I remember someone pointing out that (1) there is a very large amount of advocacy based around going to the Great Pacific Garbage Patch and harvesting microplastic particles there; and (2) this is a colossally stupid idea, because there is almost no plastic in the Great Pacific Garbage Patch. It's a a part of the ocean where the level of plastic is higher than usual. But it's still a part of the ocean.
If you want to filter plastic out of the ocean, you want to filter it out of the input stream, where it's concentrated, not out of the end product of diluting the input stream with the entire ocean.
Interestingly, the wikipedia article on the Patch is headlined by a disclaiming of a very similar mistake:
> Despite the common public perception of the patch existing as giant islands of floating garbage, its low density (4 particles per cubic metre (3.1/cu yd)) prevents detection by satellite imagery, or even by casual boaters or divers in the area.
If you want to filter plastic out of the ocean, you want to filter it out of the input stream, where it's concentrated, not out of the end product of diluting the input stream with the entire ocean.
Interestingly, the wikipedia article on the Patch is headlined by a disclaiming of a very similar mistake:
> Despite the common public perception of the patch existing as giant islands of floating garbage, its low density (4 particles per cubic metre (3.1/cu yd)) prevents detection by satellite imagery, or even by casual boaters or divers in the area.
https://en.wikipedia.org/wiki/Great_Pacific_garbage_patch