Commissioned by WWF and conducted by the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, the report “Impacts of plastic pollution in the oceans on marine species, biodiversity and ecosystems'' notes that microplastic concentrations above a threshold level of 1.21 x 105 items per cubic metre have now been estimated in several regions around the world. This threshold, above which significant ecological risks are likely to occur, has already been exceeded in certain pollution hotspots like the Mediterranean, the East China and Yellow Seas and the Arctic sea ice. In the worst case scenarios, exceeding ecologically dangerous thresholds of microplastic pollution could lead to adverse effects on species and ecosystems including reduced populations.