Scope of Aquatic Plant Management in Florida Waters

Florida has more than 100 years of experience managing aquatic plants, beginning in 1899 when Congress authorized the U.S. Army Corps of Engineers to remove water hyacinths obstructing navigation in Florida rivers. The Florida Legislature has since designated the Florida Fish and Wildlife Conservation Commission (FWC) as the lead agency in the state to “direct the control, eradication, and regulation of noxious aquatic weeds and direct the research and planning related to these activities. . . so as to protect human health, safety, and recreation and, to the greatest degree practicable, prevent injury to plant and animal life and property.” Accordingly, the FWC administers three programs under the Florida Aquatic Weed Control Act in which pesticides may be applied in, over, or near waters of the U.S. in order to control aquatic plants:

1.   State-Funded Aquatic Plant Management in Public Lakes and Rivers

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. Criteria for this program are codified in the Rules of Chapter 68F-54, Florida Administrative Code (FAC). FWC biologists work with personnel from other agencies as well as interested private-sector stakeholders to develop annual aquatic plant workplans. Major uses and functions of each public waterbody are identified along with any listed species that may be impacted by invasive plants or aquatic plant management activities. Basic management objectives are defined and plant control methods are selected that will conserve or enhance identified waterbody uses and functions. Sites are monitored at least once each year to assess management effectiveness and to determine if any adverse impacts resulted from management activities. Management plans are revised annually according to current conditions. Each year, approximately 65,000 acres of aquatic plants are managed collectively in 350-375 Florida public lakes and rivers. Pesticide use is reported to the FWC by government and private-sector contractors by quantity of active ingredient applied to acres of each target plant in each waterbody on a monthly basis, as part of the invoice process.

2.   Aquatic Plant Control Permits

The state of Florida has more than 40 years of experience issuing aquatic plant control permits under the Rules of Chapter 68F-20, FAC. These rules have been revised on several occasions so FWC staff can focus on meaningful management activities in waters of greatest significance. More than 7,000 active aquatic plant management permits are issued by FWC biologists, primarily to riparian property owners and to local governments. Most of these permits are issued to control small acreages of plants to gain shoreline access to waterbodies. Some exemptions to permitting apply, including plant management activities in waters of 10 surface acres or less, and in waters owned exclusively by one person other than the state. Additionally, some exemptions apply for controlling aquatic plants via physical or mechanical means vs. using pesticides. Site inspections are conducted for all permit requests and permits are issued so the cumulative effects of permits are compatible with overall waterbody uses and functions. Permittees are required to keep records on aquatic plant control activities.

3.  State-Funded Plant Management on Conservation-Area Lands

FWC contracts with local governments and private companies to control invasive plants in conservation-area lands in Florida including wetlands considered waters of the U.S. The state is divided into 11 Regional Working Groups with stakeholders representing government agencies and non government organizations. Priority management sites are identified annually in each Working Group and control methods are selected that are most appropriate to meet management objectives or reduce or eliminate negative impacts of invasive species and enhance native plants and animals. FWC supplies herbicides and contractors to apply them if requested. FWC biologists ensure herbicides requested for use in wetland sites are appropriately registered for that site. Contractors report acreages of invasive plants controlled and quantities of herbicides applied to public lands, including wetlands. 

Complying With NPDES Regulations

FWC has a lengthy history implementing both integrated and adaptive pest management practices in aquatic and wetland sites in Florida. Through the three aforementioned programs, the Florida Fish and Wildlife Conservation Commission has regulatory and fiscal oversight of most aquatic and wetland plant management conducted in the state. During the past 40 years, FWC’s Invasive Plant Management Section has funded more than 180 research projects totaling nearly $19 million to improve existing aquatic and invasive plant management programs and to adapt to changing conditions and new invasive plant introductions into Florida waters. The focus of the research has been to reduce overall pesticide use in Florida’s invasive plant management programs. Much of the research has been to develop biological and mechanical management tools.

While the U.S. EPA and Florida Department of Agriculture and Consumer Services (DACS) register new compounds and new use patterns for existing herbicides in Florida waters, FWC research has led to strategies that increase herbicide selectivity and reduce overall use. This is accomplished through better understanding of target and non-target plant physiology, evaluating timing and rates of applications, integrating herbicide use with other control methods, and working with industry to register new chemistries, formulations, and use patterns more compatible with current water uses and functions. After new compounds or use patterns are approved by the U.S. EPA, the FWC contracts with universities and other research institutions first to evaluate herbicides in laboratory and controlled pond settings, and then to progressively monitor applications in small lakes or small areas of larger systems before authorizing large-scale management operations.

In addition to research, the FWC supports education, outreach, and training opportunities for Florida applicators who apply herbicides to Florida waters. The FWC contributes annually to the University of Florida (UF) to maintain the world’s most extensive online information source for invasive plants with more than 80,000 articles on aquatic and invasive plants and their management. The FWC maintains an extensive website in conjunction with the UF that addresses all facets of aquatic plant management in Florida waters. The FWC sponsors workshops and seminars to distribute the latest technologies in selective invasive plant management. The FWC requires its contractors to provide at least one applicator onsite, certified by the DACS in the aquatic pesticide applicator category, when herbicides are applied to Florida waters. The FWC staff reviews all permit and contractual program requests to conduct aquatic plant management from an IPM perspective and considers the environmental and economic consequences of not controlling targeted aquatic plants.

Through nearly 100 years of experience and 40 years of research, FWC biologists are aware that invasive aquatic plants must be managed at the lowest level that technology and current conditions will allow. This enhances the uses and functions of the waterbody and lowers the overall management cost—and if herbicides are necessary, it lowers the amount of herbicides applied. They are also aware that environmental stewardship includes selecting the most appropriate control method or methods available for each operation. Therefore, control sites are routinely monitored and management plans adjusted to suit current conditions. In this way, Florida has long been a leader in aquatic plant management and frequently is called on to develop management programs in the U.S. and overseas. 

Last updated: 01 December 2011