Settling and Along-Isopycnal Subduction of Small Microplastics Into Subsurface Layers of the Western North Pacific Ocean.

ABSTRACT: The vertical distribution of small microplastics (SMPs; 10-300 μm in size) and its relation to water masses were investigated through seawater sampling and hydrographic surveys from the sea surface to 1000 m in the North Pacific Ocean. The average ± standard deviation of SMP concentrations in 12 layers at four stations was 6910 ± 2620 particles m^-3. Concentrations were high in isopycnal layers between potential densities of 23 and 25σ_θ (100-300 m depths). Elevated concentrations were also frequently detected below the North Pacific Intermediate Water (NPIW), characterized by a salinity minimum around the 26.6-27.0σ_θ (approximately 600 m depth) isopycnal layers. A simple modeling approach to reproduce the observed SMP distribution suggested two pathways for

SUBMITTER: Kuroda M 

PROVIDER: S-EPMC12490013 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature