Riverine Plastic Monitoring during the Rainy Season in the Citarum Estuary of Muara Gembong

Abstract

The restoration effort to clean up the river, known as "Citarum Harum" requires monitoring to estimate both the composition and the volumes of plastic pollution. The objective of the monitoring is to obtain a scientific baseline of marine plastics from Citarum River as a function of other influencing aspects. A static net trawl (60 m x 10 m, mesh size 2.5 cm, and about 1 meter submerged) was installed under the New Muara Gembong Bridge for eight consecutive days in March and April 2021 or during the rainy season. The trapped debris was collected manually into boxes using two boats and simple tools. After the drying, weighting, classification processes and by excluding natural organics (leaves/branches), plastics contributed as the most dominant for both abundance (83%) and weight (31%) followed by textiles, hazardous materials, construction materials and rubbers. The hydrological conditions as well as the tides were also observed to be one of dominant parameters. The quantification of macro-plastic litter transport from River Citarum into the Java Sea is also an aim for the ASEANO project (ASEAN – Norway cooperation project on local capacity building for reducing plastic pollution in the ASEAN region).