Like the setting of a campy sci-fi movie, alien invaders are all around us. Often innocuous looking or even possessing vibrant colors and attractive features, they slowly creep into our communities and make themselves at home. It would be one thing if they carved out a little niche, filling a role and providing services for others. But that’s not the case for these species. Instead, these insidious life forms arrive and take over—eating everything in sight, displacing locals who have been here for centuries, and generally upsetting the natural order of things. Who are these aliens? Well, they are not from a galaxy far, far away, but likely imported from another continent.
This year, February 20-26 is National Invasive Species Awareness Week (NISAW), and it’s a time that those of us in the ecology business talk a lot about the ramifications of invasive species. Invasive species are defined as “organisms that do not naturally occur in a specified geographic area, have been introduced intentionally or unintentionally by humans, and either do or could harm the environment, economy, or human health.”
This week, our Extension colleagues throughout northwest Florida are highlighting some of the highest-profile troublemakers that threaten our native plant and animal populations. So far, we have covered feral pigs, giant salvinia, Cuban tree frogs, lionfish, and cogongrass.
Invasive species make their way to our shores a number of different ways. Deliberate introduction—what I like to call, “seemed like a great idea at the time,” include feral pigs, Chinese tallow (aka “popcorn trees”), and kudzu. The pigs were introduced by Spanish explorers as a food source (and eventually escaped captivity), popcorn trees were considered an attractive ornamental plant, and kudzu was going to be a miracle cure for erosion. While brought with good intentions, they quickly outpaced their original intent and grew beyond control. Many species were inadvertently brought in with ship’s ballast (fire ants), others as packing material (cogongrass), and some as unwanted pets, by owners attempting to release them humanely (Burmese pythons, tegu lizards, lionfish).
So, what does one do with all these invaders? If you catch them early, you might be able to prevent them from really taking a foothold. For others, it’s learning to live with them, or finding a threshold at which you can tolerate their presence. Some plant species can be removed or maintained with herbicides, and fish and reptiles with targeted hunting and spearfishing. Biological control organisms—the natural enemies from the invasive species’ home territory—can also be deployed in the battle against them. Locally, we were part of a statewide initiative to release air potato beetles, which help manage the invasive air potato vines cropping up around our communities. While the beetles did not eradicate the vine, they did put a dent in the plants and established a beetle population that can help maintain the problematic species.
Half the battle with managing invasive species is being able to identify them and understand why they are problematic. If you see or have questions about any of the plant or animal species discussed here, feel free to reach out to your local Extension office or get involved with your local Cooperative Invasive Species Management Association (CISMA).