Lake Istokpoga Habitat Management Plan - MyFWC.com...lake’s ecology and a driver of the need for active vegetation management. Water levels of Istokpoga would Water levels of Istokpoga

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Lake Istokpoga Habitat Management Plan

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Lake Istokpoga Habitat Management Plan

Prepared For Florida Fish and Wildlife Conservation Commission

Prepared By Fisheries and Aquatic Sciences Program

School of Forest Resources and Conservation Institute of Food and Agricultural Sciences

University of Florida Gainesville, FL 32611

February 2020

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Table of Contents Acronyms and Abbreviations 4 Acknowledgements 5 Executive Summary 7 1 Introduction, Overview, and Purpose 10 2 Background, History, and Limnology of Lake Istokpoga 12 3 Overall Management Vision and Guiding Principles 52 4 Management Recommendations 63 5 Monitoring Measurables and Strategies 77 6 Actions for Other Agencies to Consider 79 Literature Cited 81 Appendix I. Aerial photographs of Lake Istokpoga taken between 1944 and 2001 Appendix II. Legacy herbicides in lake sediments are not preventing the growth of submersed aquatic plants

in Lake Istokpoga Appendix III. LAKEWATCH Report for Lake Istokpoga in Highlands County Appendix IV. Situation Assessment and First Public Meeting Report Appendix V: Lake Istokpoga Habitat Advisory Committee Members Appendix VI: LIHAC and LIWG Meeting Reports Appendix VII: Public Meeting Reports Appendix VIII: Results of Stakeholder Mail Survey Appendix IX: Public Input on Final Draft Appendix X: Relevant Florida Statutes Appendix XI: Presentations on Lake Mapping Appendix XII: Lake Istokpoga Vertebrate Species Lists Appendix XIII: Wading Bird Monitoring Protocol

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Acronyms and Abbreviations AHCR AHRE BMAP

Aquatic Habitat Conservation and Restoration Section Aquatic Habitat Restoration and Enhancement Subsection Basin Management Action Plan

FDEP Florida Department of Environmental Protection FWC Florida Fish and Wildlife Conservation Commission GIS Geographic Information System GPS Global Positioning System HMP Habitat Management Plan LIHAC Lake Istokpoga Habitat Advisory Committee (Management Plan stakeholder

committee) LIMC Lake Istokpoga Management Committee (Highlands County stakeholder committee) LIWG Lake Istokpoga Working Group (FWC) NAVD North American Vertical Datum NGO Nongovernmental organization NGVD National Geodetic Vertical Datum Plan Habitat Management Plan SAV Submersed aquatic vegetation SFWMD South Florida Water Management District SR State Road

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Acknowledgements The development of this Habitat Management Plan could not have been accomplished without the participation of stakeholders in the Lake Istokpoga Habitat Advisory Committee and stakeholders in the public meetings and surveys. The project team and the Florida Fish and Wildlife Conservation Commission appreciates the thoughtful input received from stakeholders. Lake Istokpoga Habitat Advisory Committee (LIHAC) Dave Bouse, Crappie Fishing Guide John Carson, Ph.D., Concerned Citizen, Nature-Lover Sue Clark, Realtor, Real Estate Guido Fischer, Fishing Resort Owner (deceased) Tracie Gillespie, Fishing Resort Owner Paul Grey, Ph.D., Florida Audubon Society, Ecologist Cole Harty, FWC Fisheries Biologist Don Hatcher, Bass Fishing Guide Nolan Rayburn, Duck Hunter Jim Reed, Homeowner Dawn Ritter, Highlands County Natural Resources Dave Sharpe, Duck Hunter Stakeholders and wider public More than 300 stakeholders provided input on Lake Istokpoga habitat management issues, goals and objectives, management techniques, and action strategies. Florida Fish and Wildlife Conservation Commission Eric Johnson, Project Manager Beacham Furse, Contract Manager Geoff Lokuta, Istokpoga Invasive Plant Management (IPM) Allen Martin, Planning Process Collaborator Nia Morales, Human Dimensions Specialist Carly Althoff, Istokpoga Aquatic Habitat Restoration & Enhancement (AHRE) Steve Shattler, Wading Birds Biologist Cole Harty, Freshwater Fisheries Biologist Bill Pouder, Freshwater Fisheries Research Kelle Sullivan, IPM Administrator Mark McBride, Waterfowl Biologist Amanda West, Alligator Management Craig Mallison, Freshwater Plants Research Danielle Kirkland, IPM Administrator Matt Phillips, IPM Section Leader Steve Rockwood, AHCR Section Leader Tyler Beck, Snail Kite Conservation Coordinator Patrick Pridgen, Alligator Management Don Fox, AHRE Administrator Bryan Fugate, Law Enforcement

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Highlands County Clell Ford, Natural Resources Manager Dawn Ritter, Natural Resources Manager Chris Mayhew, Invasive Plant Control Supervisor University of Florida Kai Lorenzen, Ph.D., Professor, Project Leader Chelsey Crandall, Ph.D., Research Associate, Project Manager and Researcher Joy Hazell, Lead Facilitator Mark Hoyer, Applied Limnologist

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Executive Summary Lake Istokpoga, Florida’s fifth largest lake at 27,692 acres, is highly productive in terms of both plant and animal life. Many different stakeholders use and rely on Lake Istokpoga, including anglers, hunters, recreational boaters; birdwatchers and general wildlife observers; fishing, hunting and wildlife watching-related businesses; the local hospitality industry; local residents; and a variety of civil society organizations. Many of the uses of the lake and the conservation of its biological resources rely on active management of its habitats, particularly with respect to aquatic vegetation. This task, however, is complex because of the dynamic ecology of the lake, the diversity of stakeholders, and controversies surrounding habitat management methods and targets. To promote effective, strategic habitat management for Lake Istokpoga, and to reduce stakeholder conflict, the Florida Fish and Wildlife Conservation Commission (FWC) contracted the University of Florida (UF) to engage stakeholders in developing a Lake Istokpoga Habitat Management Plan. Development of the plan involved review of existing environmental and biological information for the lake. It also involved an iterative planning process that combined stakeholder-driven identification of issues, objectives, and recommendations; with review of these outputs by the FWC Lake Istokpoga Working Group. Review of scientific information identified regulating the water level of Lake Istokpoga as a major factor in the lake’s ecology and a driver of the need for active vegetation management. Water levels of Istokpoga would naturally fluctuate by approximately 7.5 ft over the year, but are now regulated to fluctuate only about 2.7 ft. This low level of fluctuation leads to accumulation of organic matter in the littoral zone, allowing emergent vegetation to flourish. Exotic aquatic plants with tremendous growth potential like water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes), and hydrilla (Hydrilla verticillata) have also contributed to the accumulation of organic sediment in Istokpoga. With the increased growth potential of aquatic plants (especially exotics) in Lake Istokpoga, aquatic plant management became and will remain an important aspect of lake management. Stakeholder engagement in habitat management was strategic and adaptive, and included a variety of methods to ensure the highest level of participation possible. To address conflict among stakeholders, and between stakeholders and management agencies, the process aimed to allow stakeholders to voice any and all concerns about habitat management on the lake, and to foster collaborative development of objectives and recommendation to address those concerns. The process thus differed from previous habitat-planning processes where stakeholder engagement tended to focus on evaluating targets and actions proposed by the management agency. Initially, a broad-based situation analysis was conducted to assess baseline stakeholder knowledge, attitudes, and perspectives regarding management of Lake Istokpoga, as well as their general value orientations. A permanent committee of representatives from key stakeholder groups (the Lake Istokpoga Habitat Advisory Committee, or LIHAC) was formed to identify objectives, develop habitat management options, assess trade-offs among objectives, and develop plans for continued monitoring, review, and adaptive management. A wider array of stakeholders and the general public was engaged through public meetings. A stakeholder survey was conducted to obtain input from stakeholders at large who have not personally engaged with the LIHAC or public meetings. A website was maintained to document plan development and stakeholder input. Situation assessment provided important information for process design. A number of different stakeholder groups were identified. In addition, a number of different concerns and perspectives were shared regarding habitat in the lake. Overall, the situation assessment made it clear that the stakeholders around Lake Istokpoga are a passionate, engaged community. Many people view the lake as their place, regardless of whether they are long-term residents or people who visit seasonally. Even though opinions differed among stakeholder groups,

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all shared a passion for the lake, a concern for its continued viability, and a desire to see it continue as a shared natural resource.

A number of concerns were raised over the course of the LIHAC meetings, during the public meetings, and in the survey. These concerns formed the basis for the plan’s guiding principles as well as the focal goals, objectives, and actions recommended in the Aquatic Habitat Management Plan. Regarding habitat, the most prominent concern cited was the loss of submersed aquatic vegetation (SAV) and marsh habitat on the lake. However, a number of concerns focused on management operations, in particular the approach to managing aquatic invasive plants through herbicide spraying, and an overall loss of trust of management personnel. Concerns about level of herbicide spraying included the overall amount of herbicides used, frequency of application, timing of applications, apparent overlap or duplication of spraying activities by different programs or agencies, and oversight of applicators. Frequently cited concerns about overall planning and communication included lack of trust in decision-making; perceived inability to influence management decisions; confusion about why management takes certain actions or makes certain decisions; perception that management is not coordinated among different programs and organizations; lack of clarity about who is responsible for what, on the lake; and concern about who has influence where (though perceptions of who has the most/least influence were not universal). Poor communication, a lack of information, and no results seen from input were identified early in the LIHAC process as contributing to tensions surrounding habitat management on the lake.

To address these concerns, the LIHAC developed an overall management vision. Different wildlife species and human uses may differ in their habitat requirements. However, stakeholders on the LIHAC and in public meetings felt that shared concerns outweighed conflicting concerns among stakeholder groups. This reflects broadly shared interests in the lake’s habitat, fish, and wildlife and the fact that the lake is large and differentiated enough to support many different habitats and uses. Stakeholders supported the need to balance multiple perspectives and uses for the lake, and to exercise moderation in all management actions. Stakeholders also emphasized a need to maintain diversity of habitat types and their connectivity to conserve wildlife and support human uses. Focal habitats are habitats recognized as important to wildlife conservation and/or human uses. The LIHAC recommended setting target ranges for the extent of focal habitats (or vegetation types in the absence of focal habitat definitions) and rules to trigger management actions when habitat extent is outside the target range. To facilitate integration of native and invasive plant management, the LIHAC recommended including target ranges for all managed invasive plants (even if targets are “minimum feasible level”). Specific management recommendations were developed under the headings of Focal Habitat; Access and Navigation; Invasive Species; Management Operations; Communications; and Research, Evaluation and Adaptive Learning. For each category, the LIHAC and the project team created a goal statement with a set of objectives that describe specific, achievable efforts needed to attain desired future conditions. These were summarized as follows: Focal Habitat: Manage focal habitat within ranges that benefit wildlife and human uses. Target ranges and recommended management actions are defined for native submersed aquatic vegetation (SAV), hydrilla, bulrush habitat, and marsh habitat. Access and Navigation: Maintain reasonable lake access and navigation for diverse user groups. Recommended management actions include vegetation control at access points, and maintenance of navigational access. Invasive Plants: Minimize adverse impacts of invasive plants while maintaining focal habitat targets. Recommended actions include reviewing tolerability, maintenance levels, and control methods in light of habitat targets and possible collateral damage of control methods.

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Management Operations: Ensure that all management actions are strategic (informed by clear goals and objectives, and assessments of lake conditions), transparent, and followed with monitoring of effectiveness. Recommended management actions to this effect include the development of annual habitat status reports and management action plans. Communications: Promote continued growth and development of mutual understanding between FWC and stakeholders regarding management of Lake Istokpoga. Recommended management actions include connecting with an existing committee or establishing a new committee to provide input to annual management action plans and regular public meetings Research, Evaluation and Adaptive Learning: Conduct scientific studies and monitoring programs, and explore the use of management actions to proactively gain information and improve habitat status. Many current monitoring efforts are relevant to habitat management at Lake Istokpoga. Relevant metrics are monitored by multiple groups/agencies (e.g., University of Florida, FDEP, FWC, SFWMD, Highlands County), and multiple sections within individual groups/agencies. These monitoring efforts should continue. In addition, monitoring of management activities should be expanded to enhance transparency and accountability, and to allow systematic field evaluation of the efficacy of activities. Issues and concerns on Lake Istokpoga were diverse, and some of those raised by stakeholders are not fully within the mission and statutory authority of FWC. Suggestions are thus included here as potential opportunities for interagency collaboration or actions for other agencies or stakeholders to consider. Suggestions include exploring potential to change lake water-level regulation toward a more natural schedule, collaborating on infrastructure development for lake access points, reducing nutrient inputs to the lake, and reaching out to homeowners to communicate best practices for vegetation and land management.

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1 Introduction, Overview, and Purpose Lake Istokpoga, Florida’s fifth largest lake at 27,692 acres, is highly productive in terms of both plant and animal life. Many different stakeholders use and rely on Lake Istokpoga, including anglers, hunters, recreational boaters, birdwatchers and general wildlife observers, and fishing, hunting and wildlife watching-related businesses, the local hospitality industry, local residents, and a variety of civil society organizations. Many of the uses of the lake and the conservation of its biological resources rely on active management of its habitats, particularly with respect to aquatic vegetation. This task, however, is complex due to the dynamic, ever-changing ecology of the lake, the diversity of stakeholders, and their often conflicting preferences for lake-habitat characteristics and management actions. To promote effective, strategic habitat management for Lake Istokpoga and to reduce stakeholder conflict, the Florida Fish and Wildlife Conservation Commission (FWC) contracted the University of Florida (UF) to engage stakeholders in developing a Lake Istokpoga Habitat Management Plan. This document sets out the results of that planning process. Stakeholder engagement in habitat management was strategic, adaptive, and included a variety of methods to ensure the highest level of participation possible. Initially, a broad-based situation analysis was conducted to assess baseline stakeholder knowledge, attitudes, and perspectives regarding management of Lake Istokpoga and their general value orientations. A permanent committee of representatives from key stakeholder groups was formed in order to identify objectives; develop habitat-management options; assess trade-offs between objectives; and to assess plans for continued monitoring, review, and adaptive management (Lake Istokpoga Habitat Advisory Committee, or LIHAC). A wider array of stakeholders and the general public was engaged through public meetings and a stakeholder survey to obtain input from stakeholders at large who had not personally engaged with the LIHAC or public meetings. A website was maintained to document plan development and stakeholder input. The resulting Lake Istokpoga Habitat Management Plan is structured as follows: Chapter 2 provides background and a historical perspective on the lake’s ecology and habitat management. This material helps to define the broad envelope within which future habitat management actions and their outcomes should be considered. In Chapter 3, an overall management vision and guiding principles for habitat management are set out. Chapter 4 details the identification, development, and prioritization of management issues, strategies, goals, objectives, and recommendations. It provides a framework for FWC’s management activities on Lake Istokpoga that reflects and incorporates stakeholder input. The chapter sets out broad goals and specific objectives for habitat management within the purview of the FWC’s jurisdiction, and includes a suite of management actions that can be implemented when actual habitat conditions are outside the preferred or acceptable ranges specified in the objectives. Chapter 5 identifies and develops monitoring and adaptive management strategies for the continued evaluation and, when necessary, modification of habitat management strategies and practices. Chapter 6 sets out potential actions for agencies other than the FWC to consider. For instance, water level management, water quality, and watershed development provide context for FWC management actions but cannot be addressed directly by FWC since these issues are outside the agency’s jurisdiction. Nonetheless,

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such issues might be included in a listing of potential future actions by other agencies or in a discussion of other agencies’ historical efforts to address these issues. The Appendices provide documentation of all meeting/event/engagement opportunity feedback from participants and leader(s)/facilitators on meeting success, meeting organization, and facilitators’ performance.

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2 Background, History, and Limnology of Lake Istokpoga Aristotle (384—322 B.C.E.): “There is no time apart from change” Geologic History of Florida leading to Geology of Highlands/Polk County surrounding Lake Istokpoga: Geologists estimate the age of the Earth at more than 4.5 billion years. The Florida plateau, the platform on which Florida is perched, was formed about 530 million years ago by a combination of volcanic activity and marine sedimentation, during the early Ordovician Period. When the Florida plateau was part of the supercontinent, Florida was sandwiched between what were to become North and South America and Africa. Movement of the tectonic plates that compose the Earth’s crust eventually caused split into Laurasia (North America, Europe, and portions of Asia) and Gondwana (South America, Africa, India, Australia, and Antarctica). When North America split from Laurasia and drifted northwesterly, it dragged the Florida plateau with it. During the glacial periods (110,000 to 15,000 years ago), sea levels fluctuated hundreds of feet, having a profound effect on formation of Florida’s geology and resulting ecology. The changing sea levels influenced the formation of bedrock, soils, and surface topography. These geological factors influence the formation of lakes and the fertility of soils in the lake’s watersheds. Many lakes in Highlands County, including Lake Istokpoga, are nutrient-rich, located in the Kissimmee/Okeechobee Lowland where the geology is dominated by undifferentiated sand, shell, clay, marl, and peat of the Holocene (Griffith et al 1997). Settlement History of Florida leading to the creation of Highlands County Florida:

• 1565 The Spanish founded St. Augustine, the first permanent white settlement in what is now the United States. Pensacola was founded by the Spanish in 1698, but there was little significant European settlement in Florida until the late eighteenth century.

• 1763: At the close of the Seven Years' War (French and Indian War), Britain gained control of Florida. Settlers from Europe and the American colonies to the north began to move into the area. The provinces of East Florida and West Florida were formed.

• 1783: Most of the British settlers left when Spain regained the Floridas. • 1812: The United States annexed portions of West Florida to Louisiana and the Mississippi Territory. • 1812, 1816 and 1817: Seminole Indian Wars (Osceola; Seminole Chief 1804-1838) • 1819: Spain ceded the remainder of West Florida and all of East Florida to the United States for

$5,000,000. Official United States occupation took place in 1821. • 30 March 1822: Florida Territory organized. • 18 September 1822: Treaty of Fort Moultrie between the United States and the Seminole Indians. • 1835-1842: The Second Seminole War was caused by reaction to the Treaty of Payne's Landing (1832)

and the attempts by the U.S. to remove the Seminole from Florida. The Seminole, led by Chief Osceola, Wild Cat, Alligator, and Aripeka, conducted a guerrilla war. Over 1,500 U.S. troops lost their lives.

• 1842: At the close of the Seminole War, most of the Indians were removed west, to present-day Oklahoma, but a few hundred escaped into the swamps.

• 3 March 1845: Florida became a state. • 1861: Florida seceded from the Union. It was readmitted in 1868. • 1870-1900 The post-Civil War boom brought many settlers to Florida, as developers from the north

built railroads and resorts. • 1911: The Hollywood Indian Reservation was established for the Seminole Indians.

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• 1921-1925 The last 13 of the state's 67 counties were organized as the Florida land boom attracted new settlers from the north.

• 1921--Highlands County was created 23 April 1921 from DeSoto County. Starting around 1910, Lake Istokpoga’s first settlers began to lay down their roots along the marshy Northeast shore of the lake. While skilled real estate developers with capitalistic dreams of striking it rich started many towns in Florida, the first towns around Lake Istokpoga had different origins. The town of Lorida comprised cowboy homesteaders seeking the country life, building their own version of Eden on the edge of the Everglades. After the first settlers arrived, they began to adjust the land and water to make life easier, and populations in the whole county began to grow. According to the US Decennial Census, the population of Highlands County increased from approximately 9,200 in 1930 to an estimated 101,000 in 2016 (Table 2.1). With all the increased population came increased urban development, including homes surrounding the lake. This urban development has the potential to add nutrients to the Lake Istokpoga systems. Table 2.1. Population statistics for Highlands County, Florida, from the US Decennial Census Year Population 1930 9,192 1940 9,246 1950 13,636 1960 21,338 1970 29,507 1980 47,526 1990 68,432 2000 87,366 2010 98,786 Est. 2016 100,917

Lake Istokpoga Location, Physical Description, Rainfall, Water Level/Hydrology, and Land Use This brief description of Lake Istokpoga is not meant to be all-inclusive but to provide the background for evaluating an aquatic plant management plan being developed for Lake Istokpoga; this and subsequent sections summarize events and conditions up until the Habitat Management Plan was finalized in February 2020. A more complete description of Lake Istokpoga’s surroundings can be found in the report “Minimum Flows and Levels for Lake Istokpoga” developed by the South Florida Water Management District (SFWMD) (Zahina et al. 2005). The report can be downloaded using the following web site link: https://www.researchgate.net/publication/305316159_Minimum_Flows_and_Levels_for_Lake_Istokpoga. The Lake Istokpoga basin is located northwest of Lake Okeechobee in central Florida, and is within the Kissimmee Basin Planning Area (SFWMD 2000) (Figure 2.1). The Lake Istokpoga basin drains an area of approximately 920 mi2 (Milleson 1978) within Highlands and Polk counties. Approximately two-thirds of the basin is in the Southwest Florida Water Management District (SWFWMD). The remaining portion of the basin and lake are in the SFWMD. Lake Istokpoga resides in the Kissimmee/Okeechobee Lowland Region, and the Lake Wales Ridge borders it to the west (White 1970).

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Figure 2.1. Major Landscape Features in the Lake Istokpoga Vicinity, from SFWMD 2000 Lake Istokpoga is Florida’s fifth-largest lake, at approximately 27,000 acres. The lake is shallow, with an average depth of roughly 4 feet (McDiffett 1981). Direct rainfall combined with tributary inflows from Josephine creek (Josephine creek is not shown on the map but enters the lake in the northwest part of Lake Istokpoga) and Arbuckle creek. Input to Lake Istokpoga and waters are directed either to the Kissimmee River or Lake Okeechobee through a system of canals and water-control structures. The S-68 and the G-85 control Istokpoga’s water levels (Figure 2.1). The S-68, constructed in 1962 and operational that same year, is a gated water-control structure that discharges outflows into the C-41A Canal to the south. Water is generally routed to the Kissimmee River and/or Lake Okeechobee (Figure 2.1). Historically, Istokpoga Creek, paralleling today’s Istokpoga Canal, provided the only means for channelized outflow from the lake. Significant quantities of overland (sheet) surface water once flowed toward the Kissimmee River and Indian Prairie during times of high-water levels. Lake Istokpoga is a unique regional resource in several ways. It is an important source of water supply for agricultural lands southeast of the lake (Indian Prairie). The scenic beauty of the lake has encouraged the establishment of waterfront residences along the northern and eastern shores. The lake is recognized as one of the top fishing lakes in the state of Florida. Several annual bass-fishing tournaments are held there, providing significant benefit to the local economy. Waterfowl hunting is a popular sport on the lake and its fringing marshes. Remnant cypress swamps are found along the western half of the lake, providing important habitat for wildlife. Bird watching is also a significant activity. Rainfall on a lake’s watershed is the primary factor determining water levels in most lakes. Rainfall at Avon Park near Lake Istokpoga averages approximately 50 inches a year, and ranges from less than 30 inches/year to

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over 80 inches/year. This rainfall variation caused Lake Istokpoga to fluctuate considerably before stabilization of water levels. The US Geologic Society has maintained a continuous record of Lake Istokpoga’s water level since 1936 (Figure 2.2). Before any water-level manipulations (1936 to 1962), the water level in lake Istokpoga fluctuated approximately 7.5 ft, from 35.4 ft Mean Sea Level (MSL) to 42.9 ft MSL (SFWMD 2005). In 1948, the G-85 water-control structure was constructed on the Istokpoga canal, maintaining higher water during drought situations. By 1962, the flood control canal was completed, allowing water to flow southeast to Lake Okeechobee. The Army Corps of Engineers completed the S-68 water-control structure on Istokpoga. After these water-level manipulations and until 1989, Lake Istokpoga’s water level never exceeded 40 ft MSL, and only occasionally dropped below 37 ft MSL (approximately 3.9 ft fluctuation). After 1989, the US Army Corps of Engineers revised the water-level schedule in response to stakeholder complaints about access during drought situations. The new schedule allowed the lake to fluctuate only about 2.7 ft. Extreme lows in 1962 and 2001 (Figure 2.2) were actually managed drawdowns. The first drawdown was to install the S-68 structure, and the second was to scrape and remove accumulated muck in the littoral zone.

Figure 2.2. Monthly mean water level for Lake Istokpoga from 1936 to 2016 Water-level fluctuations and stabilization within lakes can have a large impact on the ecology of Florida lakes (Hoyer et al. 2005, Florida LAKEWATCH 2017). Many mechanisms are affected by water-level fluctuations.

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For example, when water levels decrease due to drought situations, nutrients increase in some lakes amd decrease in others. Nutrients can increase due to increased sediment resuspension. In some lakes, nutrients decrease because more light can penetrate to the bottom, increasing the abundance of aquatic macrophytes, which decrease open water nutrients (Hoyer et al. 2005). On the other extreme, stabilizing water levels in lake systems can cause the development of a large littoral zone of aquatic vegetation, which can both trap and create organic matter, thus dramatically increasing the buildup shoreline muck (Florida LAKEWATCH 2017). Lakes that fluctuate naturally tend to move organic matter out of a lake during extremely high-water levels, and oxidize organic matter at extreme low-water levels, both mechanisms tending to maintain cleaner shorelines. Lakes with stabilized water levels tend to accumulate organic matter in the littoral zone, allowing emergent vegetation like cattail and pickerelweed to grow well. Aquatic plants tend to get most of their nutrients from the sediments, and these nutrients are more available in organic sediment than in mineral sediments. Thus, the more organic sediments, the more aquatic plants, which create and trap more organic matter, expanding the littoral zone and creating more muck-dominated shorelines. Water-level stabilization has caused muck accumulation in many large, shallow Florida Lakes (Hoyer et al. 2008). This was probably responsible for the accumulation of muck that caused the Florida Fish and Wildlife Conservation Commission to draw Lake Istokpoga down in 2001, scraping and removing muck from about 1,300 acres of the littoral zone. Figure 2.3 shows the buildup of muck and emergent vegetation at the mouth of Arbuckle Creek, draining into Lake Istokpoga from 1958 to 2017. Consecutive (1944 to 2001) aerial photographs of Lake Istokpoga in Appendix I show extensive expansion of littoral zone after the water-level stabilization of 1962. The 1944 picture shows the clearly defined shoreline and littoral zone. The 1999 picture shows the large expansion of whole lake’s littoral zone, and especially the expansion around islands in the south part of the lake.

Figure 2.3. Mouth of Arbuckle Creek, which drains into Lake Istokpoga (aerial photographs taken in 1958 and 2017) Similar aerial photographs and rapid expansion of littoral muck accumulation after water-level stabilization are seen for Lake Tohopekaliga (Hoyer et al. 2008). This accumulation of muck caused a similar whole-lake muck-removal project for Lake Tohopekaliga. Hoyer et al. (2017) estimated muck accumulation rates for lake

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Tohopekaliga approximately 50 years before the muck-removal program in 2004, and again 10 years after muck removal. They found a significant decreased sediment accumulation rates, from 1.00 cm/year to 0.22 cm/year. One reason for the decrease in sedimentation rate during recent decades was the maintenance control of water hyacinths (Eichhornia crassipes). In tank studies, water hyacinths left uncontrolled produce three times as much organic matter as water hyacinths managed to cover less than 25% of the tank (Joyce 1985). It was not until the late 1980s that the State of Florida aggressively managed water hyacinths (Figure 2.4). Until then, large mats of unchecked water hyacinths were producing incredible amounts of organic matter on most of the big lakes in Florida.

Figure 2.4. Estimates of water hyacinth abundance over time, using statewide data from Florida’s Bureau of Aquatic Plant Management surveys A similar problem existed in Lake Istokpoga before the 1980s. Water hyacinths have been abundant on Lake Istokpoga since they arrived in the state (Figure 2.5). Florida’s Aquatic Plant Control Program was developed with the Department of Natural Resources (DNR) in the mid-1980s. At this time, the DNR worked with Highlands County as the water hyacinth control program contractor from the South Florida Water Management District (SFWMD). The District managed hyacinth out of the Okeechobee Office, but could not get to Lake Istokpoga as often as needed for maintenance control. Thus, water hyacinths were abundant on Istokpoga for almost 80 years, contributing to the acceleration of organic build-up.

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Figure 2.5. Water hyacinths abundant in Lake Istokpoga, on Arbuckle Creek, 1918; and in Istokpoga Canal, 1920

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Existing land use in the Kissimmee Basin Planning Area is generally more urban in the north than in the south. Continued urbanization is anticipated in the north. In the south, agriculture land use in Highlands, Glades and Okeechobee counties is projected to increase through 2020 (SFWMD 2000a). This projection reflects the general migration of the citrus industry to more southerly locations after the severe freezes of the 1980s. Land use in Highlands County and the Lake Istokpoga watershed is predominantly agricultural. The main agricultural types are pasture lands (including rangeland, which typically is not irrigated), citrus, cropland (including row crops and some sugarcane production), and ornamental landscape plants (“other”). Sugarcane is a growing form of agriculture in Highlands County, and production is expected to increase to 15,300 acres by 2020. Recent research on the impacts of different land uses on water quality of Florida lakes indicates that lakes with larger amounts of agriculture tend to have higher nutrient concentrations (Xiong and Hoyer 2018). These elevated nutrient concentrations can also increase algal abundances, which may contribute to increased organic sedimentation. With increases in agricultural practices and the continued use of herbicides, some stakeholders are concerned that accumulations of pollutants in the sediments may cause environmental impacts. Addressing these concerns, the Florida Department of Environmental Protection (FDEP) routinely samples sediments from Florida’s public lakes and analyzes them for certain pesticides, nutrients, metals, organics, and other compounds. Istokpoga is one of the lakes sampled in nine different years, between 2007 and 2017. Comparing the average sediment chemistry in Lake Istokpoga to the average sediment chemistry from 72 other Florida lakes shows that for every parameter, Istokpoga sediment chemistry is less than the mean for all other lakes. These data suggest that the sediment chemistry in Lake Istokpoga is not elevated in the 21 parameters listed in Table 2.2. Table 2.2. Comparison of Lake Istokpoga Sediment samples to sediment samples from 72 Florida lakes. Not all parameters were measured on all Florida lakes. Data are from the Florida Department of Environmental Protection (FDEP)

One main issue that emerged from this current stakeholder engagement process was the decreased abundance of submersed aquatic vegetation (primarily Hydrilla verticillata) and a perceived decrease in associated fish and wildlife populations. Since 2015, little hydrilla or other submersed aquatic vegetation has been reported in

Lake Istokpoga Florida Lakes Parameter Units Samples Mean Number Mean Min Max 2,4-D sediments ug/kg 2 22.4 23 34.2 4.3 180.0 Aluminum sediments mg/Kg 37 8,690.3 72 22,056.5 740.0 90,600.0 Arsenic sediments mg/Kg 37 2.4 72 5.3 0.4 23.8 Cadmium Sediments mg/Kg 37 0.2 72 0.6 0.1 2.4 Carbon, total sediments % C 37 16.5 72 15.5 0.3 50.0 Chromium sediments mg/Kg 37 12.2 72 30.6 6.2 99.9 Copper sediments mg/Kg 37 7.2 72 21.4 0.6 162.0 DDD (p,p') sediments ug/Kg 24 1.6 48 5.6 0.0 67.0 DDE (p,p') sediments ug/Kg 24 2.1 48 11.2 0.0 200.0 DDT (p-p') sediments ug/Kg 24 2.3 48 7.0 0.1 67.0 Dieldrin sediments ug/Kg 24 0.8 48 2.2 0.2 9.1 Inorganic Carbon, sediments % C 37 0.1 72 0.2 0.1 3.2 Iron sediments mg/Kg 37 6,477.4 72 10,438.0 279.0 48,503.3 Lead sediments mg/Kg 37 9.7 72 38.6 0.9 273.0 Mercury sediments mg/Kg 37 0.1 72 0.1 0.0 0.5 Methylmercury sediments mg/Kg 10 0.0 54 0.0 0.0 0.0 Nickel sediments mg/Kg 37 5.0 72 10.5 0.8 26.3 Organic Carbon, sediments % C 37 16.5 72 15.4 0.2 50.0 Phosphorus, Total (as P) sediments mg/Kg 37 638.3 72 1,139.6 38.7 8,962.5 Total Kjeldahl Nitrogen, Total (as N) mg/Kg 37 10.133.5 72 12,524.1 330.0 53,000.0 Zinc sediments mg/Kg 37 18.6 72 64.6 5.1 641.0

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Lake Istokpoga (FWC 2017). It was suggested by a general majority of the LIHAC and many stakeholders at public meetings that the longtime use of herbicides in Lake Istokpoga had built up legacy herbicide in sediments. This has prevented regrowth of submersed aquatic vegetation in the lake. To address these issues, UF’s Lake Istokpoga habitat management plan development team, with collaboration from the LIHAC and FWC staff, designed the following three-part sediment study to determine if legacy herbicides in sediments were inhibiting the growth of submersed aquatic vegetation in the Lake. This included 1) sediment bioassay studies, 2) analytical analysis of herbicide concentration in sediment, 3) a hydrilla tuber density survey within Lake Istokpoga. The following abstract summarizes these studies.

• Abstract: Stakeholders concerned about the lack of submersed aquatic vegetation (SAV, primarily Hydrilla verticillata) in Lake Istokpoga hypothesized that legacy herbicides in sediments were the possible cause of reduced SAV growth for the last 3 years. Bioassay experiments were conducted using sediments collected from nine stations located around Lake Istokpoga in areas identified by stakeholders where hydrilla had previously grown. These were compared to sediments collected from three stations in similar Lake Tohopekaliga where hydrilla was currently growing. Tomato seeds were germinated in sediments from all stations in both lakes and control soils. Bareroot tomato transplants (3.8 cm tall) planted in sediments from both lakes continued to grow. When harvested, plant dry weights were similar to transplants planted in two control soils (pure sand and 1:1 ratio potting soil and sand). Hydrilla tubers were also planted in sediments collected from three stations in both lakes and control soils. Tubers were germinated in sediments from both lakes and control soils, and percent germination was not significantly different between lake sediments and control soils. Sediment samples from all nine stations in Lake Istokpoga were sent to laboratories for chemical analyses of the nine aquatic herbicides used in Lake Istokpoga over the last 10 years and all results were “non-detect.” Sixty cores were collected from areas with a history of hydrilla growth in Lake Istokpoga, and no hydrilla tubers were collected, suggesting few or no propagules were present for resumed growth of this SAV. Bioassays and sediment analyses indicate that legacy herbicides are not causing the decreased abundance of submersed aquatic vegetation in Lake Istokpoga.

The full manuscript has been submitted for peer review and accepted for publication in the Journal of Aquatic Plant Management (Hoyer et al. 2020; Appendix II). Lake Istokpoga Water Chemistry: Florida LAKEWATCH is a volunteer water-quality monitoring program that has been monitoring Florida lakes since 1986 (Hoyer et al. 2014), including Lake Istokpoga since 1996. LAKEWATCH has been sampling northern (Istokpoga North 1, 2, and 3) and southern (Istokpoga 1, 2 and 3) parts of the lake (Figure 2.6) to monitor total phosphorus, total nitrogen, chlorophyll, color, specific conductance, and water clarity measured with the Secchi Disk. Appendix III, a summary report provided by LAKEWATCH, shows the means and ranges of water quality data for Istokpoga North and Istokpoga and how it relates to the Florida Department of Environmental Protections (FDEP) numeric nutrient concentrations. The reports also show an analysis determining any trends in the data and the time series plotted (Figures 2.7 through 2.11).

