Florida Statute and Florida Administrative Code
Aquatic plant managers in the state of Florida must manage aquatic plants so as to protect human health, safety and recreation and to the greatest degree practicable prevent injury to non-target plants, animal life, and property. Any modifications of plant control activities by the Florida Department of Environmental Protection (FDEP), however, are guided by Florida Statute (FS 369.20-369.255) and the Florida Administrative Code (FAC 62C-20). Both documents are attached in Appendix III so all participants in the workshop have access and can read them.
Prior to the recognition of hydrilla resistance, Fluridone was the only available herbicide that might offer the ability to eradicate hydrilla from an aquatic system. Initially, aquatic plant managers under the jurisdiction of FDEP may have performed many of their activities under the Florida Statute’s and the Florida Administrative Code’s definition for an Eradication Program (FS 369.22(2)(e) and FAC 62C-20.0015(11)). “Eradication program” was defined as a method for the control of non-indigenous aquatic plants in which control techniques are utilized in a coordinated manner in an attempt to kill all the target aquatic plants on a permanent basis in a given geographical area. With the continued re-growth of hydrilla it became obvious that aquatic plant managers were actually working in more of a maintenance control direction. A “maintenance control program” is defined as a method for the control of non-indigenous aquatic plants in which control techniques are utilized in a coordinated manner on a continuous basis in order to maintain the plant population at the lowest feasible level as determined by the department (FS 369.22(2)(d)). The Florida Administrative Code also clearly directs the department that “lowest feasible level” is the level of plant control permitted by funding and technology (FAC 62C-20.0015(13)). Now with the development of fluridone resistance (see Herbicide Section), the probability of eradication by fluridone will be zero, and maintenance control will continually push the target of lowest feasible level higher. Thus, the loss of a cost-effective herbicide like fluridone does not affect FDEP’s ability to manage plants, but severely limits the acreage of control due to cost and selectivity considerations of other management tools. The spread of fluridone resistant hydrilla also means that managers may have to allocate funds in such a manner that minimal or no hydrilla control activities can be implemented on a given system for one or more growing seasons. Given the current funding and technologies, we may have to accept an increased level of hydrilla in a given aquatic ecosystem. So as identified by the experts in attendance at the Hydrilla Issues Workshop, FDEP will have to establish how much hydrilla will be left in a given system given public use, environmental and budgetary considerations.
The Legislature has also established that the FDEP shall supervise and direct all maintenance programs, excluding the authority to use fish as a biological control (FS 369.22(4). Because aquatic plants can be important in lakes, it would greatly assist FDEP’s maintenance management efforts if comprehensive lake management plans were developed for the lakes requiring major expenditures for aquatic weed control. The importance of having a comprehensive management plan was clearly identified by the experts attending this issues workshop. However, the development of such plans will cost money and time. Until plans are developed, FDEP will have to expand existing plant management techniques (i.e. contact herbicides and mechanical harvesting) within their budget to achieve maintenance plant levels.
Deciding how many plants should be left in a lake can be difficult, but the Florida Legislature provides guidance in statute ((FS 369.20(2)). The Florida Aquatic Weed Control Act states it shall be the duty of FDEP to manage plants so as to protect human health, safety, and recreation. In Florida, the lack of flood control represents the greatest human health and safety concern. Consequently, FDEP staff in attendance had questions regarding the impact of dislodged hydrilla on water control structures. The current response to the potential threat of vegetation clogging a structure is for water management agencies to station or have nearby mechanical devices (e.g., track hoes or draglines) at each structure to remove plants accumulating in front of structures in emergency situations. As this workshop made clear, there is a strong potential for increased hydrilla coverage on those flood control lakes that contain structures (Lake Tohopekaliga, Kissimmee, and Istokpoga). Therefore, it is up to the SFWMD to insure that current response measures are adequate given different densities of hydrilla. With the exception of lakes containing flood control structures, the major issue regarding hydrilla management for FDEP will, therefore, be recreation. Recreation for most lake users will translate to access and fishing.
