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Center for Aquatic and Invasive Plants Logo    Plant Management in Florida Waters

Center for Aquatic and Invasive Plants Logo    Plant Management in Florida Waters

Aquatic plant management is a complex discipline that blends predictable sciences of chemistry and hydrology with the highly variable parameters of biology and meteorology, for application in venues with boundaries defined by human values and economics. Successful aquatic plant managers evaluate waterbody uses and functions, conserve or enhance natural processes and human uses of public water bodies, and assess priorities and adapt management strategies based on ever-changing: – public perceptions/demands – biological conditions – control technologies – funding availability – weather conditions – contractor availability.Algae are in the plant kingdom, but technically they are not plants. A diverse group of organisms, algae survive in even the harshest habitats. From the dry desert, to the Arctic Circle, to boiling springs, these organisms have found a way to extract enough from their environment to live. Algae range in size from microscopic to meters long and from single-celled to complex organisms that rival large plants. These organisms may look like true plants, but unlike plants, algae do not have roots or true stems and leaves. In Florida's freshwaters, algae are what make the water green. Green water is not necessarily undesirable, and neither are algae. In fact, algae are essential to the ecosystem and to life as we know it. Algae are a primary component of the food web, providing food for all types of animals, including fish, insects, mollusks, zooplankton (microscopic animals), and humans. There are microscopic algae, like phytoplankton; and there are macroalgae, visible to the naked eye. Algae occur naturally in all types of systems and can indicate the condition of an ecosystem. The mere presence of a species can indicate the amount and type of nutrients present. 


The Florida Fish and Wildlife Conservation Commission (FWC) is designated by the Florida Legislature as the lead agency to direct the control, eradication, and regulation of noxious aquatic weeds, as well as the research and planning related to these activities. The FWC created the Invasive Plant Management Section (IPMS) to oversee and fulfill these duties. The FWC issues more than 7,200 permits annually for aquatic plant management activities not eligible for state funding. For projects that are eligible for state funding, FWC contracts with local governments and private companies to control aquatic plants, especially invasive aquatic plants, in the state’s 1.25 million acres of public lakes and rivers. Funding criteria for this program, known as the Cooperative Aquatic Plant Control Program, are codified in the Rules of Chapter 68F-54, Florida Administrative Code (FAC). The following sections provide details on the various components of the Cooperative Program and explain how management plans funded by the FWC are developed and integrated into a statewide aquatic plant management strategy with the flexibility to adapt to local conditions.

The centralized approach of the Cooperative Aquatic Plant Control Program has proven effective for various reasons:

  • establishes a statewide management and resource protection plan;
  • ensures statewide priority distribution of available funds;
  • reduces administration; one agency distributes funds to areas of greatest need;
  • coordinates management operations with water managers and users;
  • avoids duplication as well as neglect;
  • adapts and implements new strategies quickly on a statewide scale;
  • ensures consistency in policy, goals, and administration.

Additionally, FWC provides a single point of contact for receiving federal funding and implementing federal policies related to aquatic plant management activities. FWC participates in a Cooperative Agreement with the U.S. Army Corps of Engineers to distribute federal funds for aquatic plant control in state sovereignty waters that also have federal significance. These waters include the Federal Navigation Project waters of the Kissimmee Chain of Lakes, the Withlacoochee, Crystal, and St. Johns Rivers and Lake Okeechobee.

The Water Hyacinth Control Example

Water Hyacinth Reported in Florida Public Lakes and Rivers 1947-2010

Water Hyacinth Reported in Florida Public Lakes and Rivers 1947-2010

Standardization of invasive plant management under the FWC has made maintenance control of some of the state’s worst weeds possible. Maintenance control is the coordinated and consistent management of invasive plants in order to maintain the plant population and associated problems at low levels. For decades, water hyacinth was uncontrolled in some waters or, in other instances, managed by several agencies with differing or narrowly focused goals. As recently as the 1970s, there was no statewide management directive, funding was inconsistent, and plant populations were out of control. Since centralizing the management of invasive plants by the state in 1971, water hyacinth has been reduced from an estimated 125,000 acres in the early 1960s to a low of approximately 730 acres (reported in public waters during 2000). There are occasional spikes in the statewide water hyacinth population, usually after droughts when seeds germinate and plants are flushed by subsequent rainfall into lakes and rivers from previously inaccessible marshes. Through frequent monitoring and rapidly deploying management crews to waters where water hyacinth outbreaks occur, maintenance control can be quickly restored.

