Florida Fish And Wildlife Conservation Commission Research Articles

Controversial opening of a limited fishery for Atlantic Goliath Grouper in the United States: Implications for population recovery

Laws protecting the Atlantic Goliath Grouper Epinephelus itajara from fishing in federal and state waters of the United States (US) occurred in 1990 after the species was identified as being severely overfished. Population increases that occurred during the first 20 years of the closure were followed by a decline in the 10 years thereafter. Despite the National Oceanic and Atmospheric Administration’s call to retain full protection for this species in federal waters, the Florida Fish and Wildlife Conservation Commission (FWC) decided to open a limited fishery in state waters for juveniles. Here, we review the literature demonstrating the initial recovery of Goliath Grouper in the U.S., the limits of that recovery, and the ensuing factors that precipitated its subsequent decline; we discuss the risks associated with management decisions that ignore the best available scientific information; and we compare management differences and difficulties among nations within the Atlantic Goliath Grouper’s global range. The major findings are that Goliath Grouper populations have not fully recovered and that FWC has not sought to conserve and protect them. Resolving these problems will require the Governor of the State of Florida to appoint Commissioners that represent a range of stakeholders with expertise in ecology, conservation, and management beyond that provided by the FWC agency; to better train appointees lacking in those areas; and to choose candidates who embrace use of the best available science in making critical decisions that affect Florida ecosystems, native species, and Florida residents.

Dorsal Fin Spines and Rays for Nonlethal Ageing of Goliath Grouper Epinephelus itajara

Atlantic Goliath Grouper, Epinephelus itajara, the largest grouper in the western North Atlantic, exhibits life history characteristics (e.g., it is slow-growing, long-lived, and late-maturing) that make it particularly susceptible to fishing pressure. Otoliths, the structure typically processed for age determination, are usually collected as part of fishery monitoring, but otoliths are not available from Goliath Grouper due to a harvest moratorium enacted in 1990 for United States waters. Alternative structures—such as dorsal fin rays or spines—can be acquired for ageing via nonlethal sampling and may provide reliable age estimates. Since 2006, the Florida Fish and Wildlife Conservation Commission (FWC) has been collecting incidental Goliath Grouper samples from mortality events including those from cold kills and red tides. Corresponding otolith, dorsal fin ray and dorsal fin spine samples were compared to determine the accuracy and precision of the external ageing structures. Marginal increment analyses indicated that annulus (translucent zone) deposition occurred primarily in March–June on spines and in April–June on rays. While ages determined from both rays and spines exhibited high precision, the accuracy compared to otolith ages was low as a result of systematic underageing of both external structures, particularly at the oldest age classes. A correction factor was applied to rays and spines that remedied the underageing, but the correction factor was more successful for spines. An analysis of ray and spine section accuracy based on nonlethal structure removal from the fish (i.e., comparing ages from sections at the base of the structure within the body to those sectioned from the external surface of the body) determined that spines can be accurately aged when sampled distal of the base of the structure, but that rays cannot. Nonlethal sampling and ageing of Goliath Grouper spines facilitated by public participation could address management goals and help determine the offshore population age structure. Simultaneously, it could contribute critical data needed for a traditional stock assessment, should such a path be warranted by the recovery or management of the species.

‘A human values issue’: Actors, arguments, and regulatory change in the Florida land‐based shark fishery

Abstract Recreational shark fisheries have been the subject of recent public attention because of the possible impacts on shark populations and conflicts between stakeholders. A case study is presented based on discussions that took place in summer 2018 about potential changes to policies regulating recreational land‐based shark fishing in Florida. Comments from public meetings and workshops (totalling 15.8 hours) and online comments (1,050) submitted to the Florida Fish and Wildlife Conservation Commission (FWC) were analysed using the lens of actor–network theory. The case study explores the intersection of conflicting stakeholder interests and types of knowledge, including how stakeholders variously defined the problem of user conflict in a coastal public space, and how they aligned themselves in relation to the problem and to each other. It further illustrates how shifting values and norms can intersect with changing technologies and environmental realities to produce new or increasing conflicts between natural resource user groups. This study underlines the importance and potential benefits of regulatory agencies explicitly and transparently engaging with value trade‐offs when managing conflicts among users of natural resources.

How do members of the public and wildlife managers understand living with wildlife versus coexisting with wildlife?

