Comment Re: One non-disturbing theory (Score 5, Insightful) 304
I am not buying the universal solvent theory, because even accounting for the salts in the water, it would take hundreds of years for most plastics to dissolve.
The bacteria theory is more likely, because I remember reading something about bacteria living in trash dumps, and supposedly breaking down plastic. I do not remember a followup, but it's still more likely than the above. The problem is, this does not necessarily result in harmless components being the end result.
Here's another theory that I consider more likely: algae and barnacles attach themselves to plastic objects, and eventually sink them out of sight. Not as perfectly conductive to happily singing "La-la-la" and dismissing all worries, but hey, if you wish, you can just come up with more comforting theories, like "Magical pink narwhals are spearing the floating plastic, and melting it in underwater volcanoes to build underwater cooling systems to fight global warming".