Microplastic Ingestion by Fishes from Jamuna River, Bangladesh

Abstract

Microplastics (MP) have been an evolving global concern by dint of the escalation of plastic pollution in the aquatic environment. However, few data document MP ingestion and accumulation in freshwater fauna as compared to marine organisms. This study investigates the prevalence of MPs in the gastrointestinal tracts (GIT) of 45 individuals belonging to seven commonly found Bangladeshi freshwater fish species with different feeding types (herbivore, carnivore, and omnivore). A total of 81 MP items of varying shapes were detected in 76% of individuals investigated, with an average abundance of 1.80±1.65 items/individual. Of these, fiber was identified as the most prevalent ingested MP type (70%) followed by film (14%), line (10%), fragment (4%), and foam (2%). Black-colored MPs were the most dominant (27%) followed by white (26%), blue (24%), red (17%), and green (6%). The results demonstrated a higher number of MPs in the carnivore (1.95 items/individual) and omnivore (1.85 items/individual) fish species as compared to herbivore fish species. Among carnivores, Wallago attu registered the highest amount of ingested MP items (3.5 items/individual), while Anguilla bengalensis registered the highest amount of ingested MP items (2.14 items/individual) among the omnivores. The amount of ingested MPs was significantly correlated (P<0.05) with body size, body weight, and gut weight, while an insignificant correlation (P>0.05) was found between the number of consumed MPs and trophic fractions. The results provide valuable insights into the prevalence of MPs in freshwater fish in Bangladesh and associated bioaccumulation through trophic transfer.