Plastic debris composition and concentration in the Arctic Ocean, the North Sea and the Baltic Sea

Jari Hänninen,Markus Weckström,Joanna Pawłowska,Natalia Szymańska,Emilia Uurasjärvi,Marek Zajaczkowski,Samuel Hartikainen,Ilppo Vuorinen

doi:10.1016/j.marpolbul.2021.112150

Abstract

Neuston samples were collected with a Manta trawl in the rim of the Arctic Ocean, in the Northern Atlantic Ocean and the Baltic Sea at eleven coastal and open-sea locations. All samples contained plastics identified by FTIR microscopy. Altogether, 110 microplastics pieces were classified according to size, shape, and polymer type. The concentrations at the locations were generally low (x̅ = 0.06, SD ± 0.04 particles m−3) as compared to previous observations. The highest concentrations were found towards the Arctic Ocean, while those in the Baltic Sea were generally low. The most abundant polymer type was polyethylene. Detected particle types were mainly fragments. The number of films and fibers was very low. The mean particle size was 2.66 mm (SD ± 1.55 mm). Clustering analyses revealed that debris compositions in the sea regions had characteristic differences possibly reflecting the dependences between compositions, drifting distances, sinking rates, and local oceanographic conditions.

Highlights

The extent of plastic pollution (Barnes et al, 2009) has reached the world’s northernmost marine realm
Frequency table of detected particle identities at each station, when particle identity is defined as its polymer type, particle type, and color
Frequency table of detected particle identities at each station, when particle identity is defined as its polymer type, size class, and particle type

Summary

Introduction

The extent of plastic pollution (Barnes et al, 2009) has reached the world’s northernmost marine realm. The rationale for this study was to find out whether a continuum of surface-dwelling plastic debris particles could be found following the main oceanographic current patterns from the south, in the Baltic Sea, along the Norwegian coast, to the north, up to the Fram Strait. We wanted to follow the Baltic Sea water, including possible plastic debris, as it mixes with the Norwegian Coastal Slope Current and eventually finds its way up to the north. These adjacent and oceanographically connected marine systems have been studied separately with the least studies concerning the Norwegian coast. We wanted to have a more holistic approach, as the surface currents, which carry plastic debris, are a unifying factor between these areas

Methods

Results

Discussion

Conclusion