Five years ago, Claar-els van Delft began to suspect that plastic waste on the beach at Katwijk in the Netherlands did not come from visitors or the sea but from the mouth of a nearby river.
“We started picking up litter, and we noticed, near the river entrance, pieces that came from freshwater – all kinds of plastic,” she says. “Tampon sheaths, brush bristles, but also crisp packages, drink packages, everything.”
Sure enough, when volunteers sifted through …