What are nurdles and why are they polluting our oceans?

Buoyant, the size of a lentil and almost impossible to recover, millions of the tiny plastic pellets are being washed up on the coast of Kerala in India in the latest in a series of global spills

Nurdles are the raw material used for nearly all plastic products. Here, a clean-up volunteer wearing protective gloves holds up small pieces of microplastic pollution.

When a Liberian-flagged container ship, the MSC Elsa 3, capsized and sank 13 miles off the coast of Kerala, in India, on May 25, a state-wide disaster was quickly declared. A long oil slick from the 184-metre vessel, which was carrying hazardous cargo, was partially tackled by aircraft-borne dispersants, while a salvage operation sealed tanks to prevent leaks.

But almost three months later, a more insidious and persistent environmental catastrophe is continuing along the ecologically fragile coast of the Arabian Sea. Among the 643 containers onboard were 71,500 sacks of tiny plastic pellets known as 'nurdles'. By July, only 7,920 were reportedly recovered.