Fate of microplastics and mesoplastics carried by surface currents and wind waves: A numerical model approach in the Sea of Japan

• Published in: Marine pollution bulletin Vol. 121; no. 1-2; pp. 85 - 96
• Main Authors: Iwasaki, Shinsuke, Isobe, Atsuhiko, Kako, Shin'ichiro, Uchida, Keiichi, Tokai, Tadashi
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.08.2017; Elsevier BV
• Subjects: Computer simulation; Drift; Environmental Monitoring; Industrial wastes; Japan; Marine pollution; Mathematical models; Mesoplastics; Microplastics; Ocean currents; Oceans and Seas; Particle tracking; Particle tracking model; Plastics; Pollution control; Sea currents; Sea of Japan; Stokes drift; Straits; Surface currents; Surveying; Temperature (air-sea); Transit time; Transport processes; Water Movements; Wind; Wind waves; Sea of Japan; Sea of Japan; Microplastics; Stokes drift; Particle tracking model; Mesoplastics
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2017.05.057

A numerical model was established to reproduce the oceanic transport processes of microplastics and mesoplastics in the Sea of Japan. A particle tracking model, where surface ocean currents were given by a combination of a reanalysis ocean current product and Stokes drift computed separately by a wave model, simulated particle movement. The model results corresponded with the field survey. Modeled results indicated the micro- and mesoplastics are moved northeastward by the Tsushima Current. Subsequently, Stokes drift selectively moves mesoplastics during winter toward the Japanese coast, resulting in increased contributions of mesoplastics south of 39°N. Additionally, Stokes drift also transports micro- and mesoplastics out to the sea area south of the subpolar front where the northeastward Tsushima Current carries them into the open ocean via the Tsugaru and Soya straits. Average transit time of modeled particles in the Sea of Japan is drastically reduced when including Stokes drift in the model. [Display omitted] •We revealed the transport processes of small plastic fragments in the Sea of Japan.•A model reproducing transport process of small plastic fragments was established.•Stokes drift during winter carries the plastic fragments toward the Japanese coast.•Stokes drift transports mesoplastics more efficiently than microplastics.•Stokes drift shortens the transit time of small plastic fragments in the sea.