ABSTRACT ‘Coexisting with wildlife’ and ‘living with wildlife’ are commonly used in communication efforts designed to mitigate human-wildlife conflicts. However, there is little information on how the public understands these terms and how their understanding compares to wildlife managers’ intended message. In 2019 we surveyed 1,045 Florida residents and 140 Florida Fish and Wildlife Conservation Commission (FWC) officials to examine their understanding of, and preferences for, the terms ‘coexisting with wildlife’ and ‘living with wildlife.’ We analyzed data using qualitative and quantitative methods. FWC officials were more likely to interpret both terms as people changing their behavior to mitigate human-wildlife conflicts or tolerating conflicts with wildlife, whereas the public tended to focus on reduced nuisance behavior by wildlife. Wildlife managers should clearly define terms to avoid confusion or miscommunication, which may result in the public not altering their behavior or mistakenly taking actions that exacerbate human-wildlife conflicts such as domesticating wildlife.

Trends of the Florida manatee (Trichechus manatus latirostris) rehabilitation admissions 1991-2017.

A retrospective study of admission data of 401 West Indian manatees (Trichechus manatus latirostris) presented to the David A. Straz Jr. Manatee Critical Care Center at ZooTampa at Lowry Park (ZooTampa) for rehabilitation from August 1991 through October 2017. Causes of admittance, location of rescue, gender, and age class were all recorded for each manatee admitted. Admittance categories as defined by the Florida Fish and Wildlife Conservation Commission (FWC) included watercraft collisions, natural causes, entanglement, entrapment, orphaned calves, captive born, mothers of rescued calves, calves of rescued mothers, human, and other. The admitted population was primarily from the southwest and northwest coasts and related waterways of Florida. The gender difference was relatively equivocal (54% female) while the adults comprised 79% of the admissions. The overall total admissions increased steadily over the study period as did the admissions for each individual categories of admission. Watercraft collisions and natural causes combined were 71% of all admissions for the entire study period and are the dominant causes of admission. Watercraft collisions are more likely to occur during May through October, whereas natural causes of admittance are more likely to occur between December and March. Rehabilitated manatees may reduce overall manatee mortality and can provide insight into population-based health concerns if evaluated appropriately. Future efforts can incorporate physical examination findings, hematology, biochemistry profiles, and ancillary diagnostic testing to continue to improve the individual welfare of this marine mammal in its natural range. Admissions data could also potentially serve the wider conservation and recovery efforts if it is proven that the data obtained is at least as informative as that obtained by the carcass salvage program. Limited conservation resources could then be re-directed as new challenges arise with the expanding population and potentially expanding range of this species.

Evaluating a Stakeholder‐Driven Bass Regulation Change in Florida: Agency Staff and Stakeholder Perspectives

We evaluated stakeholder engagement aspects of a statewide Largemouth Bass Micropterus salmoides regulation change in Florida. Staff from the Florida Fish and Wildlife Conservation Commission (FWC) who worked on the project and stakeholders who participated in outreach were interviewed and/or surveyed about their opinions of the process. This was the largest stakeholder engagement process ever conducted by FWC for freshwater fisheries management decision making; therefore, an evaluation was critical to measure the success of the process and to inform future stakeholder engagement. Staff reflected positively on the process but noted breakdowns in communication and a lack of human dimensions expertise. Stakeholders felt that their input was appreciated and used by the agency to aid in decision making. This evaluation illustrates where the project was effective and areas where improvements can be made for future projects.

Tolerance for the Florida panther in exurban southwest Florida

ABSTRACTHuman tolerance for negative interactions with the Florida panther (Puma concolor coryi) is an important component of panther conservation efforts. Residents’ tolerance for interactions with Florida panthers in exurban areas has not been explicitly studied, even though the highest number of documented human‐panther interactions has occurred in a single exurban community in Florida (i.e., Golden Gate Estates). We implemented a mail‐based survey in Golden Gate Estates in 2015 to investigate community members’ level of tolerance for the panther. Golden Gate Estates provides a case study for future conservation efforts as panthers recolonize their historical range, and the panther comes into contact with more exurban and residential communities. Based on regression analysis of survey data, we found that individuals with eco‐centric value orientations, individuals who were aware of panthers’ presence in Florida prior to moving to Golden Gate Estates, and individuals who believe that proper animal care protects domestic animals from panthers were more tolerant of the panther. Age, livestock ownership, panther depredation of domestic animals, and risk concern were significant negative determinants of panther tolerance. The majority of respondents were willing to collaborate with neighbors and the Florida Fish and Wildlife Conservation Commission (FWC) to manage panther‐related risks. Our research provides insights into how tolerance for the Florida panther in exurban and residential communities may be secured or improved. © 2018 The Wildlife Society.

