Cleaning Europe's rivers: Meet the teams trying to turn the plastic tide

Ten million tonnes of plastic end up in our oceans every year. But more and more people across Europe are taking matters into their own hands to stop the flow of plastic litter well before it reaches the sea.

The Bodrog River, a beautiful natural site in northeastern Hungary, is marred by discarded plastic bottles carpeting its banks.

"You may ask, where does it come from? It's from Ukraine's Transcarpathia [region]. Most of the waste is from there. And the reason is that basically in Transcarpathia, there is no waste management — they just dump the waste into the flood plain, and when the flood comes, it picks it up and spreads it in Hungary," explained Miklós Gyalai-Korpos, the project manager of Plastic Cup.

Plastic Cup is an annual showdown of competing teams cleaning up the banks of Hungarian rivers.

This year, over 150 enthusiasts hit the Bodrog for four days, kayaking and rafting, scooping up plastic as they go.

And there's a lot to scoop. About 90 tonnes of plastic waste cover a 50-kilometre stretch of this riverbank alone. If not removed, the litter is headed for the Danube, then the Black Sea, and eventually, the oceans.

In addition to cleaning up, one group of youngsters is also helping with a scientific study on plastic pollution.

"Children and young adults go to the river, and they collect trash in a scientific way," said Simone Berk, the project coordinator for Plastic Pirates — Go Europe!

"We collect the data, we categorise it, and then it's uploaded to an online platform so scientists can use it for their research."

Backed by the EU, Plastic Pirates — Go Europe! is a citizen science initiative that gathers young volunteers across a dozen countries.

Following a strict methodology, they clean a designated