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Figure 2.6. Location of Florida LAKEWATCH water-quality monitoring stations Lake Istokpoga is classified as a colored lake, because the average color for the lake exceeds 40 Pt-Co units (Figure 2.6), which means the water is darker in general than the color of iced tea. The long-term mean chlorophyll levels for Istokpoga (43 µg/L) and Istokpoga North (41 µg/L) exceeded FDEP’s chlorophyll standard of 20 µg/L set for colored lakes. Average total phosphorus and total nitrogen concentrations for Istokpoga (TP = 57 µg/L and TN = 1399 µg/L) and Istokpoga North (TP = 67 µg/L and TN = 1353 µg/L) also both exceeded the FDEP’s minimum calculated numeric interpretation of 50µg/L total phosphorus and 1,270 µg/L total nitrogen. While these values suggest that the lake is impaired for nutrients, the local geology must be considered. Bachmann et al. (2012) recognized the influence of geology on the productivity of Florida lakes. They used data from over 1,100 Florida lakes to partition Florida into six total phosphorus (TP) zones and five total nitrogen (TN) zones (phosphorus and nitrogen are two nutrients determining lake productivity; Appendix III). Lake Istokpoga falls within TP Zone 5 and TN Zone 5, suggesting that Lake Istokpoga is naturally nutrient-rich, based on the geology in which the lake lies. Ninety percent of all lakes in TP Zone 5 and TN Zone 5 have nutrient concentrations less than 252 µg/L (TP) and 2,701 µg/L (TN). Thus, the LAKEWATCH water

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chemistry values suggest Lake Istokpoga has nutrient and chlorophyll values that are normal for the region. However, these nutrient concentrations could be elevated above background by the large percentage of agricultural land uses in the lake’s watershed.

Figure 2.7. Average annual water color measured by Florida LAKEWATCH for Lake Istokpoga stations in south and north areas of the lake, plotted by year of sampling. The blue line is for data from Istokpoga North stations. The red line is for Istokpoga stations.

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Figure 2.8. Average annual total phosphorus concentrations measured by Florida LAKEWATCH for Lake Istokpoga stations in south and north areas of the lake, plotted by year of sampling. The blue line is for data from Istokpoga North stations. The red line is for Istokpoga stations.

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Figure 2.9. Average annual total nitrogen concentration measured by Florida LAKEWATCH for Lake Istokpoga stations in south and north areas of the lake, plotted by year of sampling. The blue line is for data from Istokpoga North stations. The red line is for Istokpoga stations.

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Figure 2.10. Average annual chlorophyll concentrations measured by Florida LAKEWATCH for Lake Istokpoga stations in south and north areas of the lake, plotted by year of sampling. The blue line is for data from Istokpoga North stations. The red line is for Istokpoga stations.

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Figure 2.11. Average annual Secchi depth (water clarity) measured by Florida LAKEWATCH for Lake Istokpoga stations in south and north areas of the lake, plotted by year of sampling. The blue line is for data from Istokpoga North stations. The red line is for Istokpoga stations. Figures 2.7 through 2.11 show apparent trends in water chemistry data from 1996 to 2017, with nutrients and chlorophyll increasing, and water clarity decreasing. Appendix III confirms that LAKEWATCH trend analyses show significant increases in total nitrogen and chlorophyll, and significant decreases in water clarity. For the period of record, phosphorus showed no significant trend. Summer average total phosphorus and total nitrogen concentrations measured in 1980 (Canfield 1981; TP = 45 µg/L and TN 995 µg/L) were somewhat less than LAKEWATCH long-term average total phosphorus and total nitrogen concentrations for Istokpoga (TP = 57 µg/L and TN = 1399 µg/L) and Istokpoga North (TP = 67 µg/L and TN = 1353 µg/L). However, some of the trends can be explained by large changes in the abundance of hydrilla in Lake Istokpoga over time, and we do not have data for aquatic plant abundance in 1980 when Canfield (1981) sampled Lake Istokpoga. As aquatic plants fill a water column with biomass, multiple mechanisms tend to clear water by decreasing open-water algae (estimated with chlorophyll) and decreasing nutrient concentrations (Hoyer et al 2005). Algae attached to aquatic plants (periphyton) compete with open-water algae for nutrients. Plants decrease waves, and thus wind resuspension of nutrients. By decreasing turbulence in the water column, algae and other suspended particles are allowed to settle out of the water column, clearing the water. For example, the average water clarity for

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LAKEWATCH stations Istokpoga 1, 2, and 3 directly follows the abundance of hydrilla (the dominant submersed aquatic plant) over time (Figure 2.12). When hydrilla is abundant, water clarity is high. When hydrilla decreases, so does water clarity. This may explain the common statement that Lake Istokpoga used to have clear water and you could see the bottom, which was the case when hydrilla covered most of the lake. Conversely, colored water (high dissolved organic matter) can significantly decrease water clarity and thus ability of aquatic plants to survive. Additionally, years with high color generally followed years with higher-than-average annual precipitation, because the water brings additional dissolved organic matter into a lake system, increasing the color of the water. For example, the highest color values in Lake Istokpoga were in 2005 and 2015 (Figure 2.7), and these years both exceeded the average annual rainfall (60 inches) recorded at Archbold Station, Highlands County with 69 and 68 inches, respectively. Therefore, large storm events, like Hurricane Irma in 2017, can dramatically increase water color, and potentially decrease the abundance of aquatic plants, by decreasing the light available for photosynthesis.

Figure 2.12. Relationhip between whole-lake average Secchi depth (ft, blue line, right-side axis) and coverage of hydrilla (acre, red line, left-side axis) over time in Lake Istokpoga

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Lake Istokpoga Aquatic Plants: Aquatic plant management is an important aspect of lake management. As with other lake-management issues, controversies come with the territory. Thus, a well-evaluated and carefully designed management plan must be developed for each waterbody. With reasonable care in the decision-making process, aquatic plants can be managed successfully without destroying the desirable attributes of lakes that attract us to these waterbodies. Much aquatic plant research has been stimulated by the need to control nuisance aquatic plant species such as hydrilla, water hyacinth, and water lettuce (Pistia stratiotes), plants common to Lake Istokpoga. Understanding aquatic plant biology is important to the immediate problems of managing aquatic plants and aquatic ecosystems. It makes for more efficient development of new management techniques, application of present techniques, and assessment of environmental impacts. Interest is growing in restoring and restructuring macrophyte communities and an appreciation for the littoral zone (the littoral zone is that portion of a waterbody extending from the shoreline lakeward, to the greatest depth occupied by rooted plants). There is also a need to make management results more predictable, especially when considered in a long-term ecosystem context. The development of effective and environmentally acceptable aquatic plant management programs requires some knowledge of lake limnology. Limnology is the scientific study of the physical, chemical, geological, and biological factors that affect aquatic productivity and water chemistry in freshwater ecosystems including lakes, reservoirs, rivers, and streams. Many limnological processes affect the species, distribution, and/or abundance of aquatic plants in a waterbody. Making things more complicated, aquatic plants can also impact limnological processes like nutrient, chemical and temperature regimes, and other biota in a lake or reservoir, especially in the littoral zone. A single written document cannot review all the aquatic plant biology, limnology, and management techniques that might be relevant to the management of aquatic plants in Lake Istokpoga. However, Florida LAKEWATCH’S Information Circular #111 “A beginners guide to water management—Aquatic Plants in Florida” is a good place to get the basics (http://lakewatch.ifas.ufl.edu/pubs/circulars/Circular111_FA16300_pdfta-10-22-14.pdf). Starting in 1982, the Bureau of Aquatic Plant Management, now the Invasive Plant Management Section, was housed in the Florida Department of Natural Resources, then the Florida Department of Environmental Protection (as the Bureau of Invasive Plant Management), and finally the Florida Fish and Wildlife Conservation Commission. Throughout that time, regional biologists have been monitoring aquatic plant coverage in Florida’s public waterbodies, primarily to keep track of invasive plant types. Thus, there is a good timeline for the abundance (acres) of major problem aquatic plants (water lettuce, water hyacinth, and hydrilla) in Lake Istokpoga (Figures 2.13 to 2.15). In addition to the three major problem species, many littoral invasive plants also require significant management efforts (e.g., cattail, pickerelweed, and primrose willow).

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Figure 2.13. Water lettuce abundance (acres covered) in Lake Istokpog,a from 1982 to 2017

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Figure 2.14. Water hyacinth abundance (acres covered) in Lake Istokpoga, from 1982 to 2017

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Figure 2.15. Hydrilla abundance (acres covered) in Lake Istokpoga, from 1982 to 2017 It is easy to see that, in the 1980s, floating plants like water hyacinth and water lettuce were the major aquatic plant problems in Lake Istokpoga, with coverages up to 800 acres for hyacinth and 60 acres for water lettuce (Figure 2.13 and 2.14). Management of water hyacinth in Istokpoga and other Florida lakes using an approach called “maintenance control” has been successful in keeping water hyacinths at a low level (Figures 2.4 and 2.14). Florida Statute 369.22 defines maintenance control as a “method for the management of aquatic plants in which control techniques are utilized in a coordinated manner as determined by the commission.” This management strategy requires many repeated treatments on a regular basis, using little herbicide, instead of allowing problem plants to cover large areas and having to spray large amounts of herbicide to achieve control. This is important, because allowing one hyacinth plant to grow will yield about one acre of hyacinth by the end of a growing season (Florida LAKEWATCH Information Circular #111). As pointed out earlier, allowing water hyacinth to reach a high level dramatically increases the production of organic matter, increasing lake succession, and decreasing the life of a lake. Hydrilla was first observed in Lake Istokpoga in 1979. By 1988, it had expanded to approximately 14,000 acres (Figure 2.15). The first herbicide treatment using fluridone began in 1987. It continued multiple times until it was discovered that hydrilla had developed a resistance to fluridone, and unique bacteria in the lake were actually able to digest fluridone. In 1992, after a largescale fluridone treatment, over 125,000 grass carp were stocked in the lake, in an attempt to control the expanding hydrilla. Even with continued herbicide treatments and carp stocking, hydrilla coverage expanded to just under 25,000 acres by 1996, and Lake Istokpoga was reportedly accessible only by airboat. However, with continued maintenance control of hydrilla

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using herbicides other than fluridone, hydrilla coverage decreased, and until 2015, fluctuated to around 5,000 acres. Statewide, the management objectives for hydrilla were a point of disagreement and contention, among different user groups and managers of the State’s freshwater lakes and rivers. Before 1 July 2008, the invasive plant management program was under the direction of the Department of Environmental Protection (DEP). The DEP rule was to manage nonindigenous aquatic plants in a coordinated manner on a continuous basis, to maintain the target plant population at the lowest feasible level as determined by DEP. The Legislature moved the invasive plant management program from DEP to the Fish and Wildlife Conservation Commission (FWC) in July 2008. With that change, FWC developed a hydrilla management policy, and this new policy is one reason we are developing a Lake Istokpoga aquatic plant management plan with input from all stakeholder groups. FWC’s current position on the management of hydrilla is as follows:

• It is the position of the Florida Fish and Wildlife Conservation Commission (FWC) that native aquatic plant communities provide ecological functions that support diverse native fish and wildlife communities in Florida waterbodies. FWC considers hydrilla to be an invasive, non-native aquatic plant that can, at high densities, adversely impact native plant abundance, sportfish growth, recreational use, flood control, and dissolved oxygen. Once established, hydrilla has proven difficult if not impossible to eradicate with current technology, and is expensive to manage. Therefore, FWC opposes the deliberate introduction of hydrilla into waterbodies where it is not currently present. FWC prefers to manage for native aquatic plants, but recognizes that in waterbodies where native submersed aquatic plants are absent or limited, hydrilla at low to moderate densities can be beneficial to fish and wildlife. FWC will manage hydrilla on a waterbody-by-waterbody basis, using a risk-based approach to determine the level of management.

• In waterbodies where hydrilla is well established, it will be managed at levels commensurate with the

primary uses and functions of the waterbody and fish and wildlife. FWC will determine the level of hydrilla management on each public waterbody, using a risk-based analysis that considers human safety issues, economic concerns, budgetary constraints, fish and wildlife values, and recreational use, with input from resource management partners and local stakeholders. Factors such as available control technology (e.g., herbicides), current waterbody condition, and activities occurring in the watershed will also influence the timing and level of hydrilla management.

The three major aquatic plants mentioned above, the tussock-forming primrose willow family of plants, and burhead sedge, are the current focus of aquatic-plant management activities in Lake Istokpoga. However, in all the plant surveys conducted since 1982, over 100 species of aquatic plants have been identified in the lake. Each of these species has varying benefits to fish and wildlife, as well as potential to impact the uses of the lake. To understand these littoral plants, FWC has been monitoring them with aerial photography since 2005 (Mallison 2018). Results of this 2005-2015 monitoring on Lake Istokpoga show 31 plant classes (groups of aquatic plant that generally occur together) that exceeded 25 acres of dominant coverage in at least one mapping year (Table 2.3). Other than open water, the most abundant class was freshwater marsh for all years. The next-most abundant class was cattail in 2005 and 2012, SAV in 2007 and 2009, and spatterdock in 2015. Between 2007 (baseline map) and 2015 (most-recent map), lake-wide coverage declined by more than 100 acres for four classes (SAV, freshwater marsh, cattail, and water primrose/knotweed-cupscale). During this period, lake-wide coverage increased by more than 100 acres for eight standard classes (marsh with shrubs and brush, cattail-

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pads, lotus, pickerelweed/arrowhead-pads, cattail-pickerelweed/arrowhead, bulrush-pads, pickerelweed/arrowhead-water primrose/knotweed, and water lily) and two new classes (mixed pads and dead vegetation). The mixed-pads class was added in 2012, in response to an observed increase in mixtures of spatterdock, water lily, and/or lotus as these classes expanded. The dead vegetation class was added in 2015, to document effects of herbicide treatments that had recently been applied (treatment of the western marsh). Fluctuation of greater than 100 acres among years was also observed for open water, spatterdock, and pickerelweed/arrowhead. Monitoring of littoral vegetation (Mallison 2018; years 2005 to 2015) also showed that without counting submersed vegetation (primarily hydrilla), emergent vegetation averaged over 17% coverage of Lake Istokpoga, ranging annually from 15.9 to 19.6 %. Additionally, wetland woody class averaged an additional 3.7% coverage of wetland ranging annually from 2.8 to 4.7%. Thus, even without including submersed aquatic vegetation outside Lake Istokpoga’s littoral area, the lake has over 15% coverage of vegetative structure. A common goal for many fisheries managers is to maintain a minimum of 15% coverage of a lake, to maintain a healthy fishery (Canfield and Hoyer 1992; Bergstrom et al. 1996; Kirk and Henderson 2006).

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Table 2.3 Area (acres) dominated by plant classes on Lake Istokpoga, based on littoral vegetation mapping in 2005-2015. Change in acres and percent were based on differences observed between 2007 and 2015 (*2005 was research and development, and did not follow standardized sampling protocols). Other emergent plants = combined coverage of all uncommon plant classes (<25 acres coverage in each year). n/a = class was not in the classification system that year and therefore was not mapped. Class *2005 2007 2009 2012 2015 Acres change

(2007 – 2015) Percent change (2007 – 2015)

Open water 23,467 21,143 21,411 20,962 21,047 -96 0% Freshwater marsh 1,014 1,546 952 1,016 947 -599 -39% Spatterdock 659 727 904 708 822 95 13% Marsh with shrubs and brush 116 304 483 504 782 478 157% Forested wetlands 460 456 448 474 505 49 11% Cattail-pads 73 90 274 290 456 366 409% Lotus n/a 199 163 666 443 244 122% SAV 11 1,473 930 363 417 -1,056 -72% Cattail 972 767 716 731 340 -427 -56% Mixed pads n/a n/a n/a 144 333 n/a - Pickerelweed/arrowhead-pads 108 77 120 122 276 199 257% Bulrush 229 281 253 254 229 -51 -18% Cattail-pickerelweed/arrowhead

58 70 276 479 183 114 163%

Bulrush-pads 32 17 47 53 178 161 977% Pickerelweed/arrowhead-water primrose/knotweed

3 18 3 68 165 147 808%

Dead vegetation n/a n/a n/a n/a 157 n/a - Water lily n/a 13 17 188 152 139 1074% Upland 142 140 136 136 140 -1 0% Water primrose/knotweed-pads

0 47 91 111 117 70 147%

Pickerelweed/arrowhead 111 116 182 239 96 -20 -17% Water primrose/knotweed 80 131 107 85 46 -85 -65% Willow 0 32 56 90 20 -12 -36% Pickerelweed/arrowhead-torpedograss

31 27 97 103 18 -9 -33%

Cattail-bulrush 11 5 15 28 16 11 231% Maidencane/Paspalidium 36 24 27 19 16 -9 -35% Torpedograss 56 49 68 36 13 -36 -73% Pickerelweed/arrowhead-bulrush

54 24 36 41 10 -14 -57%

Water primrose/knotweed-cupscale

22 110 107 34 8 -102 -93%

Cupscale 110 24 10 5 3 -21 -87% Spikerush 4 26 11 4 1 -25 -97% Spikerush-pickerelweed/arrowhead

89 32 35 12 0 -32 -99%

Other emergent plants 44 18 9 15 18 0 2%

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Lake Istokpoga Fish populations: In the late 1980s, Canfield and Hoyer (1992) examined relationships among water chemistry, aquatic plant abundance/communities, and fish abundance/communities in Florida lakes. At the time, hydrilla was dominating many lakes in Florida, and management agencies wanted to know at what level aquatic plants needed to be managed. The objective of the research was to determine what level of aquatic vegetation was needed, to have a natural population of fishes. Their overall finding: if lakes had less than 15%, or more than 85% coverage of aquatic vegetation, there was a probability of having depressed fish populations. Thus, some moderate level of vegetation is optimal for normal populations of fish, and has also been found ideal for many sportfish. The research also showed that each fish species has an individual life history that is impacted by the surrounding habitats. For example, gizzard shad and threadfin shad are found in greater abundances when a lake has little submersed vegetation and is nutrient-rich (Hoyer and Canfield 1994), probably because abundant aquatic vegetation interferes with shad feeding characteristics. Many smaller fish species (e.g., bluespotted sunfish, golden topminnow, and spotted sunfish) are more abundant in lakes with abundant aquatic vegetation, probably because they are protected from predation in abundant vegetation. Thus, when managing aquatic plants, the total abundance of fish generally stays the same, but the relative abundance of individual fish species changes depending on the life history of that species. Tremendous amounts of fisheries data have been collected on Lake Istokpoga, over the last 20 years. Fisheries-independent data (electrofishing catch per unit effort) examining the whole fish community have been collected in 15 different years, from 1999 to 2017. Fisheries-dependent data (creel data, interviewing anglers) have been collected consistently since 2006. Fisheries Independent Data In the 18 years of electrofishing, a number of native freshwater, marine, and exotic species of fish were collected (Table 2.4). Hoyer et al. (2011) examined long-term electrofishing data for 30 Florida lakes. They found, after 8 years of data collection, that no additional species of fish were added to the cumulative list of species for individual lake. This suggests that the 15 years of data for Lake Istokpoga yield a complete list of species in that sampling year. Examining all available fisheries data for the Southeastern United States, Swift et al. (1985) reported the presence of 46 fish species present in Kissimmee River Drainage, suggesting the possibility of other rare species present in Lake Istokpoga.

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Table 2.4. List of fish species collected with electrofishing in Lake Istokpoga between 1999 and 2017 Common Name Scientific Name Status Black crappie Pomoxis nigromaculatus Native Bluefin killifish Lucania goodei Native Bluegill Lepomis macrochirus Native Bluespotted sunfish Enneacanthus gloriosus Native Bowfin Amia calva Native Brook silverside Labidesthes sicculus Native Brown bullhead Ameiurus nebulosus Native Brown darter Etheostoma edwini Native Chain pickerel Esox niger Native Channel catfish Ictalurus punctatus Native Coastal shiner Notropis petersoni Native Dollar sunfish Lepomis marginatus Native Eastern mosquitofish Gambusia holbrooki Native Flagfish Jordanella floridae Native Florida gar Lepisosteus platyrhincus Native Gizzard shad Dorosoma cepedianum Native Golden shiner Notemigonus crysoleucas Native Golden topminnow Fundulus chrysotus Native Inland silverside Menidia beryllina Native Lake chubsucker Erimyzon sucetta Native Largemouth bass Micropterus salmoides Native Least killifish Heterandria formosa Native Lined topminnow Fundulus lineolatus Native Longnose gar Lepisosteus osseus Native Pugnose minnow Opsopoeodus emiliae Native Redbreast sunfish Lepomis auritus Native Redear sunfish Lepomis microlophus Native Sailfin molly Poecilia latipinna Native Seminole killifish Fundulus seminolis Native Spotted sunfish Lepomis punctatus Native Swamp darter Etheostoma fusiforme Native Taillight shiner Notropis maculatus Native Threadfin shad Dorosoma petenense Native Warmouth Lepomis gulosus Native White catfish Ameiurus catus Native Yellow bullhead Ameiurus natalis Native Atlantic needlefish Strongylura marina Marine Sailfin catfish Pterygoplichthys multiradiatus Exotic Blue tilapia Tilapia aurea Exotic Brown hoplo Hoplosternum littorale Exotic Nile tilapia Oreochromis niloticus Exotic Oscar Astronotus ocellatus Exotic Vermiculated sailfin catfish Liposarcus disjunctivus Exotic Walking catfish Clarias batrachus Exotic

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Hoyer and Canfield (1994) published statewide average electrofishing CPUE values from data collected on 60 Florida lakes ranging in nutrient concentrations and abundance of aquatic macrophytes. Largemouth bass and bluegill CPUE data collected for the last 15 years on Lake Istokpoga are generally above the statewide averages published by Hoyer et al. (1994). Black crappie and redear sunfish are generally below the statewide averages (Figure 2.16). Over the 15-year period, the estimated CPUE of these four sportfish fluctuated considerably, from a low of 70% of the long-term mean for black crappie, to a high of 138% of the long-term mean for largemouth bass. As with all fish populations, these fluctuations are caused by variations in annual reproductive success and survival (natural and angling) of each population. This is due to annual changes in many environmental pressures over time (temperature, water quality, water level, habitat availability, etc.).

Figure 2.16. Electrofishing catch per unit effort data (number/hour) collected for major sportfish (black crappie, bluegill, largemouth bass, and redear sunfish) from 1998 to 2017 on Lake Istokpoga, compared to statewide averages calculated from data collected on 60 Florida lakes (black dashed line) (Hoyer and Canfield 1994).

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Fisheries Dependent Data Florida Fish and Wildlife Conservation Commission staff routinely conduct creel surveys on many of the major fishing lakes in Florida, including Lake Istokpoga. Similar creel methods were used on nine foremost Florida fishing lakes over the same time period (2006-2017) for two of Florida’s major sportfish, largemouth bass and black crappie. Comparing all of the data shows that long-term fishing effort for largemouth bass in Istokpoga (3.2 angler hours/100 d/ha) exceeded the mean of all lakes combined (2.5 angler hours/100 d/ha) and averaged higher than five of the other eight lakes (Figure 2.17). Largemouth bass success for Lake Istokpoga averaged 0.58 fish/hour, exceeding the average for five other lakes (Figure 2.18). Fishing effort for black crappie in Lake Istokpoga averaged 1.9 (angler hours/100 d/ha), exceeding only three of the other major fishing lakes (Figure 2.19). However, Lake Tohopekaliga was one of those lakes Istokpoga exceeded, with similar water-level stabilization and hydrilla issues. Long-term average black crappie success rates (fish/hour) in Lake Istokpoga were 1.5 fish/hour, exceeding four other lakes in the data set (Figure 2.20). Comparing Lake Istokpoga creel data for largemouth bass and black crappie to other Florida lakes shows that Istokpoga is about average, when considering fishing effort and success. One interesting observation when comparing data among lakes: variability in fishing effort and success is generally smaller in Lake Istokpoga than in other Florida lakes (Figures 2.18 to 2.21). Even though Istokpoga’s variability among lakes is small, there are annual fluctuations in fishing effort and success for both largemouth bass and black crappie (Figures 2.21 and 2.22).

Figure 2.17. Largemouth bass fishing-effort summary statistics (box plot) for nine lakes, each with 11 years of creel data. Line in the middle of the box is the median. Edges of the box are the 25 and 75% data distributions. Outside bars are the minimum and maximum data. The line across the plot is the grand mean of all data.

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Figure 2.18. Largemouth bass fishing-success summary statistics (box plot) for nine lakes, each with 11 years of creel data. Line in the middle of the box is the median. Edges of the box are the 25 and 75% data distributions. Outside bars are the minimum and maximum data. The line across the plot is the grand mean of all data.

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Figure 2.19. Black crappie fishing-effort summary statistics (box plot) for nine lakes, each with 11 years of creel data. Line in the middle of the box is the median. Edges of the box are the 25 and 75% data distributions. Outside bars are the minimum and maximum data. The line across the plot is the grand mean of all data.

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Figure 2.20. Black crappie fishing-success summary statistics (box plot) for nine lakes, each with 11 years of creel data. Line in the middle of the box is the median. Edges of the box are the 25 and 75% data distributions. Outside bars are the minimum and maximum data. The line across the plot is the grand mean of all data.

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Figure 2.21. Annual largemouth bass fishing effort (red line with circle points) and success (blue line with plus sign for points) for Lake Istokpoga, with 11 years of creel data (overlay plot)

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Figure 2.22. Annual black crappie fishing effort (red line with circle points) and success (blue line with plus sign for points) for Lake Istokpoga, with 11 years of creel data (overlay plot) Largemouth bass and black crappie populations in Lake Istokpoga are healthy, but stability (a constant number in the population) is rare in nature. Typically, populations are cyclical, fluctuating naturally based on a variety of factors including spawning success; natural mortality and fishing mortality; and habitat, prey availability, and other factors. These fluctuations in addition economic considerations, weather conditions (e.g., hurricanes), lake access to fishing (e.g., hydrilla coverage) and other factors can cause fluctuations in fishing effort and success over time. Most aquatic habitat in Florida lakes is in the form of aquatic plants, which can affect fish population characteristics and actual angling activities/success. Aquatic plants influence some sportfish fish populations by increasing the abundance of small prey like macroinvertebrates; and by providing refuge for young-of-year (YOY) fish from larger predators, allowing them to reach adulthood (Savino and Stein 1982, Canfield and Hoyer 1992, Sammons and Maceina 2005). However, high abundance of aquatic vegetation (>50% coverage of the lake surface area) also can restrict angler access (Colle et al. 1987), and reduce fish feeding success and thus growth (Bettoli et al. 1992). Intermediate levels of aquatic vegetation (Canfield and Hoyer 1992, report between 15 and 85% coverage; and Sammons and Maceina 2005, report between 20 and 50% coverage) provide a good trade-off between prey production and predator efficiencies. Intermediate levels of vegetation lead to good growth, condition, and abundance of sportfish such as largemouth bass; and provide the best angling opportunities (Wilde 1992). Maintaining a moderate abundance of aquatic plants is needed for fish populations and angling. However, managing aquatic vegetation at a moderate level is a difficult task when exotic invasive plants like water

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lettuce, water hyacinth, and hydrilla are involved. The growth potential of these plants is large, requiring a constant management approach. Many aquatic-plant management tools exist to reach management goals: multiple herbicides, mechanical harvesting, water-level manipulation and scraping, biological control (insects, pathogens, grass carp), and others. Each tool’s associated cost and effectiveness must be considered when developing a management plan. Defining a target level of aquatic plant abundance is also difficult, because multiple uses are optimized at different levels of aquatic plant management. Istokpoga is primarily a fishing lake, so a moderate level is best, and target windows for good fish populations and angling are relatively large (Canfield and Hoyer 1992, report between 15 and 85% coverage; and Sammons and Maceina 2005, report between 20 and 50% coverage). Aquatic Birds and Wildlife Conventional wisdom suggests that the base fertility of a lake (trophic status) is a primary driver for the abundance of aquatic organisms, including but not limited to zooplankton abundance (Canfield and Watkins 1984), fish populations (Bachmann et al. 1996), bird abundance (Hoyer, and Canfield 1994), and even populations of top predators like the alligator (Evert 1999). All these results support the predictions of Fretwell (1987), who suggested that as nutrient levels increase among systems, the abundance of organisms, including top predators, would also increase. As with fish populations mentioned above, research shows that each aquatic bird species has an individual life history that is affected by the surrounding habitats. For example, anhingas and double-crested cormorants are found in greater abundance when a lake has little submersed vegetation and is nutrient-rich (Hoyer and Canfield 1994b). Probably this is because abundant submersed aquatic vegetation interferes with both bird species’ feeding characteristics. Many duck species (e.g., ring-necked duck) are more abundant in lakes with abundant aquatic vegetation, probably because they use abundant submersed vegetation as a food source. Thus, after significant changes in aquatic macrophytes, the total abundance of fish and/or aquatic birds generally stays the same, but the relative abundance of individual fish species changes, depending on the life history of that individual species. Following are three summaries from local experts, showing the current status of Osprey, Snail Kite, and wading bird populations in Lake Istokpoga: Osprey Michael McMillian Environmental Specialist, Highland County “I have tracked nesting Ospreys on Lake Istokpoga from 1989 to present. In 1910, DJ Nicholson rowed his boat around the shoreline of Istokpoga, including its two interior islands, and noted 75 Osprey nests. Remember that this is pre-settlement, with no people, no surrounding agriculture, and no water-control structure. In 1973, Dr. Jim Layne duplicated Nicholson’s survey and noted 9 nests, of which only 6 were active. All Osprey nests were located on one of the two interior islands. During Nicholson’s trip there was no marsh on Lake Istokpoga. There most likely was a very narrow littoral zone. During Dr. Layne’s survey, a marsh would have just started forming, because of the installation of the S68 water-control structure in the late 60s. In 1989, when I began, there were 55 Osprey nests. In 1990, there were 60. In 1991, I began tracking reproductive success. In 1995, I included all nests associated with Istokpoga, including nests located on various structures off the lake (i.e. telephone poles, communication towers). By 1993/1994, the number of Osprey nests on the lake equaled the number located by Nicholson in 1910. I thought the number might level off, but I was wrong. The number continued to increase. In 2005, the lake surpassed 300 nests for the first time. The number now appears to fluctuate around 300 nests, lower in some years and higher in others. From 2016 to present, the number has exceeded 300, with 313 in 2018. With the possible exception of Blue Cypress Lake, near Vero, this is the largest concentration of nesting Osprey in the

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world, especially when you consider the area of Lake Istokpoga (just over 28,000 acres). I have seen this claim made for the Chesapeake Bay region, however that area is immense”. Snail Kite Tyler Beck Snail Kite Conservation Coordinator Species Conservation and Planning Section Division of Habitat and Species Conservation Florida Fish and Wildlife Conservation Commission “The Snail Kite (Rostrahamus sociabilis) is an endangered raptor that inhabits shallow lakes and marshes of Florida, and feeds almost exclusively on aquatic snails in the genus Pomacea. The Florida apple snail (Pomacea paludosa) historically was the primary food of Snail Kites in Florida. However, in recent years, the invasive exotic apple snail (Pomacea maculata) makes up a substantial portion of their diet. Snail Kite nesting is monitored by a University of Florida research group. The first Snail Kite nesting in recent history (since at least 1987) on Lake Istokpoga was reported in 2005 (Figure 2.23). Four nests were found that year and all were successful. No nests were found the next year, but at least a handful of nests (1 to 4) have been found on the lake each year since then. Nesting began on the west shoreline (2005 and 2007), then expanded to the islands in 2008, then to the north and northeast shores in 2009. The invasive apple snail was first detected in Lake Istokpoga in 2011. At least 12 nests have been found on the lake every year afterward. The highest Snail Kite nesting effort to date came in 2016, with 60 active nests, 25 of which were successful”.

Figure 2.23. Lake Istokpoga Snail Kite nesting from 2005 to 2018

0

10

20

30

40

50

60

70

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

Lake Istokpoga Snail Kite nesting

Active Nests Successful Nests

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Wading Birds Mark I. Cook and Michael Baranski, editors South Florida Wading Bird Report South Florida Water Management District https://www.sfwmd.gov/sites/default/files/documents/southflorida_wadingbird_report.pdf The South Florida Wading Bird Report (Volume 24; May 2019) notes that Bumblebee rookery is the largest rookery in the region. It has been the largest in the region for a long time, and is one of the larger in Florida, period. Istokpoga has rather steep edges, so usually doesn’t furnish much foraging habitat, but the water surrounding the island makes it protected and an ideal nesting spot. A steady increase in wading bird nests since 2015 shows a healthy wading bird population on Lake Istokpoga (Table 2.5; derived from Table 19 [p. 45] of Cook and Baranski 2019)

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Table 2.5. Peak (maximum) number of wading-bird nests in Lake Istokpoga (Bumblebee Island) (2010 to 2018; sites surveyed during April and May)

Year Cattle Egret

Great Egret

White Ibis

Great Blue

Heron

Small Dark

Herons

Glossy Ibis

Small White Herons

Total Nests

Total Colonies Surveyed

Nests of Aquatic Species

2010 103 325 110 75 613 1 510 2011 381 200 50 45 676 1 295 2012 75 175 75 325 1 250 2013 250 343 55 648 1 398 2014 658 210 75 55 998 1 340 2015 434 180 829 1,443 1 1,009 2016 355 171 1,296 25 1,847 1 1,492 2017 10 124 818 35 1 6 4 998 1 988 2018 481 450 2,089 5 3,025 1 2,554

Note: Black-crowned night herons and wood storks were not observed in any surveys. In addition to the fish and wildlife species already mentioned above, other species listed by the Florida Committee on Rare and Endangered Plants and Animals (Rodgers et al. 1996; Stewart 2001, Pranty 2002; McNair et al. 2001) have significant populations in Lake Istokpoga’s watershed that should also be considered during habitat-management planning activities. Along the western boundary of the historic Lake Istokpoga floodplain lies the Lake Wales Ridge. During the recent ice ages, this unique formation was periodically isolated from the North American continent by rising sea levels. Plants and animals living in the harsh environment of those dunes were also physically and genetically isolated from the parent populations from which they descended. These isolation events allowed the development of differences that persisted when sea levels receded, and the island ridge was rejoined with North America. Many of these dune plants and animals remain restricted to the ridge habitats today, and the Lake Wales Ridge has one of the highest concentrations of endemic species in North America. As of 2000, the ridge is host to 19 plant, 3 reptile and 1 bird species federally listed as threatened or endangered (SFWMD 2000). Lake Istokpoga Recent Historical Timeline 1962: The S-68 spillway is completed and becomes operational for flood control, as now water can flow southeast to Lake Okeechobee. As a consequence, the historical water-level fluctuation of lake highs and lows is disrupted. An artificial schedule for lake levels is created to mimic the natural cycle as much as possible, while providing regional flood control. 1972-73: Private developers begin digging canals on the northeast side of the lake. The canals are in previous wetlands and the spoil is used to build up individual building lots, each of which will have separate septic systems. This area of canals, which have no natural flow into or out of the lake, are outside FWC’s normal lake-management perimeter. 1996: Hydrilla expanded to approximately 25,000 acres, shutting down boat access, and allowing only airboat access. A whole-lake herbicide treatment with fluridone (1.8 million dollars) was conducted to selectively kill hydrilla, opening up the lake while keeping over 2000 acres of eelgrass and pondweed (Potamogeton illinoensis). 2001: Taking advantage of drought conditions, water levels were brought down farther, allowing removal of tussock and muck materials with heavy equipment. Muck was disposed of, in islands created in the lake; and some was disposed of, on upland areas. Normal access was difficult, if not impossible, for shoreline residents or at public ramps. Excessive amounts of muck were largely due to lack of historical water-level fluctuation,

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and continued production of organic matter from native and especially exotic plant growth such as water hyacinth. 2004-2005: Multiple hurricanes crossed Florida, causing flooding throughout the state. A significant consequence was a sewage spill from the Spring Lake area into Lake Istokpoga. Efforts began to obtain funding, and to finish the projects needed to prevent storm water from Spring Lake, and outflow from the airport and its industries, from being released into Lake Istokpoga. 2012-13: Extensive hydrilla growth blocked access to the south and west side of Lake Istokpoga. Helicopter application of herbicides was able to restore access. 2015-2016: Aggressive FWC herbicide treatment of invasive plants including 1300 acres of hydrilla, 800 acres of primrose willow, and 250 acres of tussocks may also have removed some untargeted and advantageous submersed aquatic vegetation. 2016-2017: Public complaints of poor water quality, lack of submersed aquatic vegetation, and poor fishing began to increase. Some were concerned that management of aquatic vegetation with herbicides was the cause. 2017 September: Hurricane Irma passed over Florida and made significant changes to the lake. Strong winds from the south created a 6-foot difference in lake levels between the south and north end of the lake. Significant amounts of muck and debris shifted to the northeast side of the lake. The storm also ripped up major areas of vegetation, especially cattails and bulrush on the north and west sides of the lake. Likely the hurricane impacts (wind and water quality changes) exacerbated the decreased abundance of submersed aquatic vegetation already apparent in Lake Istokpoga. 2018: University of Florida began developing the Lake Istokpoga Habitat Management Plan with funding from the Florida Fish and Wildlife Conservation Commission (FWC). 2019: In response to stakeholder concerns, FWC implemented a short-term statewide spraying pause. Spraying activities on Lake Istokpoga paused with all other lakes. When spraying started again, it was changed so that fewer boats were used and much more information about individual spraying activities was provided to agencies and stakeholders alike. Lake Istokpoga Time Line Summary: This is a brief history of some of the important ecological components of Lake Istokpoga including geologic history, human population growth/settlement, water quality, water-level fluctuations, and aquatic plant abundances and management. The short and well-thought-out mission statement of the Florida Fish and Wildlife Conservation Commission is “Managing fish and wildlife resources for their long-term well-being and the benefit of people.” This history shows that Lake Istokpoga has been and will continue to be in a state of change, requiring consistent management activities to provide ecosystem services for both fish and wildlife, and the benefit of people. To maintain a natural abundance of all fish and wildlife species will require maintaining multiple types of natural habitats in abundances dictated by the surrounding abiotic conditions. Water-level stabilization for Lake Istokpoga has made this a difficult task. Eliminating large water-level fluctuations tended to make it favorable for extensive monocultures of individual aquatic plant species (e.g., pickerelweed, cattail), decreasing space for other unique habitats favorable for individual species of fish and/or wildlife. FWC has done excellent job identifying and monitoring individual habitat types in Lake Istokpoga and classifying those

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habitats’ quality for different fish and wildlife species (Mallison, 2018, Table 1). These littoral habitat classifications, regular aquatic vegetation mapping from aerial photography, and sonar equipment can be used to better monitor submersed aquatic vegetation. This informs management agencies when planning aquatic plant management activities. Summary

• Since the settlement of Florida, and specifically the creation of Highlands County in 1921, the population has increased from ~9,000 in 1930 to over 100,000 today. With the population increase in the Florida and Highlands County, construction projects allowed people to build and farm without flooding, and to use waterways for transportation. All of this caused many changes to the ecology of Lake Istokpoga.

