Great Pacific Garbage Patch
25 March, 2018, 12:00 am
New findings show that the Great Pacific Garbage Patch, a rotating soup of plastic in the north Pacific Ocean, contains up to 16 times more waste than previous surveys were able to detect.
A team of scientists has conducted what they say is the most comprehensive study to date of the patch’s size and the debris floating in it. Using a combination of drag netting and visual surveys from boats and an aeroplane, they estimated the patch is 1.6 million square kilometres in area — about the same size as Queensland.
Packed into this area is more than 78,000 tonnes of plastic, the researchers report in the journal Scientific Reports.
Most of the mass was made up of pieces larger than 5 centimetres. While microplastics, which account for about 8 per cent of the mass, made up a bulk of the estimated 1.8 trillion pieces of plastic floating in the patch.
Lead researcher Laurent Lebreton said the garbage patch was growing exponentially and was boosted by debris washed out to sea during the Japanese tsunami in 2011.
“We show that plastic concentration has been increasing exponentially since the 1970s for different reasons,” said Dr Lebreton, an oceanographer at the Ocean Cleanup Foundation in the Netherlands.
“We correlated that with our model and we looked at estimates from the Japanese Government in terms of how much they think was washed to sea that dayâ€¦ and we predict that about 10-20 per cent of the materials post-2011 in the larger size class came from the tsunami.”