Turtle plastic ocean pollution
© Alamy
Plastic pollution in the sea is having a devastating effect on wildlife and their habitats
The report, conducted by the Helmholtz Centre for Environmental Research in Germany, was based on dozens of reports, as well as the debris collected at 79 sampling sites along 57 rivers.

The worst offenders are some of the longest and largest waterways in the world, and are in countries with poor waste management, when it comes to collection, dumping and recycling.

They're also the rivers with the largest population of people living alongside them, with rivers from inland areas particularly affected.

While it would be impossible to clean up the damage already done, the report estimates that tackling the sources of pollution along these rivers could see overall plastic pollution from rivers almost halved.
plastic ocean pollution
© Fergregory
It's predicted up to 13 million tonnes of plastic makes its way to the sea every year
Dr Christian Schmidt, hydrogeologist and lead author of the report, said: "'Reducing plastic loads by 50 per cent in the 10 top-ranked rivers would reduce the total river-based load to the sea by 45 per cent.

"Our analysis reveals that plastic loads of large rivers disproportionately increase in relationship to the increase of plastic debris available for transport.'

The biggest offenders are indeed two of the largest rivers in the world, with the Yangtze and the Ganges carrying over 850,000 tonnes of plastic between them to the ocean every year.

By comparison, the Thames dumps 18 tonnes of plastic into the sea annually.

The worst rivers for plastic pollution

These are the rivers that the report identifies as the most polluting:
plastic pollution rivers data ocean
Researchers now plan to study how long plastic takes to get to the sea once in the river, which Dr Schmidt says is key to working out how best to prevent it.

The amount of plastic in our oceans is killing wildlife and damaging habitats. With up to 13 million tonnes of it finding its way to the sea every year. Scientists predict that the amount of plastic in the sea could outweigh fish by 2050.

Last week, the United Nations passed a resolution that called for greater action "to prevent and significantly reduce marine pollution of all kinds" by 2025.