• Lake Istokpoga is a large, shallow lake at approximately 27,000 acres and an average depth of roughly

4 feet. Direct rainfall combined with tributary inflows from Josephine and Arbuckle creeks input to Lake Istokpoga, and waters are directed either to the Kissimmee River or Lake Okeechobee through a system of canals and water-control structures. These canals, constructed around 1962, help control the water level of Istokpoga, which used to fluctuate approximately 7.5 ft but now only fluctuates approximately 2.7 ft.

• Lakes that fluctuate naturally tend to move organic matter out of a lake during extremely highwater

levels, and to oxidize organic matter at extremely low water levels. Both mechanisms maintain clear sandy shorelines. Lakes with stabilized water levels tend to accumulate organic matter in the littoral zone, allowing emergent vegetation like cattail and pickerelweed to grow well. Aquatic plants tend to get most of their nutrients from the sediments, and these nutrients are more available in organic sediment than in mineral sediments. Thus, the more organic sediments, the more aquatic plants. Aquatic plants create and trap more organic matter, expanding the littoral zone, and creating more muck-dominated shorelines. Water-level stabilization was probably responsible for the accumulation of muck that caused the Florida Fish and Wildlife Conservation Commission to draw down Lake Istokpoga in 2001, scraping and removing muck from about 1,300 acres of the littoral zone. Exotic aquatic plants with tremendous growth potential (like water hyacinth, water lettuce, and hydrilla) have also contributed to the accumulation of organic sediment in Istokpoga.

• With the increased growth potential of aquatic plants (especially exotics) in Lake Istokpoga, aquatic

plant management became an important aspect of lake management. Historical survey data in 1980s showed that hydrilla, water hyacinth, and water lettuce were major aquatic plant problems with coverages up to 25,000 acres, 800 acres, and 60 acres, respectively. Management of these plants in Istokpoga and other lakes around the state was conducted with an approach called “maintenance control” that has been successful in keeping problem plants at a low level. Florida Statute 369.22 defines maintenance control 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.” This management strategy requires many repeated treatments on a regular basis, using little herbicide, instead of allowing problem plants to cover large areas and having to spray large amounts of herbicide to achieve control. Allowing plants to cover large areas also increases organic sedimentation, and thus muck build-up.

• Management of floating plants (hyacinth and lettuce) in Florida including Istokpoga is still conducted

using the maintenance control approach. However, FWC has the following new position on management of hydrilla in Florida:

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• It is the position of the Florida Fish and Wildlife Conservation Commission (FWC) that

native aquatic plant communities provide ecological functions that support diverse native fish and wildlife communities in Florida waterbodies. FWC considers hydrilla to be an invasive, non-native aquatic plant that can, at high densities, adversely impact native plant abundance, sportfish growth, recreational use, flood control, and dissolved oxygen. Once established, hydrilla has proven difficult if not impossible to eradicate with current technology and is expensive to manage. Therefore, FWC opposes the deliberate introduction of hydrilla into waterbodies where it is not currently present. FWC prefers to manage for native aquatic plants but recognizes that in waterbodies where native submersed aquatic plants are absent or limited, hydrilla at low to moderate densities can be beneficial to fish and wildlife. FWC will manage hydrilla on a waterbody by waterbody basis using a risk-based approach to determine the level of management.

• In waterbodies where hydrilla is well established, it will be managed at levels that are

commensurate with the primary uses and functions of the waterbody and fish and wildlife. FWC will determine the level of hydrilla management on each public waterbody using a risk-based analysis that considers human safety issues, economic concerns, budgetary constraints, fish and wildlife values, and recreational use, with input from resource management partners and local stakeholders. Factors such as available control technology (e.g. herbicides), current waterbody condition, and activities occurring within the watershed will also influence the timing and level of hydrilla management.

• Lake Istokpoga is a colored lake because the average color for the lake exceeds 40 Pt-Co units (Figure

2.6), which means the water is darker in general than the color of iced tea. Long-term mean chlorophyll levels for Istokpoga (43 µg/L) and Istokpoga North (41 µg/L) exceeded FDEP’s chlorophyll standard of 20 µg/L set for colored lakes. Average total phosphorus and total nitrogen concentrations for Istokpoga (TP = 57 µg/L and TN = 1399 µg/L) and Istokpoga North (TP = 67 µg/L and TN = 1353 µg/L) also both exceeded the FDEP’s minimum calculated numeric interpretation of 50µg/L total phosphorus and 1,270 µg/L total nitrogen. While these values suggest that the lake is impaired for nutrients, the local geology must be considered.

• Bachmann et al. (2012) recognized the influence of geology on the productivity of Florida lakes. They

used data from over 1,100 Florida lakes to partition Florida into six total phosphorus (TP) zones and five total nitrogen (TN) zones (phosphorus and nitrogen are two nutrients determining lake productivity; Appendix III). Lake Istokpoga is in TP Zone 5 and TN Zone 5, suggesting that Lake Istokpoga is naturally nutrient-rich, based on the geology in which the lake lies. Ninety percent of all lakes in TP Zone 5 and TN Zone 5 have nutrient concentrations less than 252 µg/L (TP) and 2,701 µg/L (TN). Thus, LAKEWATCH water chemistry values suggest that Lake Istokpoga’s nutrient and chlorophyll values are normal for the region. However, these nutrient concentrations could be elevated above background because of the large percentage of agricultural land uses and rapid urban development in the lake’s watershed.

• Long-term fish sampling (15 years) with electrofishing showed 35 native freshwater, 2 marine, and 6

exotic species of fish present in Lake Istokpoga. Examining all available fisheries data for the Southeastern United States shows the presence of 46 fish species in the Kissimmee River Drainage, suggesting the possible presence of other rare species in Lake Istokpoga. These electrofishing data show that the major sportfish populations (largemouth bass, black crappie, bluegill, and redear sunfish) in Lake Istokpoga fluctuate annually and have estimated abundances similar to those of other

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productive Florida lakes. Angler survey data (creel data) show that fishing effort and catch rates also fluctuate significantly, from year to year. However, Lake Istokpoga’s average effort and catch rates for the last 11 years are similar or above those for other large Florida public fishing lakes including but not limited to Lake George, Lake Griffin, Lake Harris, Lake Kissimmee, Lake Lochloosa, Orange Lake, and Lake Tohopekaliga.

• Aquatic bird surveys over the last decade show that wading bird populations are high, and that

Bumblebee rookery is the largest rookery in the region. It has been the largest in the region for a long time, and is one of the larger in Florida, period. Istokpoga has rather steep edges, so usually doesn’t furnish much foraging habitat, but the water surrounding the island makes it protected and an ideal nesting spot. Annual counts for two species of special concern, the snail kite and osprey, show populations the highest they have been in decades.

• Abundant research shows that each fish and aquatic bird species has an individual life history affected

by surrounding habitats. For example, anhingas and double-crested cormorants are found in greater abundance when a lake has little submersed vegetation. This is probably because abundant submersed aquatic vegetation interferes with both bird species feeding characteristics. Many duck species (e.g., ring-necked duck) are more abundant in lakes with abundant aquatic vegetation, probably because they use abundant submersed vegetation as a food source. Similarly, gizzard and threadfin shad populations decrease in the presence of abundant aquatic plants, because the plants interfere with shad feeding behavior. Small fish like bluespotted sunfish, golden topminnow, and spotted sunfish are abundant in thick vegetation, because they can forage there and are protected from predation. Thus, after significant changes in aquatic macrophyte abundance, the total abundance of fish and/or aquatic birds generally stays the same, but the relative abundance of individual fish species changes depending on the life history of that individual species.

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3 Overall Management Vision and Guiding Principles 3.1 Vision The collective vision of FWC and Lake Istokpoga stakeholders was a cooperative approach to development of a habitat management plan for the lake. The plan takes into account the needs and interests of various stakeholders and fish and wildlife communities associated with the lake, keeping in mind the mission and statutory authority of the FWC. 3.2 FWC Mission and Statutory Authority The mission of FWC is to manage fish and wildlife resources for their long-term well-being and the benefit of people. The Commission administers six major divisions: Habitat and Species Conservation, Freshwater Fisheries Management, Law Enforcement, Marine Fisheries Management, Hunting and Game Management, and Fish and Wildlife Research. FWC is authorized to manage fish and wildlife in Lake Istokpoga through regulation, augmenting stocks of sport fish, and manipulating habitats for fish and wildlife. FWC regulates and permits fishing, hunting of waterfowl and alligators, and commercial hunting of frogs in Lake Istokpoga. It also regulates collection of alligator eggs and/or hatchlings above the elevation of sovereign submerged lands.

3.3 Public Participation

Stakeholder engagement was designed to be strategic and adaptive, and to include a variety of methods to ensure the highest level of participation possible (Figure 3.1). The UF team led and facilitated the process, and FWC staff were involved in developing all instruments and processes of engagement, and participated where appropriate. At the beginning, a broad-based situation assessment (Appendix IV) was conducted, to set the scene for project activities. This analysis was based on synthesis of existing information, site visits, meeting attendance, and interviews with stakeholders. The aim of this analysis was for the project team and FWC to obtain and summarize a good initial understanding of the lake’s ecological and socio-economic setting, and of relevant governance arrangements, and to identify stakeholder groups and their interests. A permanent committee of representatives from key stakeholder groups was formed to identify objectives; develop habitat management options; assess trade-offs among objectives; and to assess plans for continued monitoring, review, and adaptive management. This Lake Istokpoga Habitat Advisory Committee (LIHAC; Appendix V) met regularly to develop the habitat management plan. Reports from each LIHAC meeting are in Appendix VI. A wider array of stakeholders and the general public was engaged through public meetings (Appendix VII) and a stakeholder survey (Appendix VIII). An extended, initial public meeting was used to introduce the project, the engagement plan, and outcomes of the situation assessment. Additional public meetings were then held to update the public on plan development, to obtain input and feedback, and to provide science-based information on key issues. A stakeholder survey was also used to obtain input from stakeholders, and in particular to reach those who did not personally engage with the LIHAC or public meetings. The final Aquatic Habitat

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Management Plan was presented at a public meeting. Final input was solicited and received during and after the public meeting (Appendix IX). A website was maintained by the UF team, to document plan development and stakeholder input (lakeistokpoga.wordpress.com). Regular email and telephone communications were used to keep interested stakeholders up to date, as the project progressed. Public input is documented in the plan appendices (V-IX). This includes reports synthesizing the findings of the situation assessment, the public meetings, the LIHAC meetings, the stakeholder survey, and input on the final draft of the plan.

Figure 3.1. Summary overview of the stakeholder engagement process. Dark blue indicates wider public engagement. Light blue indicates LIHAC meetings. Each circle represents a series of meetings. Additional colors indicate additional steps in the process. 3.4 Situation Assessment The situation assessment provided important information for process design. A number of different stakeholder groups were identified. In addition, a number of different concerns and perspectives were shared regarding habitat in the lake. Here are the most common issues and concerns raised by the public: Concerns about declines in lake wildlife: A number of stakeholders shared concerns about perceived declines in fishing; and observed declines in catch of bass, crappie, and bait fish (shiners). In addition, some were concerned about declines in duck populations on the lake, as well as observed declines in frogs and other wildlife. Some shared the worry that lake biodiversity was threatened by current management approaches. Habitat and vegetation loss: Stakeholders also expressed concerns about the loss of habitat, in particular marsh habitat and submersed aquatic vegetation, on the lake. Many wanted to learn the cause for loss of SAV. At the time of plan development, concerns of many Lake Istokpoga stakeholders focused on the loss of invasive Hydrilla as a bass/angling habitat. Nutrients: Many were also concerned about nutrient runoff into the lake. Cited sources of concern included runoff of yard fertilizer, and the flow of nutrients into the lake from Arbuckle Creek. A number of stakeholders felt this was associated with a decline in lake water quality. Water levels: Other concerns involved lake water levels and their impact on fish, access, and habitat.

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Management: A number of stakeholders cited frustration with, and concerns about, management on the lake. This included the perception that management actions were not grounded in science, and were negatively impacting the lake. Allegedly there was no coordination among agencies or groups, and management did not listen to stakeholder input. A number of stakeholders did not feel they could meaningfully participate in management decision-making, and that decisions were made regardless of public input or feedback. An overall lack of trust in management was evident.

Herbicide Use: There was a diversity of perspectives regarding herbicide spraying on the lake. Though concerns about spraying were not universal, a number of stakeholders expressed strong concern about spraying activities. Some worried about the effects of spraying, and were concerned that it had eradicated desired species. They thought spraying might make fish unsafe to eat, and that it was negatively impacting fish populations and fishing activities. Overall, the situation assessment showed that stakeholders around Lake Istokpoga are a passionate, engaged community. Many people view the lake as their place, regardless of whether they are long term residents or people who visit seasonally. Despite differences of opinion among different stakeholder groups, all shared a passion for the lake, a concern for its continued viability, and a desire to see it continue as a successful lake. Further details are in the Situation Assessment Report (Appendix IV).

3.5 Process Design The overall habitat-management planning process was designed to address issues identified during the situation assessment. In particular, it was seen as crucial to address the lack of trust in management. Local stakeholders want to make their knowledge count, and they want to meaningfully influence management decisions. Therefore, a stakeholder advisory committee (LIHAC) was formed to specifically consider these issues, in addition to providing input for defining habitat targets and management measures. Initially, the LIHAC met in conjunction with members of the LIWG, to provide technical and policy information when needed. However, it became clear that the LIHAC needed to work with greater independence, to be able to synthesize stakeholder knowledge and articulate stakeholder priorities. The LIHAC therefore met independently, with support from the project team, for an extended period of time before exchanging outputs and recommendations with the LIWG. The LIHAC held 16 meetings between June 2018 and December 2019 (Figure 3.2). Overarching objectives of each meeting included building trust among LIHAC members, developing a shared understanding of Lake Istokpoga’s management and preferred habitat attributes of various stakeholders, and moving toward consensus regarding goals and actions to be included in the habitat management plan. Each meeting was designed by project team facilitators to continue to build trust and shared understanding, while moving the LIHAC forward in designing the habitat management plan. In addition, two LIHAC field trips were convened to observe and discuss lake conditions. The LIHAC was also involved in developing processes to engage the wider community’s input through public meetings and a stakeholder survey. Reports detailing each LIHAC committee meeting’s activities and outputs is in Appendix VI.

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Figure 3.2 LIHAC members on an airboat field trip, discussing lake habitat (left); and refining habitat management-plan objectives and actions during an LIHAC meeting (right) Input and ideas from the first series of LIHAC meeting discussions was synthesized by the UF project team, to create a first draft of habitat management plan guiding principles, targets, goals, objectives, and actions. This draft was then presented to the LIHAC for feedback and revision. The revised goals, objectives, and actions were then presented to the wider community for feedback at a public meeting of he UF project team and LIHAC members (Figure 3.3). Further drafts were revised based on feedback and input from the FWC Working Group; and back-and-forth discussions among agency personnel, the UF project team, and the LIHAC. The final habitat-management plan was vetted by all LIHAC members, and was shared with the wider community through a final public meeting.

Figure 3.3. Participants in the second Lake Istokpoga Public Meeting 3.6 Stakeholder Concerns

A number of concerns were raised over the course of the LIHAC meetings, during the public meetings, and in survey. These concerns formed the basis for the plan’s guiding principles as well as the focal goals, objectives, and actions recommended in Chapter 4 of the Aquatic Habitat Management Plan. Regarding habitat, the most prominent concern cited was the loss of SAV and marsh habitat on the lake. However, a number of concerns focused on management operations, in particular the approach to management of aquatic invasive plants through herbicide spraying and the overall loss of trust of management personnel. Concerns about level of herbicide spraying included the overall amount of herbicides used, frequency of application, timing of applications, apparent overlap or duplication of spraying activities by different programs or agencies, and oversight of applicators. Frequently cited concerns about overall planning and communication included lack of trust in decision making, perceived inability to influence management decisions, confusion about why management takes certain actions or makes certain decisions, perception that management is not coordinated among different programs and organizations, lack of clarity about who is responsible for what on the lake, and concern about who has influence where (though perceptions of who has the most/least influence was not

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universal). Poor communication, a lack of information, and no results seen from input were identified, early in the LIHAC process, as contributing to tensions surrounding habitat management on the lake (Appendix VI).

3.7 Stakeholder Characterization of Desirable Habitat Attributes

Over the course of several meetings, the LIHAC brainstormed and discussed desirable habitat attributes and concerns about specific vegetation types. Discussions balanced looking at habitat from the perspective of attributes (like structure, predictability, and density), and looking at habitat from the perspective of specific aquatic plant species. Full reports of meeting outputs are in Appendix VI. Examples of discussion outputs and different discussion perspectives are shown in Tables 3.1 and 3.2.

Table 3.1. Potential preferences of LIHAC and different stakeholders for different habitat attributes on the lake (output from a brainstorming session). Stakeholder groups: fishers, environmentalists, homeowners, duck hunters.

Attributes Fishers Environmentalists Homeowners Duck Hunters

Predictability

Natural fluctuation • Water level • Wind • Weather events • Natural fluctuation is

not predictable.

Better spray schedule transparency • What times of year so

not to affect spawning • Not over spraying in

areas that have little growth

• Consistency

Natural fluctuation are long slow processes punctuated by fire/storms Lake changes quickly Fish live in different places Birds live in different places Species disappear

Good public information Dependability of good control over invasive

Set a long-term target goal that triggers control – 30-50% Better spray schedule transparency No large scale treating plants during duck season

Density

Balance • Bulrush is thinning • Nursery habitat

(dense vegetation) • Depth dependency • Open water for crappy

and bluegill

Varies with plant zone and successional stage Littoral marsh naturally gets dense and many unique species rely on this habitat Topped out hydrilla a problem Spatterdock gets too thick

No tussock/floating islands

In littoral zone (within 100 meters of shoreline) 30%-50% mix of multiple plant types with open water

Structure (natural and artificial)

Fish attractors/marked Less muck More submersed aquatic vegetation

Littoral areas – monitoring and cause and affect research Full range of hydroperiod zones allowed to grow and remain More submersed aquatic vegetation Open water benthic structure – live and dead Sediment biogeo characteristics

Protect cypress Sparse emergent vegetation around residential areas No tussock! Stabilize shoreline

Increase water level fluctuation for more 30%-50% habitat types More submersed aquatic vegetation

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Essential Species

Hydrilla, bulrush, eelgrass, Illinois pond weed, pennywort mat, spatterdock, coontail

Full biodiversity of plants and animals including inverts Duckweed Migrant birds and insects Some exotics are innocuous and not worth attention based on limited resources*

Nothing which blocks homeowner access Bulrush, emergent species in moderation Eelgrass with lilies for habitat, no invasive exotics* Cypress Aesthetics

Hydrilla does provide habitat in moderation* Eelgrass Cypress Aesthetics

Location

Some open deeper water and leave alone important areas Several locations on the lake • North bulrush in no

name creek • East shore • West side of big

island • South of cut

Plant ones in the right place, e.g. don’t kill emergent to get submersed Tussocks are natural and offer good habitat for turtles, nesting, loafing, rabbits

Maintain boat access year round Moderate habitat around whole lake (30%-50%)

Patch Size

Some larger areas of submersed plants (multiple species Moderate emergent with edge effect

Larger marsh areas, larger patch sizes Maintain linear connectivity of concentric marsh zones Don’t hyper-fragment plant stands

Sparse vegetation around homes Intermittent access for “edge effect” in shoreline bulrush areas Open buffer areas separating shoreline from bird habitat

Manage high duck use areas for the birds Keep that habitat constant over time

Access

Navigable Canal access Creek access Trails* – clean up of old cuts in spatterdock, Henderson’s cove

Maintain trails without over dissecting plant communities* Trails allow predation into deep marsh (molting area, fish, frog refuge) Shoreline access for public (without boats) could be expanded, ex. Windy Point long dock Canal boat lanes allow nutrients to flow into shallow marsh (concern)

Conflict between homeowner access and lake regulation schedule Channels to get out during potential drawdown

Navigable Canal access Creek access Trails* – clean up of old cuts in spatterdock, Henderson’s cove

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Table 3.2. Results of an LIHAC brainstorming session in which members were asked to list their top 3 species of concern (to be managed or reduced) and top three desired but imperiled species (to be protected or restored). The number next to each indicates that multiple LIHAC members listed this species.

Imperiled Species to be Protected/Restored Undesired Species to be Manage/Reduced Eelgrass (8) Spatterdock (5)

Bulrush/Thicker Bulrush (7) Water Lettuce (5) Hydrilla (6) Hyacinth (4)

Pondweed (4) Primrose willow (4) Happy people (2) Burhead sedge (2)

Coontail moss Cattail/Cattail monoculture (2) Cypress Floating muck islands/Tussocks (2)

Floating vegetation Hydrilla (2) Kissimmee Grass Flat pads /Lotus

Maidencane Invasives Pickerelweed Pickerelweed

Protected Littoral Marsh Slimy stuff/Filamentous Algae Submerged plants in general

The LIHAC also used mapping activities to discuss important areas of use by different stakeholder groups and areas where they would like to see different habitats (Figure 3.4). Consistent across all maps was the desire for marsh restoration, more SAV, more bulrush, and ensuring open water for crappie fishing and navigation. A full report of the mapping activity is in Appendix VI.

Figure 3.4. Habitat types and user areas (maps drawn by LIHAC members)

3.8 Overarching Goal and Guiding Principles for Lake Management

Habitat in Lake Istokpoga should be managed to support the full diversity of wildlife species, along with human uses. Certain elements of wildlife conservation or habitat management are prescribed by state or federal law. Many other elements are subject to local management decision-making in the light of scientific and stakeholder knowledge and stakeholder interests.

Different wildlife species and human uses may differ in their habitat requirements, for example, in the different attributes prioritized by fishers, environmentalists, lakeside homeowners, and duck hunters in an early exercise of LIHAC (Table 3.1; Appendix VI). However, stakeholders on the LIHAC and in public meetings felt that shared concerns outweighed conflicting concerns among stakeholder groups. This reflects broadly shared

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interests in the lake’s habitat, fish, and wildlife and the fact that the lake is large and differentiated enough to support many different habitats and uses. Stakeholders supported a need to balance multiple perspectives and uses for the lake, and to exercise moderation in all management actions (Principle 1).

Stakeholders also emphasized a need to maintain a diversity of habitat types and their connectivity to conserve wildlife and support human uses. Many fish and wildlife populations rely on a mix of habitats to complete their life cycle and thrive. This matrix should be considered when deciding on habitat management actions (Principle 2). Also, the dynamic nature of habitats should be accounted for by managing within ranges, rather than tight limits, and considering the dynamics of vegetation change after management actions (e.g., will treatment to remove primrose willow lead to habitat full of bulrush and maidencane, or spatterdock).

Focal habitats are habitats that are recognized as important to wildlife conservation and/or human uses. Focal habitats can be defined in terms of structure, species composition, and/or other metrics and in a quantitative or more qualitative manner (Principle 3). In the case of Lake Istokpoga, habitat is regularly quantified in terms of area covered by different plants or plant communities. Assessments of focal habitat availability for fish and wildlife species are based on the judgment of FWC biologists in the Lake Istokpoga Working Group, informed by the aforementioned quantitative vegetation surveys and regular field visits involving qualitative observations and discussions. For Orange Lake, FWC biologists have devised an approach to focal habitat evaluation that is based on combining expert judgement on the range of habitat preferences for specific focal wildlife taxa into a set of recommended percent coverages, or a habitat matrix, for the eight habitat types found on the lake (FWC OCBWG 2014). However, in lake management, one size does not fit all lakes. The LIHAC considered the option of adopting a similar approach for Lake Istokpoga, but did not feel strongly one way or the other. The LIHAC did, however, feel that working definitions of focal habitat should include categories of habitat preferred for certain human uses such as fishing or duck hunting, and that stakeholder knowledge should be considered when defining such categories. The reason for including “human use habitats: among the focal habitat definitions is that the preferences of target fish or wildlife species are only one of the aspects that make habitats attractive for fishing or hunting (others being, for example, accessibility of the habitat by boat).

The LIHAC recommended setting target ranges for the extent of focal habitats (or vegetation types in the absence of focal habitat definitions) and rules to trigger management actions when habitat extent is outside the target range (Principle 4). Target ranges should be set while taking into account the natural fluctuations in lake habitat, for example based on historical variation. To facilitate integration of native and invasive plant management, the LIHAC recommended including target ranges for all managed invasive plants (even if targets are “minimum feasible level”). A focal habitat table is shown in Table 3.3.

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Table 3.3. Focal Species habitat targets for Lake Istokpoga, with historically observed area ranges (percentage of lake area) and frequency of occurrence and desired target ranges for different habitat types Vegetation Class Historical Acreage

Range (2007-2015) (% of lake range)

* / **/***/****

Historical Frequency of Occurrence (FOO)

Range (2015-2019)*****

Target Acreage Range (% of lake) (FOO range)

Native Submersed Aquatic Vegetation (NSAV; eelgrass and pondweed)

554-1,385 acres* (2-5%)

Eelgrass: 0.4-4% Pondweed: 0-2.5%

1,000 acres minimum (>4%)

FOO (eelgrass): 4% minimum FOO (pondweed): 2.5% minimum

Hydrilla 0.1-8,000 acres** (2-29%)

0-7% 2,500 acres minimum (>9%)

FOO = 7% minimum Bulrush 261-407 acres*

(1-2%) 2-4% 280 acres minimum

(>1%) FOO = 4% minimum

Cattail 796-1,021 acres* (3-4%)

7-9% 800-1,000 acres (3%-4%)

FOO = 7-9% Floating-Leaved Vegetation (Spatterdock/Water Lily/Lotus)

659-1,750 acres* (2-6%)

Spatterdock: 9-10% Water-lilies: 1-3%

Lotus: 1-4.5%

600-1,700 acres (2%-6%)

FOO (spatterdock) = 9-10% FOO (water-lilies) = 3% minimum

FOO (lotus) = 1-4% Shallow-water Native Emergent Vegetation (pickerelweed, spikerush, arrowhead)

320-589 acres* (1-2%)

Pickerelweed: 4-6% Spikerush: 1-2%

Arrowhead: 1.5-3%

420 acres minimum (>1.5%)

FOO (pickerelweed) = 4-6% FOO (spikerush) = 2% minimum FOO (arrowhead) = 3% minimum

Native aquatic grasses (Paspalidium, maidencane, cupscale)

19-146 acres* (<0.5%)

Paspalidium: 0.2-0.5% Maidencane: 02.-1%

Cupscale: 0-0.5%

105 acres minimum (>0.5%)

FOO (Paspalidium) = 0.5% minimum FOO (maidencane) = 1% minimum FOO (cupscale) = 0.5% minimum

Invasive Floating Plants (water hyacinth and water lettuce)

15-225 acres*** Hyacinth: 0.6-3.5% Lettuce: 2.0-4.5%

As close to 0 acres as feasible* FOO (hyacinth): 1% maximum FOO (lettuce): 2% maximum

Burhead Sedge 12-300 acres**** 1.1-4.5% As close to 0 acres as feasible* FOO: 1% maximum

Primrose 102-305 acres* (0.33-1%)

2-4.5% 105 acres maximum (<0.5%)

FOO = 2% maximum Littoral Herbaceous Marsh

3,912-5,955 acres* (14-21%)

N/A 4,000-5,600 acres (15%-20%)

* FWRI Lake Istokpoga Habitat Evaluations using aerial imagery (2007, 2009, 2012, 2015)** IPM Annual Plant Surveys for Lake Istokpoga (2007 -2019) *** IPM Annual Plant Surveys for Lake Istokpoga (2010 -2019) **** IPM Annual Plant Surveys for Lake Istokpoga (2013 -2019) ***** FWRI Annual Aquatic Plant Intercept Surveys for Lake Istokpoga (2015-2018)

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The LIHAC discussed setting habitat targets by lake region (Principle 5) but felt that at the current time, that was not necessary because most management issues applied similarly in multiple locations around the lake. For example, at the time of plan creation, increases in SAV are desired all around the lake, not only in one area.

An important recommendation was to consider, systematically at the planning stage, the likely habitat development after treatment of existing vegetation (Principle 6). For example, is treatment to remove primrose willow with herbicides likely to lead to habitat full of bulrush and maidencane, or spatterdock? Will reducing spatterdock in some areas allow other vegetation to recover? Systematic monitoring and evaluation of the outcomes of past habitat management actions could help predict the consequences of future actions.

Use of active revegetation strategies should be considered when abundance of focal species/habitats falls drastically below the target range (Principle 7). Examples of such strategies are planting of Kissimmee grass and spikerush, or the caging of eelgrass to protect it from herbivores.

The LIHAC also noted that communication issues contributed to the lack of trust and conflict surrounding lake management. They therefore recommended improving communication between the public and agencies (Principle 8). This includes taking steps to ensure that the public is informed of present and future management action plans, maintaining a dialogue with the public, and ensuring access to information.

Habitat Management Guiding Principles

Principle 1: Balance multiple needs and perspectives in habitat management.

Exercise moderation in all actions, and balance multiple perspectives and uses for the lake

Principle 2: Consider habitat diversity, connectivity and dynamics.

Promote a mix of habitat types and species (many fish and wildlife populations rely on a mix of habitats to complete their lifecycle and thrive). Consider this matrix when deciding on habitat management actions

Principle 3: Define focal habitats for maintenance, control and restoration

Clearly define focal habitats in terms of structure, species composition, and/or other metrics (where the same broad habitat type can occur in more or less desirable forms, differentiation into subtypes may be necessary).

Use both scientific and stakeholder knowledge to define focal habitats in support of monitoring and management (examples: Marsh, SAV, deep-water crappie areas).

Include managed invasive plants in focal habitat definitions to promote integration of invasive plant and habitat management.

Principle 4: Set Habitat Targets (ranges) while accounting for wildlife and human use needs and the dynamic nature of aquatic habitats.

Set target ranges for the extent of focal habitats and rules to trigger management actions when habitat extent is outside the target range.

Take into account natural fluctuations in lake habitat when setting target ranges (check historical variation).

Include target ranges for all managed invasive species (even if targets are “minimum feasible level”).

Principle 5: Set targets by lake region if necessary

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Define targets by lake region if deemed necessary. It may not be necessary (for example, increased SAV and EV is desired all around the lake).

Principle 6: Consider medium/long-term consequences of habitat management actions

Consider likely habitat development after treatment of existing vegetation.

Principle 7: Use active revegetation when abundance of focal species/habitats falls drastically below target range

Use active re-vegetation (e.g., Kissimmee grass, spikerush, maidencane plantings; eelgrass cages) to help recovery of desired native vegetation. Principle 8: Improve communication between agencies and members of the public regarding lake-management activities

Develop improved ability to keep the public informed on present and future plans.

Maintain an active dialogue regarding lake-management actions.

Maintain access to information (data, reports) that allows review and evaluation when problems occur.

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4 Management Recommendations Recommendations in this section are based on biological information summarized in Chapter 2, and on stakeholder input obtained in 2017-2019 from the LIHAC, public meetings, and a survey. Stakeholders raised a number of concerns, broadly grouped into concerns about the state of focal habitats, access and navigation, invasive species, management operations, communications, and research. These concerns were used to develop the goals, objectives, and action strategies for the HMP during LIHAC and public meetings, and internal meetings of FWC staff.

Six broad categories of issues address FWC and stakeholder concerns:

• Focal Habitat • Access and Navigation • Invasive Species • Management Operations • Communications • Research, Evaluation, and Adaptive Learning

For each category, the LIHAC and the project team created a goal statement with a set of objectives that describe specific, achievable efforts needed to attain desired future conditions. A draft list of objectives was presented to stakeholders at Public Meeting 3, for comment, and then refined in light of feedback.

The project team and the LIHAC used the public input to refine the list of objectives, and to formulate a draft list of action strategies based on management methods with a high likelihood of success in addressing the goals and objectives. Stakeholder perspectives and support for certain habitat management methods were further evaluated through a mail survey. The project team also wrote brief introductory statements summarizing key issues that the objectives and action strategies are meant to address.

Recommendations are formulated here as goals, objectives, and action strategies, and are presented in each of the following sections. Projects based on action strategies will be included in annual work plans based on FWC's evaluation of habitat conditions and available funding each year. In any given year, even action strategies with a high likelihood of improving conditions may not be implemented because of funding constraints or prevailing habitat conditions.

In addition, non-habitat specific recommendations for FWC are included in the end of this Chapter.

4.1 Focal Habitat Description of the Issues:

Water level regulation, shoreline development, and the presence of invasive plants are just a few factors. Because of these and other factors, habitats on Lake Istokpoga must be actively managed to provide desirable conditions for wildlife and for human uses. This need for active management was recognized by the LIHAC, by FWC biologists, and by the UF project team. Maintaining focal habitats and vegetation within ranges that benefit wildlife and human uses on Lake Istokpoga is therefore the overarching goal (Goal A).

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Goals, Objectives, and Action Strategies:

Goal A Maintain focal habitats within ranges that benefit wildlife and human uses on Lake Istokpoga.

Objective A-1:

Manage native submersed aquatic vegetation (NSAV) to a minimum target of at least 1,000 acres.

Actions: A-1-1

Manage activities to minimize impact on native SAV.

A-1-2 As financially feasible and practical, replant native plants to increase SAV. Objective A-2:

Manage hydrilla at a minimum of 2,500 acres.

Actions: A-2-1

Minimize management operations that reduce hydrilla to below 2,500 acres in the lake, unless hydrilla is growing in areas that meet treatment-trigger criteria specified in the habitat management plan.

A-2-2 If treatment of hydrilla is deemed necessary outside the scope of the treatment-trigger criteria, vet locations of treatment through a public stakeholder process.

