Occurrence of microplastics in the digestive tract of fishes from Reserva Natural de Usos Múltiples Monterrico, Guatemala

Abstract

The purpose of this research was to evaluate the intake of microplastics (MPs) in fishes from the Reserva Natural de Usos Múltiples Monterrico (RNUMM) and its relationship with their feeding habits and habitat. Although MPS are emerging pollutants reported in several aquatic species, to the best of our knowledge this is the first record that addresses the presence of MPS in fish from protected areas of Guatemala. The digestive tracts of 624 individuals from 16 fish species were analyzed using digestion with 20% potassium hydroxide and visual identification of the MPs on the stereomicroscope. 644 MPS were found in 47% of the individuals of 15 species, with an average ingestion range between 1 and 4 MPS. Dominant MPS shapes were fibers (82%), followed by fragments (12%) and films (6%). The highest amount of MPS were found in omnivorous and benthopelagic species. Significant differences were found in the number of MPS related to the feeding habit and habitat of the species, and a negative correlation between the condition factor and the amount of MPS for Gobionellus microdon. Our results provide the first evidence of MPS intake in RNUMM fishes. It is necessary to generate additional information to know the spatio-temporal distribution of the MPS in different habitats within the protected area, and the risks for species of fishing importance.