Most of the plastic in our oceans doesn't get dumped there directly, rivers carry it to the sea. As it turns out, a very small number of them do most of the damage.
But where to start? Well, in fact, that might be an easier decision to make than one would think. It turns out that about 90 percent of all the plastic that reaches the world's oceans gets flushed through just 10 rivers: The Yangtze, the Indus, Yellow River, Hai River, the Nile, the Ganges, Pearl River, Amur River, the Niger, and the Mekong (in that order).
These rivers have a few key things in common. All of them run through areas where a lot of people live — hundreds of millions of people in some cases. But what's more important is that these areas don't have adequate waste collection or recycling infrastructure. There is also little public awareness that plastic trash is a problem at all, so a lot of garbage, gets thrown into the river and conveniently disappears downstream.