Greenland Sea Gyre increases microplastic pollution in the surface waters of the Nordic Seas

Microplastics are ubiquitous in various ocean areas and have aroused global concern. This study investigated the abundance and characteristics of microplastic pollution in the Nordic Seas. In the sea area affected by the East Greenland Current, the abundance of microplastics was 1.19 ± 0.28 items/L, with fiber (76.1%), transparent (76.2%), and small microplastics (0.1-0.5 mm, 48.1%) being the most abundant types present. The abundance of microplastics in the cold basin affected by the Greenland Sea Gyre was 2.43 ± 0.84 items/L. Fiber accounted for 87.2% of the total microplastics, and the proportions of transparent and 0.1-0.5 mm particles were 87.6% and 63.9%, respectively. Principal component analysis (PCA) based on size spectrum data revealed that the spatial pattern of microplastics was closely related to ocean currents and the station position in the ocean current. Furthermore, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) analysis illustrated that the microplastics had many weathering and exfoliation sites and adsorbed heavy metals onto their surfaces. The Fourier Transform Infrared Spectrometer (FTIR) analysis showed that the microplastics in the Nordic Seas were mainly polyester and polyethylene. These results not only provide the latest data on microplastic pollution in the Nordic Seas, but also give evidence that ocean currents affect the transport of marine microplastics.