Pacific's plastic wasteland three times the size of France

It is estimated that items take around six years to reach the patch. Photo / Craig Leeson

The Great Pacific Garbage Patch contains 1.8 trillion pieces of plastic, 16 times more than previous estimates, experts have warned.

A three-year mapping project led by the the Ocean Cleanup Foundation, which is based in Holland, has discovered that the problem is much worse than previously thought.

The Garbage Patch, also known as the Pacific Trash Vortex, was first noticed by Charles Moore, a US boat captain, in 1997 when he was sailing from Hawaii to southern California and claimed to have stumbled upon "plastic ... as far as the eye could see".

Plastic gathers in the area because of circular ocean currents which pick up rubbish along coastlines and swirl them into the centre.

It is estimated that items take around six years to reach the patch from the coast of the US and around a year from Japan.

The new study involved traditional trawling with nets, as well as aerial scanning to map plastic in the ocean in 3D. The results show that the Garbage Patch is now three times the size of France, with nearly two million pieces of plastic, weighing the equivalent of 500 jumbo jets. The figures are four to 16 times higher than previous estimates. Ninety two per cent of the mass is represented by larger objects such as fishing nets, while eight per cent was due to microplastics.