And while they are not dangerous to humans at the moment, the pellets - called nurdles - are also heading out to sea.
Scientists at the University of KwaZulu-Natal have told Coastwatch KZN that the nurdles would soon become toxic as they get into the food chain.
“Fish see them as a food source - they look like transparent fish eggs and are the size of a lentil,” a Coastwatch KZN statement said.
Di Jones, of the Dolphin Coast Conservancy, warned: “This is comparable to an oil spill. There is a disaster in the making.”