A recent study paints a sobering picture about the state of our oceans.

According to the paper, published last month in Environmental Science and Technology, rivers deposit up to 4 million metric tonnes of plastic into the sea -- and about 95 per cent of that comes from just 10 waterways.

Previous studies suggested about 67 per cent of plastic in the oceans came from 20 rivers. For this study, researchers out of the Helmholtz Centre for Environmental Research and the Weihenstephan-Triesdorf University of Applied Science used a larger data set to reach their findings, sampling from 79 sites along 57 rivers around the world.

Eight of the 10 rivers are in Asia. [...]