Morphochemical information on microplastic fibers found in edible tissue of local commercial fishes from the South China Sea and the Straits of Malacca for potential human consumption†

Abstract

Plastic debris is widely dispersed in the marine environment, posing a growing environmental concern due to microplastic pollution. Microplastics (less than 5 mm in size) form through plastic fragmentation and include fibers, fragments, films, pellets and foams. These particles may harm marine ecosystems, as ingestion of microplastics can disturb marine life. This study investigates and characterizes the presence of microplastics in commercial fish tissues from the South China Sea (SCS) and the Straits of Malacca (SOM). A total of 80 individuals from four species (Rastrelliger kanagurta – Indian mackerel, Atule mate – yellowtail scad, Decapterus punctatus – round scad, and Pampus argenteus – silver pomfret) were examined. The results showed a high abundance of fiber-shaped microplastic in all tissues samples (mean 8.95 particles per ind.). The presence of microplastics in samples collected from the SCS (10.28 particles per ind.) was higher than in those from the SOM (7.63 particles per ind.). Microplastic was found in higher concentrations in pelagic fish than in benthic fish. The dominant color of the microplastic was black, constituting 39% (SCS) and 45% (SOM). The smallest average size of microplastics in the fish tissues was 0.04 mm, which is from South China Sea fish. Scanning electron microscopy (SEM) images indicate different surface characteristics of the microplastics as a result of environmental exposure. Microplastics were associated with polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polycarbonate (PC), polyamide (PA), polypropylene (PP), polyester, rayon and poly(vinyl methyl ketone). The estimated daily intakes (EDIs) of microplastic through fish consumption are between 1.129 and 1.582 microplastics per capita. Overall, the data show that microplastics are widely distributed in commercial marine fish from Malaysian waters, which could contribute to human exposure through fish intake.