Microplastics in the first-year sea ice of the Novik Bay, Sea of Japan.

Abstract

Sea ice is heavily contaminated with microplastics particles (MPs, <5mm). First-year sea ice cores (38-41cm thick) were taken in the beginning of spring in a narrow populated bay of the Sea of Japan. Two ice cores were examined (layer-by-layer, excluding surface) for MPs content: one using μ-FTIR for 25-300μm (SMPs), and another one - with visual+Raman identification for 300-5000μm particles (LMPs). The integral (25-5000μm) bulk mean abundance of MPs was found to be 428 items/L of meltwater, with fibers making 19% in SMPs size range and 59% in LMPs. Integral mean mass of MPs was estimated in 34.6mg/L, with 99.6% contribution from fragments of LMPs. Comparison with simple fragmentation models confirms deficit of SMPs (especially of fibers in size range 150-300μm), suggested to result from their leakage with brine. Multivariate statistical analysis indicates strong positive correlation of large fiber (>300μm) counts and ice salinity.