Category Archives: Notes from the Field

Trophy Largemouth Bass Telemetry Project

Largemouth bass commonly reach sizes in Florida that dwarf those in many other parts of the world where they are native or introduced. This trend is in part due to the long growing season in a warm subtropical climate and the natural fertility of Florida’s abundant freshwater lakes, but largely due the unique genetics of largemouth bass in Florida that allow many of them to grow to epic sizes. Their genetic character is distinct enough that FWRI geneticists advocate they are separate species (Micropterus floridanus) from largemouth bass native to the rest of North America (M. salmoides). Thus, catching trophy bass, or at least having the chance to catch one, is a major component of the attraction and allure to freshwater fishing in Florida.

To promote trophy bass fishing and conservation in Florida, the Florida Fish and Wildlife Conservation Commission (FWC) launched TrophyCatch in 2012. TrophyCatch rewards anglers for catching, documenting and releasing trophy bass while engaging anglers as citizen scientists who help the FWC build a long-term dataset of where and when trophy bass have been caught across the state. Trends or anomalies in these data may help steer FWC’s research biologists to develop new studies on largemouth bass or other species.

Kingsley Lake emerged from the TrophyCatch data as an unexpected and prolific producer of some of Florida’s largest bass. These bass were thought to be unusually old, and FWC biologists hypothesized their size and age might be linked to the lake’s unusual depths, which exceeds 40 feet deep across much of the lake’s offshore waters. If the water column at Kingsley Lake underwent thermal stratification during summer, bass there might be able to select temperature zones that maintain their metabolism closer to optimal levels compared to bass in shallower lakes that grow excessively hot, top-to-bottom, during much of the summer. Researchers working at the Harris Chain of Lakes (HCOL) had similar interests of learning more about trophy bass behavior and longevity. Communication among biologists led to hypotheses regarding differences between Kingsley Lake and lakes, such as those on the HCOL, that were more representative of Florida’s shallow-vegetated waterbodies.

Based on those discussions, FWC biologists developed two telemetry studies to learn more about the life history of bass in Florida and how these fish interact with their environments. Biologists specifically targeted the largest and oldest segment of the population because trophy bass are revered by anglers. One of the goals in this study was to document differences in lake characteristics and how the large bass behave to better understand the factors associated with Kingsley Lake bass living longer and growing to larger maximum sizes. By better understanding some of the environmental and habitat conditions that are linked to trophy bass occurrence at Kingsley Lake and HCOL, FWC can better manage fisheries for trophy bass across the state.

FWC biologists used two types of telemetry tags – acoustic and radio – to track the movements of bass. At HCOL, bass were collected by boat electrofishing, which temporarily immobilizes fish in freshwater so they can be netted. At Kingsley Lake, biologists collect bass via hook-and-line sampling. For both types of telemetry tags, biologists surgically implanted them into the body cavity of study bass. The tags were about the size of an AA battery, so the incisions were less than one inch long and required 3–4 sutures to close. What distinguished the two types of telemetry tags used was the way that they transmitted information to biologists. Because of Kingsley Lake’s smaller size (1,700 acres), biologists used acoustic telemetric tags there and were able to install a grid of acoustic receivers that covered the entire lake. The acoustic tags also included depth and temperature sensors, which provided near-continuous depth and temperature recording for tagged fish during the study. Collecting these data required biologists to routinely retrieve the receivers and downloaded the tag detection logs. Bass at lakes Eustis (one year) and Dora (four years) were implanted with radio telemetry tags because these two lakes were much larger and radio telemetry allows for much faster searching when relocating tagged bass. The radio tags contained a sensor that measured temperature and one that monitored movement and would alert biologists if the bass died and ceased moving. There, biologists conducted weekly searches to find all radio tagged bass and recorded GPS locations, temperature and habitat data for each one.

Besides water temperatures collected from the actual tagged fish locations, researchers collected temperature and oxygen profiles at fixed sites for each lake during the summer months.

The study at Kingsley Lake has been completed, but biologists plan to continue tagging more trophy bass at the HCOL and are considering transitioning the focus to Lake Apopka, which has recently experienced substantial gains in habitat and fishing effort.

Biologists confirmed that bass at Kingsley Lake reach exceptionally old ages for bass in Florida. Age estimates for several bass found dead and donated by lake residents were 14–16 years old. Conversely, bass aged from Lake Eustis, Dora and other lakes within the HCOL had a maximum age of 11 years old. Although researchers don’t have evidence that Kingsley Lake has higher growth rates, a greater average longevity may allow large bass more years to grow and a subset of trophy bass to reach sizes that are almost never achieved at the HCOL. For example, the TrophyCatch database includes 17 bass caught over 13 pounds at Kingsley Lake (1,700 acres) compared to zero bass over 13 pounds caught at the HCOL (76,000 acres). Therefore, longevity is an important factor in bass attaining trophy sizes over 13 pounds.

