Plastic debris and natural food in two commercially important fish species from the coast of Peru

The aim of this study was to evaluate the presence of plastic debris in the stomach contents of two commercially important species Ethmidium maculatum and Mugil cephalus from Peru and relate their characteristics to their diet. The contents of 1820 stomachs were analyzed visually to detect the presence of plastics and prey. Of the analyzed samples, 0.3% contained nine microplastic fragments (0.72–4.54 mm) and one mesoplastic fragment (6.65 mm). Green and blue plastics of polyethylene and polypropylene were the most common. In E. maculatum, copepods were the main prey, followed by diatoms and decapods, and they exhibited the highest amount of plastics. In M. cephalus, the main prey were diatoms, copepods, and dinoflagellates, and they exhibited only one type of microplastic. Although the characteristics of the plastics and the prey of these species may be related (sizes–colors), more research is required to understand this problem in commercially important fishery resources in Peru.