Modified MODIS fluorescence line height data product to improve image interpretation for red tide monitoring in the eastern Gulf of Mexico

Several satellite-based methods have been used to detect and trace Karenia brevis red tide blooms in the eastern Gulf of Mexico. Some require data statistics and multiple data products while others use a single data product. Of these, the MODIS normalized fluorescence line height (nFLH) has shown its advantage of detecting blooms in waters rich in colored dissolved organic matter, thus having been used routinely to assess bloom conditions by the Florida Fish and Wildlife Conservation Commission (FWC), the official state agency of Florida responsible for red tide monitoring and mitigation. However, elevated sediment concentrations in the water column due to wind storms can also result in high nFLH values, leading to false-positive bloom interpretation. Here, a modified nFLH data product is developed to minimize such impacts through empirical adjustments of the nFLH values using MODIS-derived remote sensing reflectance in the green band at 547 nm. The new product is termed as an algal bloom index (ABI), which has shown improved performance over the original nFLH in both retrospective evaluation statistics and near real-time applications. The ABI product has been made available in near real-time through a Web portal and has been used by the FWC on a routine basis to guide field sampling efforts and prepare for red tide bulletins distributed to many user groups.

Evaluation and optimization of remote sensing techniques for detection of Karenia brevis blooms on the West Florida Shelf

We evaluated the performance of several published algorithms designed to detect Karenia brevis blooms on the West Florida Shelf using satellite imagery. Algorithms were tested using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images and historical ground-truth observations collected from August 2002 to December 2011. A total of 2323 phytoplankton cell count samples collected by the Florida Fish and Wildlife Conservation Commission (FWC) matched valid ocean color satellite observations over this period. Techniques were tested using the F-measure (FM) statistic. FM evaluates the proportion of image pixels that matches or misclassifies ground-based K. brevis observations. Several ocean color data products, such as normalized Fluorescence Line Height (nFLH), were also tested independently or combined to evaluate their effectiveness to detect K. brevis blooms. Techniques were optimized by altering their specific thresholds until the maximum FM was obtained. The historical techniques with the best performance were the Red Band Difference (RBD) and the Rrs–nFLH technique. This last method (Rrs–nFLH) is a combination of two standard ocean color data products: nFLH (> 0.033 mW cm− 2 μm− 1 sr− 1) and the remote sensing reflectance at 555 nm (Rrs555 < 0.007 sr− 1). Both techniques resulted in an FM of 0.62 and less than 3% false positives. The performance of most of the techniques improved significantly after optimization (the average FM increased from 0.47 to 0.57). The addition of a nFLH criterion improved the performance of most methods. We provide a list of recommendations on how to best apply the various techniques.

A Conservation-Based Approach to Compensation for Livestock Depredation: The Florida Panther Case Study

Calf (Bos taurus) depredation by the federally endangered Florida panther (Puma concolor coryi) on ranches in southwest Florida is an important issue because ranches represent mixed landscapes that provide habitat critical to panther recovery. The objectives of this study were to (1) quantify calf depredation by panthers on two ranches in southwest Florida, and (2) develop a habitat suitability model to evaluate the quality of panther hunting habitat on ranchlands, assess whether the model could predict predation risk to calves, and discuss its potential to be incorporated into an incentive-based compensation program. We ear-tagged 409 calves with VHF transmitters on two ranches during 2011–2013 to document calf mortality. We developed a model to evaluate the quality of panther hunting habitat on private lands in southwest Florida using environmental variables obtained from the Florida Natural Areas Inventory (FNAI) Cooperative Landcover Database and nocturnal GPS locations of panthers provided by the Florida Fish and Wildlife Conservation Commission (FWC). We then tested whether the model could predict the location of calf depredation sites. Tagged calf loss to panthers varied between the two ranches (0.5%/yr to 5.3%/yr) and may have been influenced by the amount of panther hunting habitat on each ranch as the ranch that experienced higher depredation rates contained a significantly higher probability of panther presence. Depredation sites of tagged calves had a significantly greater probability of panther presence than depredation sites of untagged calves that were found by ranchers in open pastures. This suggests that there may be more calves killed in high risk environments than are being found and reported by ranchers and that panthers can hunt effectively in open environments. It also suggests that the model may provide a means for evaluating the quality of panther hunting habitat and the corresponding risk of depredation to livestock across the landscape. We suggest that our approach could be applied to prioritize and categorize private lands for participation in a Payment for Ecosystem Services program that compensates landowners for livestock loss and incentivizes conserving high quality habitat for large carnivores where livestock depredation is a concern.