Key differences between the two waterbodies may help unlock the mystery of Kingsley Lake bass living to much older ages. Mapping of the lakes revealed that nearly 50% of Kingsley Lake’s area had depths of 24 feet or greater, with a maximum depth of 82 feet; compared to Lake Dora, which has a maximum depth of 15 feet. Water quality monitoring at each lake revealed that the water column had thermal stratification at Kingsley Lake compared to Lakes Eustis and Dora where the temperature and oxygen did not decline substantially with depth. Information from tagged trophy bass showed that bass at Kingsley Lake do sometimes select for cooler layers within the water column. This was most prevalent during late spring and early summer and may be advantageous for bass recovering from spawning season. Compared to the telemetered bass at the Harris Chain of Lakes, Kingsley Lake bass inhabited cooler water 90% of the time, and temperature differences were most pronounced in spring and early summer, when Kingsley Lake bass averaged about 4°F cooler temperature. This temperature difference was a little less than biologists expected, but much of Kingsley Lake’s deepest and coolest water becomes devoid of oxygen by mid-summer, reducing the overall available thermal refuge. Studies have found (including FWC telemetry work) that bass endure the most stress and mortality during post-spawn and summer months in Florida. With bass at Kinsley Lake having access to and using the cooler strata of water during this season of high stress, it is likely this results in reduced natural mortality each summer; allowing for higher longevity to attain larger maximum size.

Although the sample sizes are low and mortality was not the primary objective at Kingsley Lake, researchers did observe much higher annual mortality at Lakes Eustis and Dora (87%) compared to Kingsley Lake (20%). At Lakes Eustis and Dora, researchers confirmed the fate for 48 tagged trophy bass and 29% were caught by anglers which resulted in a total of 17% fishing mortality (combination of harvest and release mortality). Natural mortality at the HCOL was 70% and of those that died from natural mortality or release mortality, all besides 1 died from April through September. This study helps confirm the high mortality season for trophy bass in Florida as water temperatures approach 90°F; along with providing more evidence how refuge from these extreme conditions during the hot summer months may affect mortality rates.

This research was funded by boaters and anglers through the federal Sport Fish Restoration Program. The FWRI Freshwater Fisheries Research biologists who led this study worked closely with Division of Freshwater Fisheries Management biologists. Camp Blanding Joint Training Center allowed the researchers access to Kingsley Lake through U.S. military property.

Results from this study could inform future fisheries or habitat management actions. Habitat use patterns could help fisheries managers determine the best placement for offshore fish attractors or help prioritize areas and habitats for restoration activities. Knowledge of the value of thermal refuge in deep lakes could be used to seek additional lakes with bathymetry and water column stratification similar to Kingsley Lake to create angler access or pursue trophy bass management strategies. FWC could promote the habitat use patterns documented in this study to anglers, making them more informed of bass behaviors and perhaps leading to more angling success.

Spatiotemporal Patterns in the Biomass of Drift Algae in the Indian River Lagoon

Drift macroalgae (DMA) plays key roles in the ecology of many coastal systems, including the Indian River Lagoon (IRL). In systems like the IRL, DMA play an important role in cycling of carbon, nitrogen, and phosphorus. The ability of macroalgae to take up and store nutrients makes them successful when nutrients are limiting or supplied in pulses, which allows them to compete with phytoplankton for access to elements in the water column. However, DMA are less robust and persistent than rooted macrophytes, so their death or lack of growth can add or leave carbon, nitrogen, and phosphorus that become available for uptake by fast-growing phytoplankton. In fact, shifts from dominance by benthic primary producers to dominance by phytoplankton have been observed in multiple systems with negative impacts on seagrass assemblages and their associated fauna. Such a shift may have occurred in the IRL because an unprecedented sequence of intense and longlasting blooms of phytoplankton has afflicted the system since 2011.

Patterns in the biomass of drift macroalgae were identified using new and original analyses of data from several sampling programs collected between 1997 and 2019. Fixed transects were surveyed at least twice a year (summer and winter) approximating times of annual maximum and minimum abundance of seagrasses. The location of each transect was marked with poles, and the path to be surveyed was delineated by a graduated line extending perpendicularly from the shoreline out to the deep end of the seagrass canopy. In summary, transects extended for 15–1,900 m across depths to 1.8 m. To quantify the abundance and distribution of DMA found in deeper water, large-scale acoustic surveys were conducted between April and June in 2008, 2010, 2012, 2014, and 2015. While the surveys covered up to 288 km2, we focused analysis of spatiotemporal variation on reaches 2, 3, and 4, which were completed in all 5 years.

