Nanoplastic concentrations across the North Atlantic

Sophie Ten Hietbrink ^1,2, Dušan Materić ^3,4, Rupert Holzinger ¹

⁰Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, Utrecht, The Netherlands.

Nature +

|

July 9, 2025

View abstract on PubMed

Summary

Ocean nanoplastics are a significant, unquantified plastic pollution threat. This study quantifies nanoplastics in the North Atlantic, revealing they may dominate marine plastic mass.

Area Of Science

Environmental Science
Oceanography
Chemical Oceanography

Background

Marine plastic pollution is a global issue, with research focusing on macro and microplastics.
Ocean nanoplastics (<1 μm) are largely unquantified, creating a gap in understanding plastic mass budgets.
Existing studies have not fully addressed the scale and impact of nanoplastics in marine environments.

Purpose Of The Study

To quantify nanoplastic concentrations across the North Atlantic water column.
To assess the contribution of nanoplastics to the overall marine plastic mass budget.
To investigate the distribution patterns of nanoplastics from subtropical gyres to shelf areas.

Main Methods

Ocean-basin scale transect sampling across the North Atlantic.
Measurement of nanoplastic concentrations (polyethylene terephthalate, polystyrene, polyvinyl chloride) in the water column.
Comparison of nanoplastic concentrations between mixed layer, intermediate, and bottom waters.

Main Results

Nanoplastic concentrations ranged from 1.5-32.0 mg m⁻³ throughout the North Atlantic water column.
Mixed layer nanoplastics were 1.4 times higher than intermediate depths, with peaks near Europe.
Subtropical gyre intermediate waters showed 1.8 times higher nanoplastic concentrations than the open North Atlantic.
Bottom waters had the lowest concentrations (~5.5 mg m⁻³), primarily polyethylene terephthalate.
Estimated mixed layer nanoplastic mass in the temperate to subtropical North Atlantic reached 27 million tonnes.

Conclusions

Nanoplastics constitute a substantial, potentially dominant, fraction of marine plastic pollution.
The estimated mass of nanoplastics rivals or exceeds previous estimates for macro/microplastics in oceans.
Further research is crucial to understand the full impact and fate of nanoplastics in marine ecosystems.