First record of microplastics in two freshwater fish species (Iheringhthys labrosus and Astyanax lacustris) from the middle section of the Uruguay River, Brazil

Primeiro registro de microplástico em duas espécies de peixe (Iheringhthys labrosus e Astyanax lacustris) num trecho do Médio Rio Uruguai, Brasil

Abstract 

Aim  The aim was to analyze the incidence of microplastics in the diet of fish in the middle Uruguay River.

Methods  The present work analyzed the gastrointestinal content of two species: Astyanax lacustris and Iheringichthys labrosus.

Results  This study provides the first evidence of synthetic materials, such as fibres and plastics in the gastrointestinal tract of fish species in the Middle Uruguay River basin. A sample of sixty-one A. lacustris and twenty-nine I. labrosus were examined to highlight the ingestion of microplastics in the middle section of the Uruguay River in Brazil. In the A. lacustris, eleven fibres and two fragments were found in their gastrointestinal contents, corresponding to 18.1% of the specimens, while in the I. labrosus, twelve fibres and one fragment were found, corresponding to 34.5% of the specimens analyzed. Blue staining was also prevalent in the occurrence of microplastics.

Conclusions  These data are the first record of microplastics in this zone and represent a baseline for this contamination for future studies.

Keywords:  environmental contamination; freshwater fishes; Uruguay River; microplastic ingestion