A-2-3 If hydrilla is judged to be encroaching on (with the potential to negatively impact) native SAV (Treatment-Trigger #1) or any of the other seven accepted treatment-triggers for hydrilla management, treatments will be publicized through a public stakeholder process.

Objective A-3:

Manage bulrush habitat to a minimum of 280 acres, with a target range of greater than 1% lake acreage.

Actions: A-3-1

Manage spraying activities to minimize impact on bulrush.

A-3-2 Utilize selective herbicides to minimize impact of spraying on bulrush. A-3-3 Explore projects replanting bulrush in the lake. Objective A-4:

Manage littoral herbaceous marsh habitat vegetation to a target range of 4,000-5,600 acres, or 15-20% of lake acreage.

Action A-4-1

Ensure littoral herbaceous marsh habitat includes medium to dense vegetation.

A-4-2 To the extent possible, taking into account trails for boating and access, ensure marsh habitat is contiguous and connected.

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If focal habitat levels fall outside of the target range developed in the plan, the following aquatic plant management strategies could be implemented by FWC:

Vegetation Class

Target Range Aquatic Plant Management Strategies

Below Target Range Within Target Range Above Target Range Native Submersed Aquatic Vegetation (NSAV)

1,000 acres minimum (>4%)

FOO (eelgrass): 4% minimum

FOO (pondweed): 2.5% minimum

Transplanting (in coordination with stakeholders)

Managed Drawdown (<36.5 ft.

NGVD; at most every 5 years, no less than every 10 years)

Transplanting (if desired by stakeholders in coordination with stakeholders)

Hydrilla 2,500 acres minimum (>9%)

FOO = 7% minimum

Herbicide (only when hydrilla is growing in areas that meet

treatment-trigger criteria specified in the management plan)

Managed Drawdown (<36.5 ft.

NGVD; at most every 5 years, no less than every 10 years)

Herbicide (reduction of acreage above minimum in coordination with stakeholders, navigation and access, or

when hydrilla is growing in areas that meet treatment-trigger criteria specified in the management plan)

Selective Mechanical Removal (navigation and access or

when hydrilla is growing growing in areas that meet treatment-trigger criteria specified in the management plan

and herbicide use is not feasible)

Bulrush 280 acres minimum (>1%)

FOO = 4% minimum

Transplanting (in coordination with stakeholders)

Managed Drawdown (<36.5 ft.

NGVD; at most every 5 years, no less than every 10 years)

Transplanting (if desired by stakeholders in coordination with stakeholders)

Cattail 800-1,000 acres (3-4%)

FOO = 7-9%

Managed Drawdown (<36.5 ft. NGVD; at most every 5 years, no

less than every 10 years)

Herbicide (navigation and access only)

Selective Mechanical

Removal (navigation and access only)

Prescribed Fire (green cattail in conjunction with management of other species for leaf

litter reduction)

Herbicide (selective for cattail)

Selective Mechanical Removal

Prescribed Fire (herbicide-treated and green cattail for

vegetation and leaf litter reduction

Floating-Leaved Vegetation (Spatterdock/Water Lily/Lotus)

600-1,700 acres (2-6%)

FOO (spatterdock) =

9-10% FOO (water-lilies) =

3% minimum FOO (lotus) = 1-4%

Transplanting (in coordination with stakeholders)

Managed Drawdown (<36.5 ft.

NGVD; at most every 5 years, no less than every 10 years)

Herbicide (navigation and access only within spatterdock and lotus)

Selective Mechanical

Removal (navigation and access only within

spatterdock and lotus)

Herbicide (spatterdock and lotus only; selective for spatterdock and lotus)

Selective Mechanical Removal

Shallow-water Native Emergent Vegetation (pickerelweed spikerush, arrowhead)

420 acres minimum (>1.5%)

FOO (pickerelweed) =

4-6% FOO (spikerush) = 2%

minimum FOO (arrowhead) =

3% minimum

Transplanting (in coordination with stakeholders)

Managed Drawdown (<36.5 ft.

NGVD; at most every 5 years, no less than every 10 years)

Transplanting (if desired by stakeholders in coordination with

stakeholders)

Herbicide (pickerelweed only when growing as large [>50

acres] monotypic stands; selective for pickerelweed)

Native aquatic grasses (Paspalidium, maidencane, cupscale)

105 acres minimum (>0.5%)

FOO (Paspalidium) =

0.5% minimum FOO (maidencane) =

1% minimum FOO (cupscale) = 0.5% minimum

Transplanting (in coordination with stakeholders)

Managed Drawdown (<36.5 ft.

NGVD; at most every 5 years, no less than every 10 years)

Transplanting (if desired by stakeholders in coordination with stakeholders)

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Hydrilla Trigger-Management Strategies on Lake Istokpoga FWC will manage hydrilla, if or as it returns to the lake, per the FWC’s “Agency Position on Hydrilla Management” (https://myfwc.com/media/3188/hydrilla-mgmt-position.pdf; https://myfwc.com/media/3189/hydrilla-mgmt-position-background-information.pdf). Hydrilla will be managed on Lake Istokpoga above the Lake Istokpoga Habitat Advisory Committee (LIHAC)-recommended minimum level of 2,500 acres, or 9% of the lake area, unless any trigger below is reached. If a single trigger is reached, hydrilla will be controlled within the scope of that trigger. To reduce the need for frequently-repeated management activities in areas commonly infested by hydrilla, hydrilla contiguous with trigger-initiated management areas may also be controlled (e.g., managing hydrilla surrounding eelgrass stands, in addition to hydrilla within the eelgrass stands; controlling hydrilla adjacent to the public ramp, in addition to those plants blocking access). FWC will minimize hydrilla management activities that would reduce hydrilla below the LIHAC-recommended level, where and when possible.

1) Hydrilla is impacting native submersed aquatic vegetation communities

2) Hydrilla is reducing water flow necessary to prevent flooding (e.g., through flood control structure S-68 or G-85)

3) Hydrilla is impeding access to a public boat ramp or boat ramp basin

4) Hydrilla is affecting navigation and has become a safety concern

5) Hydrilla is negatively affecting foraging and/or nesting habitat of listed wildlife species (e.g., Everglade snail kite)

6) Hydrilla is compromising the structural integrity of public property (e.g., flood control structure S68 or G85; bridge at CR 621);

7) Hydrilla is present in areas where FWC Aquatic Habitat Restoration and Enhancement Subsection (AHRE) revegetation activities are planned to occur

8) Hydrilla is in an offshore area or in a marsh area stakeholders want to control (e.g., anglers, duck hunters, recreational boaters). Vetting through public meetings will occur before treatment.

Vegetation Class Target Range

Aquatic Plant Management Strategies - continues

Below Target Range Within Target Range Above Target Range Littoral Herbaceous Marsh Vegetation

4,000-5,600 acres (15%-20%)

Transplanting (native species selected in coordination with

stakeholders)

Managed Drawdown (<36.5 ft. NGVD; at most every 5 years, no

less than every 10 years)

Herbicide (navigation and access only)

Selective Mechanical

Removal (navigation and access only)

Prescribed Fire (green

vegetation for leaf litter reduction)

Herbicide (selective for species creating monotypic stands)

Selective Mechanical Removal

Prescribed Fire (herbicide-treated and green vegetation for

vegetation and leaf litter reduction

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4.2 Access and Navigation Description of the Issues:

Access means the ability of a lake user to launch a vessel from an established public boat ramp and make their way out of the ramp area. Navigation refers to the ability to move around from one part of the lake to another. These issues can be affected by aquatic vegetation.

The overarching goal associated with this section is to improve and maintain reasonable lake access and navigation, in a way that balances the needs of diverse user groups. Stakeholder descriptions of access and navigation problems are similar to one another, despite differences among user groups. Issues surrounding access and views from lakefront properties can be more controversial, but on Istokpoga do not reach a high level of conflict.

Management of vegetation to provide access to/from public boat ramps and navigable creeks is a key objective (Objective B-1). Vegetation in these areas grows to restrict access in a fairly predictable manner and dependability of access is key. The LIHAC highlighted vegetation control at access points as a potential use for mechanical harvesting, given the regular, predictable, and spatially restricted nature of this vegetation management action.

Tussock formation can interfere with access and navigation. Manage or remove mobile floating tussocks when they pose a threat to navigation, using the most efficient method based on vegetation composition, including as appropriate mechanical harvesting and/or shredding for mud tussocks and herbicides for vegetative tussocks.

The LIHAC suggested adopting a network of boat trails in specific areas of the lake and managing vegetation within those trails to enhance navigation (Objective B-2). For example, trails can be cut through dense spatterdock and a navigation corridor could be maintained around lake. The degree to which management actions are needed to maintain trails will vary over time. However, having a specific network in place can enhance navigation and predictability of navigation. Moreover, a defined network can be designed to protect sensitive wildlife habitat, and to manage trade-offs between boater access and protecting animals/plants from predators and nutrient inputs. Non-native SAV in the adopted network of trails should be managed proactively before it limits access.

Goals, Objectives, and Action Strategies:

Goal B. Improve and maintain reasonable lake access and navigation for Lake Istokpoga in a way that balances the needs of wildlife and diverse user groups.

Objective B-1:

Manage vegetation to ensure and maintain access to/from public boat ramps and navigable creeks.

Actions: B-1-1

Manage vegetation to ensure consistency in accessibility to the lake.

B-1-2 Use mechanical means when functionally and economically feasible for access maintenance. B-1-3 Treat mobile floating tussocks when they pose a threat to navigation using the most efficient

method based on vegetation composition. Objective B-2:

Adopt a network of boat trails in specific areas of the lake and manage the vegetation within those trails to enhance recreational access and navigation.

Actions: B-2-1

Develop a network of access trails in coordination with fish camps, guides, and local tournament organizers.

B-2-2 Ensure that the trail network does not overly fragment littoral habitat.

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4.3 Invasive Plants Description of the Issues:

The abundance of invasive plants on Lake Istokpoga has varied greatly over the past decades, with several species impinging significantly on human uses or native plants and wildlife at one time or another. For example, invasive water hyacinth can block waterways and shade out native submersed plant species. On the other hand, invasive plants provide habitat for fish and wildlife species of interest. For example, hydrilla can provide habitat for juvenile bass and a food resource for ducks. Many stakeholders associate the virtual disappearance of hydrilla from the lake with a decline in fishing quality and a decline in birds such as Ring-necked Ducks and American Coots. Therefore, certain invasive plants need to be controlled, but that control can reduce habitat considered beneficial by certain stakeholders, or can cause collateral damage.

The LIHAC believes the overarching goal of invasive plant management on Lake Istokpoga should be to minimize adverse impacts of invasive plants, while maintaining the focal habitat and vegetation objectives associated with Goal A. The core concept advanced by the LIHAC and wider stakeholder input is to strengthen consideration of collateral damage to habitats and the ecosystem, when determining invasive plant management targets and actions.

Strengthening such consideration has two elements: (1) Defining and rating invasive exotics and discussing tolerability, trends, and control methods; and (2) considering invasiveness and impact vs. collateral damage from control methods (Objective C-1).

In a related objective, the LIHAC suggested the need to review and define the target goal for management of invasive, non-native plant species (Objective C-2). The core question was whether it is possible and advantageous to manage some invasive plants to a higher threshold, to reduce overall levels of spraying and/or collateral damage. Management to a higher threshold level may involve strategies such as not spraying until the threshold is reached, and then treating more aggressively; as opposed to treating more or less constantly, at a low level. The LIHAC also questioned whether some floating plants (water hyacinth, water lettuce) are over-managed and could be allowed to increase somewhat. Currently, management operations for invasive, non-native plants operate under Florida Statute 369.20 (the Florida Aquatic Weed Control Act), F.S. 369.22 (the Florida Aquatic Plant Management Act), and Florida Administrative Code Chapter 68F-54 (Funding for Aquatic Plant Management) (Appendix X). The Florida Aquatic Weed Control Act (Florida Statute 369.20) directs FWC to control, eradicate, and regulate noxious aquatic weeds so as to protect human health, safety, and recreation; and to the greatest degree practicable, to prevent injury to plant and animal life and property. Noxious aquatic plants are defined as “any part, including but not limited to seeds or reproductive parts, of an aquatic plant which has the potential to hinder the growth of beneficial plants, to interfere with irrigation or navigation, or to adversely affect the public welfare or the natural resources of this state” (Chapter 68F-54.003 (17), F.A.C.). Invasive plants on Istokpoga have been managed under a maintenance control program, defined as a “method for the management of aquatic plants in which techniques are used in a coordinated manner as determined by the Commission” (Chapter 68F-54.003 (15), F.A.C.). Management currently aims to maintain invasive plants at “low” levels, though exceptions have been made when this goal is in conflict with stakeholder preferences (e.g., for hydrilla).

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Goals, Objectives, and Action Strategies:

Goal C. Manage invasive plant species to minimize their adverse impact while maintaining the habitat objectives outlined in the habitat targets for Lake Istokpoga.

Objective C-1:

Identify and rate invasive exotic plant species and the tolerability, trends, and control methods for each.

Actions: C-1-1

Define and rate invasiveness and impact of non-native plants for consideration in setting of management strategies.

C-1-2 Assess collateral damage from invasive plant control methods and balance with impact/threat posed by invasive plants.

Objective C-2:

Review and specify the goal for management of invasive plants.

Actions: C-2-1

Explore whether allowing slightly higher levels of certain invasive plant species can reduce overall spraying and/or collateral damage to non-target plant species.

C-2-2 Set explicit thresholds defining target levels and response procedures for invasive plant management.

Should invasive plant levels fall outside of the target range developed, the following aquatic plant management strategies could be implemented by FWC (Action C-2-2):

* Control in a consistent, coordinated manner as determined by the Commission to reduce and sustain a plant population at a level that technology, finances, and conditions will allow (369.22, Florida Statutes; Netherland and Schardt 2009; Gettys et al. 2009)

Invasive Plant (Floating and Emergent) Trigger-Management Strategies on Lake Istokpoga Invasive plants on Lake Istokpoga will be maintained at as low a level as allowed by factors including funding, crew resource availability, technology, and current waterbody conditions; and will be managed based on several triggers. If any single trigger below is reached, invasive plants may be controlled. To reduce the need

Vegetation Class

Target Range Aquatic Plant Management Strategies

Below Target Range Above Target Range Within Target Range

Invasive Floating Plants (water hyacinth and water lettuce)

As close to 0 acres as feasible*

FOO (hyacinth): 1% maximum FOO (lettuce): 2% maximum

Herbicide (in coordination with stakeholders when hyacinth and/or lettuce meets treatment-trigger criteria specified in the management plan)

Selective Mechanical Removal (in coordination with stakeholders when hyacinth and/or lettuce meets treatment-trigger criteria specified in the management plan or herbicide use is not feasible)

Burhead Sedge

As close to 0 acres as feasible*

FOO: 1% maximum

Herbicide (in coordination with stakeholders when hyacinth and/or lettuce meets treatment-trigger criteria specified in the management plan)

Selective Mechanical Removal (in coordination with stakeholders when hyacinth and/or lettuce meets treatment-trigger criteria specified in the management plan or when herbicide use is not feasible)

Primrose 105 acres maximum (<0.5%)

FOO = 2% maximum

Herbicide or Selective Mechanical Removal (in

coordination with stakeholders when growing in areas that

meet treatment-trigger criteria specified in the management

plan)

Herbicide (selective as feasible for primrose)

Selective Mechanical Removal

(in coordination with stakeholders)

Herbicide or Selective Mechanical Removal (in

coordination with stakeholders when growing in areas that

meet treatment-trigger criteria specified in the management

plan)

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for frequently repeated management activities in areas commonly infested by invasive plants, invasive plants contiguous with trigger-initiated management areas may also be controlled (e.g., managing water lettuce surrounding bulrush stands, in addition to those plants within the bulrush stands; controlling hyacinth adjacent to the public ramp, in addition to those plants blocking access).

1) Invasive plants are impacting native emergent plants (e.g., pushing over or breaking off native vegetation, such as bulrush), forming monocultures that limit sunlight/space necessary for juvenile native plant recruitment)

2) Invasive plants are covering submersed plant communities, thus limiting sunlight needed for submersed plant photosynthesis and growth (e.g., water lettuce over eelgrass)

3) Invasive plants are blocking access to a public boat ramp or boat ramp basin

4) Invasive plants are affecting navigation

5) Invasive plants are reducing water flow necessary to prevent flooding (e.g., through flood control structures, S-68 or G-85)

6) Invasive plants are compromising the structural integrity of public property (e.g., flood control structure S-68 or G-85, bridge at CR 621)

7) Invasive plants are negatively affecting the foraging and/or nesting habitat of listed wildlife species (e.g., Everglade snail kites)

8) Invasive plants are present in stakeholder-identified Waterfowl Priority Areas (WPA) before waterfowl season (invasive plants are managed before waterfowl season in these WPAs, to reduce the need for management during waterfowl season)

9) An invasive plant species new to the waterbody has been identified and “Early Detection, Rapid Response” (EDRR) protocol is warranted to prevent a small population from becoming a waterbody-wide issue

10) Invasive plants are in areas desired for control by stakeholders (e.g., anglers, duck hunters, recreational boaters, riparian homeowners). Vetting through the LIMC and/or public meetings will occur before treatment.

To minimize impact of herbicide treatments on bulrush and other native focal species plants (Action A-3-2) when treating invasive and other noxious species, FWC will direct its contractors as to the recommended herbicides to use. Factors considered in these recommendation include herbicide efficiency in treating the target species, selectivity for the target species (minimize effect on non-target species), and herbicide cost. Only herbicides labeled for aquatic use will be used to treat plants in Lake Istokpoga.

Herbicides may be used alone (with adjuvants to improve herbicide performance), or in combination with other herbicides, especially when treating multiple species of invasive plants. In accordance with the herbicide labels, treatment rate (number of pounds or ounces of herbicide) may be adjusted to improve herbicide performance or to reduce impact to non-target species. As new herbicides and herbicide technologies are developed that improve performance or selectivity on target species, FWC will incorporate that information into its treatment protocol.

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4.4. Management Operations Description of the Issues:

Stakeholders voiced substantial (but not universal) concerns about habitat and invasive plant management operations. The LIHAC therefore felt it important to address these concerns in the management plan. Concerns about operations fell into two broad categories: overall planning and communication about management operations (4.4.1), and the level of herbicide spraying (4.4.2).

4.4.1 Overall management of operations

Regarding overall operations, the LIHAC formulated a goal of managing focal habitats and invasive plants strategically and transparently, according to habitat targets (Goal D). The aim is to ensure transparency and accountability, such that all management actions can be traced back to clearly stated objectives and assessments of conditions. At present, the FWC Lake Istokpoga Working Group makes such decisions, and posts the resulting work plans However, the process of decision making itself is not documented in a way that is accessible to the public.

The LIHAC recommends addressing this by developing annual habitat status reports and management action plans, to document current conditions relative to the long-term targets, and to set management priorities and actions based on this assessment (Objective D-1). Assessment of conditions is based on aerial and/or satellite mapping, IPM Plant Surveys, BioBase SAV surveys, and GIS analysis of habitat composition every 3 years, and interim observations and more frequent field assessments of changing conditions (Appendix XI). This analysis will result in an annual habitat status report that will communicate observed changes in habitat composition during interim mapping years. When developing annual work plans, identify and develop projects to address habitat deficiencies based on results of these assessments. A detailed work plan should be set out clearly in relation to the assessment. The LIHAC also recommended systematically documenting the outcomes of habitat management actions to allow evaluation and to provide information to guide future decision-making. Increasing transparency of habitat management activities including spraying is also an objective. This would be achieved by transparent planning processes as outlined above, and by widely communicating the outcomes of these processes (e.g., posting spray schedules, with brief explanations, online and at boat ramps).

The LIHAC also recommended expanding the “toolbox” of habitat management, such as by considering increased use of mechanical harvesting where feasible,and not involving excessive cost (e.g., maintenance of access) (Objective D-2). These activities include use of prescribed burns as a viable tool for managing marsh habitat to the extent feasible given weather and safety conditions, including smoke management, and as authorized by the Florida Forest Service; and exploration of future drawdowns in conjunction with vegetation and muck-management actions.

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Goals, Objectives, and Action Strategies:

Goal D. Manage focal habitats and invasive plants on lake Istokpoga strategically and transparently according to habitat targets.

Objective D-1:

Develop annual habitat management action plans and work plans to increase focus, accountability, and transparency of management actions.

Actions: D-1-1

Conduct aerial or satellite mapping, IPM Plant Surveys, BioBase SAV surveys, and GIS analysis of habitat composition and field assessments of changing conditions in order to produce an annual habitat status report that will communicate observed changes and assess compliance with the habitat targets.

D-1-2 Develop annual habitat management action plans to prioritize management actions in light of the long-term habitat management plan and the habitat management status report.

D-1-3 Develop detailed work plans in the light of the habitat management action plan priorities and availability of funding.

D-1-4 Document outcomes of habitat management actions to allow evaluation of effectiveness and provide information on successes and failures to guide future decision making and management activities.

D-1-5 Post annual habitat action plans and work plans to provide increased transparency about decision-making.

D-1-6 Post a detailed spray schedule in advance of spraying activity to allow lake users to adapt their plans accordingly.

Objective D-2:

Expand the “toolbox” of habitat management.

Actions: D-2-1

Consider increased use of mechanical harvesting where feasible and not involving excessive cost (e.g. maintenance of access).

D-2-2 Restore the use of prescribed burns as a viable tool for managing marsh habitat to the extent feasible given weather and safety conditions, including smoke management, and as authorized by the Florida Forest Service.

D-2-3 Explore use of a drawdown in conjunction with vegetation and muck management activities as a tool for habitat management

4.4.2 Herbicide spraying and other management actions

Regarding concerns voiced over herbicide spraying, the LIHAC formulated the goal to minimize adverse impacts and negative perceptions of management actions. A core objective is to establish and implement policies that minimize the scope and scale of management-related disturbance to fish and wildlife resources and the public (Objective E-1). Most important, management actions should be scheduled to minimize conflicts with wildlife critical life-history events (e.g., nesting, spawning, molting) and public use opportunities (e.g., fishing, hunting) to the greatest extent feasible. At the time of plan formation, this was already being done for some activities, for example duck hunting. The LIHAC recommended developing a comprehensive list of critical timing considerations for fish and wildlife, and for stakeholder concerns (e.g., minimize management actions during fish-spawning season, during winter months when seasonal residents are present, 1-2 weeks before opening, and during various waterfowl hunting seasons). Another suggestion was to avoid spraying under conditions where herbicide drift is likely (e.g., during high winds).

Opportunities should be explored to reduce spraying activity (Objective E-2). The LIHAC recommends pilot-testing and reviewing alternative approaches to spraying activities:

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1) The first pilot test would explore dividing the lake into five (5) management zones and treating only two (2) zones at a given time, with clear communication to stakeholders which zones have work occurring.

2) A second pilot test (December through February) would explore conducting a 6-week spraying pause for two of the zones (e.g., Zones 2 and 4), followed by another 6-week pause for another two zones (e.g., Zones 1 and 3). These “pause” periods might minimize conflicts with public-use opportunities (e.g., fishing and waterfowl hunting) to the greatest extent feasible (Action E-1-1).

Herbicide treatments would occur Monday-Thursday only. Exceptions would be in place for impacts to endangered species, access/ navigation/flooding concerns, use of mechanical harvesting, and large-scale treatments that have been publicly vetted.

Better co-ordination of spraying and other habitat management activities between groups was also suggested, to consolidate/reduce spraying activity where possible (Objective E-3). This includes incorporating homeowner activities in plant-management considerations.

Current science regarding herbicides used and available should be continually reviewed, to ensure that the herbicides used are the most effective for the purpose, and cause the least collateral damage (Objective E-4).

Enhancing oversight of applicators was considered important, to promote accountability and trust (Objective E-5). The LIHAC recommended monitoring applicator behavior through technology (e.g., GPS on nozzles, and video cameras on boats), onsite supervision to ensure that applicators follow BMPs, and channels for specific public feedback to reach oversight personnel. Also, ensuring training of applicators in BMPs and habitat management was recommended. Training of applicators in communication skills, to provide information to and respond to questions from lake users, would also improve interactions and build trust.

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Goals, Objectives, and Action Strategies:

Goal E. Minimize adverse impacts and perceptions of management actions Objective E-1:

Establish and implement policies that minimize scope and scale of management-related disturbance to fish and wildlife resources and the public.

Actions: E-1-1

Schedule management actions to minimize conflicts with wildlife critical life history events (e.g., nesting, spawning, molting) and public use opportunities (e.g., fishing, hunting) to the greatest extent feasible.

E-1-2 Develop a comprehensive list of critical timing considerations for fish and wildlife and stakeholder concerns.

E-1-3 Avoid spraying under conditions where herbicide drift is likely high, e.g. high winds. Objective E-2:

Minimize overall level of spraying activity.

Actions: E-2-1

Develop work plans that minimize the overall level of spraying activity where possible.

E-2-2 Pilot test and review alternative approaches to spraying activities.

Objective E-3:

Better coordinate within and between agencies.

Actions: E-3-1

Enhance coordination across FWC management programs.

Actions: E-3-2

Better coordinate spraying and other habitat management activities to consolidate/reduce spraying activity where possible.

Objective E-4:

Continually review herbicides used.

Actions: E-4-1

Continually review the herbicides used.

E-4-2 Adapt use of herbicides in the light of new information. Objective E-5:

Enhance oversight and training of applicators.

Actions: E-5-1

Enhance monitoring of applicator behavior through technology (GPS on nozzles, video cameras on boats), onsite supervision to ensure applicators follow BMPs, and channels for specific public feedback to reach oversight personnel.

E-5-2 Ensure training of applicators in BMPs and habitat management. E-5-3 Consider training of applicators in communication skills to provide information to and

respond to questions from lake users.

4.5. Communications Description of the Issues:

A large number of stakeholders have a wide range of interests in Lake Istokpoga and its associated resources. Several hundred stakeholders participated in developing these recommendations. The LIHAC played a central role in gathering, synthesizing, and articulating stakeholder views and knowledge. Stakeholders voiced appreciation for the resulting higher level of communication, interaction, and trust.

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The central goal of these recommendations is to promote the growth and development of a mutual understanding between FWC and stakeholders regarding habitat management at Lake Istokpoga. An important objective is to maintain and further enhance opportunities to exchange information (Objective F-1). The LIHAC was assembled specifically to develop the Lake Istokpoga Habitat Management Plan and will expire once the plan is finalized. However, the LIHAC and the project team felt that a Technical Advisory Committee (including FWC Staff, Highlands County Staff, UF Staff, and stakeholders similar to the existing LIHAC committee) should be established to help guide implementation and future direction of the plan. This role would likely require less effort and less frequent meetings. This new committee could be constituted independently, or it could be incorporated as a role of the Lake Istokpoga Management Committee (LIMC; https://www.highlandsfl.gov/citizen_committees/lake_istokpoga_management_committee.php). The new committee would likely benefit from some continuity of membership from the current LIHAC but should also draw in new representation, possibly through limited-term membership. The committee would provide input to annual work plans, and would review activities and progress at regular meetings. In addition, one or two public forums should be conducted annually, to provide opportunities for communication with the wider public about the condition of the lake, annual work plans, results of recent management actions, and pertinent information relative to habitat management. Finally, annual habitat assessments, and action and work plans, should be posted publicly on the web, and at boat ramps and other public places.

Informative content should be provided on the FWC website, to improve communication between FWC and stakeholders (Objective F-2). This should include annual assessments and action plans, and work plans for the Aquatic Habitat Restoration/Enhancement Subsection and the Invasive Plant Management Section. Also posted should be schedules of FWC management activities and opportunities for stakeholder involvement, maps that identify areas where habitat management has occurred and is proposed, and evaluations of the outcomes of past habitat management activities.

Current and historical data on a broad range of habitat, fish, and wildlife indicators should be provided on the web to make results of regular monitoring easily accessible. This initiative is already under way (“What’s Happening on my Lake”, https://myfwc.com/wildlifehabitats/habitat/invasive-plants/lakes/).

A document library should be developed to consolidate pertinent current and historical information on Lake Istokpoga, including management plans and evaluations, scientific studies, physical and biological conditions, habitat enhancement, access/navigation maintenance, invasive plant management, surveys and monitoring, fish and wildlife rule changes, and fishing and hunting conditions.

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Goals, Objectives, and Action Strategies:

Goal F. Promote the growth and development of a mutual understanding between FWC and stakeholders regarding habitat management at Lake Istokpoga.

Objective F-1:

Improve stakeholder engagement with FWC by maintaining and increasing opportunities to exchange information.

Actions: F-1-1

Constitute a Technical Advisory Committee or incorporate as a role of the LIMC to provide input to annual work plans; review HMP activities and progress at regular meetings.

F-1-2 Conduct 1-2 public forums annually to provide opportunities for communication about the condition of the lake, annual work plans, results of recent management actions, and pertinent information relative to habitat management.

F-1-3 Post information about lake condition annual work plans on the internet and at boat ramps and other public places.

Objective F-2:

Improve communication between FWC and stakeholders by providing informative content on the FWC website.

Actions: F-2-1

Post annual work plans for the Aquatic Habitat Restoration/Enhancement Subsection and the Invasive Plant Management Section.

F-2-2 Provide a schedule of FWC management activities and opportunities for stakeholder involvement.

F-2-3 Provide maps that identify areas where habitat management is proposed and has occurred and document the results.

F-2-4 Provide current and historical data on a broad range of habitat, fish and wildlife indicators on the web.

F-2-5 Develop a document library that consolidates pertinent current and historical information on Lake Istokpoga.

4.6 Research, Evaluation, and Adaptive Learning Desription of the Issues:

Research, evaluation, and adaptive learning are important elements of the habitat-management process. Research refers to targeted scientific studies. Evaluation refers to documenting conditions before and after management actions, to evaluate effectiveness. Adaptive learning occurs when habitat management actions are explicitly used to gain information and understanding, as well as desired habitat outcomes.

The LIHAC and other stakeholders expressed a strong desire for research, to determine the cause for decline in SAV in the lake, and to determine what factors may negatively impact desired habitats (Objective G-1). The LIHAC hypothesized several potential causes for the decline in SAV in the lake, including but not limited to hurricane impacts; nutrient inputs into the lake; and the impacts of multiple organisims including non-native apple snails, tilapia, and armored catfish. Research recommendations included developing an exploratory model, experimental research, literature reviews, and synthesis of watershed-level impacts. Though the LIHAC’s interest lies in impacts on Lake Istokpoga, these questions are relevant to lakes in other parts of the state. As such, the research does not necessarily need to be conducted on Lake Istokpoga exclusively.

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Goals, Objectives, and Action Strategies:

Goal G. Improve information base for management of Lake Istokpoga through research and adaptive learning

Objective G-1:

Conduct research to determine factors that affect desired habitats on the lake.

Actions: G-1-1

Investigate the development of a model that can be used to look at the relative impacts of hurricanes, etc. on lake habitat.

G-1-2 Conduct experimental research to identify/rule out factors such as water quality, residual herbicides, or the impacts of species like exotic apple snails, tilapia, and armored catfish that might be responsible for current declines in SAV.

G-1-3 Conduct detailed in-situ field experiments, for example in small quadrants, to quantify total impacts of spraying, including possible collateral impacts on periphyton and vertebrate/invertebrate species and overall marsh biomass.

G-1-4 Synthesize available relevant literature and findings in a literature review. G-1-5 Synthesize information and potential impacts at the watershed level, including nutrient

inputs to the lake, land use in the watershed, best management practices, and storm water treatment.

Objective G-2:

Promote learning from management actions.

Actions: G-2-1

Document management actions and the state of habitat before and after implementation to allow evaluation of effectiveness of actions when feasible.

G-2-2 Document costs of management actions for future cost-benefit analysis. G-2-3 Whenever possible, design management actions with controls (areas where the actions are

not implemented) and replication (multiple areas where actions are implemented and multiple control areas).Provide current and historical data on a broad range of habitat, fish and wildlife indicators on the web.

4.7 Additional Actions for FWC to Consider The LIHAC recommended further consideration of the potential to enhance fishing opportunities by placing artificial structures (fish attractors) in some areas of the lake currently devoid of structure. This may mitigate for some loss of fishing opportunities caused by the decline of submersed aquatic vegetation. However, some stakeholders are concerned about putting artificial things into a lake seen as largely natural. Further consideration of these issues is encouraged.

The LIHAC also recommended collaborating with other agencies to improve public-access facilities, and providing opportunities for shoreline fishing and nature viewing, as discussed in Chapter 6.

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5 Monitoring Measurables and Strategies Many current monitoring efforts are relevant to habitat management at Lake Istokpoga. Relevant metrics are monitored by multiple groups/agencies (e.g., University of Florida, FDEP, FWC, SFWMD, Highlands County), and by multiple sections within individual groups/agencies. These monitoring efforts should continue. In addition, monitoring of management activities should be expanded to enhance transparency and accountability, and to allow systematic field evaluation of the efficacy of management activities. All groups/agencies involved should make greater efforts to coordinate the sharing and merging of data to evaluate success/failure of management actions, informing future management directions. The LIHAC recommends developing a wildlife survey protocol to monitor overall ecosystem health on Lake Istokpoga. This includes identifying wildlife species that can serve as indicators of overall habitat quality, and developing sampling designs for this and other lakes that can document the abundance and distributions of these indicator species. Comprehensive lists of all vertebrate species in Lake Istokpoga are in Appendix XII. Indicator species should be monitored on a regular, standardized basis, and resulting data should be incorporated into evaluations of the outcomes of management actions on the lake. Though a variety of indicator species should be identified, monitoring should begin by following the wading bird protocal (Appendix XIII). It should include the indicator species identified there (great egret, little blue heron, tricolored heron, and great blue heron). Wildlife monitoring should be paired with vegetation metrics to explore relationships. In addition, the following monitoring efforts should be maintained or initiated on Lake Istokpoga: For biological, chemical and physical metrics:

● Focal habitats: o The primary habitat metric currently used by FWC is coverage of focal habitats (acres). FWC

has historically conducted aerial mapping and GIS analysis of habitat composition on the lake to determine the effects of management activities over the lake as a whole, and to monitor changes in focal habitat coverage and quality. As funding allows, such monitoring should continue on the lake,to monitor focal habitats and evaluate their status regarding the target ranges recommended in this plan. This includes monitoring the status of submersed aquatic vegetation and percent of hydrilla abundance, based on submersed vegetation surveys (FWC Long-Term Fish Monitoring Program-BioBase sonar plant analyses, and FWC’s IPM Annual Plant Surveys).

o If possible, the plant density should be added to the vegetation analyses, as suggested by stakeholder input.

● Lake wildlife: o Population surveys of focal indicator species, as recommended above, should be designed and

conducted to measure ecosystem quality and lake biodiversity. o Fish population surveys, creel surveys (FWC, Long-Term Fish Monitoring Program), and

Largemouth Bass trophy Catches (FWC Trophy Catch Program using Citizen Scientists) should continue to be used to monitor fisheries status and trends.

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o Surveys of wading birds and rookery nesting success, osprey and snail kite nesting and fledgling counts (FWC, Highlands County, Water Management District) should continue.

o Alligator population and nesting surveys (FWC) should continue.

● Measurements of water quality, particularly nutrients, chlorophyll, water clarity, color, conductivity (Florida LAKEWATCH, and Florida Department of Environmental Protection) should continue.

● Water level monitoring (Water Management District, US Army Corps Engineers) should continue.

● Sediment accumulation should be monitored on a regular basis to inform potential muck removal projects in high accumulation areas.

For management actions:

● Document annual amount of herbicide used by type (FWC’s IPM, Plant Management and Accounting Retrieval System (PMARS) database).

● All herbicide treatments should be individually documented and made available (agency involved, location of application, herbicide used, amount of herbicide and results of application).

● Mechanical harvesting activities should be likewise be individually documented, to facilitate evaluation

of effectiveness.

● All planting activities should also be individually documented (agency involved, location, species, quantity, size).

● The costs of all habitat management activities should be documented and made available for future

cost-benefit analyses.

● Public/stakeholder feedback on management activities should be documented systematically and as specifically as possible, and made available to FWC staff who have oversight of these activities.

