I just read an interesting article on lionfish, to paraphrase it a bit it stated that genetic mapping had pretty much pinpointed the source of Atlantic lionfish to be South Florida and Biscane bay through the hurricane Andrew breach of an aquaculture farm and aquarium releases by the public. Personally I think there are other sources too such as New Providence facilities such as Coral World (defunct) and atlantis.

The article goes on to explain that these fish have 'free-floating' spawn so the spread of larvae is inevitable and inexorable.

There is also a very cool web site www.lionfishhunter.com based out of the Bahamas. Inside the site there is the first glimmer of hope for a predator other than humans - the trigger fishes. The site mentions that where the queen triggers are prevalent you never see lionfish. This makes sense as in the Bahamas Queen triggers are the only predators capable of killing and eating the big black sea eggs. Every few years there is a population explosion of these nasty long spined urchins and the triggers help keep them in check by picking off the spines one by one until they can flip the egg over and eat it from underneath. It would be a short hop from there to pulling off the spines of a lionfish and then eating the defenseless and tasty fish exposed.