All available data show a relatively low biomass of drift macroalgae in 2010–2012, and surveys of fixed transects and seining as part of a fisheries independent monitoring program also recorded low biomass in 2016. Low light availability and potentially stressful temperatures appeared to be the main influences as indicated by the results of incubations in tanks to determine environmental tolerances and data on ambient conditions. Decreased biomass of drift macroalgae had implications for cycling of nutrients because carbon, nitrogen, and phosphorus not stored in the tissues of drift macroalgae became available for uptake by other primary producers, including phytoplankton. The estimated 14–18% increases in concentrations of these elements in the IRL could have promoted longer and more intense phytoplankton blooms, which would have reduced light availability and increased stress on algae and seagrasses. An improved understanding of such feedback and the ecological roles played by drift macroalgae will support more effective management of nutrient loads and the system by accounting for cycling of nutrients among primary producers.

Map showing the Indian River Lagoon, five inlets, nine reaches, fixed transects through seagrass, and water quality stations.

New Shared Stewardship Partnership Helps Implement Landscape Conservation

By Matthew Chopp

History

“Let’s bring the FWC into the Shared Stewardship Program here”, said Ivan Green. Ivan was the U.S. Forest Service (USFS) District Ranger on Osceola National Forest, and he was talking to Chris Wynn, FWC North Central Regional Director. It was 2019, and Ivan was eager to enhance conservation efforts on the national forest in a bold new way – with the establishment of a co-funded employee position. The timing was right for this partnership too – the USFS had an employee vacancy, and the ink was still wet on the new Florida Shared Stewardship Agreement. Chris championed this idea, and in 2021 Beth Stys (FWRI Center for Spatial Analysis) used Landscape Conservation Strategic Initiative program funds to make it happen.

Matthew Chopp was hired to serve in this new role – Shared Stewardship Coordinator on Osceola National Forest.

Mission

The USFS Shared Stewardship Program includes a forest management strategy that builds capacity through collaboration and focuses on landscape-scale outcomes. Agency and stakeholder partnerships are required to achieve success at this level. So then, Matthew’s position was established to help coordinate (1) projects on Osceola National Forest, (2) conservation planning for Florida National Forests, and (3) implementation of the FWC’s Landscape Conservation Strategic Initiative in the North Central Region – benefits that may not have happened without this direct collaboration.

Accomplishments

Matthew is currently assisting FWC colleagues with development of the Connect, Collaborate, and Conserve Southwest Region pilot project – a flexible model designed for future use in all five FWC regions. Southwest Regional Staff are using landscape conservation prioritization tools developed by the FWRI’s Center for Spatial Analysis to help identify a pilot project location. Matthew’s position represents a touchstone of success for the Landscape Conservation Strategic Initiative – the “connect, collaborate and conserve” approach is his position’s focus.

Matthew also established the Osceola National Forest Coordinating Committee – a group of stakeholders from the FWC, USFS and universities, many who are already conducting research and management projects on this national forest. Connecting with colleagues in this way is a valuable investment towards engaging large landscape conservation projects like the Ocala to Osceola Wildlife Corridor, which overlaps the Osceola National Forest.

This example of cost-sharing an employee position represents a novel approach to filling a specific need for these partnering agencies, and may be repeated as opportunities arise around the state.

Acknowledgements

Partnerships require team efforts, and the establishment of this Shared Stewardship Coordinator position would not have been possible without the support and initiative of the following leaders:

FWC

Eric Sutton, Executive Director

Thomas Eason, Assistant Executive Director

Chris Wynn, North Central Regional Director

Gil McRae, Director, FWRI

René Baumstark, Information Science and Management Section Leader, FWRI

Kristen Nelson Sella, Biological Administrator, Center for Spatial Analysis, FWRI (Matthew’s supervisor)

Beth Stys1, Associate Research Scientist, FWRI

USFS

Kelly Russel, Forest Supervisor, National Forests in Florida

Ivan Green, Deputy Forest Supervisor, National Forests in Florida

Thomas Scott, OSC District Ranger

1Current position: Regional Climate Adaptation Ecologist, U.S. Fish & Wildlife Service, Southeast Region

Photo Credit: North Florida Land Trust

Many-Lined Salamander Surveys

By Aubrey Greene

The many-lined salamander (Stereochilus marginatus) occurs along the Atlantic Coastal Plain as far north as Virginia and reaches the southern edge of its range in extreme northeastern Florida where it is a Species of Greatest Conservation Need (SGCN). This species is highly aquatic and inhabits a variety of permanent lentic or lotic wetland habitats such as cypress swamps, ditches, slow blackwater streams, and shallow backwaters. Many-lined salamanders were first documented in Florida in 1973 in Baker County. Since then, this species has been documented from three additional counties (Columbia, Union, and Nassau) but is apparently restricted to the St. Marys and Nassau River drainages. Most known localities are from Osceola National Forest and John M. Bethea State Forest, with a few other documented populations on private lands.

Limited research or monitoring has been done to determine the status of many-lined salamanders in Florida, and over the years, FWC personnel occasionally surveyed known localities but have not detected the species in ca. two decades. Many-lined salamanders were also undetected at several historical sites during dusky salamander (Desmognathus auriculatus) surveys from 2016-2019. The lack of recent sightings along with more frequent and extreme drought conditions in the region over the past 20 years raises concern regarding the status of many-lined salamanders in the state. Occasional mild drought conditions are less of a concern for this species given their preference for permanent bodies of water. However, frequent, prolonged drought conditions could pose a threat to the species’ life cycle as larvae require over a year within aquatic habitats to metamorphose. Adults are also closely tied to aquatic habitats and are rarely encountered far from the water’s edge. 

