This project is not capable of collecting usable plastic. It is too degraded, too small. Everyone thinks there are big islands of garbage, but in fact it is distributed in small (often microscopic) particles throughout the first 100 meters of water.
This project is 100% BS. I do quantitative work in ocean conservation, and I can tell you everyone just considers Boyan a scam artist.
If this effort continues, eventually the only reasonable sink for this material will be to melt everything into slugs that may be dropped to the bottom.
It's a good question. Perhaps the answer is that we don't care about the benthic food chain? Perhaps the answer is that it will take a really long time? There's not much energy at the bottom to cause this degradation.
This project is 100% BS. I do quantitative work in ocean conservation, and I can tell you everyone just considers Boyan a scam artist.