A critical review on various trophic transfer routes of microplastics in the context of the Indian coastal ecosystem

Microplastics irrespective of their myriad sources eventually are discharged into the world's oceans, posing a serious threat to marine life. Evidence has shown the increasing threat posed by accumulation of microplastics along shore lines and sandy beaches to the species that inhabit these ecosystems. This study evaluates the species at potential risk due to microplastic pollution along the coastal regions of India, through a combination of existing literature and original observations. The harmful effects of microplastics on various classes of aquatic and coastal species through both direct ingestion and indirect consumption by the process of bio-accumulation, have been discussed in this study. The species at risk in other ecosystems such as freshwater lakes, brackish water sites, swamplands and marshlands have also been covered. The various species recorded at these ecosystems were evaluated on the basis of their potential risk of consumption of microplastics. Potential routes for bioaccumulation of microplastics through trophic transfer have been proposed, with special emphasis on the routes involving those species at risk, in order to fill the existing knowledge gaps. Further studies in the Indian scenario are therefore necessary, in order to truly gauge the impact of the bioaccumulation in specific species and on the coastal ecosystem as a whole.