Understanding people's willingness to implement measures to manage human-bear conflict in Florida

In 2009, the Florida Fish and Wildlife Conservation Commission (FWC) began surveying individuals who reported human–bear conflicts. The purpose of this survey is to assess whether individuals take actions recommended by the FWC to reduce or eliminate conflicts. Using logit analysis, we determined which factors influenced the likelihood that surveyed individuals would follow the advice provided by the FWC for managing human–bear conflicts. We found outreach efforts by the FWC increased the probability that people who report conflicts to the agency adopted recommended measures to reduce these conflicts. Our results indicate that outreach efforts by wildlife agencies increase the likelihood that people will alter their behavior to reduce human–bear conflicts. © 2015 The Wildlife Society.

Testing Bear-Resistant Trash Cans in Residential Areas of Florida

Abstract Human—bear interactions in Florida are becoming more common as human populations grow and as the range of Ursus americanus floridanus (Florida Black Bear) increases and bears adapt to finding food in a human-modified environment. The number of calls to the Florida Fish and Wildlife Conservation Commission (FWC) concerning human—bear interactions increased from approximately 1000 calls in 2000 to more than 4000 in 2010. Almost 70% of the calls received in 2010 were related to bears consuming garbage or other unnatural foods (e.g., pet food) in residential areas. Therefore, the FWC used telephone surveys in 2 Florida communities to evaluate the effectiveness of using 2 types of bear-resistant trash cans. Surveys revealed a significant reduction in the number of bears consuming garbage and of other human—bear interactions over a 1-year period and, consequently, a positive attitude from residents toward using these trash cans. Apportioning the cost of issuing bear-resistant trash cans, however, remai...

Possible Generational Effects of Habitat Degradation on Alligator Reproduction

ABSTRACT Population decline of the American alligator (Alligator mississippiensis) was observed in Lake Apopka in central Florida, USA, in the early 1980s. This decline was thought to result from adult mortality and nest failure caused by anthropogenic increases in sediment loads, nutrients, and contaminants. Reproductive impairment also was reported. Extensive restoration of marshes associated with Lake Apopka has been conducted, as well as some limited restoration measures on the lake. Monitoring by the Florida Fish and Wildlife Conservation Commission (FFWCC) has indicated that the adult alligator population began increasing in the early 1990s. We expected that the previously reported high proportion of complete nest failure (θ0) during the 1980s may have decreased. We collected clutches from alligator nests in Lake Apopka from 1983 to 2003 and from 5 reference areas from 1988 to 1991, and we artificially incubated them. We used a Bayesian framework with Gibbs sampler of Markov chain Monte Carlo simulation to analyze θ0. Estimated θ0 was consistently higher in Lake Apopka compared with reference areas, and the difference in θ0 ranged from 0.19 to 0.56. We conducted change point analysis to identify and test the significance of the change point in θ0 in Lake Apopka between 1983 and 2003, indicating the point of reproductive recovery. The estimated Bayes factor strongly supported the single change point hypothesis against the no change point hypothesis. The major downward shift in θ0 probably occurred in the mid‐1990s, approximately a generation after the major population decline in the 1980s. Furthermore, estimated θ0 values after the change point (0.21) were comparable with those of reference areas (0.07–0.31). These results combined with the monitoring by FFWCC seem to suggest that anthropogenic habitat degradation caused reproductive impairment of adult females and decreases in θ0 occurred with the sexual maturity of a new generation of breeding females. Long‐term monitoring is essential to understand population changes due to habitat restoration. Such information can be used as an input in planning and evaluating restoration activities.

Florida Landowner Incentive Program

WEC-212, a 2-page illustrated fact sheet, describes the Florida Fish and Wildlife Conservation Commission (FWC)'s program to provide science-based recommendations and financial assistance to landowners for adopting practices that conserve and enhance Florida's habitat resources on private lands. Published by the UF Department of Wildlife Ecology and Conservation, May 2006.

