The contribution of estuaries to the abundance of microplastics in Jakarta Bay, Indonesia. (November 2022) - Purwiyanto, Anna Ida Sunaryo
Abstract: Rivers are one of the main pollution routes to the ocean. This study examines the source of microplastics (MPs) in Jakarta Bay based on their characteristics and estimates MPs emissions from 9 estuaries around Jakarta Bay in 3 administrative areas (Tangerang, North Jakarta, and Bekasi). The sample used was the water's surface taken using a round net. The highest abundance was found in the Dadap River, and the lowest was in the Angke River. The characteristics of the MPs are dominated by fragments, the size of 300–500 μm, and composed of polyethylene. It shows that the MPs originate from the fragmentation of residents' plastic waste that has been in the waters for a quite long time. The nine estuaries also showed a high contribution to MPs in Jakarta Bay: from North Jakarta > Tangerang > Bekasi. The emission is highly correlated with water discharge and MPs' particles in each estuary. Highlights: The abundance of microplastic in Jakarta Bay has a low correlation with the population size. The microplastics are derived from the fragmentation of local residents' plastic waste. The emissions of microplastics are influenced by river discharge and the number of particles. The emission at the southeast monsoon is lower than in the northwest.