Amsterdam is trying out a "bubble barrier" to help remove plastic from the city's canals by capturing trash hidden beneath the surface of the water.
Although the project, launched in November, is just a small-scale test right now, the startup behind it hopes it could be deployed elsewhere, if successful.
"A bubble barrier is basically a tube that we place on the bottom of the river or canal that has holes in it, and we press air through it; that creates a bubble curtain," said Francis Zoet, the Great Bubble Barrier project's technical director.