Microplastic pollution in natural waters is a growing concern throughout the world. Rivers transport around 8 million pieces of plastics to our oceans every day. South Asia ranks 2nd globally in plastic pollution and three mighty rivers (Ganges, Brahmaputra, Irrawaddy) transport most of them to the Bay of Bengal. Considering the huge volume of discharges and discards the Brahmaputra River (9th largest river in the world by water discharge) receives and transports to the sea, the proposed CRRP is aimed at investigating transboundary microplastics contaminations in fish and aquatic food chain along the course of this river, trophic transfer of microplastics and ecological consequences derived therefrom. During 1st year, fish, fish’s food, river water & sediment samples from 2 tributaries of the Brahmaputra in Bhutan, 5 locations in India and 3 locations in Bangladesh will be studied. Focus group discussions & key informant interviews will be performed along the corresponding sampling sites of this river to find out the dietary habits of local people, their dietary dependency on riverine fish & implications of these findings to locals’ exposure risks. In the second year, fish & invertebrate species will be exposed in vivo to assess trophic transfer of microplastics in the aquatic food chain & physiological stresses upon exposure.