A couple of tourist deciding to drink beer in another port really won't, but dredging the sea bed and sea walling for development is so dramatically effecting the fish that Fisherman and divers alike will soon elect to visit a more ecomature ( i think I just invented a new word)country. The developers deriving profit will leave having been successful and those that call this home, will be left staring at a lot of empty condos and suffering a collapsed economy.
Whats going to happen to Ambergris happened to the Cayman Islands in the late 70's and early 80's. They came back after implementing environmental restrictions that set a world standard, but only after a decade of loss.
Damn there I go with the soap box again.

White Sands Dive Shop