We aim to clarify the status and distribution of many-lined salamanders within Florida by surveying historic many-lined salamander localities and other potentially suitable habitat over the next two years. To do this, we are using a variety of survey methods (i.e., dredging, dipnetting, hand raking, and minnow traps) and conducting monthly time-based surveys to detect adult and larval many-lined salamanders. In January 2022, we started conducting surveys at seven historic sites and one potentially suitable site and will continue surveying these thru December 2022. Additional potentially suitable sites will be identified and surveyed January – December 2023. We will use aerial imagery and ground truthing to identify potential sites to survey within the known drainages. If salamanders are found, we will use landscape data to determine habitat associations and the repeated surveys to assess detectability.

So far, after three rounds of surveys, we have not detected adult or larval many-lined salamanders at any of the survey sites. In the coming months we hope to visit known occupied sites in SE Georgia to gain a better understanding of preferred habitat and survey methodology as well as develop a search image for the species. Additionally, we are planning a blitz for the April surveys with the idea that more boots on the ground will give us a better chance at finding that needle in the haystack, or in this case, salamander in the muck.

Effects of Submarine Groundwater Discharge on Seagrass Communities in Western Florida Bay

By Brad Furman

The warm shallow waters of Florida Bay are home to expansive turtlegrass (Thalassia testudinum) meadows that provide more than 500,000 acres of essential fish habitat and support a vibrant ecotourism industry, as well as important commercial and recreational fisheries. Found at the southern terminus of mainland Florida within Everglades National Park, Florida Bay is a unique and enigmatic ecosystem, one that has long been recognized as an estuary of national importance, and whose storied decline was once a catalyst for Everglades Restoration. Now, as end-of-pipe for our nation’s largest wetland restoration effort: the Comprehensive Everglades Restoration Project (CERP), Florida Bay remains at the center of debate regarding freshwater delivery and its conveyance through the vast Everglades ecosystem.

Since the 1880s, wholesale changes to the hydrology of South Florida and the conversion of roughly half the ecosystem to agriculture and urban uses left Florida Bay with a fraction of the freshwater input it may have once enjoyed. Today, the estuary is reliant on the vagaries of direct rainfall to balance intense seasonal evaporation, exposing the system to regular bouts of hypersalinity. Calm wind conditions or water column stratification, combined with high water temperatures, facilitate the development of widespread hypoxia and anoxia that can lead to intense hydrogen sulfide production, particularly in the densest turtlegrass meadows. Hydrogen sulfide is a strong phytotoxin that can quickly kill seagrasses if it reaches sensitive meristematic tissues. It is thought that this process led to widespread turtlegrass mortality or die-off in the late 1980s, which set off nearly a decade of recurrent algal blooms and damaging sediment resuspension events, all of which significantly impacted benthic macrophyte communities and reduced fishery yields. Despite ongoing restoration and management efforts in Florida Bay, hypersalinity remains an issue, and another large-scale seagrass die-off was observed in 2015.

Figure 1: Map of study area including the three focal basins: Rankin Lake (RAN), Rabbit Key Basin (RKB) and Whipray Basins (WHP).

Although the drivers and mechanisms of turtlegrass mortality are now well known, there are important questions about how groundwater discharge might influence hypersalinity in areas prone to die-off within Florida Bay. To date, groundwater dynamics are poorly resolved for western Florida Bay and the relationship, if any, between groundwater discharge and seagrass condition remains a mystery.

Submarine groundwater discharge (SGD) is the flow of terrestrially derived water into the coastal zone. Discharge can rival surface water inputs in terms of nutrient delivery and the outflow of groundwater can have major implications for coastal flora and fauna. For seagrasses, SGD could stimulate plant growth and influence community composition and, as a source of fresh or less saline water, might alleviate hypersalinity. Conversely, anoxic groundwater could facilitate sulfide production and intrusion into roots and rhizomes in vulnerable seagrass meadows. Exploring groundwater-seagrass interactions across a gradient of turtlegrass die-off severity will provide new insights into the pace and distribution of seagrass loss and could offer new metrics for assessing ecosystem resilience.

Figure 2: The towed resistivity cable (A) which is used to measure conductivity, water column depth, and subsurface sediment depth and the radon gas partitioner (B) where the radon gas escapes the water through turbulence and is detected in the radon detector.

