As an invasive species though, they are easy to spot and don't swim fast, so easy to kill with a Hawaiian sling
Hank that's what I thought till I speared one last week. It shook off the spear and swam like lightning never to be seen again. Our boats are equipped with foot-long 1/4" steel rods. Sharpened on one end and a rubber band tied on the other end. You use your thumb and index finger as a crutch to launch the spear like a sling shot. Has been very effective in eradicating lionfish and we have been doing a good job about it. Once 1 is spotted the area is marked and a crew member goes down during surface interval and says hello. We are not allowing spear guns and Hawaiian slings because we don't want DMs coming back saying a grouper or hogfish got in the way and "we didn't want to leave it behind!"
At Turneffe they are popping up faster than we can control. We don't see much juveniles anymore guess they stay in the mangroves and come out to the reef when they grow up.
Check out this pic of an uninvited guest in my bachyard.