Pathways and Hot Spots of Floating and Submerged Microplastics in Atlantic Iberian Marine Waters: A Modelling Approach

Plastic pollution has been observed in many marine environments surrounding the Iberian Peninsula, from the surface water to deeper waters, yet studies on their pathways and accumulation areas are still limited. In this study, a global ocean reanalysis model was combined with a particle-tracking Lag...

Full description

Bibliographic Details
Published in:Journal of Marine Science and Engineering
Main Authors: Eloah Rosas, Flávio Martins, Marko Tosic, João Janeiro, Fernando Mendonça, Lara Mills
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2022
Subjects:
Online Access:https://doi.org/10.3390/jmse10111640
https://doaj.org/article/def32c43ffe64b048cd5e0a9b6ed9165
Description
Summary:Plastic pollution has been observed in many marine environments surrounding the Iberian Peninsula, from the surface water to deeper waters, yet studies on their pathways and accumulation areas are still limited. In this study, a global ocean reanalysis model was combined with a particle-tracking Lagrangian model to provide insights into the pathways and accumulation patterns of microplastics originating in southern Portuguese coastal waters (SW Iberian). The study investigates microplastics floating on the surface as well as submerged at different water depths. Model results suggest that the North Atlantic Gyre is the main pathway for microplastics in surface and subsurface waters, transporting the microplastics southwards and eastwards towards the Mediterranean Sea and the Canary Islands. Currents flowing out of the Mediterranean Sea act as the main pathway for microplastics in deep waters, transporting the microplastics along western Iberia. An average residence time of twenty days in the coastal waters suggests that microplastics do not accumulate close to their sources due to their relatively fast transport to adjacent ocean areas. Notably, a significant proportion of microplastics leave the model domain at all depths, implying that SW Iberia may act as a source of microplastics for the adjacent areas, including the Mediterranean Sea, Morocco, the Canary Islands, Western Iberia, and the Bay of Biscay.