Spraying herbicides to manage Florida’s aquatic vegetation: a blanket approach that damages water quality, affects ecosystems, and threatens human health
Throughout Florida’s freshwater lakes and rivers, fast-growing invasive plant species can interfere with navigation and threaten the biodiversity and natural processes of a water body.
The Florida Fish and Wildlife Conservation Commission (FWC) is the state agency responsible for coordinating and funding two statewide programs controlling invasive aquatic and upland plants on public conservation lands and waterways throughout the state.
The use of chemical herbicides to control non-native species has long been a public concern as a major contributor to Florida’s growing water crisis.
What is herbicide spraying?
Herbicides are chemicals that are designed to target and kill certain undesired plants. In Florida’s freshwater lakes and rivers, spraying herbicides is the go-to method for controlling non-native aquatic and subaquatic vegetation—an approach that comes with far too many negative consequences to water quality and the health of our ecosystems.
The background and current system
Lake management practices in Florida over-rely on the application of herbicides in order to control non-native or “nuisance” plants in water bodies. It has developed into a chemical dependence that can fuel harmful algal blooms and have adverse impacts on water quality, fish habitat, and breeding in freshwater lakes and rivers.
While targeted machine or hand removal methods exist to control non-native aquatic plants like water hyacinth, torpedo grass and others that compete with native vegetation, the State of Florida and other water managers apply the cheapest, one-size-fits-all approach by spraying. This leads to degraded water bodies, often with areas devoid of wildlife.
The problems with chemical spraying
- It damages or kills native plants: Although the herbicides are designed to be selective towards non-native plant species, when those non-native plants die, their decaying matter often smothers native species and prevents photosynthesis. The decaying plants also release an abundance of nutrients that create an environment much more conducive to non-native species, which have higher nutrient requirements than native species.
- It fuels toxic algal blooms: Nutrients released from decaying plants can fuel harmful algal blooms (HABs) that contain toxic cyanobacteria, especially when combined with warm weather
- It prevents natural filtration: When the decaying non-native plants kill off native plants—like eel grass and other plants that naturally remove nutrients from the water—it limits the lake’s natural defense against major algae blooms.
- It has negative effects on fish habitat: Not only does spraying result in habitat loss, it can also lead to low-oxygen conditions when too many plants die and decompose simultaneously. This creates the potential for isolated fish kills, especially during very warm weather.
- Human Health concerns: The main ingredient in the herbicide that is being used for aquatic plant spraying is glyphosate—a chemical that might be linked to cancer according to some studies.
Recent developments
For decades, users of these waterways—bass fishermen, waterfowlers, and other outdoorsmen—have been speaking out about the harmful impacts of these careless practices. Finally, thanks to their voices and others getting involved, there is a growing effort to reevaluate the current system and seek improved management strategies.
In late 2019, the FWC established a Technical Assistance Group (TAG) to assist in developing a completely new management strategy for plants in Florida’s waters. The TAG is made up of 30 individuals, each representing a different stakeholder group that has an interest in the way these plants are managed. Our co-founder and hunting guide, Capt. Chris Wittman, was appointed as one of the representatives who will be working collectively to address issues and develop solutions and safer alternatives for aquatic plant management in Florida.
What’s next and how can you be involved?
Ultimately, through this reevaluation and with the help of the TAG, we want our managers to completely rethink the way our water bodies are managed. Each body of water needs to be looked at individually to develop a holistic management plan for that specific body of water—just as is done for all Wildlife Management Areas (WMAs).
To do that, we need to ask questions like:
- What should that lake or river look like?
- What’s the ideal situation for the wildlife, the flora and fauna, the overall ecology, and the people that enjoy that body of water?
- Is complete eradication of all non-native aquatic plants really necessary, or even beneficial?
- Maybe only a 50% reduction in non-natives is actually best for a particular lake when considering the needs of the lake as a whole?
These are the types of questions that need to be answered in order to create goals, or targets, for each body of water.
Once those goals are established through a management plan, lake- or river-specific work plans can then be developed to control aquatic vegetation in a way that supports those specific goals. Thankfully, FWC is in the process of developing those management plans, and they’re currently looking for public input.
They’ve invited the public to attend virtual public meetings that will provide updates on the lake management plans currently in development. The development of these plans will allow for local stakeholders and FWC staff to jointly craft management targets and approaches that will ensure the long-term well-being of these resources and their benefit to people.
Current schedule of virtual public meetings
- March 9th, 2021: Harris Chain of Lakes Management Plan
- March 16th, 2021: Lake Okeechobee Management Plan
- March 23rd, 2021: Kissimmee Chain of Lakes Management Plan
Make your voice heard
We encourage you to participate in these meetings and to urge the FWC to pull the plug on Florida’s management of aquatic vegetation by way of chemical assault. Although each body of water will require a unique approach, there’s one thing that’s clear across the board—blanket, all-in chemical herbicide spraying operations are not the answer. We have to get away from this destructive system and seek alternative control plans that support goal-driven, holistic approaches to our lakes and rivers.