My guess would be because lionfish is non-indigenous to the Carribean and species such as shark,grouper,eel,large angelfish,triggerfish and pufferfish that are, known to be or potential, lionfish predators will have to learn to hunt them here. Obviously, this is not seem to be instinctive but it seems that little by little the predatory behaviour toward lionfish is growing over time. Hope it continues to evolve. I believe support of protecting grouper from overfishing and growing the grouper population will be important to longer term control of lionfish.