Plastic Ingestion by Commercial and Non-Commercial Fishes from a Neotropical River Basin

Abstract

The pollution of Brazilian freshwater ecosystems by plastic began to appear in the scientific literature only in this century. We provide herein reports of plastic ingestion by members of the ichthyofauna in the Paraíba do Sul River basin. Our study area comprised the Simplício Hydroelectric Complex, located in the middle section of the Paraíba do Sul River. Fish specimens were caught with gillnets and the stomach contents examined using a stereomicroscope and, when necessary, a compound microscope. Out of a total of 218 individual stomachs from 19 species examined, six individuals belonging to five species contained plastic in their stomachs. The synthetic polymers were determined to be polyethylene (PE) and polypropylene (PP). Three of the species had not previously been reported to consume plastic in natural ecosystems. In addition, at least three of the five species are commercially valuable. Our work, together with other published records, raises to 46 the number of Brazilian freshwater fish species known to have ingested plastic particles. Implementation of policies at the river basin level are needed to avoid plastic pollution in the Paraíba do Sul and tributaries in the southeastern Brazil.