Comparison of Presence of Microplastics in Two Edible Fish Species from South India

One of the emerging contaminants in water bodies is plastics. The smaller pieces of plastic particles of size less than 5 mm are known as microplastics (MP). MPs adversely affect the health of the aquatic biota and subsequently get ingested by humans through their food chain. The present study investigates the comparison of the MPs contamination in edible fishes from two different species. The species used in this study are Rastrelliger kanagurta (Indian Mackerel) and Oreochromis mossambicus (Tilapia). The fishes were dissected, and MPs from different organs (gills, intestine, kidney, liver, and muscles) were extracted, analyzed, and identified using microscopic examination and ATR-FTIR spectroscopy. Approximately 33% (132 out of 400 fishes) of fishes ingested MPs with an average of 4.52 ± 0.40 and 3.06 ± 0.64 per individual in Indian mackerel and Tilapia, respectively. The intestine and liver were the major organs detected with MPs in both species. Rastrelliger kanagurta (39%) was found to have ingested more MPs significantly than Oreochromis mossambicus (27%). The MPs in fishes were significantly dominated by fragments (in shape) and translucent (in colour). The most common types of polymers found were polypropylene and polystyrene. The study concludes that both the edible fish species (even though from different ecosystems) are exposed to MPs. As fishes are the major routes of human exposure to MPs, this study highlights the potential risk to human health and the urgent need for more research on different edible fishes, their risk assessment, and regulations to minimize human exposure to these particles.