Abundance and size of microplastic particles in filtered seawater samples collected on a north-south transect in the Atlantic Ocean during cruise AMT26 (JR16001), September - November 2016.

This dataset provides number counts and measurements of horizontal dimensions of polyethylene, polypropylene, polystyrene particles detected in filtered seawater samples collected at three discrete depths in the Atlantic Ocean along a north-south passage of cruise AMT26/JR16001 (September-November 2016). The number data are presented as total number counts of polymer-specific plastic particles detected in each pre-selected area of a filtered seawater sample (IR image marker). The measured horizontal dimensions of the polymer-specific plastic particles include i) maximum Feret diameter defined as the longest distance between any two points along the particle boundary and ii) particle length measured as length of major axis of the best fitting ellipse. Plastic particles were detected and identified using Fourier-Transform infrared imaging technique with their particle count and horizontal dimensions measured subsequently FIJI Image J software. The data on polymer-specific plastic counts can be used to assess the spatial/vertical abundance and distribution of plastic litter in the study area. The measured horizontal dimensions (in essence, particle size) can be used to investigate particle size distribution of plastic contaminants in the study area. Sample collection and analytical work was performed by Katsiaryna Pabortsava (NOC Southampton, UK). Note that both datasets represent the analysed subset of samples collected for microplastics analysis during AMT26/JR16001. The remaining samples are stored at NOC Southampton awaiting resources for analysis.