Microplastic ingestion in deep-sea fish from the South China Sea

Monitoring the ingestion of microplastics by fish in the environment is crucial to understanding the risks posed by microplastics in the marine ecosystem. In this study, we investigated the ingestion of microplastics in deep-sea fish from the northern continental slope of the South China Sea. All fish samples were contaminated by microplastics, reflecting a high level of microplastic pollution in this region. The average abundance of microplastics in the stomachs of sampled fish was 1.96 ± 1.12 items/individual and 1.53 ± 1.08 items/g, and levels in the intestines of sampled fish were 1.77 ± 0.73 items/individual and 4.82 ± 4.74 items/g. Fish were collected from depths of 200 to 209 m and 453 to 478 m, and no significant difference in the quantity of microplastics ingested was detected among different depths in this range. The microplastics ingested by fish were dominated by plastics that were <1 mm in size, film-like in shape, transparent in color and composed of cellophane. Our results suggest that the ingestion of microplastics by fish is closely related with the microplastic pollution in the marine environment.