Quantitative and qualitative assessment of microplastics in freshwater and marine water fishes in India: Exploring the significant impact of microplastics on fish health

Abstract

Plastic pollution particularly microplastics (MPs), poses a significant threat to the aquatic ecosystems and subsequently the human health. This study explores the effects of microplastics on fish populations in the Indian aquatic system, their route of entry into the fishes and the physiological and behavioral alterations that are induced due to such exposure. India produces 26,000 tons of plastic waste each day and plastic contaminants results in pollution of both freshwater and the marine water habitats. Ingestion patterns observed in fishes classifies microplastics as primary and secondary MPs. The present study extensively reviews the wide distribution of microplastics across fish populations in different habitats and also estimates their quantity among different fish species. It has been observed that fishes infected with microplastics often become hyperactive, alters their feeding behavior and this results in reduction of their fitness levels, making them more susceptible to predators. Oxidative stress along with immunotoxicity and subsequent organ damage poses a major threat to fishes. Accumulation of microplastics in fish liver interrupts the normal metabolic operations and hence causes detrimental impact on fish health. Further research needs to be done to have a comprehensive understanding of microplastic pollution on fish health. This is a serious issue as fish is a cheap source of animal protein specially in India, and MPs have been reported to affect human health as part of biomagnification. Food security standards also needs to be addressed in future studies. Advanced analytical technologies together with geographical information systems (GIS) shall strengthen microplastic monitoring efforts and propose reduction strategies in the coming years.