Microplastics contamination in commercial fish landed at Lengkong Fish Auction Point, Central Java, Indonesia

Plastic is one of the main pollutant sources that are difficult to decompose and then carried into the ocean and fragmented into smaller parts (microplastics) due to UV radiation and water currents. Their small size means that microplastics are often ingested by aquatic organisms, such as fish. This research aimed to determine the presence, abundance, and types of microplastics in the digestive tract of four dominant fishes landed at Lengkong Fish Auction Point, Cilacap, Central Java, i.e. threadfin (Eleutheronema tetradactylum), mackerel (Rastrelliger sp.), threadfin bream (Nemipterus japonicus), and hairtail (Trichiurus lepturus). We found microplastics in the digestive tract of four selected fishes with a frequency of occurrence of 100%. The concentration of microplastics in fish digestive tracts is relatively high, with a value range of 12 ±2.86 to 28.33 ±8.11 particles∙ind.^–1. Microplastics were found in films, fibres, fragments, and granule shape types with various colours: brown, purple, blue, black, green, transparent, and yellow. The polymers found were polystyrene (PS), nylon, acrylonitrile butadiene styrene (ABS), polyurethane (PU), polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE). The present study provides baseline data for microplastics contamination in commercial fish species landed at Lengkong Fish Auction Point, Cilacap, Central Java, Indonesia. The fact that we discovered PU, the most harmful polymer, piques our attention.