Concentrations of plastic litter in surface waters of the global ocean and the Mediterranean Sea at basin scale (zoomed in the top right corner inset). In the global map, dark and light grey areas represent inner and outer accumulation zones, respectively, modelled for the five subtropical gyres; white oceanic areas represent non-accumulation zones. The grey-scale base map in the Mediterranean basin shows the relative surface plastic concentrations predicted by numerical modelling. Darker areas are predicted to have higher concentrations. The coloured circles indicate average mass concentrations from in-situ sampling.

Sourced from Cozar et al., “Plastic Accumulation in the Mediterranean Sea”, published in http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0121762