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6 Actions for other Agencies to Consider 6.1 Introduction and Background

Issues and concerns on Lake Istokpoga were diverse, and some of those raised by stakeholders are not fully within the mission and statutory authority of FWC. Suggestions are therefore included here as potential opportunities for interagency collaboration, or actions for other agencies or stakeholders to consider. Though not falling under the jurisdiction of FWC, many of these issues and suggestions directly or indirectly impact habitat.

For example, LIHAC members and the wider public recognize the impact of lake water-level stabilization on aquatic plants, and in particular on muck accumulation in the lake. However, they also recognize the complicated nature of water-level changes, as they would need to take into account the needs of lakeside homeowners and other stakeholders for flooding control and access to the lake and water. Muck was a frequently cited concern of community members, as was the fact that water-level stabilization impairs the lake’s ability to regulate habitat naturally. Therefore, the LIHAC recommends exploring changes to the water-level schedule (Action 1).

In addition, water quality was repeatedly raised as a concern by members of the LIHAC and the wider community. Concerns included fertilizer use by other lakeside residents, and associated yard nutrient runoff; as well as the flow of nutrients into the Lake from Arbuckle creek. There was a perception of resulting decline in water quality, with dark water and algae blooms. Therefore, the LIHAC recommends actions to reduce nutrient input into the lake (Action 3).

6.2 Potential Opportunities

For each of the potential opportunities, a brief description is provided, along with agencies and other partners involved.

Action 1. Change in water level schedule

LIHAC members and the wider public recognize the impact of lake water level stabilization on aquatic plants, particularly on muck accumulation in the lake. However, they also recognize the complicated nature of water level changes, as they would need to take into account the needs of lakeside homeowners, lakeside businesses, and other stakeholders concerning flood control and access to the lake and water. Agricultural interests must also considered for permitted irrigation dependent on Lake Istokpoga. Muck build-up in the lake and canals was a frequently-cited concern of community members, as was the negative impact water level stabilization has on the lake’s ability to regulate habitat naturally. Therefore, the committee recommends exploring changes to the water level schedule to restore more-natural levels (expanding fluctuation range) in a way that minimizes impacts to businesses and those using the lake, and the implementation of regularly-scheduled managed drawdowns of the lake to allow muck sediments to dry and decompose, promote expansion of native submerged vegetation and other desirable focal species, and provide opportunities for noxious plant and organic sediment removal, revegetation, and other plant management projects that benefit from lower water levels.

Such actions would require collaboration with the Army Corps of Engineers, water management district, and other stakeholders, such as private landowners.

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Action 2. Collaborate on infrastructure improvement at public boat ramps and other public access points.

The LIHAC recommends creating opportunities for shoreline fishing and nature viewing along the lake, as well as creating shoreline at Windy Point for boats that pull up. In addition, the LIHAC recommends improving facilities. FWC is encouraged to collaborate with other agencies and partners to maintain and/or upgrade public access facilities (e.g, by improving boat ramps and/or improving parking at Lake Istokpoga Park).

Such actions could require, or be achieved, through collaboration with the Florida Park Service and Highlands County.

Action 3. Reduce nutrient inputs to the lake.

The LIHAC recommends actions to reduce nutrient-based impacts to water quality. This action includes reduction of nutrient inputs into the lake. This action could include work conducted by or with the Florida Department of Environmental Protection. Action 4. Reach out to community members to communicate best management practices, encourage understanding of their impacts to the lake, and ensure compliance with regulations regarding vegetation and land management.

Lakefront homeowners have the right to remove aquatic vegetation, subject to permitting and within strict limits. Many homeowners make use of these rights. In addition, land management on their property can impact the lake’s ecology on a cumulative basis. Acknowledging the desire for homeowners to preserve their viewsheds and access to the lake, the LIHAC recommended increased outreach to homeowners about vegetation and land management, to promote adherence to BMPs and conservation-oriented practices.

Lakeshore homeowners and their contractors often undertake spraying and other habitat-management activities on and near their properties. These activities are governed by the homeowner’s statutory rights and specific regulations. While the actions of individual homeowners are “a drop in the bucket,” collectively they can affect the state of nearshore habitats. The LIHAC therefore recommended enhancing outreach to homeowners about best management practices and voluntary conservation-oriented actions.

In addition, the LIHAC recommends outreach to community members about the various causes of declines in water quality and impacts to the lake. These might include lawn maintenance activities, poor water flow in canals, septic systems, trash, or other impacts or activities.

Agencies potentially involved in such efforts could include Highlands County or the Extension Service.

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Literature Cited Bachmann R. W., B. L. Jones, D. D. Fox, M. V. Hoyer, L. A. Bull, and D. E. Canfield, Jr. 1996. Relations between trophic state indicators and fish in Florida (U.S.A.) lakes. Canadian Journal of Fisheries and Aquatic Sciences 53: 842-855. Bachmann, R. W., D. L. Bigham, M. V. Hoyer, and D. E. Canfield, Jr. 2012. A strategy for establishing numeric nutrient criteria for Florida lakes. Lake and Reservoir Management, 28: 84-92. Bergstrom J. C., R. J. Teasley, H. K. Coordell, R. Souter, and B. B. K. English. 1996. Effects of reservoir aquatic plant management on recreational expenditures and regional economic activity. Journal of Applied Economics, 28: 409-422. Bettoli, P. W., M. J. Maceina, R. L. Nobel, and R. K. Betsill. 1992. Picivory in largemouth bass as a function of aquatic vegetation abundance. North American Journal of Fisheries Management, 12: 509-516. Canfield, D. E. Jr. 1981. Chemical and trophic state characteristics of Florida lakes in relation to regional geology. Final Report. Cooperative Fish and Wildlife Research Unit, University of Florida, Gainesville FL. Canfield, D. E., Jr. and M. V. Hoyer. 1992. Relations between aquatic macrophytes and the limnology and fisheries of Florida lakes. Final Report. Bureau of Aquatic Plant Management, Florida Department of Natural Resources, Tallahassee, Florida. Canfield, D. E. Jr. and C. E.Watkins II. 1984. Relationships between zooplankton abundance and chlorophyll a concentrations in Florida Lakes. Journal of Freshwater Ecology, 2: 335–344. Colle, D. E., J. V. Shireman, W. T. Haller, J. C. Joyce, and D. E. Canfield, Jr. 1987. Influence of hydrilla on harvestable sportfish populations, angler use, and angler expenditures at Orange Lake, Florida. North American Journal of Fisheries Management, 7: 410-417. Cook, M. I. and M. Baranski. South Florida Wading Bird Report: Volume 24. South Florida Water Management District. 59pp. Evert J. D. 1999. Relationships of alligator (Alligator mississippiensis) population density to environmental factors in Florida Lakes [master’s thesis]. [Gainesville (FL)]: University of Florida. Florida Fish and Wildlife Conservation Commission Orange Creek Basin Working Group (FWC OCBWG). 2014. Fish and wildlife habitat management guidelines for the aquatic resources of the Orange Creek Basin. Revised December 2014. Florida Fish and Wildlife Conservation Commission. Tallahassee, Florida. <https://orangecreekbasin.files.wordpress.com/2014/08/orange-creek-basin-habitatguidlines-document-12-30-2014.pdf >

Florida LAKEWATCH. 2017. A beginners guide to water management-Muck: Causers and Corrective Actions. Information Circular #112. Program of Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, University of Florida/Institute of Food and Agricultural Sciences. Library, University of Florida. Gainesville, Florida.

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Florida LAKEWATCH. 2007. A beginners guide to water management-Aquatic Plants in Florida. Information Circular #111. Department of Fisheries and Aquatic Sciences, University of Florida/Institute of Food and Agricultural Sciences. Library, University of Florida. Gainesville, Florida. Fretwell S. D. 1987. Food chain dynamics: the central theory of ecology? Oikos, 50: 291–301. Gettys L. A, W. T. Haller and M. Bellaud, eds. 2009. Biology and control of aquatic plants: a best management practices handbook. Aquatic Ecosystem Restoration Foundation, Marietta GA. 210 pages. Griffith G. E., D. E. Canfield, Jr., C. A. Horsburgh, and J. M. Omernik. 1997. Lake Regions of Florida. Corvallis (OR): US Environmental Protection Agency; National Health and Environmental Effects Research Laboratory; EPA/R-97/127; [cited 5 July 2010] Available from http://www.epa.gov/wed/pages/ ecoregions/fl eco.htm. Henderson, J. E., J. P. Kirk, S. D. Lamprecht, and E. Hayes. 2003. Economic impacts of aquatic vegetation to angling in two South Carolina reservoirs. Journal of Aquatic Plant Management, 41:53-56. Hoyer, M. V., and D. E. Canfield Jr. 1994. Handbook of common freshwater fish in Florida lakes. SP 160. University of Florida/Institute of Food and Agricultural Sciences. Gainesville, Florida. Hoyer, M. V., and D. E. Canfield Jr. 1994b. Bird abundance and species richness on Florida lakes: Influence of lake trophic status, morphology, and aquatic macrophytes. Hydrobiologia 297/280: 107-119. Hoyer, M. V., C. A. Horsburgh, D. E. Canfield, Jr., and R. W. Bachmann. 2005. Lake level and trophic state variables among a population of shallow Florida lakes and within individual lakes. Canadian Journal of Fisheries and Aquatic Sciences, 62: 1-10. Hoyer, M. V., R. W. Bachmann and D. E. Canfield, Jr. 2008. Lake management (muck removal) and hurricane impacts to the trophic state of Lake Tohopekaliga, Florida. Lake and Reservoir Management, 24: 57-68. Hoyer, M. V., J. P. Bennett and D. E. Canfield, Jr. 2011. Monitoring freshwater fish in Florida lakes using electrofishing: Lessons learned. Lake and Reservoir Management, 27: 1-14. Hoyer, M. V., D. L. Bigham, R. W. Bachmann, and D. E. Canfield, Jr. 2014. Florida LAKEWATCH: Citizen Scientists Monitoring Aquatic Systems and How Data Are Used. Florida Scientist. 77: 184-197. Joyce, J. C. 1985. Benefits of maintenance control of water hyacinth. Aquatics 7(4):11-12. Mallison C. 2018. Littoral vegetation trend analysis for Lake Istokpoga (2005-2015). Annual Report. Florida Fish & Wildlife Conservation Commission, Lakeland, FL.

Mallison, C. 2018 Littoral vegetation trend analysis for Lake Istokpoga (2005-2015). Florida Fish and Wildlife Conservation Commission. Tallahassee, Florida.

McDiffett, W. F. 1981. Limnological Characteristics of Eutrophic Lake Istokpoga, Florida. Florida Scientist, 44(3): 172–81.

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McNair, D. B., M. A. McMillian and K. D. Meyer. 2001. A Review of the Breeding Status of the Short-Tailed Hawk in the Lake Istokpoga Region, Highlands County, Florida. Florida Field Naturalist, 29(2): 41–46. Milleson, J. F. 1978. Limnological Investigations of Seven Lakes in the Lake Istokpoga Drainage Basin. Technical Publication 78–1. Resources Planning Department, SFWMD, West Palm Beach, FL. Netherland, M. D. and J. D. Schardt. 2009. A Manager’s Definition of Aquatic Plant Control. Aquatics, 31(1):6, 9-19. Pranty, B. 2002. The Important Bird Areas of Florida: 2000–2002. Audubon of Florida, Tampa, FL. Available from http://www.audubon.org/bird/iba/florida. Rodgers J.A., Jr., H. W. Kale II, H. T. Smith and R. E. Aston, Jr. 1996. Rare and Endangered Biota of Florida: Volume V. Birds. University Presses of Florida, Gainesville, FL. Sammons, S. M. and M. J. Maceina. 2005. Effects of aquathol K treatments on activity patterns of largemouth bass in two coves of Lake Seminole, Georgia. Journal of Aquatic Plant Management, 43:17-24. Savino J. F. and Stein R. A. 1982. Predator-prey interactions between largemouth bass and bluegills as influenced by simulated, submerged vegetation. Transactions of the Americal Fisheries Society, 111: 255– 266. SFWMD (South Florida Water Management District). 2000a. Kissimmee Basin Water Supply Plan. Water Supply Department, SFWMD, West Palm Beach, FL. Available from http://www.sfwmd.gov/org/wsd/wsp/kisswsp.htm. SFWMD (South Florida Water Management District). 2000b. Lower West Coast Water Supply Plan. Water Supply Department, SFWMD, West Palm Beach, FL. Available from http://www.sfwmd.gov/org/wsd/wsp/lwcwsp.htm. SFWMD (South Florida Water Management District). 2005. Technical documentation to support development of minimum levels for Lake Istokpoga. Water Supply Department, SFWMD, West Palm Beach, FL. 122 pages. Swift C. S., C. R. Gilbert, S. A. Borton, G. H. Burgess, and R. W. Yerger. 1985. Zoogeography of the freshwater fishes of the southeastern United States: Savannah River to Lake Pontchartrain. Hocutt CH,Wiley EO, editors. The zoogrography of North American freshwater fishes. New York (NY): John Wiley & Sons. Stewart, D. 2001. A Little Osprey-Tality Goes a Long Way. National Wildlife, 39(6): 46–51. White, W. A. 1970. The Geomorphology of Florida. Florida Department of Natural Resources. Tallahassee, FL, p. 164. Wilde, G. E., R. K. Riechers, and J. Johnson. 1992. Angler attitudes toward control of freshwater vegetation. Journal of Aquatic Plant Management, 30:77-79. Xiong C. and M. V. Hoyer. 2018. Influence of land use and rainfall variability on nutrient concentrations in Florida lakes. Lake and Reservoir Management. In Review. Zahina, J., A. Huffman, C. McCarthy, T. Petti, D. Swift, and J. Van Arman. 2005. Minimum Flows and Levels for Lake Istokpoga. DO - 10.13140/RG.2.1.1411.9920.

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Appendix I. Aerial photographs of Lake Istokpoga taken between 1944 and 2001.

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Aerial photographs of Lake Istokpoga taken 1944.

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Aerial photographs of Lake Istokpoga taken 1951.

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Aerial photographs of Lake Istokpoga taken 1962.

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Aerial photographs of Lake Istokpoga taken 1974.

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Aerial photographs of Lake Istokpoga taken 1978.

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Aerial photographs of Lake Istokpoga taken 1981.

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Aerial photographs of Lake Istokpoga taken 1984.

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Aerial photographs of Lake Istokpoga taken 1992.

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Aerial photographs of Lake Istokpoga taken 1996.

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Aerial photographs of Lake Istokpoga taken 1997.

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Aerial photographs of Lake Istokpoga taken 1998.

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Aerial photographs of Lake Istokpoga taken 1999.

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Aerial photographs of Lake Istokpoga taken 2001.

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Appendix II: Legacy herbicides in lake sediments are not

preventing the growth of submersed aquatic plants in Lake Istokpoga

Mark V. Hoyer, William T. Haller, Jason Ferrell, and Dean Jones

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ABSTRACT

Stakeholders concerned about the lack of submersed aquatic vegetation (SAV, primarily Hydrilla verticillata)

in Lake Istokpoga have hypothesized that legacy herbicides in sediments were the possible cause of reduced

SAV growth for the last three years. Bioassay experiments were conducted using sediments collected from

nine stations located around Lake Istokpoga in areas identified by stakeholders where hydrilla had previously

grown. These were compared to sediments collected from three stations in similar Lake Tohopekaliga where

hydrilla was currently growing. Tomato seeds germinated in sediments from all stations in both lakes and

control soils. Bareroot tomato transplants (3.8 cm tall) planted in sediments from both lakes continued to grow

and when harvested plant dry weights were similar to transplants planted in two control soils (pure sand and

1:1 ratio potting soil and sand). Hydrilla tubers were also planted in sediments collected from three stations in

both lakes and control soils. Tubers germinated in sediments from both lakes and control soils and percent

germination was not significantly different between lake sediments and control soils. Sediment samples from

all nine stations in Lake Istokpoga were sent to laboratories for chemical analyses of the nine aquatic

herbicides used in Lake Istokpoga over the last ten years and all results were “non-detect”. Sixty cores were

collected from areas with a history of hydrilla growth in Lake Istokpoga and no hydrilla tubers were collected

suggesting little or no propagules are present for resumed growth of this SAV. Bioassays and sediment

analyses indicate that legacy herbicides are not the cause of decreased abundance of submersed aquatic

vegetation in Lake Istokpoga.

Key words: herbicide, aquatic plant management, lake sediment, tomato bioassay, hydrilla, tuber, hurricanes.

*First author: Director, Florida LAKEWATCH, School of Forest Resources and Conservation, University of

Florida, 7922 NW 71st Street, Gainesville, FL 32653. Second author: Emeritus Professor, University of

Florida, Center for Aquatic and Invasive Plants, 7922 NW 71st Street, Gainesville, FL 32653. Third author:

Professor, University of Florida, Center for Aquatic and Invasive Plants, 7922 NW 71st Street, Gainesville, FL

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32653. Fourth author: Research Biologist, University of Florida Center for Aquatic and Invasive Plants, 700

Experiment Station Road, Lake Alfred, FL 33850. Corresponding author’s E-mail: [email protected].

INTRODUCTION

Lake Istokpoga, Florida’s fifth largest lake at approximately 10,900 ha, is highly productive in terms of both

plant and animal life. Many different stakeholders use and rely on Lake Istokpoga, including anglers, hunters,

recreational boaters, birdwatchers and general wildlife observers, fishing, hunting and wildlife watching-

related businesses, the local hospitality industry, local residents, and a variety of civil society organizations

(Greater Sebring Chamber of Commerce 2019, https://sebring.org/). Many uses of the lake and the

conservation of its biological resources rely on active management of its habitats, particularly with respect to

control of aquatic vegetation (O’Dell et al. 1995, Alam et al. 1996). This task, however, is complex due to the

dynamic, ever-changing ecology of the lake, the diversity of stakeholders, and their often-conflicting

preferences for lake habitat characteristics and management actions.

Water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes), and hydrilla (Hydrilla verticillata) are

the most common problematic aquatic plants in Lake Istokpoga and throughout Florida, often requiring

aggressive management programs. If left alone for a growing season, one hyacinth plant can yield one acre of

plant coverage (Joyce 1992) and one hydrilla stem can grow 486 cm d-1 (Glomski and Netherland 2012)

through production of lateral shoots and apical meristems. These plants can physically interfere with many

lake uses and in large abundance create oxygen deficits causing related fish kills while adding organic

sediments causing expansion of littoral emergent vegetation. The management of these plants in Istokpoga and

other lakes in Florida is currently conducted with an approach called “maintenance control”. Florida Statute

369.22 defines maintenance control 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

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population at the lowest feasible level as determined by the department.” It is important to note that this

management strategy requires many repeated treatments on a regular basis using less herbicide than allowing

problem plants to cover large areas and having to apply greater amounts of herbicide to achieve control.

While herbicides are thoroughly tested and registered for use by the US EPA to assure unintended harm to

lakes will likely not occur, many people are averse to using chemicals in lakes. This can foster an adversarial

environment and result in conflict or a lack of consensus among stakeholders. These conflicts are often

unnecessary and counterproductive to the extent that they are mostly based on misinformation and/or the lack

of a comprehensive management policy or plan for a given lake. In order to promote effective, strategic habitat

management for Lake Istokpoga, and reduce stakeholder conflict, the Florida Fish and Wildlife Conservation

Commission (FWC) contracted with the University of Florida (UF) to engage stakeholders in the development

of a Lake Istokpoga Habitat Management Plan.

Stakeholder engagement in habitat management was strategic, adaptive and included a variety of methods to

ensure the highest level of participation possible. Initially a broad-based situation analysis was conducted to

assess baseline stakeholder knowledge, attitudes and perspectives regarding the management of Lake

Istokpoga as well as their general value orientations. A permanent advisory committee of representatives from

key stakeholder groups was formed in order to identify objectives, develop habitat management options, assess

trade-offs between objectives, and plans for continued monitoring, review and adaptive management (Lake

Istokpoga Habitat Advisory Committee or LIHAC). A wider array of stakeholders and the general public was

engaged through public meetings and a stakeholder survey to obtain input from stakeholders at large who have

not personally engaged with the LIHAC or public meetings.

One of the main issues that emerged from stakeholder engagement sessions was the decrease abundance of

submersed aquatic vegetation (primarily Hydrilla verticillata) and a perceived decrease in associated fish and

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wildlife populations. Since 2015 little hydrilla or other submersed aquatic vegetation has been reported in Lake

Istokpoga (FWC 2017). It was suggested by the LIHAC and many stakeholders at public meetings that the

longtime use of herbicides in Lake Istokpoga had built up legacy herbicide in sediments, which has prevented

regrowth of submersed aquatic vegetation in the lake.

UF’s Lake Istokpoga habitat management plan development team, with collaboration from the LIHAC and

FWC staff designed the following three-part sediment study to determine if legacy herbicides in sediments

were inhibiting the growth of submersed aquatic vegetation in the Lake. This included 1) sediment bioassay

studies, 2) analytical analysis of herbicide concentration in sediment, 3) a hydrilla tuber density survey within

Lake Istokpoga.

MATERIALS AND METHODS

Bioassay Study

The specific objectives of this study section were to:

1. Determine if tomato seed germination and growth, tomato bare root transplant growth and hydrilla tuber

germination in lake sediments collected from Lake Tohopekaliga and Lake Istokpoga are similar to each other

and to germination/growth in control soils.

On May 23, 2019 a Petite Ponar sediment sampler was used to collect five gallons of sediment from each of

three locations identified by the LIHAC as areas that historically supported hydrilla in Istokpoga (Stations I-1,

I-2, and I-3, Figure 1a). Sediments were also collected from three locations (May 13, 2019) in Lake

Tohopekaliga where hydrilla was currently growing (Stations T-1, T-2, and T-3, Figure 1b). Lake

Tohopekaliga was chosen for comparison to Lake Istokpoga because of similarities between the two lakes.

Istokpoga is a large (surface area 10,900 ha), shallow (mean depth= 1.6 m), eutrophic lake (annual mean

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chlorophyll range from 12 to 62 µg/L) and hydrilla coverage from 1982 to 2017 averaged 19% exceeding 90%

coverage in 1996 (O’dell et al. 1995, Florida LAKEWATCH 2018, FWC 2017). Tohopekaliga is also a large

(surface area = 9,800 ha), shallow (mean depth = 2.1 m), eutrophic lake (annual mean chlorophyll range from

10 to 54 µg/L) and hydrilla coverage from 1982 to 2017 averaged 38% exceeding 80% coverage in 2002

(Hoyer et al. 2008, Florida LAKEWATCH 2018, FWC 2017). Since 2009 the use of herbicides in both lakes

has also been similar with total annual herbicide applications averaging 2.743 kg/ha and 3.948 kg/ha in Lakes

Istokpoga and Lake Tohopekaliga, respectively (Table 1).

Sediment were delivered to the Center for Aquatic and Invasive Plants (CAIP) for processing and all bioassay

work. Sediments from each lake (Istokpoga: Stations I-1, I-2, and I-3; Tohopekaliga: Stations T-1, T-2, and T-

3) were dried, sifted through a 0.6 cm screen and put into two groups of four, 10.1 cm pots. Similarly, two

control groups, one pure sand and one sand/potting soil mix (Control (Sand); and Control (Sand & OM) 1:1

ratio by volume) were also set up. The sand controls likely have too few nutrients to grow tomatoes so three

grams of Osmocote slow release (3-4 month) fertilizer/kg of soil weight was added to all control pots, but no

fertilizer was added to the lake sediment samples. Ten tomato seeds were each planted 1 to 2 cm deep in four

pots from each station and the two control soils. Two to 8 cm tall tomato plants were purchased from a local

nursery and all soil washed from the their roots. Two of these bare root transplants were planted in each of four

pots of the two control soils and the six soil samples from lakes Istokpoga and Tohopekaliga. Tomato seeds

and transplants were used for this study because they are both easy to grow and extremely sensitive to

herbicides and other stresses (Fernow 1967, Neal 1991). Tomato seeds and transplants were planted on April

12, 2019 and number of seeds germinated in each pot determined on May 10, 2019. Seedlings were also

harvested on May 10, 2019 dried in a drying oven (103 °C) for several days and weighed (gm).

Hydrilla tubers collected from experimental tanks located at Center for Aquatic and Invasive Plants, University

of Florida were planted in 4-inch pots (six tubers per pot) using the exact experimental design mentioned

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above. The tubers had been held in refrigeration for several days prior to planting causing concern about the

tubers after none had germinated for two weeks. Therefore, using the remaining unused experimental

sediments from Istokpoga and Tohopekaliga four new pots per station were prepared and six fresh tubers from

different culture tanks planted in each. Six additional tubers were planted in each of the original control pots

yielding 12 tubers in each control pot. The second round of tuber planting occurred on June 4, 2019 and the

number of tubers germinated per pot was determined on July 3, 2019.

Preliminary results (Istokpoga stations I-1 to I-3, Tohopekaliga T1 to T-3, and two controls) from this study

were presented to multiple Lake Istokpoga stakeholders who then requested better lake-wide coverage for the

bioassay work because of the lakes large surface area. Therefore, on June 6, 2019 sediment samples were

collected from six additional stations in Lake Istokpoga (Figure 1a, stations I-4 to I-9) for additional bioassay

tests. The sediments were processed and the experimental design was the same as the experiments conducted

with sediments from the first three stations. However, only tomato seeds were planted to evaluate seed

germination. Ten tomato seeds were planted on June 24, 2019 and geminated seeds (plants) counted on July

15, 2019.

Herbicide concentration in sediment study

Florida Fish and Wildlife Conservation Commission (FWC) maintains a database called Plant Management

and Accounting Retrieval System (PMARS: https://public.myfwc.com/HSC/PMARS/LoginForm.aspx), which

records all of the herbicides applied annually to each individual Florida public lake under their management

program. Table 1 lists the number of years an individual herbicide was used in Lakes Istokpoga and Lake

Tohopekaliga and the sum of active ingredient applied during those years (kg and kg/ha of the lake). The

LIHAC requested sediments be collected from the same nine stations used in the bioassay study (Figure 1a)

and have them tested for the nine aquatic herbicides listed in Table 1. The objective of this section was to

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identify the concentrations (if any) of the aquatic herbicides in sediments collected from nine different stations

in Lake Istokpoga.

On June 6, 2019, sediment samples were collected from all nine stations (Figure 1a) using a Petite Ponar1

sediment sampler. Samples were placed in 2-gallon plastic bags, sealed, and shipped on ice to Waters

Agricultural Laboratories, Inc. for analyses of all herbicides except diquat and endothall. An additional set of

sediment nine samples were sent to North Coast Laboratories LTD laboratories for analyses of diquat. We

could find no laboratories that would analyze sediments for endothall due to the low partition coefficient of

endothall to hydrosoil (Reinert and Rodgers 1984) and the relatively short persistence in water (half-life 4.01

days) (Reinert et al. 1985). All analyses were conducted using standard methods.

Hydrilla tuber density in Lake Istokpoga study

Hydrilla (dioecious) reproduces asexually through fragmentation, and production of turions, and tubers (Gettys

et al. 2014). Turions are small (up to 0.6 cm diameter), green in color, and grow from the plant leaf axils,

whereas tubers are larger in size (up to 1.3 cm diameter), white to yellow to near black in color, and grow in

the lake sediments. Hydrilla populations in Florida are limited to the dioecious biotype and thus can only

spread and reproduce by vegetative means (Gettys et al. 2014). Turions have a longevity of roughly one year

(Netherland 1997), but tubers have been observed to survive in lake sediments for several years (Nawrocki et

al. 2016, Hofstra et al. 1999). Thus, the primary means for regrowth and long-term persistence of hydrilla in

Lake Istokpoga are sprouting of dormant tubers.

The LIHAC was concerned that hydrilla has not been observed in Lake Istokpoga for the last three years

(2016-2019) and wished to determine if hydrilla tubers were present in the sediments of the lake. A total of 60

sediment cores were collected on April 5, 2019 from three stakeholder-identified sampling locations (Figure

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1a; Stations I-1, I-2 and I-3). Twenty cores were collected in the area of each station, four sub-sample sites

were selected (1-4), each located roughly 30 to 40 m in distance from each other along a north-bearing. At

each of the four sub-sample sites, five samples were collected from the bow of the boat.

Samples were collected using a core sampler constructed from PVC pipe and fittings, a paint pole, and an air

release value (modified from Sutton 1982). The PVC pipe was 15.2 cm diameter and thus the sampling area

for a single sediment core was 182.5 cm2. Samples were collected to a depth of 20.3 cm and were washed in

the field with lake water through a 0.3 cm mesh basket to remove the sediment from retained material. The

retained material was then sorted by hand and the number of tubers was counted and recorded for each sample.

The objective of this section was to determine tuber density in the three identified hydrilla growth areas of

Lake Istokpoga and compare to literature densities reported in other studies.

Data analyses were performed using the JMP statistical package (SAS 2000). An analysis of variance was used

with results to determine significance of bioassay treatments (control, Lake Istokpoga, Lake Tohopekaliga)

followed with a Tukey-Kramer HSD test for individual group differences. All statements of significance are at

p < 0.05.

RESULTS

Tomato seeds planted in the sediments from Lake Istokpoga stations I-1, I-2, and I-3 germinated in all

sediment soils (Figure 2). An analysis of variance showed significant treatment effects (p< 0.05). Average

germination in control treatments (mean = 94% germination) exceeded mean germination in sediments from

Lakes Istokpoga and Lake Tohopekaliga (mean = 61% and 63% germination, respectively). However, there

was no significant difference between tomato seed germination in soils from Lake Istokpoga and Lake

Tohopekaliga (Figure 2). Seed germination in sample I-2 was lower than germination in other soils. This soil

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was extremely fine and difficult to wet and formed a “crust” after watering on the soil surface, which we

suggest caused the reduced germination.

Tomato seeds planted in sediments collected from the additional Lake Istokpoga stations I-4 through I-9 also

germinated in all pots (Table 2). Seed germination on the control pots for this second part of the tomato seed

germination study had a mean of 88% germination and means of Istokpoga stations I-4 through I-9 ranged

from ranged from 28% to 83% out of 10 seeds planted in each of the four replicates, with an overall mean of

57%.

Bare root tomato transplants in sediments from Lake Istokpoga stations I-1, I-2, and I-3 grew well and no

plants died (Figure 3). An analysis of variance on transplant biomass showed treatment effects were significant

(p< 0.05). Average plant biomass in controls (mean = 1.5 gm-dry-wt.) and Lake Istokpoga (mean = 1.3 gm-

dry-wt.) were not significantly different but both were significantly greater than plant biomass from transplants

planted in Lake Tohopekaliga soils (mean = 0.5 gm-dry-wt.).

Hydrilla tubers in sediments from Lake Istokpoga stations I-1, I-2, and I-3 germinated in all treatments (Figure

4). An analysis of variance showed no significant treatment effects (p < 0.05). Average germination in controls

(mean = 53% germination) was not significantly different from germination in Istokpoga sediments (mean =

59% germination) and Tohopekaliga sediments (mean = 44% germination). There was no significant

difference in tuber germination between sediments from Lake Istokpoga and Lake Tohopekaliga.

No evidence of the eight aquatic herbicides historically used in Lake Istokpoga and analyzed for could be

found in sediments at any of the nine stations identified by the LIHAC (Figure 1a). Analyses from Waters

Agricultural Laboratories Inc. reported for herbicides in stations 1-9 as undetected (Table 3). Similarly, North

Coast Laboratories LTD reported no diquat was detected for all stations.

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To put herbicide analyses in a general perspective, the label rates of herbicide concentrations for aquatic plant

applications and the minimum detection limit (MDL) for laboratory analyses are also listed in Table 3. These

two values are not comparable, but they give a general perspective for ranges of herbicide concentrations. The

MDL’s for all herbicides (except diquat) are orders of magnitude less than the allowable application

concentration. The MDL for diquat is approximately five times higher than the actual application rate.

However, if diquat were accumulating in the sediments and not breaking down, it would have been found in

Lake Istokpoga sediments because an average of 687 kg per year of diquat are used in Lake Istokpoga (Table

1). Additionally, North Coast Laboratories LTD spiked sediments with known concentrations of diquat and

their analysis method recovered over 80% of the spike suggesting excellent recovery (data not shown).

No hydrilla tubers were found in any of the 60 soil core samples collected, 20 around each of stations I-1, I-2,

and I-3. All samples had high levels of organic matter, especially stations 2 and 3 (Figure 1a). Retained

material in the mesh baskets was primarily fine roots and larger fibrous plant material at station 1, whereas

material from stations 2 and 3 was primarily fine roots and woody material.

DISCUSSION

The Lake Istokpoga Habitat Management Planning process has identified multiple concerns but one major

concern was the hypothesis that regular use of herbicides in Lake Istokpoga was causing a buildup of legacy

herbicides preventing growth of submersed aquatic vegetation (primarily hydrilla). The average annual use of

herbicides in relatively shallow lake Istokpoga from 2009-2018 indicates that there was an annual application

of 2.7 kilograms of aquatic herbicide use per hectare per year in this lake. Despite the reported short half-lives

of less than a week in the water of most of these herbicides (Netherland M. D., chapter 11, in Gettys, Haller

and Petty, 2014) there was a concern expressed by many that these may be accumulating in the sediment and

111

affecting re-establishment of hydrilla and other SAV in the lake. The sediment work conducted during this

study shows that sensitive tomato seeds/transplants and hydrilla tubers germinate and grow well in Lake

Istokpoga sediments. Analyses for nine herbicides, historically used in Lake Istokpoga over the last 10 years,

from sediments collected at nine different locations around the lake showed no detectable levels of any

herbicide. These data do not support the hypothesis of legacy herbicides in the sediments of Lake Istokpoga

are suppressing the growth of hydrilla.

Confusing the findings of these sediments bioassays and herbicide analyses is the fact that no hydrilla tubers

were found in core samples taken from 60 stations in Lake Istokpoga. Similar sampling effort (40 to 120 cores)

in six different coves of Lake Gaston, North Carolina yielded 31 to 293 tubers m-2 (Nawrocki et al. 2016), even

after seven years of herbicide management with floridone. Various studies have investigated the longevity of

monoecious hydrilla tubers. Van and Steward (1990) conducted a long-term study with monoecious hydrilla

and found tubers survived in undisturbed sediments greater than four years after being produced. Other field

studies have found viable tubers between six to eight years old (Nawrocki et al. 2016, Hofstra et al. 1999).

Studies on dioecious hydrilla tubers by Netherland (1999) indicated that this biotype likely has similar tuber

dormancy periods of several years when compared to monecious hydrilla. Hydrilla was abundant in Lake

Istokpoga approximately three years prior to the current tuber sampling and therefore tubers should still be

present and viable in the lake sediments based on tuber longevity studies. However, the lack of hydrilla

coverage, coupled with the lack tuber presence, may be an indication that there are little to no vegetative

propagules left in Lake Istokpoga to facilitate hydrilla regrowth.

We do not have an explanation for why hydrilla and other submersed aquatic plants appears to have vacated

Lake Istokpoga. The evidence provided in these sediment studies suggest that legacy herbicides in the

sediments are not the reason and continued research will be needed to explain the hydrilla disappearance.

However, this is not an isolated instance in Florida since hydrilla has disappeared from other Florida lakes in a

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similar manner without an explainable reason. For example, hydrilla appeared in Lake Weohyakapka, Polk

County FL around 1992 (FWC 2017) and by 1995 covered over 6,000 acres of the lake (surface area

approximately 7,500 acres). Hydrilla dominated Lake Weohyakapka for the next decade and then after 2004

when three hurricanes passed over the lake, hydrilla disappeared and has not returned. While hydrilla coverage

was already low in Lake Istokpoga due to herbicide treatments when hurricane Irma passed over the lake

(September 10, 2017) the continued absence of hydrilla from the Lake Istokpoga may be related to hurricane

activity, similar to Lake Weohyakapka. Additionally, many shallow lakes from around the world have

switched from macrophyte dominated lakes to algal dominated lakes for various reasons including changes in

salinity, waterfowl grazing, water level changes, grass carp introductions and others (Scheffer 1988). However,

none of these explanations can be used to explain the situation in Lake Istokpoga.

