The Lionfish.

You may have heard of a spiny looking fish before. They’re one of the most invasive species in Florida, but they’re not the only creature lurking in our waters unwelcome.

Have you ever heard of green mussels?

“They tend to attach to docks, bridge pilings, or anywhere you’ve got significant amounts of rock,” said University of North Florida Biology Professor Dr. Matt Gilg. “They tend to be in clusters. If you find one, there’s usually more.”

“They can be pretty tasty with some garlic and butter!”

While they might sound like something you’d order at a nice seafood restaurant, chances are you don’t want to eat the green mussels living off our coast.

“Most of the places we find them are in areas where shellfish collection is restricted essentially because of pollution, so I wouldn’t suggest eating them in the United States but the species is edible,” added Gilg.

So, where did they come from? And why are they here? Dr. Matt Gilg leads the University of North Florida’s research on this invasive species.

”When these reproduce, they produce little larvae that float around in the ocean and so when a ship takes in water for ballast that ballast water can contain that larvae. So, they take a little boat ride across the ocean and then when the ship releases the ballast, the larvae have the potential to settle in that new location.”

Green mussels are native to the Indo-Pacific. They were first found in the early 2000s in Tampa Bay. Within a couple of years, they were found on the Atlantic Coast right here in St. Augustine.

“In Tampa Bay, these green mussels were reported to displace oyster reefs and they are causing economic damage as far as clogging intake pipes for power plants and things like that, so they have to be removed on a consistent basis,” Gilg commented.

Ready for some good news? Green mussel growth has been limited here along the First Coast in the past few years – thanks to winter cold snaps and bouts of heavy rain. The species thrives in warm waters with high salinity. But that doesn’t mean we can let our guard down.

“Once they’re entrenched it’s very hard to control them. The main thing to always remember is that we really have to be careful. In a lot of cases, species get introduced to areas and they don’t pose any problems. The problem is it’s very difficult to predict which cause problems and which don’t,” Gilg warned.

So, Dr. Gilg continues to study the green mussels to make sure this uninvited house guests doesn’t cause any drama.