Microplastic abundance in three commercial fish from the coast of Lima, Peru

Microplastics (< 5 mm) are widespread within the marine environment, posing a major threat to marine biota. The aim of the present study was to investigate microplastic contamination in three widespread and highly commercial fish from the coast of Lima, Peru. Peruvian silverside (Odontesthes regia), Peruvian morwong (Cheilodactylus variegatus), and Peruvian grunt (Anisotremus scapularis) specimens were caught off the coast of Lima. Fish stomach and intestines were extracted and submerged in 10% (w/v) KOH, followed by 24 h incubation at 60 °C. The resulting supernatant solution was vacuum filtrated and filters were then observed under an optical microscope and stereomicroscope. Strict quality control and external contamination prevention measures were taken. Microplastic abundance, type and color were recorded. Quality control measures resulted in reduced external contamination. C. variegatus was the most contaminated fish (5.13 ± 0.81 MP/individual), similar to A. scapularis (5.00 ± 0.46 MP/individual), but significantly different to O. regia (0.43 ± 0.11 MP/individual). Fibers were the overall most abundant microplastic type, while blue the dominant color. Results indicated highly contaminated fish, compared to those from other parts of the SE Pacific. Microplastic ingestion by C. variegatus and A. scapularis may be subject to trophic transfer from their natural prey. Highly populated cities and poor solid waste management may contribute to worsen microplastic ingestion by native marine species. The need for further research and a marine microplastic monitoring program was discussed.