The occurrence of microplastic in specific organs in commercially caught fishes from coast and estuary area of east China

Microplastics > 20μm are often present in gills and guts but are rarely when occurred in fish muscles and liver from Lateolabrax maculatus. [Display omitted] •Microplastics were detected in gut and gills of fish from east China.•The size of microplastics in gills were smaller than those found in guts.•No microplastics larger than 20 μm were detected in the liver or muscle of bass.•Large numbers of procedure blanks are critical for measurements of microplastic. It is important to understand where microplastics go in the body of organisms. They can readily affect target organs and transport microplastic-associated chemicals to humans via consumption. The plastics (>20 μm) in guts and gills of 13 species of fishes from coast estuary areas of China were examined for the presence of microplastics. Muscle and liver were analyzed from a commercial species, the Asian seabass (Lateolabrax maculatus), of which 73% of the suspected items were verified by micro-Fourier Transform Infrared Spectroscopy. We targeted the organ specific distribution of microplastics. Microplastics were detected in gut and gills in 22%-100% and 22%-89% of total individuals, respectively. Microplastics in gut varied from 0.3 to 5.3 items/ind. and varied from 0.3 to 2.6 items/ind in gill, respectively. The size of microplastics in gills were smaller than those found in the guts. No microplastics were detected in the liver or muscle tissue of L. maculatus, and several non-plastic items detected in muscles can be attributed to background contamination. Further research is required using a larger number of specimens and better quality control and quality assurance are required to assess the presence of small microplastics or nanoplastics in fishes internal organs and muscle.