Lake Okeechobee battles invasive plants with herbicides and other methods

Lake Okeechobee, a 450,000-acre lake in Florida, is home to a diverse native ecosystem, but invasive plants like water hyacinth and water lettuce threaten its survival.

Since the 1920s, the U.S. Army Corps of Engineers has worked to manage these invasive species, which are native to South America. Biologists describe them as "troublemakers" because they have few natural predators, can double their coverage in one to two weeks, and outcompete native vegetation, jeopardizing the lake's health.

Efforts to control these plants have sparked debate, particularly over the use of herbicides. The Corps uses GPS data and research to direct crews to target specific areas of the lake with spray applicators.

"It makes you feel pretty good that, you know, our management is working. And, you know, we're doing such a great impact on the lake and, for the better. When I first started, right after the spray pause happened, I have videos where I was driving for six minutes straight, going 30 miles an hour on the airboat. 100% hyacinth," said an invasive species biologist with the U.S. Army Corps of Engineers.

An applicator with Applied Aquatic Management, LLC, shared his experience, saying, "Working in the industry, not just the aquatic industry, pretty much my whole life as an applicator, right out of high school, 40-plus years as an applicator. Looking to help make a difference."

Safety concerns have grown for workers managing the invasive plants. Applicators have faced harassment, threats, and even gunfire while performing their duties.

“That’s the part that most people don’t understand. When one would say that I’m out there destroying the environment, it’s the total opposite. We’re working on invasives to prevent that from happening,” the applicator said.

Since 2020, the Corps reports that its management efforts have reduced invasive aquatic vegetation on Lake Okeechobee by 96%. However, many still question the use of herbicides.

An invasive species biologist explained why mechanical removal alone is not practical for a lake of this size.

“A really big misconception that we can do. Why don’t we use mechanical control at all times? Again, it’s a 450,000-acre lake. There isn’t a budget in the world that can sustain that. But without even considering funding. They’re not just like here. They’re constantly moving around. And when they’re at maintenance levels, there might be one tiny plant in there, and then maybe a group of plants way over there, and then maybe an acre way down there. And this distance can range from a couple feet to a couple miles. So being that’s why, we have to continue to use all the tools in our toolbox,” the biologist said.

The Corps emphasized that invasive plants are constantly moving with wind and water currents, and small patches can appear miles apart, making it difficult to rely on a single management strategy. Officials say they use every tool available, including chemical treatments and helpful insects that feed on and break down invasive plant species.

Protecting Lake Okeechobee is critical, as these fast-growing plants can block boat traffic, clog water control structures, create breeding habitats for mosquitoes, and increase muck buildup in lakes and canals. Without management, this Florida treasure could one day be overtaken by the very species threatening its survival.