Work

Modelling transboundary plastic pathways to Norwegian coastal and inland waters

Year: 2025

Type: article

Abstract: Marine plastic debris (MPD) is a form of transboundary pollution, with many common types having far-field transport potential. Such movement can undermine efforts to tackle marine plastic pollution and disincentivize taking action. Norway’s extended coastline, which borders a major transport pathway out of the North Sea – the Norwegian Coastal Current (NCC) – makes it susceptible to transboundary fluxes of MPD from other countries. The complex network of fjords along the coast can act as natural traps for marine litter transported via the NCC. In this study, we investigate the origins of transboundary plastic reaching Western Norway using a nested modelling approach. Buoyant plastic emissions from major European rivers serve as input for a Lagrangian particle tracking model. Background currents are provided by three nested ocean models with increasing resolution: a 4 km model of the North-East Atlantic, an 800 m model of the Norwegian coast, and a 160 m hydrodynamic model for western Norway. As particles move through these grids, we track their pathways to the Norwegian Exclusive Economic Zone (EEZ) and into western Norwegian fjords. Between 15%–88% of released plastic mass enters the Norwegian EEZ from the countries bordering North Sea, of which 1%–35% enters fjords along the west coast. Five major rivers are identified as significant contributors to the simulated plastic load (both in terms of mass and number of particles) in these fjords, where concentrations can be an order of magnitude higher than in surrounding waters. The study highlights key processes in both near- and far-field plastic transport and offers insight for agencies working on international pollution policy and cleanup efforts. • Marine plastic drift across the NW European shelf was modelled using particle tracking. • Particle masses were released at river mouths of countries bordering the North Sea. • Three-level nested model was used to simulate pathways into Norwegian coastal waters. • Simulations indicate transboundary plastic is readily transported into Norwegian fjords, where it becomes concentrated relative to adjacent open waters. • Results show international cooperation is needed to curb plastic in Norwegian waters.

Source: The Science of The Total Environment

DOI: 10.1016/j.scitotenv.2025.180582

Authors: Prithvinath Madduri, Anna Oleynik, James R. Clark, Helge Avlesen, Guttorm Alendal

Institutions: University of Bergen, Plymouth Marine Laboratory, Bjerknes Centre for Climate Research, NORCE Research AS

Language: English

Topic: Microplastics and Plastic Pollution

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDG: Life below water

Open Access status: hybrid

Estimated APC paid: $4,250