Recent studies have shown that sea water around the Florida Keys has become increasingly acidic due to global warming. As a result it has begun eating away a tiny part of the limestone framework for coral reef in the upper Florida Keys. It's something that scientists had expected, but not so soon. The water eats away at the limestone foundation, making them more porous and weaker. So far the effect is subtle, not noticeable to the eye but as ocean acidification increases, scientists expect more reefs to dissolve and become flatter, and that fish will leave.