Expensive yes, although I have it on good authority that I could get a discount on that quantity :-) Also in discussing this briefly with some folks the entrapment systems would be more complex than nets or coffee filters. But lets say your investment was, all in $10B over 10 years and you remediated 60 - 70% of the problem. Would that be, in your opinion, a waste of money? Understand the alternative is to live with existing fish stocks absorbing material as they feed in the area and to have the problem get worse. Seems like, if nothing else, it would make for a good NSF grant to understand the question better.
It definitely merits study, but I imagine the best ideas are going to be in plastic-digesting microbes, and measures to reduce the amount of new plastic that gets into the system. I'm afraid we're going to have a layer of microscopic plastic sediment on our crust, just as we have a layer of radioactive soil from atomic testing in the 50s and 60s. It will be one of the geological landmarks of our era.