In partnership with researchers from Georgia Southern University and Florida International University, we began the first of a three-year EPA-funded project to explore the spatiotemporal patterns of SGD and its relationship to seagrass community composition and meadow physiognomy in western Florida Bay (Figure 1). This research will combine radon-222 and electrical resistivity tomography (ERT) to map seasonal patterns in SGD in three Florida Bay basins, each with different histories of seagrass die-off (Figure 2). We will then relate spatiotemporal patterns in SGD to seagrass community composition and distribution using remote-sensing mapping of seagrass coverage and discrete in situ sampling of species identity and abundance. By combining the expertise of benthic and spatial ecologists, and groundwater geologists with data end-users, we will use a multidisciplinary, iterative approach to examine the relationship between groundwater and seagrasses.

To date, we have completed the first of several SGD surveys (Figure 3) and are looking forward to hitting the water to hunt for groundwater in Florida Bay in June 2022.

Figure 3: Preliminary map of radon-222 collected from surface waters of Whipray Basin in November 2021. Interpolation prepared by Brielle Robbins of Georgia Southern University.

Habitat Restoration in the Peace River Watershed

Habitat degradation is one of the primary factors contributing to the decline of diversity in aquatic systems in the southeastern United States. Human factors including poorly managed agricultural practices and construction can increase sedimentation and lead to channel instability in rivers and streams. This in turn can have severe biotic impacts on food chains, habitat complexity, spawning and rearing habitats, instream cover and water temperatures. The initial step to restore degraded streambeds is to identify those areas of impairment. Once impaired areas are identified, management must correct the problem through prevention, mitigation, stabilization or restoration.

The Peace River Watershed in southwest Florida was listed in the highest-ranking group of watersheds for habitat enhancement by The Florida Wildlife Legacy Initiative’s (FWLI) State Wildlife Action Plan (SWAP) due to its high potential for urban development, high number of threats and high number of Species of Greatest Conservation Need (SGCN). During a previous project from 2015-2019, 512 impaired sites with varying levels of severity were identified in the Peace River as potential candidates for restoration. Funding from State Wildlife Grants and FWC’s Aquatic Habitat Restoration and Enhancement subsection allowed for the formation of a restoration project to address two severely degraded sites: a 450-foot streambank on Peace River Valley Ranch near Zolfo Springs, and a 1000-foot streambank on King Ranch near Arcadia. Restoration of these streambanks would benefit a variety of SGCN inhabiting aquatic, semi-aquatic and terrestrial habitat by reducing sediment smothering, providing instream habitat and improving water quality and riparian habitat.

Active construction at King’s Ranch restoration site on the Peace River.

The restoration sites were characterized as highly eroding streambanks devoid of functioning riparian habitat. Restoration was completed using natural channel design where the eroded streambank was re-contoured using heavy machinery and the new streambank was stabilized using toe-wood structures. Toe wood structures were comprised of root wad logs cantilevered over foundation logs to reduce erosive flows and create an undercut bank for instream cover and fish refugia. Native vegetation planted along the streambank also served to stabilize the floodplain and create a natural habitat. Sampling was scheduled before and after construction to evaluate the effects of the restoration and will continue through June 2022. Electrofishing was conducted to monitor fish communities and a laser level and stadia rods were used to measure river cross sections and bank profiles. 

This project addresses goals and objectives of the FWLI’s SWAP by improving aquatic ecosystem habitat quality and connectivity for species of greatest conservation need. The restoration method used here, natural channel design, has been successfully used in other systems in north Florida (St. Mary’s River) and the panhandle (Chipola River), but had not been used in peninsular Florida until now. FWRI’s monitoring is designed to document the effects of restoration on fish communities, bank stability and sedimentation/erosion rates. The data obtained in this study will provide support and justification for future work in the Peace River and beyond, as well as working toward meeting the FWLI objective to restore at least 3,000 feet of stream habitat by 2025.

The project is made possible through the exhaustive efforts of FWC scientists Craig Mallison, Jamie Richardson, Amanda Christiansen and Maggie Bass, as well as former FWC employee Greg Knothe.

North Florida Deer Study

As with many states in the Eastern U.S., white-tailed deer (Odocoileus virginianus) are an important terrestrial mammal for woodland ecosystems, as well as a vital game species for Florida hunters. Following a successful study in south Florida, which provided a wealth of information on deer ecology and population dynamics, the decision was made to initiate a North Florida Deer Study (NFDS), which began in January 2020 and is set to last 5 years. The main objectives of the NFDS are to estimate adult deer survival, to assess cause-specific mortality, to describe space use (movement, habitat use, response to disturbance, etc.) using GPS collars and to estimate population density and abundance using a combination of trail cameras and GPS collars.

As part of this study, biologists will also investigate how hunting, habitat management practices such as prescribed fire and predators impact deer populations, including stress and recruitment (the process by which new individuals are added to a population, whether by birth or by immigration). The project provides tools for science-based management, including a better understanding of how habitat management practices and specific hunting methods can impact deer populations. Deer are one of the most popular game species in Florida and a valued resource for non-hunters as well. Although the key species in this study is deer, camera surveys can provide information on other wildlife species. For example, the camera data from South Florida has been used in other projects, including a multi-state evaluation of mesomammals (any medium-size mammal larger than a rodent but smaller than a bear).

