Abundance and Characteristics of Microplastics in Commercially Sold Fishes from General Santos City Fish Port Complex

The excessive global production and inadequate recycling of plastics have led to the accumulation of plastic waste, which degrades into microplastics and poses a threat to marine organisms and human health. The need to study microplastic contamination in wet markets, such as the General Santos City Fish Port Complex in the Philippines, is crucial for assessing exposure risks and implementing measures to mitigate pollution and protect public health. This study aimed to quantify and characterize the ingested microplastics in the gastrointestinal tract of Decapterus macarellus, Euthynnus affinis, and Selar crumenopthalmus, and compare the data among the different fish species. In general, seven (7.07%) of 99 individuals contained ten microplastic particles with a mean size of 0.789 ± 0.379 mm. The most abundant microplastic recovered were microfragments (90%) with a dominant color of blue (100%). Based on the polymer composition, ethylene-propylene copolymer is the most prevalent (50%), followed by poly (vinyl stearate) (30%), polyethylene (10%), and polypropylene (10%). The results revealed that all fish species examined exhibited similar susceptibility to microplastic contamination, with D. macarellus ingesting 0.15 particles per individual, followed by S. crumenopthalmus with 0.12 particles per individual and E. affinis with 0.03 particles per individual. Additionally, there was a significant difference (p < 0.05) in microplastic size, indicating that D. macarellus were likely to ingest larger debris compared to S. crumenopthalmus. The study revealed evidence of microplastic contamination in commercial fish species at the General Santos City Fish Port Complex. Highlighting the potential risks to human health and the environment of Mindanao, further assessment of smaller fish species and trophic transfer are necessary for a comprehensive understanding of the contamination patterns.