"Other than their physical presence they pose no other danger of, or potential for pollution."
I don't think I'd be too worried about their physical presence posing a "danger of ....pollution". I think I'd be more concerned about twatting their physical presence with my boat. I suppose that could cause pollution as a by-product but that is but naught compared to a knackered boat front and the attendant sea rushing through a bloody big hole.
Ah, bits still exist. You can see some in Shanklin Chine.
But as Ballistic mentioned, is Pluto a planet now or not? I believe there may have been a re-think.
If not, Mickey and Donald think he's still a bit of a dog.