Levels of Microplastics in Common Carp (Cyprinus carpio), Apple Snails (Pila ampullacea), and Macroalgae (Filamentous Algae) in the Kedung Ombo Reservoir, Central Java, Indonesia

Microplastic pollution in Indonesian waters is a critical environmental issue. The Kedung Ombo Reservoir, which contributes to the economic well-being of the surrounding community, is one of the affected water bodies. Poor management of plastic waste can lead to microplastic contamination, which threatens aquatic organisms such as algae, snails, and fish through respiratory and food chain processes. In addition to being a source of high-quality protein, fish can serve as a media for microplastic contamination in humans. One fish species in high market demand from this reservoir is the carp. This study aimed to determine the concentration of microplastics in carp (Cyprinus carpio), snails (Pila ampullacea), macroalgae (filamentous algae), water, and sediment in the Kedung Ombo Reservoir, Central Java. The research used laboratory tests and Fourier Transform Infrared (FTIR) analysis. The results revealed significant differences (P< 0.004) in microplastic concentrations in carp from cages and fishermen's catch based on sampling time, with the digestive system exhibiting the highest microplastic exposure. Snail specimens from the reservoir and outlet showed significant differences in microplastic concentrations (P< 0.012), whereas macroalgae from the outlet and tourist areas did not differ significantly (P> 0.342). Sediment samples exhibited the highest average microplastic concentration of 31.3 particles/g. The identified microplastics were categorized into five morphological forms (fibers, fragments, films, pellets, and foam), nine colors (black, red, purple, yellow, brown, gray, blue, transparent, and green), and five polymer types (PA, PE, PET, PS, and PVC).