The main aim of this study was to assess the presence of microplastics in the water and sediments of the Surakarta city river basin in Indonesia. In order to accurately reflect the river basin, a deliberate selection process was employed to choose three separate sampling locations and twelve sampling points. The results of the study revealed that fragments and fibers were the primary types of microplastics seen in both water and sediment samples. Furthermore, a considerable percentage of microplastics, comprising 53.8 % of the total, had dimensions below 1 mm. Moreover, the prevailing hues identified in the water samples were blue and black, comprising 45.1 % of the overall composition. In contrast, same color categories accounted for 23.3 % of the microplastics found in the soil samples. The analysis of microplastic polymers was carried out utilizing ATR-FTIR spectroscopy, which yielded the identification of various types including polystyrene, silicone polymer, polyester, and polyamide.
This research aims to understand the extent of microplastic contamination in Pekalongan waters, Central Java, and its potential impact on fishing grounds, aligning with Indonesia's National Action Plan for Handling Marine Debris 2018-2025. The study employs a 2D hydrodynamics modelling approach with Mike 21 Software to map the spatial distribution of microplastic movement concerning fishing areas during the west and east monsoon seasons. The results showed that microplastic particles follow tidal currents in Pekalongan waters, with their movement influenced by factors such as current, wind, and tidal conditions. The trajectory of microplastics entering fishing ground areas poses potential contamination risk for fish caught by fishermen, threatening the health of marine ecosystems and the stability of their structure and function.