Occurrence of microplastics in the gastrointestinal tract of Amazonian fish species with different feeding habits.

Abstract

Plastic pollution has become commonplace and knowledge about microplastics is limited in relation to their real threat to the aquatic biota present in the Amazon basin. Through fish species collected in Lake Janauacá and the Anavilhanas Archipelago, in the state of Amazonas, Brazil, we investigated the ingestion of microplastics by Amazonian fish species with different eating habits. The fish were dissected, and the gastrointestinal tract underwent alkaline digestion for the separation of the microplastic particles. Using a stereomicroscope, the items characterized as microplastics were subjected to Fourier-transform infrared spectroscopy. Almost >60% of the analyzed fish species contained microplastics in their gastrointestinal tracts. Most of the microplastics were found in the intestine (91.5%) and the rest (8.5%) in the stomach. There were no significant differences in the feeding habits of the studied species, or between the locations. The characterization of microplastics highlights the possible sources of the microplastics such as discarded fishing artifacts, the lack of basic sanitation evident in the region and the lack of environmental education for tourists. This study provides data that can assist in the development and formation of practices that combat plastic pollution and raises awareness in regard to the correct disposal of plastics.