Comparison of microplastic abundance in aquaculture ponds of milkfish Chanos chanos (Forsskal, 1775) at Muara Kamal and Marunda, Jakarta Bay

Jakarta contributes to 12% of the plastic pollution in Indonesian waters. Most of the plastic trash is mismanaged and end up accumulating in river mouths located along Jakarta Bay. This research analyzed the abundance and types of microplastic in milkfish Chanos chanos, surface water, and sediment of milkfish aquaculture ponds in Muara Kamal and Marunda, Jakarta Bay. Samples of each subject were obtained from each location. Digestive tracts extracted from milkfish were destructed with strong nitric acid. Water samples were filtered while sediment samples were dried. Concentrated NaCl solution was used to achieve microplastic flotation. Counting of particles was done under a light microscope. Overall results from Muara Kamal showed the microplastic abundance was 9.58±3.3 particles g^-1 in milkfish digestive tracts, 103.8±20.7 particles L^-1 in water, and 111,680±13,204 particles kg^-1 in sediments. Microplastic abundance was found lower in samples from Marunda with 8.80±2.7 particles g^-1 in milkfish digestive tracts, 90.7±17.4 particles L^-1 in water, and 82,480±11,226 particles kg^-1 in sediments. These results were consistent with the water pollution levels obtained by the Living Environment Agency DKI Jakarta that states heavier pollution by Pollution Index in Muara Kamal drain than in Marunda drain.