Much was learned from the recently completed South Florida Deer Study (SFDS) that informed this current project. Several of the methods developed during the SFDS, including the camera-based surveys, can guide deer management throughout Florida. However, demographic parameters such as adult survival, fawn recruitment, and potential impacts of habitat management, predators and diseases on deer are typically site-specific, and results cannot easily be extrapolated outside of south Florida. In north Florida, demographic data are currently lacking or date back several decades. In addition, very little is known about the details of deer habitat use and movement patterns in north Florida. Moreover, the poor productivity soils in north Florida may make deer populations particularly sensitive to habitat management practices and stressors associated with predators and human activity.

For managers, this project will provide information on monitoring methods and how specific management practices can benefit deer. Information on movement, home-range size and detection rates are valuable from disease management perspective. Survival and recruitment data provide key information for population models.

One of the captured deer with unique piebald coloring. Piebaldism is a rare, recessive trait that occurs in less than 2% of deer.

The two main methods of research on this project include use of GPS collars to monitor deer movement, habitat use and survival, and remote sensing trail cameras to evaluate deer and other wildlife activity and to estimate fawn recruitment. GPS collars and cameras together will be used to estimate deer population density and abundance. Population density estimates will also be derived using distance sampling methods using both spotlights and a forward looking infrared (FLIR) unit. These methods will be used in both hunted and unhunted populations, across different habitat types and management regimes.

It is important to note that this project is still in its early days, as it only began in January 2020, and some of the subsequent work was delayed due to the COVID pandemic. The next step in the project is to begin a new study site at Osceola Wildlife Management Area (WMA). This will provide biologists an area where deer are exposed to very different stresses, including deer hunting and hunting of other game with dogs, potentially impacting deer indirectly. FWC researchers will continue to monitor deer survival and are currently conducting a variety of population surveys to compare several methods. By partnering with University of Florida and bringing in a PhD student, biologists are expanding this project further, which will continue through 2026.

Although the NFDS is still in the beginning days of the study, some interesting findings have already been noted. FWC biologists documented 2 cases where alligators killed deer and one additional incident where a deer was eaten by an alligator (it is unclear if the deer was killed by one). Although alligators have been documented to kill fawns and in South Florida have been documented to kill adult deer, alligator predation is relatively rare and researchers were surprised how often their “terrestrial mammal” work ended up involving canoes! The biologists also had an interesting capture event where they darted and radio-collared a piebald buck. Piebaldism is rare, occurring in less than 2% of deer. It is a recessive genetic trait, meaning both parents of this buck had to carry the gene. Because the same genetic code for coat color impacts other traits, piebald deer may have issues, such as “roman nose”, shortened lower jaw, curved backbone (scoliosis) and short/deformed legs. The piebald buck captured in this study appears healthy, however, thus far his home-range is considerably smaller than any other collared buck and even smaller than most female deer.

Once the field work is completed, the next steps will be to complete manuscripts, reports and other documents (e.g., monitoring guidelines). From the initial concept to drafting specific objectives, FWC researchers and biologists have collaborated with managers, particularly with WMA biologists. This research addresses several objectives of the 10 Year Deer Management Plan and will provide key information for Florida’s deer and habitat managers and the broader public interested in deer. Monitoring techniques evaluated in this study can provide guidelines for deer surveys beyond Florida.

The FWRI groups involved with this project are the Terrestrial Mammals Research section and Fish and Wildlife Health. The project is funded by Division of Hunting and Game Management (HGM), using Deer Permit funds. Key partners include HGM deer biologists, Osceola Wildlife Management Area biologists and University of Florida Department of Wildlife Ecology and Conservation researchers.

Assessing Florida’s Species and Ecosystems for the Future

Florida has a high density of species and ecosystems of conservation concern as well as many threats to native species and their habitats, including high human population growth and urbanization, habitat fragmentation, climate change and sea level rise. Mitigating these threats to promote persistence of intact ecological systems in the twenty-first century will require substantial effort and the identification of clear and attainable conservation targets on a landscape-scale. Indicators are an important tool in biological planning to achieve effective outcomes. Indicators provide a focus for planning, design, conservation action and collaborative monitoring of environmental trends to guide landscape-scale conservation to improve the quality and quantity of key ecological resources.

The Florida Ecological report cards are designed to provide a broad, habitat-based framework to evaluate current condition and trends of a set of Conservation Assets – the set of biological, ecological and cultural features and ecological processes collaboratively identified as most important through a series of partner/stakeholder workshops. The Conservation Assets developed for Florida represent broad landcover types, such as High Pine and Scrub, Freshwater Forested Wetlands and Coral Reefs. Two report cards have been developed, one for freshwater and terrestrial Conservation Assets and one for marine and estuarine Conservation Assets. Multiple Indicators were identified for each Conservation Asset. Each Indicator represents a quantifiable attribute of the Conservation Asset, has an appropriate unit of measure, and has an appropriate numerical endpoint to consider as a target. The Indicators will be used to monitor the overall condition and trend of the Conservation Assets. The terrestrial and freshwater report card includes targets for each Indicator – the desired future condition (e.g., quality, quantity, location and spatial configuration) of each Indicator, for the year 2030. To illustrate all this: nesting shorebirds (American oystercatcher and Snowy plover) is an Indicator for the coastal uplands Conservation Asset; the metric for this Indicator is total number of breeding adults with a target of increasing the number of breeding adults by 10% by 2030.  This target provides managers, biologists and stakeholders a clear goal.

