We've been snorkeling around Sint Maarten / Saint Martin since 2013. Every year we notice a few species of fish that are rarer than they used to be -- for example, queen triggerfish, queen angelfish, and fairy basslets.
This year, however, we have noticed one charismatic megafauna -- the spotted eagle ray -- is thriving. Almost every time we go snorkeling, on all sides of the island, we see more spotted eagle rays than ever before.