Publication Abstract

While rivers are known to be major sources of ocean plastic waste, the mechanisms controlling the fate and transport of microplastic in river networks are still poorly understood. This study reveals spatial patterns of microplastic concentrations in water and streambed sediments of the iconic river Ganga in India. By analysing the evolution of microplastic concentrations and particle loads from the Ganga’s headwaters in the Himalayas to its confluence at the Bay of Bengal, we identify distinct hotspots and discuss interactions of hydrological and landuse controls on observed patterns. The results of this study reveal that local source controls on downstream microplastic concentrations are quite limited in their spatial footprint and rather important for determining local exposures, while hydrological controls and water management including reservoirs, barrages and abstractions for irrigation have substantial downstream impact on the fate and transport of microplastics.

Holly A. Nel*, Uwe Schneidewind, Laura A. Richards, Bethany G. Fox, Gillian Clayton, Michael J. Bowes, Ben Howard, Robin M. S. Thorn, Arun Kumar, Ashok Ghosh, Himanshu Joshi, Tapan K. Dutta, Kieran Khamis, Liam Kelleher, Daren C. Gooddy, David A. Polya, Darren M. Reynolds, Daniel Magnone, David M. Hannah, Gregory Sambrook Smith, Daniel Read, Alex Billings, Stefan Krause