National Pollution Discharge Elimination System (NPDES)

FWC also plays a substantial role in streamlining and implementing NPDES regulations in Florida related to pesticide use in, over and near waters of the state. The Florida Department of Environmental Protection (DEP) administers the state's NPDES programs and relies closely on FWC expertise regarding the use of herbicides for aquatic plant control. See the Pesticide General Permit for applying pesticides to Florida waters for the purpose of aquatic plant control. Most aquatic plant management in Florida is either permitted or contracted by FWC using integrated pest management strategies that are addressed in this section of the website. FWC's standardization and oversight through permit conditions and contract reporting requirements ensures compliance with U.S Environmental Protection Agency (EPA) regulations and lowers expenses for hundreds of businesses, as well as other government agencies, related to filing and reporting individual herbicide application activities to DEP and EPA.

Authorities and Funding Responsibilities

FWC funding for aquatic plant control comes from a variety of sources including boat registrations, gasoline tax, documentary stamp tax, and contributions from the U.S. Army Corps of Engineers. Funds are appropriated to the FWC annually by the Florida Legislature depending on available revenues and program needs. State funding alone has never been sufficient to control all aquatic plant problems in Florida. Additionally, many aquatic plant problems are not considered to be State responsibilities. Eligibility criteria were established by policy in 1989, and later by rule in 1997 (§ 68F-54.0035 (1), FAC), to identify waters for which the IPMS distributes aquatic plant management funding.

The FWC applies the following principles to distribute aquatic plant management funding:

  • statewide benefit vs. a few localities;
  • public benefit vs. special interests;
  • objective, competitive review process;
  • other funding sources (FWC funds are not used for areas with other fiscal authority).

Aquatic plant management agencies including water management districts, water control districts (§ 298, Florida Statutes), and other special districts have authority to raise funds for control of aquatic plants in canals constructed for flood control and water transport. Sovereignty lakes that do not have public boat ramps benefit small groups, and thus are not eligible for State aquatic plant control funding through the FWC Cooperative Program. Aquatic plant management in these systems is the responsibility of adjacent property owners or some other unit of government.

Water bodies must meet the following eligibility criteria to receive Cooperative Program funding through the FWC:

  • the water body must be sovereignty lands;
  • the water body must have public boat ramp access (a fee may be charged if it is not unreasonable in keeping with ramp charges in the area);
  • a sign must be posted at the ramp stating the water body is open to public use;
  • there must be signs directing the public from roadways to the public ramp; and
  • the public ramp area must be sufficiently large to launch boats and park vehicles

Management Objectives

Goals of Florida’s Cooperative Aquatic Plant Management Program are to:

  • Reduce the abundance of non-native invasive aquatic plants infesting Florida public water bodies;
    • emphasize control of water hyacinth, water lettuce, and hydrilla;
    • eradicate new infestations of invasive aquatic plants;
    • maintain established invasive plant populations at low levels;
  • Initiate management of established stands of other invasive aquatic plants.
  • Sustain public water body attributes such as navigation, flood control, and recreation while conserving or enhancing diverse native vegetation communities for fish and wildlife habitat.
  • Evaluate biological, chemical, mechanical, and physical control techniques and integrate appropriate tools into cost-effective invasive plant management strategies that are compatible with the uses and functions of each water body.
  • Review current management strategies and assess and incorporate new technologies and techniques that enhance invasive aquatic plant management objectives where appropriate.

Management Priorities

During the 1980s and 1990s, aquatic plant management funding was insufficient to address even high priority hydrilla problems in public water bodies. The following priority list was developed (§68F-54.005 (2) (a-g), FAC) to distribute available funds to areas of greatest need and to programs that achieve the most positive impacts. Increased funding beginning in FY 2001-2002 allowed managers to initiate aquatic plant control programs up to Priority Level 6.

Aquatic Plant Management Priorities in Florida Public Waters

  1. Floating vegetation
    • water hyacinth and water lettuce
    • floating plants that could impact all public waters
    • floating plants in canals that could spread to public lakes and rivers
  2. New hydrilla infestations
    • if controlled prior to establishing tubers, when low-cost eradication is possible
    • at boat ramps
    • hydrilla in canals that could spread to public lakes and rivers where there is little to no existing hydrilla
  3. Boat ramps, navigation trails, and flood control structures
    • invasive plants as well as nuisance growths of native and non-native plants when blocking these areas or jamming against bridges or flood control structures
    • includes floating tussocks / islands
  4. Create open areas in extensive hydrilla mats if funding is insufficient to address all problems in Priority Level 5
    • recreation
    • fisheries
  5. Large-scale hydrilla management
    • control projects of approximately 500 – 25,000 acres
  6. Other plants that impair or may impair primary uses and functions of the water body
    • remaining FLEPPC Category I invasive aquatic plant species
    • more than 100 other exotic and native aquatic plant species
  7. Residential canals or boat trails servicing private homes or clubs except for:
    • water hyacinth or water lettuce
    • hydrilla, if connecting to public water that has little or no existing hydrilla 