The report cards can be used to assess the status and trend of the Conservation Assets by tracking changes across Indicators and progress towards Indicator targets. The information in the report cards will be used to help conservation practitioners working at different scales to contribute to regional conservation goals. The ability to monitor current conditions and progress towards targets will provide researchers and managers with an understanding of how their collective conservation actions are impacting fish, wildlife and their habitats statewide.

Development of Conservation Assets and Indicators was conducted using expert opinion through a series of workshops and webinars. Literature and data searches were conducted to collect and assess the applicability of potential Indicators suggested by workshop/webinar participants. GIS was used to assess spatial and temporal validity of data representing Indicators. Additional criteria were used to evaluate and select Indicators for inclusion in the report cards. For the terrestrial and freshwater Conservation Asset Indicators, additional evaluation was conducted to determine targets. Targets were established through literature review and expert opinion. A “gap” analyses was conducted to determine current status versus the target set for 2030. Graphical representations to illustrate current condition, target and progress towards targets were developed for inclusion in the report cards.

The Ecological Report cards and associated technical reports (version 1.0) are complete and are available on the Florida Conservation Planning Atlas (https://flcpa.databasin.org/). The report cards will be updated on a regular basis to provide current status and trends and progress towards targets. Work has been initiated on version 2.0 of the freshwater and terrestrial report card, including new Indicators, as well as updating the status for Indicators that can be tracked annually. Work has also begun on development of a quick reference document.

FWRI’s Information Science and Management section led this project, but many other groups contributed work as well, thanks to FWC’s Wildlife Research, Ecosystem Assessment and Restoration, Marine Fisheries Research, and Wildlife Diversity Conservation sections and the FWC Landscape Conservation Strategic Initiative. Key partners include theU.S. Fish and Wildlife Service, Florida Natural Areas Inventory, U.S. Geological Survey, Florida Department of Environmental Protection, Tall Timbers Research Station and many others through participation in workshops and providing data.

Age and Growth of American Eel in the Lower St. John’s River

By Kimberly Bonvechio, Trevor Knight, Allen Martin, Jay Holder, Jessica Carroll, and Noretta Perry

Figure 3: American eel infected with nine adult A. crassus swimbladder nematodes.

FWRI and DFFM biologists in five offices collaborated on a recent research study on American Eel Anguilla rostrata in the lower St Johns River. The Atlantic States Marine Fisheries Commission declared the American Eel stock to be in a state of decline, both in its 2012 American Eel Benchmark Stock Assessment and its 2017 American Eel Stock Assessment Update. However, there is a paucity of information about American Eel populations in the southern U.S., in particular Florida, where little is known about its life history and population dynamics. Given that Florida’s commercial American Eel harvest almost exclusively occurs in the St Johns River, this study provides important information about this exploited population to inform future management of the stock. Our primary objectives were to 1) obtain sex-specific growth rates for this population; 2) assess incidence and prevalence of Anguillicoloides crassus infection, as a function of age, size, and sex; and 3) determine timing of outward migration of mature eels.

Figure 1: Sections of the lower St Johns River that were sampled by electrofishing for American eel.

For this study, the 90-km stretch of the lower St Johns River was split into 3 sections, each sampled by electrofishing twice during each 3-week sampling period (Figure 1). Over the course of 12 weeks, from August to November, biologists collected 128 American eels. Finding them proved difficult, requiring nearly 40 hrs. of pedal time in all! Most of the eels collected were in the lowest section of the river, but all combined, individuals ranged from 150 to 626 mm TL with a large peak observed for the 32-cm size class (Figure 2). We observed adult A. crassus in 45% of swimbladders (Figure 3), but over 70% exhibited some kind of damaged swimbladder, as indicated by non-zero swimbladder degenerative index (SDI) scores (Figure 4; Lefebvre et al. 2002). Fish samples are currently being processed for age and sex determination, but we did observe morphologically distinct individuals which may indicate some maturing males were readying for outward migration to the Sargasso Sea for spawning (cover image).

Figure 2: Length distribution of eels collected during the study period in the lower St Johns River.