Aquatic plant management has been, is and will continue to be a major issue in Florida and around the world.

Florida LAKEWATCH and CAIP have worked and collaborated with FWC for decades and understands that

FWC’s aquatic plant management program is sound and based on the best available science, much of which

has been conducted by University of Florida scientists. However, the difficulty comes with the diversity of

stakeholders utilizing individual lake systems and that there is no one-size-fits-all management plan. For

example, the Harris Chain of Lakes Restoration Council and local stake holders are currently communicating

with the State Legislature and County Government to acquire more funding for herbicides to control hydrilla in

lakes under their jurisdiction, while stakeholders from Lake Istokpoga are loudly requesting the stoppage of all

herbicide use for Lake Istokpoga.

Making the management of aquatic plants even more complicated is the fact that these two stakeholder

viewpoints are moving targets depending on what the aquatic plants in each system have to “say”. For

example, in the early 1990s there was little or no submersed aquatic vegetation in the Harris Chain-of-lakes

and the stakeholders/anglers were advocating for submersed aquatic plants (primarily hydrilla) for fish habitat,

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which is opposite to the current consensus. Similarly, in late 1990s, Lake Istokpoga was covered with over

25,000 acres of hydrilla and at that time the stakeholders were advocating for aggressive herbicidal

management and even the stocking of grass carp. Thus, heading in the direction of individual lake management

plans that can be adjusted as plants come and go in a system with a long-term goal/target of maintaining some

moderate level of vegetation seems a solid approach.

Finally, this manuscript is a small section of a much larger effort to develop a habitat management plan for

Lake Istokpoga where stakeholders and management agencies are working together to develop a plan to best

manage this system for the benefit of stakeholders and the resident fish and wildlife. While this is a small

section of a bigger plan, the collaboration between stakeholders and agency personnel working together to

identifying an issue, locate areas that need to be examined and carrying out studies to address the issue is a

positive step in the successful development of Lake Istokpoga Habitat Management Plan.

SOURCE OF MATERIALS

1Petite Ponar. Wildco ®. 86475 Gene Lasserre Blvd, Yulee, FL 32097.

ACKNOWLEDGEMENTS

This research was supported by Florida Fish and Wildlife Conservation Commission, Invasive Plant

Management section. We thank Jacob Thayer for assistance with bioassay studies. We thank Geoffrey Lokuta

for help sampling hydrilla tubers and help collecting sediments for herbicide analyses. We thank the Lake

Istokpoga Habitat Management Plan Advisory Board for their comments during the study process.

114

LITERATURE CITED

Alam, S. K., L. A. Ager, T. M. Rosegger, and T. R. Lange. 1996. The effects of mechanical harvesting of

floating plant tussock communities on water quality in Lake Istokpoga, Florida. Lake Reserv. Manage.

12:4,455-461.

Gettys, L. A., W. T. Haller, and D. G. Petty, (eds). 2014. Biology and control of aquatic plants: a best

management practices handbook, 3rd edition. Aquatic Ecosystem Restoration Foundation, Marietta.

Fernow, K. H. 1967. Tomato as a test plant for detecting mild strains of Potato spindle tuber virus.

Phytopathology. 57:1347-1352

Florida LAKEWATCH. 2018. Annual lake reports. http://lakewatch.ifas.ufl.edu/.

Florida Fish and Wildlife Conservation Commission. 2017. Annual Report of Activities Conducted under the

Cooperative Aquatic Plant Control Program in Florida Public Waters for Fiscal Year 2016-2017. FL Fish and

Wildlife Conservation Commission, Invasive Plant Management Section, 3900 Commonwealth Blvd. MS705.

Tallahassee, FL 32399.

Glomski, L. M. and M. D. Netherland. 2012. Does hydrilla grow an inch per day? Measuring short-term

changes in shoot length to describe invasive potential. J. Aquat. Plant Manage. 50:54-57.

Hofstra, D. E., J. S. Clayton, P. D. Champion, and J. D. Green. 1999. Distribution and density of vegetative

hydrilla propagules in sediments of two New Zealand lakes. J. Aquat. Plant Manage. 37:41-44.

115

Hoyer, M. V, R. W. Bachmann, and D. E. Canfield, Jr. 2008. Lake management (muck removal) and hurricane

impacts to the trophic state of Lake Tohopekaliga, Florida. Lake Reserv. Manage. 24: 57-68.

Joyce, J. C. 1992. Benefits of maintenance control of water hyacinth. Aquatics.

Nawrocki, J. J., R. J. Richardson, and S. T. Hoyle. 2016. Monoecious hydrilla tuber dynamics following

various management regimes on four North Carolina reservoirs. J. Aquat. Plant Manage. 54: 12-19.

Neal, J. 1991. Conducting a bioassay for herbicide residues. Cornell Cooperative Extension WeedFacts #3.

Netherland, M. D. 1997. Turion ecology of hydrilla. J. Aquat. Plant Manage. 35:1-10.

Netherland, M. D. 1999. Management impacts on the quiescence and sprouting of subterranean turions of

diecious hydrilla (Hydrilla verticillata (L.F. Royle). PhD Dissertation, University of Florida, Gainesville,

Florida, 192 pp.

O'Dell K. M., J. Van Arman, B. H. Welch, and S. D. Hill. 1995. Changes in water chemistry in a macrophyte-

dominated lake before and after herbicide treatment. Lake Reserv. Manage. 11:311-316.

Reinert K. H. and J. H. Rodgers. 1984. Influence of sediment types on the sorption of endothall. Bull. Environ.

Contam. Toxicol. 32:557-564.

Reinert K. H., J. H. Rodgers, M. L. Hinman, and T. J. Leslie. 1985. Compartmentalization and persistence of

endothall in experimental pools. Ecotoxicol. Environ. Safety 10:86-96.

116

SAS. 2000. JMP Statistics and graphics guide. SAS Institute, Inc., Cary, NC.

Scheffer, M. 1998. Ecology of shallow lakes. Chapman & Hall. New York.

Sutton, D. L. 1982. A core sampler for collecting hydrilla propagules. J. Aquat. Plant Manage. 20:57-59.

Van, T. K. and K. K. Steward. 1990. Longevity of monoecious hydrilla propagules. J. Aquat. Plant Manage.

28:74-76.

Walker, W. and K. E. Havens. 2003. Development and Application of a Phosphorus Balance Model for Lake

Istokpoga, Florida, Lake Reserv. Manage. 19:79-91.

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Table 1. Number of years (starting from 2009) an individual aquatic herbicide was used in Lake Istokpoga, and

Lake Tohopekaliga listed with mean amount (kg and kg/ha) of active ingredient applied during those years.

Kg/ha is the is the weight of active ingredient divided by the whole lake surface area.

Istokpoga Tohopekaliga

Control Method Years Mean (kg) Mean (kg/ha) Years Mean (kg) Mean (kg/ha)

Endothall 6 27806 2.551 9 34006 3.470

2,4-D (Amine) 9 687 0.063 6 119 0.012

Glyphosate 9 624 0.057 7 734 0.075

Diquat 9 617 0.057 9 3545 0.362

Triclopyr (Amine) 4 65 0.006 2 7 0.001

Imazamox 7 45 0.004 5 52 0.005

Flumioxazin 7 45 0.004 6 36 0.004

Penoxsulam (liquid) 5 8 0.001 5 190 0.019

Imazapyr 3 1 0.000 1 1 0.000

Total Annual Average 29898 2.743 38690 3.948

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Table 2. Mean, minimum, and maximum percent tomato seed germination in second round of control pots and

second round of Istokpoga station (I-4 through I-9).

Soil Sample Site Pots Mean Minimum Maximum

Control (Sand & O.M.) 4 87.5 80 100

I-4 4 52.5 30 80

I-5 4 82.5 80 90

I-6 4 47.5 10 80

I-7 4 40 10 60

I-8 4 77.5 60 90

I-9 4 27.5 20 40

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Table 3. Concentrations of herbicides (ppb), except diquat, in sediments collected from nine locations in Lake

Istokpoga on June 6, 2019 and analyzed/reported from Waters Agricultural Laboratories, Inc. Samples from

the nine locations were analyzed for diquat by North Coast Laboratories LTD. All nine samples had the same

results (U for undetected) for each analyte reported below. MDL = Minimum Detection Limit, in ppb (µg/kg

of soil). Actual aquatic plant treatment rates from herbicide abels are also listed.

Method Analyte Concentration Label Rates MDL

EPA 3540 Flumioxazin U 100-400 ppb 20

LCMSMS Glyphosate U 6.0-9.2 kg/ha* 50

LCMSMS Imazamox U 50-500 ppb 10

LCMSMS Imazapyr U 2.5-7.4 kg/ha* 10

EPA 3540 Penoxsulam U 10-150 ppb 10

EPA 8151A (Modified) 2,4-D U 2000-4000 ppb 50

EPA 8151A (Modified) Triclopyr U 750-2500 ppb 50

Diquat U 375 ppb 2000

* Areal application rates

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CAPTION FOR FIGURES

Figure 1. Google earth maps locating sediment sampling stations on Lake Istokpoga (1a) and Lake

Tohopekaliga (1b). These lakes are of similar size and depth and located in central Florida about 200 km apart.

Figure 2. Box plot showing percent of tomato seeds germinated by the individual treatment and station. Line in

the middle of the box is the median, top and bottom edges of the box are the 25% and 75% of the data

distribution. An analysis of variance was conducted using all data to determine treatment group (Controls,

Lake Istokpoga, Lake Tohopekaliga) effects and a Tukey-Kramer test checked for significant differences.

Treatment groups with different letters are significantly different (p < 0.05).

Figure 3. Box plot showing total dry weight of tomato seedings by the individual treatment and station. Line in

the middle of the box is the median, edges of the box are the 25% and 75% of the data distribution. An analysis

of variance was conducted using all data to determine treatment group (Controls, Lake Istokpoga, Lake

Tohopekaliga) effects and a Tukey-Kramer test checked for significant differences. Treatment groups with

different letters are significantly different (p < 0.05).

Figure 4. Box plot showing percent of hydrilla tubers germinated by the individual treatment and station. Line

in the middle of the box is the median, top and bottom edges of the box are the 25% and 75% of the data

distribution. An analysis of variance was conducted using all data to determine treatment group (Controls,

Lake Istokpoga, Lake Tohopekaliga) effects and a Tukey-Kramer test checked for significant differences.

Treatment groups with different letters are significantly different (p < 0.05).

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Figure 1. Google earth maps locating sediment sampling stations on Lake Istokpoga (left) and Lake Tohopekaliga (right).

Figure 2. Box plot showing percent of tomato seeds germinated by the individual treatment and station. Line in the middle of the box is the median, top and bottom ends of the box are the 25% and 75% of the data distribution. The line across the plot is the grand mean of all values. An analysis of variance was conducted using all data to determine treatment group (Controls, Lake Istokpoga, Lake Tohopekaliga) effects and a Tukey-Kramer test checked for significant differences. Treatment groups with different letters are significantly different (p < 0.05).

122

Figure 3. Box plot showing dry weight of tomato seedings by the individual treatment and station. Line in the middle of the box is the median, top and bottom ends of the box are the 25% and 75% of the data distribution. The line across the plot is the grand mean of all values. An analysis of variance was conducted using all data to determine treatment group (Controls, Lake Istokpoga, Lake Tohopekaliga) effects and a Tukey-Kramer test checked for significant differences. Treatment groups with different letters are significantly different (p < 0.05).

123

Figure 4. Box plot showing percent of hydrilla tubers germinated by the individual treatment and station. Line in the middle of the box is the median, top and bottom ends of the box are the 25% and 75% of the data distribution. The line across the plot is the grand mean of all values. An analysis of variance was conducted using all data to determine treatment group (Controls, Lake Istokpoga, Lake Tohopekaliga) effects and a Tukey-Kramer test checked for significant differences. Treatment groups with different letters are significantly different (p < 0.05).

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Appendix III. LAKEWATCH Report for Lake Istokpoga in Highlands County

Using Data Downloaded 10/17/2016

125

Introduction for Lakes In this report, we present summary data collected on individual systems that have been part of the LAKEWATCH program. This summary is from the whole period of record for individual systems. The first part of this summary will allow a comparison of the long-term mean nutrient concentrations with the nutrient zone concentrations published by LAKEWATCH staff (Bachmann et al. 2012; http://lakewatch.ifas.ufl.edu/publications.shtml). The second part of the summary will allow the comparison of data with Florida Department of Environmental Protections Numeric Nutrient Criteria. Finally, this report examines data for any long-term trends that may be occurring in individual systems but only for systems with five or more years of data. Base File Data: Definitions The long-term data summary will include the following parameters listed with a definition after each one: County: Name of county in which the lake resides. Name: Lake name that LAKEWATCH uses for the system. Latitude and Longitude: Coordinates identifying the exact location of station 1 for each system. Water Body Type: Four different types of systems; lakes, estuaries, streams and springs. Surface Area (ha and acre): LAKEWATCH lists the surface area of a lake if it is available. Mean Depth (m and ft): This mean depth is calculated from multiple depth finder transects across a lake that LAKEWATCH uses for estimating plant abundances. Period of Record (year): Years a lake has been in the LAKEWATCH program. TP Zone and TN Zone: Nutrient zones defined by Bachmann et al (2012). Long-Term TP and TN Mean Concentration (µg/L: min and max): Average of all annual means (µg/L) listed with minimum and maximum annual means. Lake Classification: The new numeric nutrient criteria for Florida require that lakes must first be classified into three group based on color and alkalinity or specific conductance; colored (color greater than 40 Pt-Co units), clear soft water lakes (color less than or equal to 40 Pt-Co units and alkalinity less than or equal to 20 mg/L as CaCO3 or specific conductance less the or equal to 100 µs/cm @25 C), and clear hard water lakes (color less than 40 Pt-Co units and alkalinity greater than 20 mg/L as CaCO3 or specific conductance greater 100 µS/cm @ 25 C). Lake Trophic Status (CHL): Tropic state classification using the long-term chlorophyll average concentration and the classification system from; Forsberg, C and S. R. Ryding. 1980. Eutrophication parameters and trophic state indices in 30 Swedish waste receiving lakes. Arch. Hydrobiol. 89:189-207).

126

Base File Data and Nutrient Zone Comparisons for Lakes

County Highlands Name Istokpoga Latitude 27.3428 Longitude -81.3073 Water Body Type Lake Surface Area (ha and acre) 12188 ha or 30116.54 acre Mean Depth (m and ft) 1.4 m or 4.6 ft Period of Record (year) 1996 to 2016 Lake Classification Colored Lake Lake Trophic Status (CHL) Hypereutrophic TP Zone TP5 Long-Term TP Mean Concentration (µg/L, minimum and maximum)

56 (34 to 74)

TN Zone TN5 Long-Term TN Mean Concentration (µg/L, minimum and maximum)

1382 (983 to 1634)

Figure 1. Maps showing Florida phosphorus and nitrogen zones and the nutrient concentrations of the upper 90% of lakes within each zone (Bachmann et al. 2012c).

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FDEP Nutrient Criteria Lakes For lakes, the applicable numeric interpretations of the narrative nutrient criterion in paragraph 62-302.530(47)(b), F.A.C., for chlorophyll a are shown in the table below. The applicable interpretations for TN and TP will vary on an annual basis, depending on the availability of chlorophyll a data and the concentrations of nutrients and chlorophyll a in the lake, as described below. The applicable numeric interpretations for TN, TP, and chlorophyll a shall not be exceeded more than once in any consecutive three-year period. If there are sufficient data to calculate the annual geometric mean chlorophyll a and the mean does not exceed the chlorophyll a value for the lake type in the table below, then the TN and TP numeric interpretations for that calendar year shall be the annual geometric means of lake TN and TP samples, subject to the minimum and maximum limits in the table below. However, for lakes with color > 40 PCU in the West Central Nutrient Watershed Region, the maximum TP limit shall be the 490 µg/L TP streams threshold for the region; or if there are insufficient data to calculate the annual geometric mean chlorophyll a for a given year or the annual geometric mean chlorophyll a exceeds the values in the table below for the lake type, then the applicable numeric interpretations for TN and TP shall be the minimum values in the table below. Long-Term Data Summary Lakes: Definitions The following long-term data are the primary trophic state parameters collected by LAKEWATCH volunteers and classification variables color and specific conductance (LAKEWATCH recently began analyzing samples quarterly for color and specific conductance): Total Phosphorus (µg/L): The nutrient most often limiting growth of plant/algae in Florida’s fresh and saltwater environments. Total Nitrogen (µg/L): Another nutrient needed for aquatic plant/algae growth but only limiting when nitrogen to phosphorus ratios are generally less than 10. Chlorophyll-uncorrected (µg/L): Chlorophyll concentrations are used to measure relative abundances of open water algal population. Secchi (ft), Secchi (m): Secchi measurements are estimates of water clarity (how far one can see into the water) and are listed with English and metric units. Color (Pt-Co Units): LAKEWATCH measures true color, which is the color of the water after particles have been filter out. Specific Conductance (µS/cm@25°C): Measurement of the ability of water to conduct electricity and can be used to estimate the amount of dissolve materials in water.

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Parameter Minimum and Maximum Annual Means

Mean of Annual Means (Sampling years)

Total Phosphorus (µg/L) 34 - 74 56 (19) Total Nitrogen (µg/L) 983 - 1634 1382 (19) Chlorophyll- uncorrected (µg/L) 22.7 - 62.4 41.9 (19) Secchi (ft) 1.8 - 4.4 2.5 (19) Secchi (m) 0.6 - 1.3 0.8 (19) Color (Pt-Co Units) 36 - 110 77 (14) Specific Conductance (µS/cm@25 C) 102 - 193 153 (8) Lake Classification Colored Lake

FDEP Numeric Nutrient Criteria

1 For lakes with color > 40 PCU in the West Central Nutrient Watershed Region, the maximum TP limit shall be the 490 µg/L TP streams threshold for the region. For the purpose of subparagraph 62-302.531(2)(b)1., F.A.C., color shall be assessed as true color and shall be free from turbidity. Lake color and alkalinity shall be the long-term geometric mean, based on a minimum of ten data points over at least three years with at least one data point in each year. If insufficient alkalinity data are available, long-term geometric mean specific conductance values shall be used, with a value of <100 µS/cm@25 C used to estimate the mg/L CaCO3 alkalinity concentration until such time that alkalinity data are available.

Long Term Geometric Mean Lake Color and Long-Term Geometric Mean Color, Alkalinity and Specific Conductance

Annual Geometric Mean Chlorophyll- corrected

Minimum calculated numeric interpretation

Maximum calculated numeric interpretation

Annual Geometric Mean Total Phosphorus

Annual Geometric Mean Total Nitrogen

Annual Geometric Mean Total Phosphorus

Annual Geometric Mean Total Nitrogen

> 40 Platinum Cobalt Units Colored Lakes

20 µg/L 50 µg/L 1270 µg/L 160 µg/L1 2230 µg/L

≤ 40 Platinum Cobalt Units and > 20 mg/L CaCO3 or >100 µS/cm@25 C Clear Hard Water Lakes

20 µg/L

30 µg/L

1050 µg/L

90 µg/L

1910 µg/L

≤ 40 Platinum Cobalt Units and ≤ 20 mg/L CaCO3 or < 100 µS/cm@25 C Clear Soft Water Lakes

6 µg/L

10 µg/L

51 µg/L

30 µg/L

930 µg/L

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Trend Analyses Lakes The following data are for linear regression statistics derived by plotting annual average total phosphorus, total nitrogen, chlorophyll, and Secchi data by year of data collection. Linear regression analysis is a common statistical approach used to determine if significant trends are occurring over time. These analyses define statistics based on the best fit line drawn through the data after plotting them with year on the horizontal line (x-axis) and the data value on the vertical line (y-axis). Figure 2 shows example plots with linear regression statistic of lakes that show significant total phosphorus increases, decreases and no change over time. The statistics that are listed include the following: Number of years (n): This is simply the number of years of data that were used to calculate annual means. Intercept (a): This is the value on the y-axis that the fitted line would cross if the x-axis where zero. Slope (b): This is the rate at which the fitted line increases (positive number) or decreases (negative number). Coefficient of determination (R2): This value is an indication of how much variance above and below the fitted line there is in the data. This value ranges from 0 to 1. A high value means a tight fit and a low value means a loose fit. Probability of Significance (p): For most statistical analyses a p-value of less than 0.05 means the statistic is significant and analyses with p-values greater than 0.05 are not significant.

Statistic Total Phosphorus

Total Nitrogen Chlorophyll Secchi

Number of Years (n) 19 19 19 19 Intercept (a) -896 -34821 -2023 133 Slope (b) 0.47 18.05 1.03 -0.06 Coefficient of Determination (R2)

0.08 0.46 0.36 0.39

Probability of Significance (p)

0.24 0.00 0.01 0.00

Potential Trend No Trend Increasing Increasing Decreasing

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LAKEWATCH Report for Istokpoga North in Highlands County Using Data Downloaded 10/17/2016 Introduction for Lakes In this report, we present summary data collected on individual systems that have been part of the LAKEWATCH program. This summary is from the whole period of record for individual systems. The first part of this summary will allow a comparison of the long-term mean nutrient concentrations with the nutrient zone concentrations published by LAKEWATCH staff (Bachmann et al. 2012; http://lakewatch.ifas.ufl.edu/publications.shtml). The second part of the summary will allow the comparison of data with Florida Department of Environmental Protections Numeric Nutrient Criteria. Finally, this report examines data for any long-term trends that may be occurring in individual systems but only for systems with five or more years of data. Base File Data: Definitions The long-term data summary will include the following parameters listed with a definition after each one: County: Name of county in which the lake resides. Name: Lake name that LAKEWATCH uses for the system. Latitude and Longitude: Coordinates identifying the exact location of station 1 for each system. Water Body Type: Four different types of systems; lakes, estuaries, streams and springs. Surface Area (ha and acre): LAKEWATCH lists the surface area of a lake if it is available. Mean Depth (m and ft): This mean depth is calculated from multiple depth finder transects across a lake that LAKEWATCH uses for estimating plant abundances. Period of Record (year): Years a lake has been in the LAKEWATCH program. TP Zone and TN Zone: Nutrient zones defined by Bachmann et al (2012). Long-Term TP and TN Mean Concentration (µg/L: min and max): Average of all annual means (µg/L) listed with minimum and maximum annual means. Lake Classification: The new numeric nutrient criteria for Florida require that lakes must first be classified into three group based on color and alkalinity or specific conductance; colored (color greater than 40 Pt-Co units), clear soft water lakes (color less than or equal to 40 Pt-Co units and alkalinity less than or equal to 20 mg/L as CaCO3 or specific conductance less the or equal to 100 µs/cm @25 C), and clear hard water lakes (color less than 40 Pt-Co units and alkalinity greater than 20 mg/L as CaCO3 or specific conductance greater 100 µS/cm @ 25 C). Lake Trophic Status (CHL): Tropic state classification using the long-term chlorophyll average concentration and the classification system from; Forsberg, C and S. R. Ryding. 1980. Eutrophication parameters and trophic state indices in 30 Swedish waste receiving lakes. Arch. Hydrobiol. 89:189-207).

131

Base File Data and Nutrient Zone Comparisons for Lakes

County Highlands Name Istokpoga North Latitude 27.401 Longitude -81.3332 Water Body Type Lake Surface Area (ha and acre) 12188 ha or 30116.54 acre Mean Depth (m and ft) m or ft Period of Record (year) 1996 to 2016 Lake Classification Colored Lake Lake Trophic Status (CHL) Hypereutrophic TP Zone TP5 Long-Term TP Mean Concentration (µg/L, minimum and maximum)

67 (53 to 91)

TN Zone TN5 Long-Term TN Mean Concentration (µg/L, minimum and maximum)

1347 (973 to 1614)

Figure1. Maps showing Florida phosphorus and nitrogen zones and the nutrient concentrations of the upper 90% of lakes within each zone (Bachmann et al. 2012c).

FDEP Nutrient Criteria Lakes For lakes, the applicable numeric interpretations of the narrative nutrient criterion in paragraph 62-302.530(47)(b), F.A.C., for chlorophyll a are shown in the table below. The applicable interpretations for TN and TP will vary on an annual basis, depending on the availability of chlorophyll a data and the concentrations of nutrients and chlorophyll a in the lake, as described below. The applicable numeric interpretations for TN, TP, and chlorophyll a shall not be exceeded more than once in any consecutive three-year period. If there are sufficient data to calculate the annual geometric mean chlorophyll a and the mean does not exceed the chlorophyll a value for the lake type in the table below, then the TN and TP numeric interpretations for that

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calendar year shall be the annual geometric means of lake TN and TP samples, subject to the minimum and maximum limits in the table below. However, for lakes with color > 40 PCU in the West Central Nutrient Watershed Region, the maximum TP limit shall be the 490 µg/L TP streams threshold for the region; or if there are insufficient data to calculate the annual geometric mean chlorophyll a for a given year or the annual geometric mean chlorophyll a exceeds the values in the table below for the lake type, then the applicable numeric interpretations for TN and TP shall be the minimum values in the table below. Long-Term Data Summary Lakes: Definitions The following long-term data are the primary trophic state parameters collected by LAKEWATCH volunteers and classification variables color and specific conductance (LAKEWATCH recently began analyzing samples quarterly for color and specific conductance): Total Phosphorus (µg/L): The nutrient most often limiting growth of plant/algae in Florida’s fresh and saltwater environments. Total Nitrogen (µg/L): Another nutrient needed for aquatic plant/algae growth but only limiting when nitrogen to phosphorus ratios are generally less than 10. Chlorophyll-uncorrected (µg/L): Chlorophyll concentrations are used to measure relative abundances of open water algal population. Secchi (ft), Secchi (m): Secchi measurements are estimates of water clarity (how far one can see into the water) and are listed with English and metric units. Color (Pt-Co Units): LAKEWATCH measures true color, which is the color of the water after particles have been filter out. Specific Conductance (µS/cm@25°C): Measurement of the ability of water to conduct electricity and can be used to estimate the amount of dissolve materials in water.

Parameter Minimum and Maximum Annual Means

Mean of Annual Means (Sampling years)

Total Phosphorus (µg/L) 53 - 91 67 (21) Total Nitrogen (µg/L) 973 - 1614 1347 (21) Chlorophyll- uncorrected (µg/L) 11.2 - 52.4 41.1 (21) Secchi (ft) 1.5 - 3.1 2.0 (21) Secchi (m) 0.4 - 0.9 0.6 (21) Color (Pt-Co Units) 46 - 165 94 (15) Specific Conductance (µS/cm@25 C) 109 - 197 162 (9) Lake Classification Colored Lake

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FDEP Numeric Nutrient Criteria

1 For lakes with color > 40 PCU in the West Central Nutrient Watershed Region, the maximum TP limit shall be the 490 µg/L TP streams threshold for the region. For the purpose of subparagraph 62-302.531(2)(b)1., F.A.C., color shall be assessed as true color and shall be free from turbidity. Lake color and alkalinity shall be the long-term geometric mean, based on a minimum of ten data points over at least three years with at least one data point in each year. If insufficient alkalinity data are available, long-term geometric mean specific conductance values shall be used, with a value of <100 µS/cm@25 C used to estimate the mg/L CaCO3 alkalinity concentration until such time that alkalinity data are available. Trend Analyses Lakes The following data are for linear regression statistics derived by plotting annual average total phosphorus, total nitrogen, chlorophyll, and Secchi data by year of data collection. Linear regression analysis is a common statistical approach used to determine if significant trends are occurring over time. These analyses define statistics based on the best fit line drawn through the data after plotting them with year on the horizontal line (x-axis) and the data value on the vertical line (y-axis). Figure 2 shows example plots with linear regression statistic of lakes that show significant total phosphorus increases, decreases and no change over time. The statistics that are listed include the following: Number of years (n): This is simply the number of years of data that were used to calculate annual means. Intercept (a): This is the value on the y-axis that the fitted line would cross if the x-axis where zero. Slope (b): This is the rate at which the fitted line increases (positive number) or decreases (negative number).

Long Term Geometric Mean Lake Color and Long-Term Geometric Mean Color, Alkalinity and Specific Conductance

Annual Geometric Mean Chlorophyll- corrected

Minimum calculated numeric interpretation

Maximum calculated numeric interpretation

Annual Geometric Mean Total Phosphorus

Annual Geometric Mean Total Nitrogen

Annual Geometric Mean Total Phosphorus

Annual Geometric Mean Total Nitrogen

> 40 Platinum Cobalt Units Colored Lakes

20 µg/L 50 µg/L 1270 µg/L 160 µg/L1 2230 µg/L

≤ 40 Platinum Cobalt Units and > 20 mg/L CaCO3 or >100 µS/cm@25 C Clear Hard Water Lakes

20 µg/L

30 µg/L

1050 µg/L

90 µg/L

1910 µg/L

≤ 40 Platinum Cobalt Units and ≤ 20 mg/L CaCO3 or < 100 µS/cm@25 C Clear Soft Water Lakes

6 µg/L

10 µg/L

51 µg/L

30 µg/L

930 µg/L

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Coefficient of determination (R2): This value is an indication of how much variance above and below the fitted line there is in the data. This value ranges from 0 to 1. A high value means a tight fit and a low value means a loose fit. Probability of Significance (p): For most statistical analyses a p-value of less than 0.05 means the statistic is significant and analyses with p-values greater than 0.05 are not significant.

Statistic Total Phosphorus

Total Nitrogen Chlorophyll Secchi

Number of Years (n) 21 21 21 21 Intercept (a) 1010 -28285 -1101 42 Slope (b) -0.47 14.77 0.57 -0.02 Coefficient of Determination (R2)

0.08 0.35 0.13 0.06

Probability of Significance (p)

0.22 0.00 0.11 0.28

Potential Trend No Trend Increasing No Trend No Trend

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Appendix IV: Situation Assessment and First Public Meeting Report

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Report: Identification of Stakeholder Groups and Stakeholder Desires and Concerns May 22, 2018

Introduction Lake Istokpoga, Florida’s fifth largest lake at 27,692 acres, is highly productive in terms of both plant and animal life. Many different stakeholders use and rely on Lake Istokpoga, including anglers, hunters, recreational boaters, birdwatchers and general wildlife observers, fishing, hunting and wildlife watching-related businesses, the local hospitality industry, local residents, and a variety of civil society organizations. Many of the uses of the lake and the conservation of its biological resources rely on active management of its habitats, particularly with respect to aquatic vegetation. This task, however, is complex due to the dynamic, ever-changing ecology of the lake, the diversity of stakeholders, and their often conflicting preferences for lake habitat characteristics and management actions. In order to promote effective, strategic habitat management for Lake Istokpoga and reduce stakeholder conflict, the Florida Fish and Wildlife Conservation Commission (FWC) has contracted the University of Florida (UF) to engage stakeholders in the development of a Lake Istokpoga Habitat Management Plan. The current document sets out the results of an initial situation assessment to identify stakeholder groups associated with the lake and their desires and concerns with regard to lake management. Approach

As outlined in the Stakeholder Engagement Plan, the project has started with a broad-based situation analysis conducted to set the scene for project activities. As part of this analysis, a variety of methods were employed to identify stakeholder groups and their desires and concerns with regard to lake management.

To begin, an interview guide was developed consisting of a series of open-ended questions aimed at identifying the components in the situation analysis (Table 1) as well as gauging stakeholder knowledge, attitudes, interests, and experiences surrounding the lake and its management. The guide incorporated ideas from the Reasonable Person Model, appropriate public participation, social learning, and actor-linkage matrices (Box 1).

Table 1. Situation Assessment Stakeholder Position Interest Power How to Engage History/

Relationship Who are the interested parties? a) Those who can impact the decision, b) Those who will be impacted by the decision, and c) Those with special expertise or experience related to the issue.

Stakeholders’ preferred answers; what is important to them.

Why those answers are important to them?

1. Substantive 2. Procedural 3. Psychological

How much power do they have to influence the situation? Where does power derive from?

How might the issue(s) be framed or reframed for them? Who should be messenger? How should message be delivered?

How long has this been an issue? How did it arise? What relationships exist between key stakeholders? Between you (or your organization) and key stakeholders

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Box 1. Theories used to create the interview guide.

Three stakeholders were engaged in person in pilot testing the interview instrument on January 17. Pilot testers included a representative of the Friends of Istokpoga group as well as a bass and a crappie fisher; all were also lakeside homeowners. Pilot interviewees were identified with assistance of FWC and Florida Lakewatch. An additional two lakeside homeowners gave feedback on the interview questions but were not formally interviewed. Based on the results and feedback from the pilot interviews, the interview questionnaire was retooled slightly to alter the flow of the questions. The final interview guide is appended to this report.

Interview respondents were obtained using a combination of snowball sampling and opportunistic sampling. Initial interviewees were identified by FWC; in addition, pilot interviewees were asked to recommend other individuals for interviews. Each respondent was then also asked to recommend additional interviewees. Opportunistic sampling was used simultaneously by asking for volunteers at a Friends of Istokpoga meeting. Interviews were conducted in person. When possible, interviews were recorded. However, in some cases this was not logistically possible; in those instances interview responses were recorded on paper. Responses were then coded and grouped according to theme. In addition to conducting interviews, the UF team also attended meetings to introduce themselves and to gauge levels of engagement, interests, values, and perceptions of lake habitat. A UF team member attended 2 LIMC meetings, 1 FOI meeting, and 4 FWC meetings at fish camps. Attendance at these meetings allowed the UF team to introduce themselves and the project to those who were already engaged, involved, and/or highly interested in Lake Istokpoga habitat management. Finally, a public meeting was held in March to introduce the engagement plan and habitat management plan process to stakeholders. The meeting was widely advertised and open to the public, and was held in March to

•Collaborative management efforts should provide “supportive environments” for participation in decision-making, which is accomplished by creating shared mental models/understanding, ensuring people feel supported and effective in applying those mental models, and providing opportunities for them to feel they can act and contribute in a meaningful way (e.g., see links between their participation and outcomes). (Kaplan and Kaplan 2003, Monroe et al. 2014)

Reasonable Person Model

•Successful public engagement looks different to different people, but consistent across groups are the ideas that appropriate stakeholder engagement should: reach out to all stakeholders, share information open and readily, engage people in meaningful interaction, and attempt to satisfy multiple positions (Webler and Tuler 2006).

Appropriate Public

Participation

•Social learning is an important component of successful collaboration. Identifying whether individuals understand each others' perspectives and have opportunities to interact with others (and therefore to learn from them) is one important component of social learning. (Schusler et al. 2003)

Social Learning

•Identifying the actors in the system and their relationships in a simplified table/matrix as a way to investigate stakeholder relationships (Reed et al. 2008).

Actor-Linkage Matrices

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ensure that seasonal residents could be present. The meeting included presentations from the UF team on the habitat management plan and lake history, followed by a question and answer session; participants were then asked to identify their top three issues/concerns about Lake Istokpoga. The full meeting report is appended to this report. In addition, evaluations were distributed to assess attendance, how people felt the meeting went, and to obtain baseline information on participants’ levels of trust, knowledge, and attitudes toward lake management as well as the level of interaction among stakeholders of varying viewpoints (as an indicator of the level of opportunity for social learning across stakeholder groups).

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Results I. Interviews In total, 23 Lake Istokpoga stakeholders participated in interviews (Table 2). Interviews are still ongoing, and there are plans in place to interview at least one duck hunter and one agriculture stakeholder in the near future. In addition, a separate series of interviews is ongoing with members of the FWC Lake Istokpoga working group and with other FWC administrators; 10 have been conducted to date, though these results are not included in this report. Table 2. Interview respondent codes, gender, and stakeholder group(s).