Evaluating Scientific Inferences about the Florida Panther

At the request of the U.S. Fish and Wildlife Service (USFWS) and the Florida Fish and Wildlife Conservation Commission (FWC), we provide an independent assessment of the reliability of the scientific literature used to support conservation of Florida panthers (Puma concolor coryi). We independently reached similar conclusions about unreliable scientific inferences before discussing the issues with each other or with others. Although a quarter-century of research supports many published conclusions, 2 sets of unreliable inferences may compromise efforts to conserve the species. The first is a set of 4 unreliable inferences that underlie the Panther Habitat Evaluation Model (PHEM), used by agencies to evaluate projects that may affect panther habitat. Specifically, the following assertions are unreliable: 1) panthers are forest obligates, 2) panthers require large (>500 ha) forest patches, 3) panthers are reluctant to cross 90-m gaps of nonforest habitat, and 4) the value of potential panther habitat declines linearly with distance to a population core in south Florida, USA. These assertions are unreliable because the analyses excluded (without mention or rationale) almost half the available data, compared used habitats to an inappropriate set of available habitats, made inferences about habitat preference without any data on available habitats, were based only on panther locations during daytime, ignored telemetry error, or suffered from other flaws. The second is a set of 2 unreliable inferences about panther demography prior to the genetic restoration effort initiated in 1995. Inferences that neonate survival was ≥0.84 and that the panther population was demographically vigorous prior to 1995 are flawed because the survival analysis ignored mortality during the first 4 months and because other inferences were based on numbers of births and deaths in samples of convenience rather than appropriate vital rates. These faulty inferences about panther demography brought unwarranted credibility to challenges of the genetic restoration program. Faulty inferences of both sets were repeated in subsequent scientific and popular articles; in several instances, previously published work was mis-cited. In its current (2002–2005) version, PHEM is unreliable and should not be used in decisions about panther habitat. Biologists should obtain better demographic estimates and fully analyze how the introgression program has affected these rates.

Population declines and generation lengths can bias estimates of vulnerability

Wildlife Society Bulletin 2004, 32(3):979–982 Peer edited A recent analysis of avian population trends (Dunn 2002) has engendered debate over the use of trend data in attempts to identify species of conservation and management concern (Butchart 2003,Dunn 2003). Dunn (2002) used breeding-bird survey data (Sauer et al. 2003) and methods proposed by the International Union for Conservation of Nature and Natural Resources ([IUCN] 2001) and Gibbons et al. (1996) to identify vulnerable species. Dunn (2002) found that many bird species triggering conservation alerts (i.e., perceived to be imperiled) due to population declines were not actually suitable candidates for management attention because the species were widespread and still common. As Dunn (2002) stressed, alerts based exclusively on population declines can be misleading because extinction risk is a multidimensional problem requiring simultaneous consideration of several variables. Conservation and management alerts based on population trends are influenced by 1) the level of decline producing an alert, and 2) the time period over which trends are evaluated (Dunn 2002). Managers must carefully weigh these parameters and the costs (Millsap et al. 1990) associated with species considered vulnerable. However, the parameters commonly used vary considerably (Millsap et al. 1990, Gibbons et al. 1996, IUCN 2001). A fixed time period was used by Millsap et al. (1990) and Gibbons et al. (1996), while IUCN (2001) used flexible time periods determined by an organism’s generation length. The latter approach may seem more appropriate because it includes species-specific parameters, but the approach can produce distorted estimates of relative extinction risks. This note provides an example of this problem and serves to bolster recommendations provided by Dunn (2002) to consider population trends in combination with other variables associated with extinction risk. In 2002 the Florida Fish and Wildlife Conservation Commission (FFWCC) adopted criteria developed by IUCN (2001) for estimating extinction risk and incorporated the criteria in the state’s legal definitions of protected species (Florida Administrative Code Rule 68A-27.0012). The FFWCC’s goal was similar to IUCN (2001), namely to gauge the global extinction risk of hundreds of species falling under the agency’s jurisdiction (FFWCC 2001). The new criteria considered population declines as well total population size, area occupied, and geographic distribution. The history and development of FFWCC’s new laws were described in Cox et al. (2002). Proposed reclassifications of the red-cockaded woodpecker (Picoides borealis) and the gopher tortoise (Gopherus polyphemus) occurred soon after the new criteria were adopted (Cox et al. 2002). The petition for the red-cockaded woodpecker (FFWCC 2002a) concluded that the species Commentary: Population declines and generation lengths can bias estimates of vulnerability