Microplastics abundance in four different species of commercial fishes in Bali Strait

Plastic wastes in marine environment will be degraded for long period of time to become microplastics. The small size of microplastics could be ingested by marine species which has lead to harmful impacts not only to the marine species but also to human. This research aimed to investigate microplastics ingestion in four commercial fishes in the Bali Strait, namely largehead hairtail (Trichiurus lepturus), Indian scad (Decapterus ruselli), Bali sardinella (Sardinella lemuru), and Indian mackerel (Rastrelliger kanagurta). Thirty fish samples from each species of fishes were obtained from the fishermen. Microplastics contents were identified visually using microscope from the gastrointestinal tracks of the fish and polymer of microplastics were identified using Fourier Transform Infra-Red (FTIR) test. The results showed that three types of microplastics (fiber, film and fragment) were found in the four species of fishes with different total abundances. The highest abundance was found in Bali sardine (7.03±0.49 particle individual-1), followed by Indian mackerel (5.03±0.50 particle individual-1), Indian scad (4.23±0.38 particle individual-1) and largehead hairtail (3.83±0.50 particle individual-1). FTIR test showed that polymer types of microplastic found were polyvinyl chloride (PVC), polyamide (PA), polycarbonate (PC), dan polyethylene (PE).