This post was written by guest author Gabriela Rodriguez

With their serene waters, Florida’s freshwater bodies are vital to Florida’s natural ecosystem and all who enjoy it. However, the management of hydrilla has become a growing concern for Florida residents as this aggressive invasive aquatic plant grows at a rapid pace, clogging waterways and upending the balance of the natural ecosystem. 

To address the issue effectively, Olesya Savchenko, assistant professor in the Food and Resources Economics Department, has been working with an interdisciplinary group of researchers to understand stakeholder preferences for determining the most effective ways to keep hydrilla under control.

“Collaborating with researchers from the UF’s Center for Aquatic and Invasive Plants, the Agronomy Department, and experts from the FWC has significantly enriched our project by bringing together diverse and policy-relevant perspectives,” Savchenko said. “Such interdisciplinary work is critical, especially when addressing the complex challenges of water resource management.” 

Candice Price and James Leary, assistant professors in the Agronomy Department and the Center for Invasive Aquatic Plants at UF, are two of Savchenko’s key collaborators. Several graduate students from the Food and Resource Economics Department have also played a pivotal role in this research, working under Savchenko’s mentorship and participating in all stages of this research, from the initial survey design to data analysis and preparation of the infographic and the research manuscript.

Hydrilla Management in Florida

The Florida Fish and Wildlife Conservation Commission (FWC), which partially funded this project, keeps hydrilla populations from running rampant by applying EPA-approved aquatic herbicides, which can stop the invasive weed from growing for almost 300 days. However, it can muddy the water as the killed-off hydrilla decays, decreasing visitor enjoyment. Other methods of hydrilla removal, such as mechanical harvesting that removes hydrilla from the water, are used less often because it is significantly more costly, can unintentionally kill other wildlife, and must happen three times as frequently to be effective. However, it requires no wait times before water usage and reduces muck build-up. With these tradeoffs in mind, it is important to consider residents’ opinions in the decision-making process.

“Stakeholders have a tremendous impact on the management of invasive aquatic species, so understanding their perceptions behind the most commonly used control measures is essential for policymakers to establish holistic responses, including education and extension,” said Amanda Heinzmann, a Ph.D. student in Food and Resource Economics on the project.

Understanding Floridian’s Hydrilla Management Opinions 

Using a large-scale survey to collect over 3,000 responses from Florida residents. The survey questions implemented by Savchenko and her colleagues were used to find which of the two methods residents preferred, their level of concern regarding these methods and their willingness to pay for them.  

“This research is pivotal for informing policy decisions on hydrilla management in Florida’s public lakes, ensuring environmentally sound and cost-effective strategies,” said Abhishek Rajan, a Ph.D. student in Food and Resource Economics on the project. “Understanding public preferences enables more effective public engagement and supports the development of policies that reflect community values and scientific insights.” 

Key insights were revealed about Florida residents’ opinions, some of which have been published in a recent infographic for CHOICES.  

The survey results illustrated in this infographic show that most Florida residents are willing to pay for hydrilla management and prefer combining both herbicides and mechanical harvesting over utilizing a single solution. While supportive of these management practices and willing to pay for them, they did express great concern for the potential negative impacts perceived on native plants and animals from both methods, as well as the impact on recreational use of the water from herbicides and potential pollution risk from mechanical harvesters.  

“These results can inform the policy related to invasive plant management and public education efforts,” Savchenko said.   

The analysis of survey responses also shows substantial differences in hydrilla management preferences among various stakeholder groups, such as freshwater fishermen or waterfowl permit holders and individuals who engage or do not engage in recreation on Florida public lakes. Now, Savchenko and her colleagues plan to continue their work by delving deeper into the preferences of key stakeholders.  

“Of those that visit Florida public lakes, recreational freshwater fishermen make up a sizable stakeholder group,” said Liam Corcoran, an M.S. student in Food and Resource Economics exploring the topic with Savchenko. “Freshwater fishermen have been highlighted as a stakeholder group with preferences for hydrilla management that may differ to those held by other stakeholder groups who visit Florida public lakes.”

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