Some participants at the issues workshop believe it is possible to use grass carp in a maintenance program and help reduce aquatic plant control costs. Florida statutes, however, are clear that use of fish such as the grass carp is not under the control of FDEP (FS 369.20(2)). Use of Grass carp is under the control of the Fish and Wildlife Conservation Commission (FWC) and their regulation is detailed in the Florida Administrative Code (FAC 68A-23.088; see Appendix III). Pertinent to any discussion about using grass carp in a maintenance program is the FWC’s authority to deny any permit to stock triploid carp in any water body, other than private ponds, if such proposed stocking is inconsistent with the principal or planned use of the water body, the optimum sustained use by the public of the water body’s living aquatic resources, or sound biological management principals (FAC 68A-23.088 (3) (d)). FDEP, however, is charged with the guidance and coordination of all plant management activities of all public bodies, authorities, agencies, and special districts (FS 369.20(3)). Thus, FDEP and FWC must work together to determine how best to use grass carp as a tool for aquatic plant management in the state.
Because issues requiring research have been raised concerning the use of grass carp, FDEP must recognize that it has the statutory authority to promote, develop, and support research activities directed toward the more effective and efficient control of aquatic plants (FS 369.20(4)). If a research project involving barriers to carp movement is advanced (see grass carp section), FDEP also is charged with the authority to construct, acquire, operate, and maintain facilities and equipment (FS 369.20(4)(c)).
Recommendations
Recommendation 12: FDEP and cooperators shall consider implementing a maintenance program using registered contact herbicides and/or mechanical harvesting on water bodies with fluridone resistant hydrilla. The initial focus shall be on public and private access points and trails to maintain recreational use. If there are funds available after access allocations, FDEP will set as the working objective of maintaining submersed plant coverage above 15% of the water body’s surface area. FDEP unless advised differently by the working group establishing the lake management plan shall not attempt to manage submersed vegetation coverage below 15% of the water body’s surface area, especially on large lakes where the submersed vegetation is the vast majority of fish habitat. In many aquatic systems hydrilla constitutes the vast majority of remaining submersed vegetation. Therefore, while goals are to maintain native submersed plants above a certain percentage, aquatic managers will often be faced with recognizing hydrilla as a constituent of the submersed vegetation community.
Justification: The Florida Aquatic Weed Control Act states it shall be the duty of FDEP to manage plants so as to protect human health, safety, and recreation. Access and fishing are two important issues in each category mentioned by the Legislature. Access and fishing are also two areas that can draw public ire if not managed properly. Research has shown the probability of encountering an impacted fish population increases when aquatic plant coverage is below 15% or greater than 85%, thus providing a wide “window of opportunity” for managing plants and fishing. This is critical because with the development and spread of hydrilla resistance to fluridone, the existing funding and technology means fewer acres of hydrilla can be managed. Implementing a maintenance program as recommended can buy time until improvement in technology and funding can be achieved.
Recommendation 13: FDEP work with their cooperators (i.e., become the lead agency) to seek funding for the establishment of a comprehensive aquatic plant management plan at each lake requiring major amounts of state dollars for weed control. These planning efforts should directly incorporate stakeholder concerns and directions for management.
Justification: Participants in the Hydrilla Issues Workshop acknowledged throughout the meeting that what is “done” depends upon having a lake management plan. FDEP is mandated by the Florida Legislature to guide and coordinate weed control activities on all public waters (FS 369.20(3)). Because aquatic plants affect water quality and FDEP works with FWC on plant/fish management problems, FDEP is a logical state agency to lead the long-term effort to get a workable lake management plan for each lake requiring aquatic plant management. FDEP is also the state agency best positioned with the Legislature to ask for funds for the development of a comprehensive aquatic plant management plan because FDEP and the water management districts have developed similar surface water improvement plans (SWIM) for Florida.