As most of us can relate, doing research during a pandemic has been chock full of challenges. Not only was this study delayed a year, when the time finally came to start, we couldn’t get supplies shipped in time to process samples. We are thankful for the many people who chipped in to fill in where needed, both with missing supplies and when others were sick or quarantined. Despite the challenges, we successfully completed the study and will be able to provide important data for a population in the species’ southern range. We will leave you with a couple of interesting tidbits from our work this past fall. Did you know American eel isn’t the only species that can be collected upriver in freshwater? Despite being deemed “the freshwater eel,” another species, the speckled worm eel, can be also found in similar habitats and is sometimes misidentified at first glance. About one week before Halloween, we also captured a one-eyed American eel, so naturally we nicknamed it “One-Eyed Jack” (Figure 6). That there, mateys, was like finding sunken treasure, a rare find indeed!  

Figure 4: Distribution of SDI scores for eels collected during the study period in the lower St Johns River.
Figure 6: Figure 5 American eel collected that only had one eye.

Enhanced and Created Sport Fish Nursery Habitat at Cape Haze Peninsula

By Philip Stevens

Worldwide, coastal wetlands are threatened by disrupted hydrology, urbanization, and sea level rise. In southwest Florida, coastal wetlands include tidal creeks, many of which terminate into a series of coastal ponds that provide primary habitat for juvenile Common Snook and Tarpon. Such coastal ponds occur at the interface between the estuary and upland habitats and are only temporarily connected to the open estuary, creating conditions of variable dissolved oxygen (0.5–7 mg/L) and salinity (0–40 psu). Recently, scientists from FWC’s Fisheries-Independent Monitoring, Fish Biology, and Habitat and Species Conservation programs have been intensely studying coastal pond habitats along a tidal wetland gradient on the Cape Haze peninsula of Charlotte Harbor. One of the research goals is to identify juvenile Common Snook and Tarpon nurseries, and to track the abundances of these species over several years in natural coastal ponds. Another research goal is to follow up on restoration projects that have occurred on the Cape Haze peninsula. These restoration projects were specifically designed to either create or enhance juvenile sport fish nurseries to offset those already lost to coastal development. 

One of the created/enhanced habitats on the Cape Haze peninsula is the Lemon Creek Wildflower Preserve. This preserve was once a private 18-hole golf course that was bought by the Lemon Bay Conservancy (LBC). Interestingly, two of the man-made ponds on the property had limited connections to the estuary through a marsh and a series of culverts, which allowed recruitment of juvenile Tarpon into the preserve. Biologists at the Bonefish and Tarpon Trust, working with volunteers at LBC, discovered that the juvenile Tarpon at Wildflower were leaving the relic golf course ponds rather early (prior to March) and at small sizes of less than 12 inches (instead of 16 inches as observed at other locations). Presumably, this could make them more susceptible to predation. Something about the juvenile habitat just seemed off. Subsequent seining by LBC volunteers corroborated the earlier findings, although there were some differences observed during years when Tarpon were abundant compared to years when there were fewer of them. This raised the possibility that the juvenile Tarpon could be overcrowded. A restoration effort involving a wide range of partners (LBC, NOAA, SW FL Water Management District) greatly expanded the coastal pond habitat and was completed in early 2021. Some ponds were enlarged, new ponds were created, and pathways for temporary connections were added to some preexisting ponds at higher elevations. The idea was to provide more space for the juvenile Tarpon while still retaining the limited connections to the estuary that provides protection from larger aquatic predators.

FWC’s Matt Bunting and Lemon Bay Conservancy volunteers with a juvenile Tarpon collected from Lemon Creek Wildflower Preserve.

                Following the expansion of coastal ponds at Wildflower Preserve, researchers are beginning to see juvenile Tarpon using several of the newly created ponds and preexisting ponds with the added limited connections; more importantly, Tarpon are staying longer and reaching larger sizes. Only a few sampling events have been conducted since the restoration was completed, but early results are promising. Instead of leaving around March, the juvenile Tarpon were present through at least May, and they had achieved lengths similar to the 16 inches seen in natural ponds. The FWC team is exploring the possibility of using acoustic tagging to learn more about juvenile Tarpon emigration from the Wildflower Preserve. This type of tagging strategy uses a “pinger” attached to the fish and a network of “listening stations” to detect if they have passed by. From an ongoing FWC study of natural coastal ponds on Cape Haze, preliminary acoustic tagging data have shown that juvenile Tarpon tend to leave the ponds during storm events. About half of the juvenile Tarpon that leave the natural ponds move to the mouths of major rivers where they appear to have found a secondary nursery in freshwater/low salinity habitat. So, the FWC team and partners are excited about documenting when juvenile Tarpon leave the newly restored Wildflower Preserve, and where they go next.

Our ongoing FWC research on coastal ponds in the Cape Haze area has currently documented over 15 Tarpon and Snook nurseries and our findings are being directly incorporated into an applied research plan being developed cooperatively by county and state agencies. It will be used to  encourage conservation policies for sustainability of fisheries and the adaptive management of restored fish habitat.

Aerial view of the Lemon Creek Wildflower Preserve during restoration construction. Note that preexisting ponds have shorelines lined with mature vegetation while newly created ponds have shorelines without vegetation.