Refining Objectives and Management Timetable

FWC field biologists identify the uses of each of Florida's 466 public lakes and rivers which cover more than 1.25 million acres of fresh water. These waters serve a variety of functions including:

  • recreation
  • commerce
  • navigation
  • fish and wildlife habitat, including endangered species
  • ecotourism
  • drinking water
  • flood control
  • irrigation

Some waters may support only a few uses while others provide multiple uses and benefits to many stakeholder groups. FWC biologists inspect each public water body at least once annually; more often depending on the number of uses and complexity of plant management. These inspections by regional biologists can result in early detection of new plant problems and, if necessary, rapid deployment of management crews. Inspections also provide an assessment of invasive plant and management impacts on waters, and provide information essential in establishing management priories. Public input is valued and stakeholders who have expressed interest in invasive and nuisance plant management meet periodically to discuss progress.

Plant management programs are revised each year for public waterbodies. FWC field biologists and government contractors draft plans that are reviewed by local, state, and federal agency personnel and other stakeholders with expressed interest in individual waters. Click here to see a FWC sample annual workplan that summarizes the uses of the waterbody, management objectives, plant problems with estimated acreages, control methods and budget, and a map locating the waterbody and the plants proposed for control. Reviewers then meet to authorize individual work plans and establish statewide priorities within the overall legislative budget allocation for the ensuing year. As new problems arise or if anticipated problems do not materialize, funds are reallocated among contractors to accommodate these changes. In this way, the program maintains statewide standards while adapting quickly to local and regional needs.

The annual work plans provide a summary of anticipated control for the ensuing state fiscal year that runs from July 1 through June 30. FWC biologists or government contractors notify stakeholders with specific information about upcoming management operations via the Schedule of Operations and any number of public notification procedures including posting signs at ramps, notices in newspapers, or email messages. Management activities are then reported electronically to FWC. This information is summarized in an annual report to document expenditures and achievements toward maintenance control of aquatic plants in Florida public waters. Information related to herbicide use is forwarded to DEP in compliance with annual NPDES reporting requirements.

Administrative and Management Timetable for Aquatic Plant Control in Florida Public Waters

Feb. 1 – Apr. 10 FWC biologists and stakeholders develop regional plant management requests and budgets for the ensuing fiscal year.
Apr. 10 – 15

Compile information from draft workplan requests into database.

Apr. 15 – Nov. 15 FWC field biologists inventory aquatic plants in public waters to monitor control impacts and revise management priorities.
Apr. 20 – 24 Consider comments, develop workplans for each water body and set statewide priorities for ensuing fiscal year during meetings with contractors, agency staff, and other interested persons. Reallocate current year funding as necessary.
Apr. 27 – May 15 Incorporate approved workplans into contracts and task assignments.
May. 15 – Jun. 30 Execute task assignments.
Jul. 1 – Jun. 30 Manage aquatic plants pursuant to contracts and task assignments; revise and reallocate funds to adapt to changing conditions.
Sep. 1 – Feb. 1 Managers and contractors meet to develop large-scale hydrilla control projects.
Nov. 15 – Apr. 15 Most large-scale hydrilla control projects are initiated.
Nov. 15 – Dec. 15 Compile and verify data from plant inventories and management invoices.
Dec. 15 – 31 Prepare annual report and develop ensuing fiscal year budget needs after analyzing plant inventory and management information. File report on herbicide use to DEP.


A critical component of successful invasive plant management programs is the availability of sufficient and adequately trained managers. This includes experienced supervisory personnel who can identify potential invasive plant problems and provide practical solutions, as well as experienced field technicians who can respond quickly and professionally. Additionally, FWC ensures that appropriate materials and machinery are available throughout the year and on a moment's call for emergency situations. FWC has more than 30 primary and secondary private sector and government agency contractors available to manage aquatic plants in all 466 Florida public lakes and rivers eligible for state funding through the Cooperative Program.

Benefits of contracting with federal, state and local government agencies include:

  • extensive knowledge of local conditions and public demands;
  • incentive to ensure that invasive plants are under control to conserve local economic, environmental, and flood control attributes;
  • provide field supervisors to develop management plans and direct field crews, reducing the need for additional FWC staff;
  • provide funding and in-kind services to control plants in sovereignty waters;
  • personnel on call to quickly respond – imperative for eradication, maintenance control and emergency issues.

Benefits of contracting with private companies include:

  • work where government contractors are not available;
  • augment government agency contractors in all public waters to provide:
    • specialized services such as harvesting, shredding, bathymetric mapping, drafting management plans, and conducting aerial herbicide applications;
    • temporary assistance for large projects or during government contractor personnel or equipment shortages.