To clean up microplastics from the oceans, we could use
genetically engineered fish and bacteria. The
fish would have an organ for storing plastic, which could
be a modified appendix (because fish have
those, right?), as well as gut bacteria (because fish have
those, right?) designed to concentrate
plastic particles and move them into that organ.
Anyway, we release these fish. Then, as in the original
idea [link], we put a bounty on them, but with
the condition that they're returned alive. The ones that
come in have the plastic extracted,
measured, and recycled. Those that collected the most
plastic are bred to form the next generation.
Over time, this should result in fish and bacteria
optimized for collecting plastic.
I expect this will result in better collection of
microplastic pollution than the original idea, which
seems to me that it would only work for macroplastic.