Which "this" are you referring to? If you're talking about the release of water from the salt ponds into Great Bay after heavy rains, that happens periodically. As far as pollution from land in general, most places in the Caribbean, SXM included, do not have sewage plants up to the level of those in the US. Again, if you are staying in Little Bay, which is what I understood, pollution in Great Bay should have no affect on you.