Stakeholder groups identified: A number of stakeholder groups were identified by interview respondents. These include duck hunters; fishermen (bass anglers, bass tournament fishers, bass tournament organizers, crappie anglers, retiree fishers, and shiner fishers), gator hunters, gator egg collectors, froggers, birders, airboaters, ranchers, members of the professional environmental community, lakeside residents, people associated with the Calladium fields, people that are part of the Spring Lake Improvement District, county commissioners, Highlands Parks and Natural Resources, FWC, USFWS, ACOE, general business owners, people who travel to the lake to use it, FOI, Audubon, members of the Lakeside Estates Homeowners Association, boaters, and horseback ecotours. Lake vision: Different overall visions of what the lake is and what it should be managed to be were discussed by interview participants. Some viewed the lake primarily as a fishing lake, and not for example a general recreational lake. Others viewed it as an ecosystem and wanted to protect and enhance its natural values. Still others pointed out that you can’t conjure up your own vision for the lake as it is always changing. Repeatedly mentioned was the desire to have a viable lake now and for generations to come. What they like about the lake:

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There are many things people like about Lake Istokpoga. The lake was lake described as a natural paradise, a serene environment where one can see mother nature at work. The beautiful sunsets came up repeatedly, as well as the general beauty of the lake. In addition, many talked about how much they enjoy fishing on the lake. Changes they have seen: People discussed many changes they had seen or heard of on the lake, though how much change they had seen themselves partly depended on how long they had been on the lake. It was noted that historically the lake used to free flow (before the dam was put in). Changes in lake vegetation, specifically the loss of hydrilla, loss of marsh habitat, and the impression that some to all of the underwater vegetation is gone were cited and an increase in muck was identified. Respondents also indicated that the fish are harder to catch now that there is no hydrilla, though they felt that access was worse in the peak hydrilla period-some noted that the lake was impassible, that their motors burned up. The impression that ducks have left the lake and that the frogs and apple snail eggs are gone and that bird populations in general have declined was noted by some respondents. Some also felt that the lake was really good after the drawdown. There was also an impression that new areas are open that were never open before due to current spraying. What is causing changes: Natural impacts such as droughts, floods, and hurricanes were cited as major factors causing change on the lake, as well as the historical damming of the lake and the drawdown and scraping. Aquatic plant management was also cited as a factor, with one respondent stating that the “biggest changes are caused by aquatic plant management”. Spraying was thought to influence both the loss of vegetation (desired and undesired) and the increase of muck. Also discussed was the influx of nutrients from Arbuckle Creek causing algae blooms and dark water, which is shading out plants (both hydrilla and native plants). Concerns on the lake: Spraying: Many had concerns about spraying or its perceived impacts, with some who didn’t like spraying at all, some who understood there needs to be spraying but believed it had gone too far, and some who felt that though they didn’t like it they understood why management had to do it. One respondent asked: “Is it safe to eat the fish with all the chemicals in the water now?” Some had experienced a decline in fishing after spraying (“When they spray out here to kill the weeds in this canal the fish here won’t bite”). Other concerns included: Believed to have eradicated desired species such as eelgrass and pepper grass; Sprayers get yards half the time; Spraying continues in high winds; Lakeside residents with expensive homes have to pay for the spraying themselves; Daily presence of spray boats; Misunderstandings about what they are spraying, targeted vs. blanket and “spraying” high into the air in the middle of the lake (might just be flushing the tanks out but looks like spraying in excess); Concerns about goals of spraying, contractor’s actions and lack of oversight of contractors (spraying not coordinated). Fishing: Perception that it is harder to catch fish, in particular bass (for some people who relied on fishing hydrilla) and crappie, and that trophy fish are disappearing. Concerns about tournaments and where they are releasing fish as well as the high number of tournaments were raised. Others cited concerns about tournament numbers declining (overall, in # of fishers and in catch), and concerns about lack of bait fish, especially shiners. Management: The impression that management preferentially focuses on Lake Okeechobee and ignores Lake Istokpoga was mentioned, as well as the impression that “the lake is impacted enough by nutrients and water levels, and managers are beating up on what is left” and that the Lake is over-managed. The perception that management makes decisions with no research to back them up was cited. With regard to the process, the perception that there is too much talking and not enough action and no coordination between agencies , with a

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lack of an overall plan, were cited, as well as the impression that management does whatever it wants, even after listening to stakeholders. Ducks: Concerns about the perceived decline in duck populations were raised by respondents. LE: Concerns that there is not enough law enforcement coverage on the lake. Muck: Muck buildup after spraying and its aesthetic impacts as well as questions about its potential impacts on fish (e.g., can bass spawn in muck?) were additional concerns. The impression that it stinks in the summer when water levels are low and that their canal is full of muck were mentioned, as well as the impression that though we need to be able to flush muck, we can’t now that lake levels are stabilized. Snowbirds: Some were concerned about the influx of seasonal residents and the impression that they are overfishing crappie, with the intention to take them all back up north. Some cited the impression that people were taking more than their limit of crappie on the lake. However, another respondent noted that many were functionally subsistence fishing and needed the crappie to take back home as a source of meat throughout the year. Water levels: Water levels in the lake and their impact on fish were another concern, as well as access during drawdowns from their canal and the perception that water levels are impairing lake. Nutrients: Fertilizer use by other lakeside residents and associated yard nutrient runoff was a concern, as well as the flow of nutrients into the Lake from Arbuckle creek. There was the perception of a resulting decline in water quality, with dark water and algae blooms. Calladium farm dust clouds were another concern cited by southern lakeside homeowners in particular. Airboats: Some were concerned about the noise caused by the high number of airboats out on the lake at night near their home. Ecosystem: Concerns about how are we impacting habitat and what is the natural system of the lake were raised, as well as the worry that biodiversity is threatened by how we are managing the lake. Concerns about birds and animal life as well as a worry that habitat fragmentation was negatively impacting animal populations were also raised. Spoil islands: There were conflicting views surrounding the spoil islands. Some viewed them negatively, for example as a permanent harm created for a short term good and saying that they should be bulldozed back down. However, others felt that doing that would just return all the muck back into the lake and undo the good that had been done by creating the islands. Vegetation/habitat: Loss of marsh and the recent spraying of marsh habitat were of concern, and the desire to find out what was negatively impacting the plants was raised. Some were worried that there were no weeds for the bass, with some particularly concerned about lack of eelgrass and pepper grass. The impression that the lake is mismanaged as far as aquatic vegetation goes was also mentioned. Construction: Concerns about new construction coming to the north end of the Lake and that it will lead to increases in water demand. This process: Another concern was regarding this process, in particular the need to ensure that all views are identified (“don’t confuse special interests with stakeholders, a lot of people won’t be part of this interview process”).

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What is your ideal lake: People cited different things when asked what their ideal lake would look like. Some wanted clean, clear water, and a lake with better nutrient levels (e.g., low P, normal N). Others had varying ideals regarding hydrilla (get rid of all of it---have it in some areas). For some, an ideal lake would have natural water level fluctuation; for others, it would not get drawn down as far to ensure that their access could be retained through their canals. Some cited a natural lake as ideal, with historic white sand beaches, “a trillion cypress trees”, as much natural and native vegetation as possible (and then whatever fishing comes with that), that is some version of what it used to be, or a lake with concentric bands of vegetation and good emergent marsh or a balance of submersed and emergent aquatic vegetation. One wanted the lake to look like it did back in 2013, while others wanted their fishing to return. A lake that is clear of plants for Spring Lake residents or where lakeside homeowners could have clear views and year round access were also cited as ideal. One respondents described three positions people held with regard to how the lake should be:

- Fishing-focused: want a good healthy hydrilla supply, other invasive exotics, because they want to catch fish (bass tournaments, need fish today, fish for food, can’t worry about 10 years from now need fish today puts money in pocket)

- Nature-focused: want an all native lake, nothing but native plants, the way nature intended it (sportsmen, fly fishing, fishing as a sport not a source of meat)

- Anti-spraying: prioritize no spraying, want no chemicals in water Ideal management/process: Respondents were also asked what a successful management process would look like to them. One wanted a process that incorporated the LIMC. Others wanted to have a real conversation about how much ecology/human use/public perception should drive the plan; improved communication (with all stakeholders) was frequently cited, as well as improved communication between management entities and contractors and ensuring that all stakeholders are enabled to provide input (for example: listen to stakeholders who spend lots of time on the lake versus relying solely on those with degrees). Respondents wanted management to provide detailed information on the amount of chemicals used in the lake. Some talked about wanting a written and defined plan with an idea of what the lake should be and how we are trying to get there, that is adaptive and is reviewed and evaluated at least annually, and that is able to react quickly to environmental changes, with monitoring to ensure that goals are reached. A faster process was also cited, as well as ensuring that a plan is not just a document for show but is actually turned into action. Some wanted management to spend more time working with communities north of the lake and to fix what is coming down into the lake. Minimal chemical application, enforcing bag limits, and moderation and reasonability in vegetation management (we are “not asking for the moon”) were also cited, as well as a process that finds out why “nothing can grow in the lake”. One stated that management needs to put in a best management practice that will keep the lake viable as long as possible (regardless of its impact on local businesses). Sources of information: LIMC, word of mouth, FOI, FWC meetings, newspaper articles. Many don’t understand management/decision making process, and there is the impression that lots of rumors go around. Management activities they would like to see changed include: Truly incorporate input from the LIMC; gather input earlier on in the process, before decisions are made; consider nutrient inputs from the North of the lake; reduce the frequency of airboats spraying; drawdown and clear out the muck; have a greater water level fluctuation; have a plan; have a more open relationship between stakeholders and managers, more cooperation; better communication; don’t spray during spawning season/snowbird season; better consideration of desired and undesired plants and location of these plants

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Participation in the process: Many did not perceive that they could meaningfully participate in the management decision-making process. There was the impression that decisions are already decided ahead of time (“I think they are probably gonna do what they are gonna do no matter what”), with management giving “lip service to public input but do what they want”. The impression that management thinks they know more than anyone else and has meetings and listen but then go do what they want, with no connection between FWC listening and what happens, was also cited, and the impression that FWC’s response to concerns is “yeah yeah you just don’t understand”. Also the impression that FWC doesn’t follow the LIMC recs closely at all. One respondent noted the impression that past bad interactions have made FWC reluctant to engage people; another shared the impression that FWC overrides people’s long term local knowledge because they can cite scientific data. One stated that he was burned out from trying to engage and felt like he was being ignored and so had stopped going to meetings. Another cited the impression that, though minds are made up before meetings, sometimes the FWC has to do that because they know more than the average member of the public. Interactions across groups: Some respondents shared the impression that different stakeholder groups don’t interact all that much, while others shared impressions of or experiences with conflict between: fishermen and duck hunters, FOI and sportsmen (impression that they have little common interests), naturalists and lakeside homeowners, fishermen and lakeside homeowners, homeowners who do and don’t fertilize their lawns, and the public and management (“not easy to get along with management”). There was also an impression that “everyone is mad at duck hunters” and that FWC doesn’t like the duck hunters. There were varying degrees with which nongovernmental stakeholders had interacted with management, ranging from those who were highly engaged and had interacted with varying agencies to those who felt they never really interacted with managers or management (“I am not involved in that so I don’t really know much about the management end of it other than the guy who runs around on the lake checking us”). There was also the impression that “everyone has their own idea of what they want” and so are in conflict, as well as the impression that all groups want the lake to have a positive impact on the area and to be successful and just differ in their definitions of what a successful lake looks like. Power: Who was perceived to have greater influence on management varied across respondents. Overall, fishermen and duck hunters were most frequently cited, with the perception that those are the most vocal groups. Respondents shared the perceptions that duck hunters have a lot of power and are well-organized, that FWC gives duck hunters special treatment, that when DU speaks “people jump”, and that duck hunters have great political clout. Bass fishermen were perceived by some to be powerful, with the impression that tournaments and fish camps are “big business” in the area and that fishing drives how the habitat is managed. Others felt that FOI had a lot of influence on management, and that birders could due to being well-organized but “don’t exercise their influence very often”. FWC, the Highlands County Lake Manager, and the County Commissioners were also cited as highly influential. One respondent shared the concern that management responds too strongly to special interest groups, who wield a lot of influence. When asked if anyone was left out, some felt that LIMC had good coverage and so no one was left out right now. Others shared that bird watchers and lakeside homeowners (and in particular Spring Lake residents) are left out of the process. Frequently shared was the impression that the general community is left out (“most of the public has a vague understanding”, “regular homeowners don’t want to engage don’t know much about lake management and are happy to trust FWC and the state to do what is best”). In addition, some felt that fishermen are left out, and are not as well-organized and aren’t represented on the LIMC. In addition, the view that Spring Lake in general is left out by FWC was shared.

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Optimism: There was a range in optimism with regards to the future of the lake. Some felt that the lake is on the right path and were very optimistic. Others were less optimistic, sharing the views that: the lake is in a slow decline and dying, they will be dead before the lake returns to what it used to be, the only chance is that mother nature defeats the reactive planning of the FWC, they have no optimism whatsoever that FWC is going to help them, pessimistic that education won’t be able to get people to understand what is really happening and why. One respondent was also under the impression that management isn’t optimistic either. Other perceptions of management: During the course of the interviews, other perceptions of and experiences with management were shared, for example the sentiment that fishermen don’t trust management. In addition, there was the impression that management does not have a plan but runs “by the seat of their pants”, with nothing written down and no clear defined goals that could be used to evaluate and monitor management actions. There was also the impression that groups within FWC don’t work together and are in conflict with each other. In addition, there was the perception that there is no coordination across spraying entities and that no one knows who is spraying and when, as well as a lack of coordination between those who are in charge and those who are actually doing the spraying. There was concern that management does not talk about fishing trends over time, and that management does not communicate at a level that people can understand (“too sciencey, don’t bring it down to our level so they can get buy in”), and one individual expressed frustration about the participatory process and shared a preference for action over consensus. Respondents also shared that FWC has improved their communication, saying that they are doing a good job of communicating when “bigger stuff” is going to happen and holding public information meetings. Also shared was the impression that management is doing a good job helping birds on the islands. One respondent felt that FWC was “doing the best they can with what they have”, and another shared that some areas have improved after spraying, with a return of native plants and good fishing now. II. Meetings A UF team member attended 2 LIMC meetings, 1 FOI meeting, and 4 FWC meetings at fish camps. In total, approximately 160 stakeholders were observed and/or engaged by the UF team member. Attendance at these meetings allowed the project team to introduce themselves, to meet with those who were already engaged, and to observe the meetings. III. Public Meeting Full results of the public meeting are attached in the appendix to this report. In total, 73 stakeholders attended the meeting, and 39 completed and returned an evaluation at the end of the meeting. Evaluations showed participants included members of all stakeholder groups (with the exception of “other hunter”)(Table 3). Participants were mostly male, with a mean age of 68. A number of issues and concerns were identified by workshop participants. Full responses are included in the appended report. Broadly, issues included concerns about aquatic plant management (including concerns about spraying and about marsh and hydrilla levels), fish and wildlife (e.g., declines in fish and duck populations), muck on the lake bottom, water quality in the lake, interactions with management (e.g., better communication and the perception that fishermen aren’t listened to), access, aesthetics (e.g. beauty), economics (maintaining property values), and water levels.

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Overall, participants rated the meeting well on average (Table 4). 32 respondents said they would attend future meetings of this type, with 7 selecting “maybe” (and none selecting “no”). Respondents on average felt they understood the current status of aquatic habitat in the lake relatively well, but understood the process by which management decisions are made less well (Table 5). Respondents on average scored low with regard to their perceived ability to influence management decisions, their satisfaction with management, and the level of trust they have for agency personnel managing the lake. Respondents were in the middle with regard to how often they interact with people whose ideas are different from their own, how well they feel they understand perspectives that are different from their own, and how well they feel able to discuss lake management with people whose ideas are different from their own. Table 3. Workshop participant demographics (self-identified stakeholder group(s), gender, and zip code).

Table 4. Mean responses to workshop evaluation questions (response scale 1-4). Mean

How well: Informed participants about the habitat management plan engagement process 3.00 How well: Gathered input from participants 3.31 I was able to communicate my ideas 3.00 Others heard my ideas 3.05 I heard the ideas of others 3.20 To what extent did you find today's meeting useful 3.72 How would you rate the meeting overall 3.67

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Table 5. Mean responses (response scales 1-5). Mean

How well do you understand the current status of aquatic habitat in the lake 3.92 How well do you understand the process by which management decisions are made for the lake? 2.79 To what extent do you feel able to influence management decisions for Lake Istokpoga? 2.28 How satisfied are you with management of Lake Istokpoga's aquatic plants/habitat? 1.79 How much trust do you have for the agency personnel managing the lake? 2.23 How often do you interact with people whose ideas about lake management are different from your own? 3.18 How well do you feel you understand perspectives about lake management that are different from your own? 3.11 How well do you feel able to discuss lake management with people whose ideas are different from your own? 3.59

Synthesis A number of different stakeholder groups were identified through this process. In addition, a number of different concerns and perspectives with regard to habitat in the lake were shared. To summarize a few main points:

- Different views of ideal lake across stakeholders o Some focused on water quality/clarity o Others were fishing-centered o Varying ideals with regard to aquatic plants

- Many stakeholders are concerned about water quality, fish populations, lake water levels, and lake habitat

o Different thoughts about lake habitat related to how they think about the lake (e.g., fishing, boating, ecosystem)

- Concern about spraying was strong (but not universal) - Concerns about management were frequently cited

o Lack of trust o Public does not feel able to influence management decisions o Confusion about why management takes certain actions or makes certain decisions o Perception that management is not coordinated, unclear who is responsible for what on the lake o Concern about who has influence where (though perceptions of who has the most/least influence

is not universal)

The process also made clear that this is a passionate, engaged community. There is a lot that people like about the lake, and a lot of people feel very strongly connected to the lake. Many people view the lake as their place, regardless of whether they are long term residents or people who visit seasonally. Though there does appear to be some conflict across different stakeholder groups, all share a passion for the lake, a concern for its continued viability, and a desire to see it continue as a successful lake. References

Kaplan, S. and R. Kaplan. 2003. Health, supportive environments, and the reasonable person model. American Journal of Public Health 93:1484-1489.

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Monroe, M. 2015. Working toward resolutions in resource management. Pages 239-259 in Kaplan, R. and A. Basu. 2015. Fostering Reasonableness: supportive environments for bringing out our best. Maize Books, Michigan Publishing, United States:412 pp.

Reed, M.S., A. Graves. N. Dandy, H. Posthumus, K. Hubacek, J. Morris, C. Prell, C.H. Quinn, and L.C. Stringer. 2008. Who’s in and why? A typology of stakeholder analysis methods for natural resource management. Journal of Environmental Management 90: 1933-1949. Schusler, T.M., D.J. Decker, and M.J. Pfeffer. 2003. Social learning for collaborative natural resource management. Society and Natural Resources 16(4): 309-326. Webler, T. and S. Tuler. 2006. Four perspectives on public participation process in environmental assessment and decision-making: combined results from 10 case studies. The Policy Studies Journal 34(4): 699-722.

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Appendix IV-A: Interview Guide Consent form for interviews Informed Consent: Please read this consent page carefully before you decide to participate in this interview.

Purpose of this interview: The purpose of these interviews is to learn from your experiences in Lake Istokpoga.

Time required: 30-60 minutes

Risks and benefits: There is no risk to you from participating in this study. There is no direct benefit to you in participating in this interview, other than the opportunity to make your experiences and views known to researchers and management agencies.

Compensation: There is no compensation for participating in this study.

Confidentiality: Your identity will be kept confidential to the extent provided by law. Your information will be assigned a code number. Your name will not be used in any report.

Voluntary participation: Your participation in this study is completely voluntary. There is no penalty for not participating, and you may withdraw your consent to participate at any time without penalty.

Whom to contact if you have questions about this project:Chelsey Crandall, Ph.D., School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32653, Phone: (813) 690-2334 E-mail: [email protected]

OR

Kai Lorenzen, Fisheries and Aquatic Sciences Program, University of Florida, 7922 NW 71st Street, Gainesville, FL 32653, E-mail: [email protected]

Whom to contact about your rights as a research participant in this study:IRB2 Office, Box 112250, University of Florida, Gainesville, FL 32611-2250, Phone: (352) 392-0433.

WOULD YOU LIKE TO PARTICIPATE IN THIS STUDY? ARE YOU 18 YEARS OLD OR OLDER? IF YES: Thank you! We’ll continue on to the interview. IF NO: Thank you for your time!

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Interview Instrument Opener (I.D. Positions, interests, knowledge of change and causes, concerns) (Talk about your experiences on the lake) What do you like most about Lake Istokpoga? How do you use the lake? How long have you lived/visited/fished/duck hunted/boated on Lake Istokpoga? What changes have you seen to the lake in that time? What do you think has caused these changes? What concerns would you like to see addressed on the Lake? How would you like to see those changes come about? What does your ideal lake look like? Prompts: vegetation (floating, submersed, emergent), water clarity, water level, access Possible prompts: What would an unacceptable lake look like to you? Anything in between? Range you feel is acceptable? How do you feel about the lake right now?

Are you happy with the current vegetation/water clarity/etc.? What is your source of information about the lake/Where do you go to find out about what is going on in the lake? Are there any management actions or activities that you would like to see changed? Views on Management and Engagement (Talk about your experiences with management) How well do you feel you understand the management process? Do you feel you understand how decisions are made for the lake? How would you interact if you had an issue? What agencies or informal groups are you aware of that are involved in managing the lake? Have you been involved in decision-making around the lake? How? (If yes) how successful did you feel when you engaged? Did you feel able to influence the management decisions? (expand prompts) How much control do you feel you have over management decisions? In general, how much do you think management incorporates public input into their decisions? Identifying Stakeholders/Positions/Interests (Fill out table)

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Table Q1: In your experience, what are the different groups who care about Lake Istokpoga? Table Q2: How do they use the lake? Table Q3: What are the most important issues for each group? Table Q4: How have you interacted with each group? Prompt: describe the interactions you have had Prompt: were they negative/positive? Looking at the groups identified: Table Q5: which groups are involved/influence/have a role in decision-making for management? Table Q6: do any of them have stronger influence on management decisions? Who? Why do you think that is? Table Q7: Are any of them left out of the decision-making process? Who? Why do you think that is? Table Q8: are there any who shouldn’t be involved in decision-making? Who? Why? Closing Are there any objectives common to all groups? What do you think everyone wants? What would a successful management process look like to you?

How would you prefer to be engaged? How optimistic do you feel about the future of the lake and lake management?

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Group Lake

Use Most Important Issues

Past Interactions

Management Role

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Appendix IV-B: Public Meeting Agenda

Lake Istokpoga Public Meeting Process Agenda March 21 2018

Facilitators: Joy Hazell and Chelsey Crandall

5:30 Registration and Reception Activity: sign in and place star sticker on map location 6:00 Welcome and Introduction 6:30 Presentations and Q&A Habitat Management Plan and Engagement Process (Chelsey Crandall) Istokpoga Lake History (Mark Hoyer) 7:30 Activity to gather input Activity: write top three concerns/issues on separate sticky notes and place on wall 7:50 Wrap up and Next Steps 8:00 Adjourn Futher informal discussion

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Summary

On Thursday, March 22, 2018 the University of Florida convened a Lake Istokpoga Public Meeting in Sarasota, FL. Project principal investigator Kai Lorenzen, limnologist Mark Hoyer, research scientist Chelsey Crandall, and lead facilitator Joy Hazell designed the meeting. The public was invited through a press release, direct contact with interview subjects, and distribution of a meeting flyer.

Approximately 75 people attended the meeting including members of the public, Florida Fish and Wildlife Conservation commission staff, and county staff and elected officials. The meeting was facilitated by Joy Hazell. The meeting objectives were to:

• Inform Lake Istokpoga supporters on the development of the management plan and the stakeholder engagement plan process

• Open communication building community and trust • Gather input on the engagement plan

Before entering, meeting attendees were asked to place a star on a map of Lake Istokpoga to indicate the place that is most important to them. The meeting began with 30 minutes of activities designed to set a positive collaborative tone for the rest of the meeting. Activities included introductions, an explanation and clarification of the meeting agenda and objectives, and participant generated ground rules for the meeting (Appendix IV-A). Participants were asked to identify their category as stakeholder through a show of hands as an icebreaker.

Dr. Chelsey Crandall gave a presentation summarizing the Lake Istokpoga Stakeholder Engagement project activities and objectives. Project activities include in depth exploratory interviews and an internet based and/or mail survey of stakeholder perceptions of and experiences with Lake Istokpoga. Project objectives are to Identify stakeholder groups’ interests, values, knowledge base and preferred methods of engagement; reach a shared understanding about habitat and habitat management in Lake Istokpoga; and create a habitat management plan where stakeholders have ownership. Mark Hoyer then gave a presentation on the history of Lake Istokpoga. The presentation overviewed changes in lake hydrology, water quality, and habitat trends.

During the presentations, participants were asked to write questions or thoughts on index cards which the presenters would answer at then end of the presentations. Due to time constraints not all questions were answered but each one is listed below and will be addressed in the near future.

(Facilitator Joy Hazel introducing the meeting and presenter Mark Hoyer talking about the history of Lake Istokpoga)

Lake Istokpoga Public Meeting Bert J. Harris Jr. Agricultural Center Auditorium 4509 George Blvd; Sebring, Florida 33875 March 22, 2018

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Questions or comments written on index cards (all questions and comments are verbatim, including emphasis): • What are your measurables going to be? • FWC has been very inflexible and unwilling to compromise. How can we be sure this is going to

change? • Can less spraying be adopted in the interim while the study takes place? • How about stocking (Bass etc.)? Fishermen would be willing to help fund. • Is boating an issue? I hope you are not planning to make Istokpoga a water ski lake. • Hurricanes did not cause 4 feet of dead vegetation underwater on all three sides of my dock or sea wall,

did it? No exaggeration, 4 foot, 2008 when I bought property there was white sand • 20 years ago water management drew the lake down and cleaned the bottom for spawning fish and

created islands, what changed that program: possible dead vegetation from excessive spraying? • What happened to the SOS management group from past years? • As of year 2012-2013 the long-term plan for Istokpoga was trophy bass lake. How many 12 lb+ have

been recorded since 2012? • Is there any testing of muck on bottom of lake to see if any chemicals deter growth of submersed weeds? • It’s not fun to fish on the lake anymore. • Muck build up is horrible – tough to navigate. • Midge – blind mosquito outbreaks becoming longer and more severe. • Number and quality of bass is shameful! • Cannot understand spraying schedules, where, when, why? • Bass stocking plan needed. • Ok, so there is a plan developed, who is the do’er – i.e. who does the implementation of the plan? • Why isn’t wildlife management making strategic decisions regarding wildlife conservation instead of

ignorant bureaucrats? – For example a decision was made in the past to spray herbicides during spawning season! Idiotic!

• What is the state purpose of the spraying problem? • What makes a good lake? • Are tributaries monitored for pollution sources? • What did the Orange Lake plan at this time result in? • What are the bubbles coming up from the bottom of the lake when you stop your motor? Could be

methane from decaying vegetation. Do fish thrive with methane or oxygen? • Do fish spawn in muck? • Do live plants add oxygen to water? “fry cover” “fish food” • Is it possible to remove dead bottom vegetation? • Address to FWC – several years ago it had been reported in one year period the FWC biologist weight

add tournament weigh ins that 1,000 largemouth bass were weighed in at tournaments that were over 8 lbs, since then how many over 8 lbs have been caught?

• Nothing is going to work as long as the spraying daily is going on. • Spraying why? Excessive? • Spraying when fish are trying to spawn • Spraying with crop spraying planes! • Spraying when temp and wind were not considered

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• Rumor has it that the lake may be drained, if so, how are you disposing the debris? Burning or landfill? • What happens to fish, wildlife during this time? Is it in stages? • Worst speck fishing season I’ve seen this past year. Is this because lake bottom is not sufficient for fish

to bed? Water quality poor? • Stop the never ending spraying. • Replant all the eelgrass, pepper grass, hydrilla that is almost gone. • When will they stop overspraying? • How large is Orange Lake compared to Lake I? • Why do you say water quality does not need to be looked at? • Are the fish safe to eat? • What was the trigger that got UF involved in Lake Istokpoga? • Once a plan is developed what kind of oversight will there be? • Why do you call hyacinth a problem? • How much influence will this have with FWC? • What will spraying come to management, not overkill? • No one in charge of lake DO NOT FISH – and yet do not listen to people who do and do nothing we

ask, they say they want our input but do NOTHING we say and lie to us all the time about major projects and things they are or are not doing.

• No one is overseeing it all, we are trying to fight mother nature for our interests • How did the hurricane affect fishing and habitat? • How did spraying affect fish population? • Does this plan affect other lakes? • Fish population over the years? • How do you plan to improve the fishery, wildlife and plant life of the lake? • Who dictates water levels? • If this takes two years the lake will be completely dead • Is FWC able? Lake got this way on their watch. • Who has final say, FWC, Commissioners, Senators, Congressmen? • What can be done about…

o There is no longer any submersed vegetation in the lake (formerly abundant) o The marshes of Istokpoga have been destroyed o The bird population of the lake have been devastated o These conditions are not improving

Gathering Stakeholder Input Activity

Meeting participants were given an activity to complete after the presentations. They were given 3 large post-it notes and asked to write their top 3 Lake Istokpoga issues.

Answers are listed below.

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Issue 1 Issue 2 Issue 3

Istokpoga catch and release only Poor water quality (levels) Spraying

Fish population decline Needless spraying Listen to us

Less spraying for more weed beds Decline of fish population and supporting eco-diversity

Too many tunnel vision agencies controlling lake supervision

More fish habitat Better bass fishing Keep water levels constant

Better crappie fishing Lake bottom silt – fish can’t bed Lack of progress in reducing Ag run off and excessive nutrients pouring into the lake

Less spraying (real targeting) Lack of vegetation More bass and specs

Sustain biodiversity Would like better crappie fishing Why to get rid of some water hyacinths did they destroy ever marsh?

Crappies have few minnows and grass shrimp to feed on/eat Why is the fish declining? Access to main lake from rim

canals

More ducks Fisheries management – biological studies of fish #s and growth, fish mortality rates

Less spraying

Not enough bass More submersed vegetation Will lake have to be drained?

Better fishing Management accountability Better bass fishing

Increase fish population Lake front property management, trees and access Wildlife management

More marsh Maximize native plant communities Harvesting as much as possible instead of spraying

Stop spraying More vegetation Not enough room for boats at Windy Point

Creation of more muck due to overspraying More submersed weeds in open lake Public lake access, ex. Parks

and ramps

Bring back ducks Not enough vegetation (hydrilla, eel grass etc.) More bass for fishing

Much less midges Bass catch rate How did hurricane affect fish habitat?

No spraying herbicides Control spraying Water levels

Decline in fish population Why spray in bedding areas at bedding time Better bass fishing

Less spraying More vegetation More birdlife

How to control spraying Cooperation

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Issue 1 Issue 2 Issue 3

Spraying too much at one time More big bass Would like to see better fish numbers

Less spraying Better natural balance in ecosystem Better speck fishing

Better spray management Habitat Increase bird/snail population

Better explain spraying – when you spray, time of year you spray, look at age of your audience

Better spec fishing Improved shoreline area at Windy Point for boats to pull up before loading on trailer

Lack of fish Pay attention to the fisherman. Listen to the people who use the lake. It is not a recreational lake.

Bass stocking plan

Mag. Spraying Better bass fishing Will the lake ever come back to its glory of the past?

Why won’t submersed vegetation grow in the lake? Replant grasses Beauty

Less spraying, let the public know where and when, have certain days with no spraying.

Communication Communication

Recruit knowledgeable professionals to carry out plan

How do you plan to approve the quality of the fishery?

Control spraying Does spraying affect people and fish? (Bass)

Enforcement

Less spraying Balance No concern for the fish

Unnecessary spraying and muck buildup and its negative impact on ecosystem and navigation

More hydrilla – 50% of the lake at all times

Maintain good aesthetics to maintain lake and property values

Less spraying so more seaweed An interim plan. Change something now!

Why is the state trying to kill all vegetation in the lake and then replant?

Less muck on the bottom Destruction of habitat due to over spraying

Find a balance with the vegetation, quit spraying as if its going to get out of control

Maintain wildlife habitat, bald eagles More grasses near shore No knowledge of when and where spraying will occur

Habitat management – (something?) plants, focus on planned spraying, regrowth of vegetation

More native plant life Lying to us

Too much spraying has taken away eelgrass

Will the lake ever be in the top twenty-five bass fisheries again?

Stop spraying poison (herbicides) into the lake

Less spraying Bass tournaments need to release all fish where they’re caught Airboats need mufflers

Fish population decline Over spraying Water levels too low in summer

Spraying less Explore alternates to spraying Alligator levels – cull

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Issue 1 Issue 2 Issue 3

Habitat – vegetation for fish reproduction and cover More hydrilla Better coordination between all

people that spray the lake Submersed plant management (not eradication) Hydrilla, eel grass, pepper grass, milfoil, etc.

Listen to fishermen because fishing is 98% of what the lake is used for and brings in most money for our county

Gates that open from top – will not loose as many fish

Invasive vegetation removed Shallow water plant overgrowth and sedimentation

Protect Arbuckle creek/Istokpoga’s water supply

Bass stocks Lake must be managed for all stakeholders

Don’t allow special interests to result in violating best BMPS. Don’t be afraid to spray invasives!

No over spraying on non-invasive plants

Less spraying Better fish limits (specks) and tournaments

Water quality, is lake dying? Winter resident taking too many fish

More bird life Rehabilitate ecosystems back to balance

Manage for fish cover with native plants/manage shoreline for good wading bird habitat

More rule enforcement by fish and game – fish limits

Dead (sprayed) vegetation piling up on lake bottom

Wildlife habitat preservation and conservation includes birds, animals, fish (stop spraying poison)

After the exercise it was requested that FWC staff provide their top 3 Lake Istokpoga issues too. In order to preserve the relative anonymity of the exercise the facilitator requested this information the following day via email. A copy of the email request is attached as Appendix IV-B.

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FWC staff answers are listed below

Issue 1 Issue 2 Issue 3

Aquatic habitat management Fisheries management Better stakeholder engagement

Relative lack of water level fluctuation compared to the historic, NATURAL regime and associated lack of physical ecological disturbances (over-cypress-ridge flooding and dewatering of the littoral zone) = need for managed drawdowns to or below 36.5 ft. NGVD for at least 3 months (mid-February through May) on at least a 20-year cycle, 10-year cycle preferred. This is doable by FWC because we can provide necessary water supply to downstream permittees by installation of pumps @ S-68 structure during drawdown. This would also address my next two concerns.

Lack of natural submersed aquatic vegetation (eel-grass, pondweed, etc.); periodic drawdowns would facilitate recovery of native SAV, as well as hydrilla for hydrilla-lovers

Proliferation of primrose, specifically Ludwigia peruviana and L. octovalvis, with associated accumulation of organic sediments in littoral zone. Key is herbicide treatment while plants are small and periodic drawdowns with associated mechanic removal of noxious plants and associated organic sediments.

Water quality (i.e nutrients, chlorophyll a, and their interrelatedness) and its role in the lack of submersed plants

CONSTANT presence of applicators. This causes 99% of the problem and hinders the ability of managers to do other projects and work constructively with the public

Zone management mentality in regards to submersed plants. The whole of the lake should be considered, not just certain areas, independent of each other. Not a good way to manage a system

A general agreement between FWC, management partners and Lake Istokpoga stakeholders on strategies to effectively control and manage aquatic vegetation

A plan and agreement between FWC, management partners, and Lake Istokpoga stakeholder to conduct a whole lake drawdown within the next 5 years

A better understanding of what stakeholder’s expectations and desires are related to the fisheries, fish populations, and habitats (aquatic vegetation) on Lake Istokpoga

Improve communication. In addition, we (FWC) need to make sure we are listening to our stakeholders

Addressing short-term management desires/outcomes. How do these support long-term management goals?

