This discussion was part of a presentation on invasive species that was given by Dr. Michelle Johnston, a sanctuary researcher, during the sanctuary's Seaside Chat series in 2012.
One of the invasive species that I'd like to spend time on tonight is the invasive lionfish. I don't know how many of you know about the lionfish problems that we're starting to see in the Gulf, but they're here, they're coming, and it's kind of scary.
Lionfish are very popular in the aquarium trade because they're beautiful fish. I mean, look at them. They have these beautiful stripes, these long spines. They get the name lionfish because when they flair their fins, it actually looks like they have a lion's mane.
Again, these are native to the Pacific Ocean. But, it was thought that these were released in the late '80s off the coast of Florida. The rumor is there was a hurricane, the hurricane damaged one of the aquariums in Florida and the species of fish got out. Now whether that's true or not, this release from an aquarium, we don't know. But, they started establishing themselves on the east coast, of the Atlantic, gradually came down to the Caribbean, made their way to the Florida Keys, and have now hopped over to the Gulf.
The bad news about these guys is that they...basically a summary of all the bad things about them...is that they inhabit all marine types and depths, so they're not picky. They'll live in shallow water, they'll live in water 500 feet deep, they really don't care.
They're sexually mature in less than one year, and once they're mature they reproduce every 3-4 days. So, they grow fast and they're producing a lot of babies. They can reach densities of greater than 200 adults per acre and that's kind of the norm once they get established. There's actually been sightings in the Carolinas, off Cape Hatteras, where they've seen over a 1,000 adults per acre at about 200 feet depth.
So, they like to hang out together, they like to reproduce, and they're also venomous. It's like a triple threat. It just keeps getting worse. They're venomous fish and may also carry a toxin called ciguatera, and I'll talk about that a little bit later [ciguatera discussion is not part of this video segment].
They're also opportunistic predators, so essentially, you put something in front of them, they'll eat it. They're not picky. A lot of times they're eating ecologically, recreationally, and commercially important fish species. So they're eating the little fish that the fishermen like to fish and when they eat the little fish, the little fish aren't growing up to be big fish, and that creates problems.
They're also causing phase shifts on coral reefs. They're eating the little fish that eat the algae and the little fish aren't there to kind of "mow the lawn," so to speak. The reefs are getting dominated by algae and that creates a lot of problems.
Also, they're competing, obviously, with our native fish species for food. They're competing with the snapper and the grouper. They're eating the fish that the snapper and grouper would eat. They, again, have a voracious appetite so they're eating a lot of fish and there's not really anything in this area that's known to eat lionfish.
So, they're venomous, they reproduce, they eat a lot, and nothing is eating them.
Video Length: 3:21