From the FAQ[1]:
> Is it possible to remove microplastics from water by using a Bubble Barrier? During the Berlin Bubble Barrier Pilot, the Bubble Barrier was able to catch plastic as small as 1 millimetre. It depends on the catchment system whether the microplastics are able to be brought ashore. In the pilot at Wervershoof, we are investigating whether we can catch microplastics measuring 20 micrometers up to 500 micrometers (0,5 millimeters).
Only stopping larger plastic could be enough of a win, I think, as this would prevent it from being broken down into microplastic...