastics was significantly different among locations (p < ۰.۰۵, F = ۲.۱۱۵), with microplastics in sediments were higher in Ancol, and Muara Angke - Muara Karang have the highest microplastics in surface water. These results can provide valuable information on which parts of the
Jakarta Bay areas should be prioritized first regarding microplastics management.