Receiving Funding for Restoration Projects

Develop stakeholder engagement process to serve as a guide for future habitat management

Propose habitat management activities as per #1 above

Inform and educate the public on aquatic plant management

Promoting expansion of desirable aquatic plants while containing/controlling invasive plants

Managers and stakeholders reaching agreement as much as possible, and reaching tolerable compromise on the rest

Dealing with stabilized water levels – how can we mimic natural processes that used to occur when waters fluctuated? Floods, droughts/fires,…

Low quality littoral zone (shallow water) marsh

Fast growing exotics - primrose willow and burhead sedge

Water stabilization and not enough total fluctuation in Lake levels

Increased emergent plant species richness and increased plant densities relative to openwater within the littoral zones lakewide

Increased submersed plant species coverage and density lakewide

Increased stakeholder partnerships, communication, input, support in the plant management process

Ownership/commitment long term (stakeholders and managers)

Trust/honesty (stakeholders and managers)

Consistency (stakeholders and managers)

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Issue 1 Issue 2 Issue 3

Angler dissatisfaction…whether it be perception or reality

Lack of effective two-way communication/trust between stakeholders (specifically anglers) and FWC

Managing habitat with considerations for various stakeholder desires (trying to balance what the stakeholders want with what managers think needs to be done and have the tools to do)

Water level stabilization Nutrient loading Invasive species

(Facilitator Joy Hazel reviewing the post-it note responses, and responses posted for each category)

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Wrap Up/Next Steps The meeting officially closed with a description of next steps in the process. Immediate next steps include continuation of interviews, the development of a situation analysis, and formation of a representative stakeholder committee. The next public meeting will be held after two committee meetings, and the University of Florida will use suggestions from meeting participants on increasing awareness of the meeting including posting flyers at boat ramps and contacting more RV parks. Information about the process, upcoming events, and meeting reports will be uploaded to the project website at lakeistokpoga.wordpress.com. Following official closing, discussion continued between attendees and program staff. Discussion included concerns about fishing and the impact of a decline on fishing on the local economy and on whether people remain in the area or move away. In addition, it was brought up that there has been a lot of bad press about fishing in the lake that is impacting how many people come there to fish, and the question was raised as to whether word could get out about this habitat management plan and how it might improve conditions in future. Before leaving, participants were asked to fill out an evaluation, which will be used to evaluate how the meeting went as well as determine who attended and what groups may have been missing.

(Map with stars indicating the most important place to each meeting participant)

Meeting Evaluation Survey Please read this document carefully before participation in this study.

The purpose of these evaluations is to assess the success of the meeting and to assist in our situation assessment for Lake Istokpoga. There is no compensation for participation, but know that your participation is important. The survey is anonymous; be assured that in our analysis and reporting of results your answers will not be connected with you. There are no risks to you from participating in this study. Your participation in this study is completely voluntary, you have the right not to answer any specific questions and you may withdraw your consent at any time. There is no penalty for not participating.

If you have any questions concerning this study, please contact: Kai Lorenzen, Ph.D., Professor School of Forest Resources and Conservation University of Florida Gainesville, FL 32653 Phone: (352) 273-3646 E-mail: [email protected] Whom to contact about your rights as a research participant in the study: UFIRB Office Box 11225 University of Florida, Gainesville, FL 32611-2250 Phone: (352) 392-0433

Please rate how well this meeting did each of the following:

(Not at all) 1 2 3 (Very Well) 4

Informed about the habitat management plan engagement process ο ο ο ο

Gathered input from participants ο ο ο ο

Please state your level of agreement with the following statements:

Strongly Disagree Disagree Agree Strongly

Agree

I was able to communicate my ideas ο ο ο ο

Others heard my ideas ο ο ο ο

I heard the ideas of others ο ο ο ο

To what extent did you find today’s meeting useful?

(Not at all) 1 2 3 4 5 (Very) How would you rate the meeting overall?

(Poor) 1 2 3 4 5 (Excellent)

Would you attend future meetings of this type?

No Maybe Yes How would you improve this meeting?

Now please tell us a little about yourself: 7. How are you connected with Lake Istokpoga? (Select all that apply)

Homeowner ο

Boater ο

Recreational angler ο

Commercial fisher ο

Charter captain/guide ο

Bait/tackle shop owner/employee ο

Fishing tournaments ο

Fish Camp owner/employee ο

Resource manager ο

Birder ο

Duck Hunter ο

Other hunter ο

Concerned citizen ο

Other: ο

What is your zip code? _______________ Are you a: Full-time resident Part-time resident Visitor Are you: Male Female Prefer not to say What year were you born? _________________

How well do you understand the current status of aquatic habitat in the lake?

(Not at all) 1 2 3 4 5 (Very well) How well do you understand the process by which management decisions are made for the lake?

(Not at all) 1 2 3 4 5 (Very well)

How well do you feel you understand perspectives about lake management that are different from your own?

(Not at all) 1 2 3 4 5 (Very well) How often do you interact with people whose ideas about lake management are different from your own?

(Never) 1 2 3 4 5 (Frequently) How well do you feel able to discuss lake management with people whose ideas are different from your own?

(Not at all) 1 2 3 4 5 (Very well) To what extent do you feel able to influence management decisions for Lake Istokpoga?

(Completely unable) 1 2 3 4 5 (Completely able) How satisfied are you with management of Lake Istokpoga’s aquatic plants/habitat?

(Very unsatisfied) 1 2 3 4 5 (Very satisfied) How much trust do you have for the FWC personnel managing the lake?

(No trust at all) 1 2 3 4 5 (Complete trust)

Appendix V: Lake Istokpoga Habitat Advisory Committee Members

Below is a comprehensive list of all members of the LIHAC who participated in meetings and contributed to the creation of the habitat management plan: Dave Bouse, Crappie Fishing Guide John Carson, Ph.D., Concerned Citizen, Nature-Lover Sue Clark, Realtor, Real Estate Tracie Gillespie, Fishing Resort Owner Paul Grey, Ph.D., Florida Audubon Society, Ecologist Cole Harty, FWC Fisheries Biologist Don Hatcher, Bass Fishing Guide Nolan Rayburn, Duck Hunter Jim Reed, Homeowner Dawn Ritter, Highlands County Natural Resources Dave Sharpe, Duck Hunter

Appendix VI: LIHAC and LIWG Meeting Reports

Summary Overview

On Wednesday, June 20, 2018 the newly formed Lake Istokpoga Advisory Committee met in Sebring Florida. Project principal investigator Kai Lorenzen, research scientist Chelsey Crandall, and lead facilitator Joy Hazell designed and facilitated the meeting (Appendix A, Agenda).

Approximately 6 working group and 5 members of the general public attended the meeting. The meeting objectives were to:

• Develop trust and community between committee members • Develop shared understanding of Lake Istokpoga history and evolution of the need for a lake habitat

management plan • Develop shared understanding of stakeholder analysis • Brainstorm structure, next steps and key talking points

Welcome and Introductions

The meeting began with 30 minutes of activities designed to set a positive, collaborative tone for the rest of the day. Activities included introductions, an explanation and clarification of the meeting agenda and objectives, and participant generated ground rules for the meeting (Appendix B). As an icebreaker, participants were asked to identify their favorite thing about Lake Istokpoga.

Timeline Activity

Participants were then asked to create a timeline of their Lake Istokpoga experiences from their first time on the lake to present day. Timelines can help gather, share, organize, and analyze information as steps in seeking common ground; they are simple and can be very effective. Participants were asked to write out key moments including trips, projects, natural events, interactions with other stakeholders, memorable moments, etc. They were then asked to place 4 colored dots on the timeline to identify:

• Red dot: Favorite memory on the lake • Green dot: Moment they felt frustrated • Yellow dot: Moment they felt optimistic

Lake Istokpoga Advisory Committee Meeting Bert J. Harris Jr. Agricultural Center Auditorium, Conference Room 2 4509 George Blvd; Sebring, Florida 33875 June 20, 2018

Figure 1: Portion of the timeline generated by meeting participants.

Presentation and Discussion of External Stakeholder Analysis

Joy Hazell presented a summary of the results of the stakeholder analysis. Meeting participants will receive the full stakeholder analysis report and a copy of the PowerPoint presentation. Following the presentation, participants were divided into 2 small groups and asked to discuss what the current stakeholder situation means for the HMP moving forward by answering a series of questions (Table 1). Table 1. Reflections on the stakeholder analysis.

What are the main sources of tension that may prevent the execution of a successful HMP?

What has contributed to the tension?

What could be done moving forward to deescalate the tension/increase the likelihood of a successful HMP?

-Lack of public knowledge/perception, education -Inadequate explanation of the plan and its merits -Optics/perception (spraying) -Difference in group opinions

-Complexity/difficulty of problem -Lack of info -Unclear definition of goals -Poor communication and interaction

-Take stakeholders on the lake/involve them -More engaged and frequent interaction -Create public buy-in and understanding -Modification to FWC management structure

-LIMC not responsive to input -Homeowner view vs. users view -Is FWC responsive to public and/or LIMC? -Different goals by stakeholders

-No result from input -Deteriorating habitat perceptions -Applied aquatic goals and supervision -Lack of accountability/documentation -not much done/successful discussion of multiple goals/needs lacking

-Communicate! Listen and adjustment -Allow people to address LIMC formally -Monitor results better, e.g. why such limited regrowth -Research (Irma impact opportunity)

Pulling it all Together and Next Steps Joy Hazell then led a discussion to synthesize the meeting and to think about next steps for the committee including additional committee members, communication with the general public, and future meetings. Below are points raised by working group members and recorded on the meeting flipchart: Potential Committee Members and Committee Point of Contact (If no name then Joy is responsible for contacting)

• Real Estate Person – Sue Clark (Jim Reed) • Fish Camp Owner – Tracie (Don Hatcher) • Farmer – Hart and Sons, Casey (Don Hatcher) • Local Audubon Club • County Person • Spring Lake • Crappie Angler • Royce Ranch – Matt Vance (Nolan Rayburn) • Bass Tournament Directors • B.A.S.S.

• Commercial Fishermen • Airboater

Next Meeting and Future Considerations • Meetings in the morning, mid week, mid August • Consensus as a decision making rule (if it is possible) • History of Lake Istokpoga presentation at next meeting • Discussion of desired plants • Discussion of zonation • Public meetings from Nov-April when possible to capture the snowbird community

This then closed the meeting.

Appendix A: Agenda

Lake Istokpoga Committee Meeting Wednesday, June 20, 2018

Meeting Objectives

1. Develop trust and community between committee members 2. Develop shared understanding of Lake Istokpoga history and evolution of the need for a lake habitat

management plan 3. Develop shared understanding of internal stakeholder analysis 4. Brainstorm structure, next steps and key talking points

Meeting Agenda

1:00 Welcome, Introduction and Setting the Tone

1:30 Timeline activity

2:15 Presentation of External Stakeholder Analysis: Interview and Public Meeting Finds

2:45 Break

3:00 Discussion of External Stakeholder Analysis

3:45 Description of Habitat Management Plan (HMP) and Decision Making on How the Committee

will create the Lake Istokpoga HMP

5:00 Adjourn

Appendix B: Group Norms • Be on time • Good A.C. • No one person dominates • Be an active/good listener • Tough on issues, not on people/individuals • Don’t tell someone else what their motives are • Limit use of electronics • Recognize different types of knowledge • Use data when available

Summary

Overview

On Thursday, August 9, 2018 the Lake Istokpoga Advisory Committee attended their second meeting in Sebring, Florida. Project principal investigator Kai Lorenzen, research scientist Chelsey Crandall, and lead facilitator Joy Hazell designed and facilitated the meeting (Appendix A, Agenda).

Approximately 8 committee members and 3 Florida Fish and Wildlife Conservation Commission (FWC) staff attended the meeting. The meeting objectives were to:

• Develop trust and community between committee members • Develop shared understanding of Lake Istokpoga history and Habitat Management Plan proposed

chapters • Develop shared understanding of preferred Lake Istokpoga attributes

Welcome and Introductions

The meeting began with 30 minutes of activities designed to set a positive, collaborative tone for the rest of the day. Activities included introductions, an explanation and clarification of the meeting agenda, objectives, and participant generated ground rules for the meeting (Appendix B). As an icebreaker, participants were asked to identify their favorite thing about Lake Istokpoga and the most exciting thing they had done since the first meeting.

Presentation on the History of Lake Istokpoga

Mark Hoyer, Lake Management Specialist and Director of Florida Lakewatch, delivered a PowerPoint presentation detailing the history of Lake Istokpoga. A PDF of the presentation can be found at https://lakeistokpoga.wordpress.com under project documents. The presentation was a summary of Chapter 2 of the habitat management plan (HMP). Following a question and answer session, advisory committee members were asked what key events, data etc. were missing from the history. Their responses follow:

• Snail kite data • Waterfowl data • Osprey data (Mike McMillan) • Wading birds • Spring lake: 2010-2015 pollution • 2015: Sewage dump, Arbuckle Creek • Hurricane Irma Impacts

Lake Istokpoga Advisory Committee Meeting 2 Bert J. Harris Jr. Agricultural Center Auditorium, Conference Room 2 4509 George Blvd; Sebring, Florida 33875 August 9, 2018

Overview of Habitat Management Plan Chapters

Dr. Kai Lorenzen, the project principal investigator, shared the habitat management plan chapters as outlined by the FWC request for proposal.

Habitat Management Plan Chapters

1. Introduction, Overview and Purpose 2. Habitat Management Background and History 3. Overall Management Vision and History 4. Identification, Development and Prioritization of Management Issues, Strategies, Goals, Objectives and

Recommendations 5. Identification and Development of Monitoring Measurables and Strategies 6. Actions for Other Agencies to Consider 7. Summary and Conclusions

Activity to Identify Preferred Habitat Attributes

Advisory committee members were split into small groups representing four of the most prominent stakeholder groups (Homeowners, Fishers, Environmentalists, Duck Hunters). Seven flip charts were placed around the room, each labeled with a different general habitat attribute (predictability, density, structure, essential species, location, patch size, and accessibility). Each group was then asked to move around the room and use each flip chart to record what was important to their stakeholder group with regard to each attribute. The objective of this activity was first to generally characterize preferred habitat attributes for each stakeholder group and second to identify points of agreement between stakeholder groups and points that need to be discussed further in future to come to consensus on best options. This activity did not end in decision making of any kind but rather elaborated on points of further discussion.

Table 1.

Attributes Stakeholder Groups

Fishers Environmentalists Homeowners Duck Hunters

Predictability

Natural fluctuation • Water level • Wind • Weather

events • Natural

fluctuation is not predictable.

Better spray schedule transparency • What times of

year so not to affect spawning

• Not over spraying in areas that have little growth

• Consistency

Natural fluctuation are long slow processes punctuated by fire/storms Lake changes quickly Fish live in different places Birds live in different places Species disappear

Good public information Dependability of good control over invasive

Set a long term target goal that triggers control – 30-50% Better spray schedule transparency No large scale treating plants during duck season

Density

Balance • Bulrush is

thinning • Nursery

habitat (dense vegetation)

• Depth dependency

• Open water for crappy and bluegill

Varies with plant zone and successional stage Littoral marsh naturally gets dense and many unique species rely on this habitat Topped out hydrilla a problem Spatterdock gets too thick

No tussock/floating islands

In littoral zone (within 100 meters of shoreline) 30%-50% mix of multiple plant types with open water

Attributes Stakeholder Groups

Fishers Environmentalists Homeowners Duck Hunters

Structure (natural and artificial)

Fish attractors/marked Less muck More submersed aquatic vegetation

Littoral areas – monitoring and cause and affect research Full range of hydroperiod zones allowed to grow and remain More submersed aquatic vegetation Open water benthic structure – live and dead Sediment biogeo characteristics

Protect cypress Sparse emergent vegetation around residential areas No tussock! Stabilize shoreline

Increase water level fluctuation for more 30%-50% habitat types More submersed aquatic vegetation

Essential Species

Hydrilla, bulrush, eelgrass, Illinois pond weed, pennywort mat, spatterdock, coontail

Full biodiversity of plants and animals including inverts Duckweed Migrant birds and insects Some exotics are innocuous and not worth attention based on limited resources*

Nothing which blocks homeowner access Bulrush, emergent species in moderation Eelgrass with lilies for habitat, no invasive exotics* Cypress Aesthetics

Hydrilla does provide habitat in moderation* Nothing which blocks homeowner access Bulrush, emergent species in moderation Eelgrass Cypress Aesthetics

Location

Some open deeper water and leave alone important areas Several locations on the lake • North bulrush

in no name creek

• East shore • West side of

big island • South of cut

Plant ones in the right place, e.g. don’t kill emergent to get submersed Tussocks are natural and offer good habitat for turtles, nesting, loafing, rabbits

Maintain boat access year round Moderate habitat around whole lake (30%-50%)

University of Florida Project Team Synthesis

The objective of the above activity was to identify points of convergence and divergence in how different stakeholder groups think about the listed attributes and to explore how the different groups conceptualize habitat and what aspects of different attributes are important to each.

Points of convergence or agreement examples included:

1. Moderation in all actions and a willingness to understand that there is a need to balance multiple perspectives and uses for the lake

2. Desire for a mix of species 3. Understanding that natural fluctuations impact lake habitat 4. Desire for improved public access for boaters and non boaters including

a. Improved public ramps b. Improved parking at Lake Istokpoga Park c. Docks for shoreline fishing and nature viewing

Points of divergence or issues that will need to be discussed at length in futue (noted in table by *)

Attributes Stakeholder Groups Fishers Environmentalists Homeowners Duck Hunters

Patch Size

Some larger areas of submersed plants (multiple species Moderate emergent with edge effect

Larger marsh areas, larger patch sizes Maintain linear connectivity of concentric marsh zones Don’t hyper-fragment plant stands

Sparse vegetation around homes Intermittent access for “edge effect” in shoreline bulrush areas Open buffer areas separating shoreline from bird habitat

Manage high duck use areas for the birds Keep that habitat constant over time

Access

Navigable Canal access Creek access Trails* – clean up of old cuts in spatterdock, Henderson’s cove

Maintain trails without over dissecting plant communities* Trails allow predation into deep marsh (molting area, fish, frog refuge) Shoreline access for public (without boats) could be expanded, ex. Windy Point long dock Canal boat lanes allow nutrients to flow into shallow marsh (concern)

Conflict between homeowner access and lake regulation schedule Channels to get out during potential drawdown

Navigable Canal access Creek access Trails* – clean up of old cuts in spatterdock, Henderson’s cove

1. Trade-offs between boater access and protecting animals/plants from predators and nutrient inputs 2. Definition of tussocks and tolerability, trends and control methods 3. Definition of invasive exotics and discussion of tolerability, trends and control methods

Pulling it all Together and Next Steps A parking lot was created to identify next steps and additional information desired by the committee. The following will be addressed in the next several months:

• Creation of a document detailing who works on Lake Istokpoga including working group and those external to FWC

• Creation of a document of acronym definitions • Ensure all slide presentations are available on the website • Bring Invasive Plant Management (IPM) to talk about homeowner rules • Increase public information/education on rules about spraying by homeowner hired contractors • More info on snail kite patch size needs and what happened to bulrush • Share IPM yearly plan • Add Paul Gray’s presentation, maps, etc. to website • Add Lake Istokpoga draft plan to website

Next Meeting and Future Considerations

• Next public meeting will be held in late 2018 to capture seasonal residents o This next public meeting will be planned at the October Advisory Committee Meeting

• Next Advisory Committee Meeting (October 11, 2018) will be preceded by a field trip on the lake (October 10, 2018)

o One to two points of divergence will be discussed in detail at October meeting o Advisory Committee Members will send Joy places/habitats of interest they would like to see

during the field trip

This then closed the meeting.

Post Report Review Comments from Committee Members Committee Member Comment on Habitat Plan Chapters: This layout of a management plan minimizes or misses four important elements: 1. Identification and discussion of trends, which will affect the plan’s operation. Planning needs to be based on the

future environment. In my opinion, these trends include: a. Increased population pressure on this and other lakes, which impacts on pollution, lake recreational uses,

shoreline environment and similar concerns. b. Increased pollution from non-point sources, (which could eventually result in a requirement for all homes to

convert to a central sewage system). Population growth and continued local use of septic tanks raise the probability of increased nutrients and sewage flowing into the lake.

c. Increased number of new invasive and exotic plants and animals with the concurrent requirement to identify and immediately control them

d. Increased use of the lake for recreational, non-sporting activities. e. Impact of climate change, which may significantly increase plant growth thru warmer temperatures, and

increase the amount of rainfall and number of violent storms. 2. Expansion of Chapter 5, for explicit implementation and monitoring of the plan’s components. Without knowing

how it will be implemented and managed or monitored the follow-on lake management will always be subject to disagreements and subjective evaluation.

3. What will implementing the plan cost, and is a budget going to be available to implement the plan’s recommendations. (There is likely to be a strong push from some to implement ineffective and expensive plant control methods. Planning needs to consider the cost of lake management activities with some assurance the funds will be available.

What changes should be made to FWC’s interface with the public and methods of providing information and education about lake management topics? Committee Member Comments on Table: Predictability-Shallow (0-6ft)in depth. Marsh mimicking and/or food source types of submersed aquatic vegetation species for bird and fish species. Density- Littoral zone being 100 yards from furthest extending Emergent aquatic vegetation in and around lake. With some open water mixed in, but covered from outside wave energy and sight up to 10 ft off water in height if possible. Structure- Flooding/ drought stages on lake expressed to maximum levels allowed to mimic a natural wetland cycle. Increase submersed aquatic vegetation populations and protected interior marshes. Access- Homeowners can have trials cut for access, not entire portions of lake sprayed for submergent or emergent vegetation that may cause issues. Committee comment: To quote Gen Eisenhower (architect of the WW II D-Day plan): “The Plan is useless.” “PLANNING is indispensable.”

Appendix A: Agenda

Lake Istokpoga Advisory Committee Thursday, August 9, 2018

Meeting Objectives

5. Develop trust and community between committee members 6. Develop shared understanding of Lake Istokpoga history 7. Develop shared understanding of preferred Lake Istokpoga attributes

Meeting Agenda 8:30 Welcome and Introductions 9:00 History of Lake Istokpoga 9:45 Overview of Proposed Habitat Management Plan Chapters 10:15 Break 10:30 Activity to Identify Preferred Habitat Attributes 11:45 Proposed Habitat Restoration Project 12:15 Pulling it all Together and Next Steps 12:30 Adjourn

Appendix B: Group Norms • Be on time • Good A.C. • No one person dominates • Be an active/good listener • Tough on issues, not on people/individuals • Don’t tell someone else what their motives are • Limit use of electronics • Recognize different types of knowledge • Use data when available

Summary Overview

On Thursday, November 8, 2018 the Lake Istokpoga Advisory Committee convened in Sebring Florida. Project principal investigator Kai Lorenzen, research scientist Chelsey Crandall, and lead facilitator Joy Hazell designed and facilitated the meeting (Appendix A, Agenda).

Eleven committee members and three Florida Fish and Wildlife Conservation Commission (FWC) staff attended the meeting. The meeting objectives were to:

• Develop trust and community between committee members • Begin process of consensus building on species/habitats of concern and management actions to address

concerns • Develop a plan to engage the wider public in the Lake Istokpoga Habitat Management Plan

Welcome, Introductions and Looking Back

The meeting began with 30 minutes of activities designed to set a positive, collaborative tone for the rest of the day. Activities included introductions, an explanation and clarification of the meeting agenda, objectives, and participant generated ground rules for the meeting (Appendix B).

In order to bring two new committee members up to speed the committee spent some time looking back at past meetings.

Discussion on definition of imperiled and desired species and discussion of tolerability, trends and control methods

In the first activity committee members wrote their three top species they want to see less of, one species for each sticky note, and stuck them to the wall. They then wrote their top three species they want to see more of, one species for each sticky note, and stuck them to the wall. The results are as follows (if more than one person wrote the same species the number of responses is in parenthesis next to that species).

Lake Istokpoga Advisory Committee Meeting 3 Bert J. Harris Jr. Agricultural Center, Conference Room 3 4509 George Blvd; Sebring, Florida 33875 November 8, 2018

See More Of: See Less Of: Floating vegetation Hyacinth (4)

Pickerelweed Water lettuce (5) Maidencane Floating muck islands/Tussocks (2)

Kissimmee Grass Burhead sedge (2) Cypress Pickerelweed

Bulrush/Thicker Bulrush (7) Hydrilla (2) Hydrilla (6) Cattail/Cattail monoculture (2)

Coontail moss Primrose willow (4) Pondweed (4) Flat pads /Lotus Eelgrass (8) Spatterdock (5)

Submersed plants in general Slimy stuff/Filamentous Algae Happy people (2) Invasives

Protected Littoral Marsh

Activity to Identify Concerns about Spatterdock, Pickerel Weed and Eelgrass

Advisory committee members were split into small groups. Each group was given a plant species (guild) of concern and asked to respond to the questions in the table header.

Table 2. Spatterdock Pickerelweed Eelgrass What is the problem?

In the big island barge work changed flow then it filled with spatterdock, then had to go back in so cost more for maintenance Cleared areas fill with spatterdock Navigation issues when area fills Defeats purpose of control for flow (fills it up) Grows fast Becomes monoculture Can’t fish there very easily Part of challenge – don’t want easy fishing, want sport fishing Thick, lines gets hung up in it IPM hard to manage in spatterdock Stakeholders get upset when spraying happens in spatterdock

Native but grows in larger zone year Tricky plant Extra nutrients Access of shoreline Not fishing (shallow) Dominates west wall/SE wall Can become a monoculture Overdominates protected littoral zone Dense monoculture accumulates organics, shed, create tussock, fills lake in

Vulnerable to wave energy – edges protected

What is the benefit?

Large fish in spatterdock SAV under monoculture (but don’t see) Mixed (not monoculture) Ducks like it to molt in parts of the year and like it thick to hide (wood/mottled duck) Seeds are important forage Productive Edge good for fishing Great blue heron in thick spatterdock

Butterflies/pollinators love, birds like it Long hydroperiod plant grows all the way to the shoreline Fish will spend time in it

Waterfowl use it Fish habitat

What change would you like to see?

Trails through spatterdock Density or access (trails) Moderate amounts are good – some of the best habitat on the lake Want it managed, not eradicated

Why kill natives? Natives: leave alone unless it is a problem Put it back in its place Native/Invasive: what do we manage? Not naturally functioning system

Revegetation: experiments including cotton fiber Doing experiments here: have tried sod mats with low success, now trying cages and pots

Public Meeting and Next Steps After a brief discussion on pros and cons of January 2019 public meeting it was determined that the pros (seasonal residents will be here, folks are anxious to hear what is going on, committee would like to know where the public sits and gather input) outweighed any concerns and that we would have a second public meeting in April, May or June. A parking lot was created for additional areas for future discussion and/or information desired by the committee. The following will be addressed in the next several months: Next Meeting and Future Considerations

• All committee members represent the lake • Documentation is important

o LIMC plan o Hydrilla plan o Aquatic Habitat Restoration Enhancement (AHRES FWC) conceptual plan o Invasive Plant Management (IPM FWC) plan o What were the hurricane impacts? o Why is the lake in the condition it is? Why things won’t grow?

Some issues beyond scope of this plan, i.e. nutrient inputs, lake levels but committee could come up with strategies they could recommend to the Basin Management Action Plan (BMAP) and water regulations.

o Percent of invasive plant infestation • Need presentations on habitat monitoring technologies • Field trip so all are on the same page with species and habitat quality - date to be determined • Concern that science will trump what the committee has to say

o How to work together to address disconnect between data and lake users’ experiences • Next Advisory Committee Meeting will be held the morning of December 13, 2018

This then closed the meeting.

Appendix A: Agenda

Lake Istokpoga Advisory Committee Thursday, August 9, 2018

Meeting Objectives

8. Develop trust and community between committee members 9. Begin process of consensus building on species/habitats of concern and management actions to

address these concerns 10. Develop a plan to engage the wider public in the Lake Istokpoga Habitat Management Plan

Meeting Agenda 2:00 Welcome and Introductions 2:30 Looking Back 3:15 Discussion on definition of imperiled and desired species and discussion of tolerability, trends

and control methods Break 4:45 Engaging the Public in Committee’s Work 5:45 Pulling it all Together and Next Steps 6:00 Adjourn

Appendix B: Group Norms • Be on time • Good A.C. • No one person dominates • Be an active/good listener • Tough on issues, not on people/individuals • Don’t tell someone else what their motives are • Limit use of electronics • Recognize different types of knowledge • Use data when available

Summary

Overview

On Wednesday, December 12, the Lake Istokpoga Habitat Management Plan Advisory Committee members took an airboat trip on Lake Istokpoga. Ten committee members were in attendance, in addition to one guest, UF project team members, and FWC staff. Below is a summary of the trip stops and discussions, followed by a map indicating where the stops occurred and photos depicting the plant species discussed.

Stop 1: Primrose willow (removed) area north of Windy Point Why did we stop here? This was an area that had been treated in the past (which included using a helicopter) to remove primrose willow. Habitat is now full of bulrush and Maidencane. Discussion points:

• This is now good fish habitat, there are big fish here now • Sometimes people call Maidencane Kissimmee grass, this is Maidencane here • There is no emergent marsh here, it is devoid of plants where there should be plants • Homes here along the shoreline where people manage the plants in front of their property (affects

what we see as far as plants go) • Discussion about the rights of homeowners, each home basically has its own mini-management plan • Issue brought up: sometimes people clear out plants right before they move to help sell the house,

then the new homeowners don’t know o Opportunity to educate realtors about this, get a list and connect over chances to send

information to realtors or give talk(s)

Lake Istokpoga Advisory Committee Airboat Trip

• Question: How do wildlife use Maidencane? As cover, some birds roost in it, invertebrates use it, apple snails

• Noted that this is an area where the shoreline has been developed, and is what it looks like when you have developed property management; should look different in areas to the north and west (where there is not shoreline property)

o Area here where people are managing the vegetation in front of their homes

Stop 2: Site where AHRES is planting Why did we stop here? To see an example of FWC’s revegetation work in progress. Discussion points:

• FWC has been doing revegetation work at this site: Kissimmee grass and spikerush plantings (Maidencane didn’t do well here), as well as eel grass cages

• Hurricane blew a lot back at this site • This should all be marsh, full of plants. There should be pickerelweed, Kissimmee grass, bands of

vegetation all the way out to the bulrush line, then submersed plants, then floating plants • Question: is this what you (FWC) want to see here? Response: no, not how we want it to look, we

want higher coverage of emergent plants

• The water schedule on this lake means the lake doesn’t have the natural wet/dry periods, which affects which plants we see

• Looks totally different on the other side, where the airboat trail is • Ideally we would have fire here • Plant identification: looked at spikerush, Kissimmee grass, and bulrush • Question: is this blown out material from the storm? It pushed back some things • Further discussion: this system is not acting naturally, noting that we get monocultures of

spatterdock and pickerelweed in places on the lake, having muck is natural but we have sped it up, and there are elevated nutrient levels in the lake

• Question: why plant spikerush? It is a good establisher, creates structure and food, it is a native species, fish and birds use it, and it has properties that keep other plants from invading the area

• We should see more pickerelweed here • Irma blew a lot of things to shore • If it is good habitat but it is too deep, then the birds can’t use it • You see good habitat on the lake inside the islands, where nutrients are lower • One year hydrilla topped out here, had birds that year • Emergent/submergent plants in here • What would you like to see come back in here? • Marsh plants decrease nutrients, clean the water: skinny marsh means more nutrients, cattails grow

better then, for example • Question: What do waterfowl like here? Submersed as far in as we can get • If it burned here (the plants along the shore), it would be great for birds and ducks • Puddleduck potential: submersed and floating leaf plants • There is good duck habitat up by No Name • Should we burn the plants along the shore here? It is state lands, so don’t have to worry about

homeowners • Wetlands are fire communities too, had muck fires historically • Lake has to be managed, our best management plan should get the lake where we want it • Not a natural lake anymore • Discussion: in other places (other water bodies), we can vary water levels and there we get great

habitat (for ducks, for example)

Stop 3: Henderson’s Cove Why did we stop here? This was a historically good area for ducks, and an example of an area with a lot of spatterdock in it now Discussion

• Used to have little muck islands here with no vegetation, they had ducks • Not as open before, now it is more exposed, used to be lily and bladderwort here • Had lots of ducks, puddleducks, diverducks • Was top 3 for ducks in the lake • Worst I have ever seen it now • No food here, too open, changes in vegetation • Before: all lily, nothing emergent, ducks ate bladderwort, it had low wave energy • More bird life and plants here than elsewhere (other sites seen that day so far) • Pre-2001: was the number 1 waterfowl site

o A lot of attention during the drawdown, cited a vocal landowner (Royce), wanted subdivision on property

• Trails in here based on angler requests • Plant species want to see decrease in our committee discussion: spatterdock (seen here) • Anglers want floating vegetation out where we can use it, can’t use it back here • Pennywort will be left from spraying at all costs (current policy) • Pointed out that primrose dies off in winter, so that is why it all looks brown now • Discussion on spraying and avoiding pennywort: do the applicators know that is the policy? They

are monitored • Further spraying discussion: noted a fishing location (elsewhere) which got sprayed multiple times,

even after the lettuce was all gone • Question: can I move pennywort? Tell them not to spray it/put a stake in it?

o We can try, there are 10+ guys who spray this lake, but can tell them GPS coordinates o Some rules about moving native plants

• Pennywort is now everywhere you can’t fish • Waterfowl areas: don’t touch it during the season

o It is in winter, 2 months, so cold that things don’t grow anyway

• Study on spatterdock seedheads, effects of Diquot mentioned • Ducks: like tussocks • Spatterdock is at least a plant, maybe we should let it be • Thick bulrush stands noted, that is where the fish will be • Should we have trails in here? Cut trails anywhere, anglers will use them • I would knock out at least 50% of the spatterdock, increase the submersed aquatic vegetation • Site-selective block treatments? • How do we encourage submersed plants? There is a reason they are not growing, could be water

quality. Unless we decrease nutrients in the water, we won’t see submersed plants

Stop 4: marsh by Bumblebee island Why did we stop here? Good example of marsh habitat in the lake Discussion

• Bluegill, shellcracker spawn back in here • Duck potato, peppergrass before • Shallow here and you see emergent plants • We call this the Bumblebee marsh complex • Harvested here/ further in the marsh to open it up • Historically: had hydrilla, duck potato, bulrush • Wading birds nest, snail kites nest back inside the marsh • Island: has private landowners • Water lily here • Good duck habitat • Spent some time going over plant species • Pickerelweed: butterflies, bees love it • Less nutrient input back in here and further back in the marsh • Fish: submersed vegetation great for all, not adult sportfish but juveniles and forage fish back in here • Boats can’t get in here, too dense to fish • Water temperature fluctuates a lot in here • Do we have water quality data after the storm flushed? We can get it from Lakewatch

Stop 5: open area near Bumblebee island Why did we stop here? Discussion

• Used to be topped out hydrilla here, waterfowl, used to go frog gigging here • Now spatterdock • Multiple harvesting projects here (years ago)

o Burrhead sedge o Primrose o Cattail

• No hydrilla here now • Can we spray the spatterdock back? • Do we let it be or do we want to change it?

o Spatterdock will likely be what comes back if we do spray it o Will likely be spatterdock here whatever we do

• Nesting in willows • There is lettuce peppered in here within the spatterdock • Sedge and torpedo grass examples shown • Question: Can we get hydrilla back in here? Bet there is a tuber source here, only gone a few years,

but need openings, it won’t fight through the coontail • Harvest spatterdock so the hydrilla can come back? Maybe • Is this good for fishing/fish?

o Not ideal for fishing, good submersed plants but not ideal to fish in o Fish on the edge, but not this far back

• Gamefish nursery here? Probably

Map of the 5 Airboat Trip Stops

Maidencane, Panicum hemitomon

Kissimmee grass, Paspalidium geminatum (also called Egyptian paspalidium, knotgrass)

Giant bulrush, Scripus californicus

Spikerush (jointed spikerush), Eleocharis interstincta

Eelgrass, Vallisneria americana (also known as tapegrass)

Spatterdock, Nuphar advena (also known as yellow cow lily)

Marsh pennywort, Hydrocotyle umbellata (also known as water pennywort, dollarweed)

Fragrant water lily, Nymphaea odorata (also known as white water lily)

Bladderwort, Utricularia sp. (we saw conespur and leafy bladderworts)

Pickerelweed, Pontederia cordata

Cattail, Typha sp.

Coontail, Ceratophyllum demersum

Water lettuce, Pistia stratiotes

Torpedograss, Panicum repens