A study by Germany’s Helmholtz Centre for Environmental Research suggests that over 90 percent of all the plastic waste in the ocean flows into it from just 10 rivers. Alex Gray of the World Economic Forum reports: By analyzing the waste found in the rivers and surrounding landscape, researchers were able to estimate that just 10 river systems carry 90% of the plastic that ends up in the ocean. Eight of them are in Asia: the Yangtze; Indus; Yellow; Hai He; Ganges; Pearl; Amur; Mekong; and two in Africa – the Nile and the Niger.