Understanding the link between indicator species and their environment is imperative to managing and conserving anthropogenically-altered ecosystems. Seasonally-pulsed wetlands are uniquely complex ecosystem where water-level fluctuations shape trophic interactions. Anthropogenic manipulation of water-level fluctuation threatens the integrity of these systems worldwide. Wading birds, a group of species sensitive to landuse changes and fluctuating habitat conditions, serve as important indicators for wetland health. I used wading birds in the Everglades, as a model system to address the challenges of environmental restoration within an ecosystem heavily impacted by anthropogenic activities. Specifically, I 1) identified the nesting response of Great Egret (Ardea alba), White Ibis (Eudocimus albus), and Wood Stork (Mycteria americana) to hydrologically-mediated changes in food availability and 2) quantified spatiotemporal foraging-habitat selection of Great Egrets, White Ibis, and Wood Storks to fluctuating hydrologic conditions. Collectively, model selection results suggest food availability, generated through dynamic hydrological conditions, is a strong predictor of the abundance of nesting birds in a given year. Great egret and white ibis produce the highest nests numbers in years when the frequency of days of rising water is low. Wood stork nest numbers are the highest in years with high prey production coupled with continuous prey availability. My study of resource selection indicated wading birds select foraging sites based on similar hydrologic parameters, but the response varies by species. Wood storks are more likely to forage in shallow cells (< 10 cm) drying with high recession rates (0.5-1.5 cm/day), and long time since last drydown (600 days). White ibises selected foraging cells with relatively shallow water depths (0-15 cm), intermediate recession rates (0.5-1.0 cm/day), and long time since drydown (600 days). Great egrets selected foraging cells with a wider range of water depths (0-20 cm) where recession rates were lower (0.5 cm/day). All species are more likely to forage in cells where water has not increased by more than 3 cm in the previous two weeks. These differences in resource selections correspond to morphological and behavioral differences in the species, whereby wood storks were more constrained hydrologically and would be more affected by water-level manipulation. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Peat soils are known to be a significant emitter of atmospheric greenhouse gasses. However, the spatial and temporal variability in production and release of greenhouse gases (such as methane) in peat soils remains uncertain, particularly for low-latitude peatlands like the Florida Everglades, as the majority of studies on gas dynamics in peatlands focus on northern peatlands. The purpose of the work outlined here is focused on understanding the spatial and temporal variability in biogenic gas dynamics (i.e. production and release of methane and carbon dioxide) by implementing various experiments in the Florida Everglades at different scales of measurement, using noninvasive hydrogeophysical methods. Non-invasive methods include ground-penetrating radar (GPR), gas traps, time-lapse cameras, and hydrostatic pressure head measurements, that were constrained with direct measurements on soil cores like porosity, and gas composition using gas chromatography. By utilizing the measurements of in-situ gas volumes, we are able to estimate gas production using a mass balance approach, explore spatial and temporal variabilities of gas dynamics, and better constrain gas ebullition models. A better understanding of the spatial and temporal variability in gas production and release in peat soils from the Everglades has implications regarding the role of subtropical wetlands in the global carbon cycle, and can help providing better production and flux estimates to help global climate researchers improve their predictions and models for climate change. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

The hydrological and topographical variation of wetlands can affect the behavior, population growth, and local densities of aquatic species, which in turn can drive the behavior and density dynamics of gleaning predators. Prey availability, primarily determined by prey density and water depth in wetlands, is an important limiting factor for nesting wading bird populations, top predators in the south Florida Everglades. The Everglades is able to support large colonies of nesting wading birds because of the microtopographic variation in the landscape. Some types of prey concentrate in flat, shallow sloughs or become trapped in isolated pools as they move down from higher elevation ridges with receding water levels. Manipulations to the hydrology and landscape of the Everglades has negatively impacted nesting wading bird populations in the past, and may continue to be detrimental by allowing flat, shallow sloughs to be intersected by deep canals, a potential refuge for wading bird prey. In addition, the subtle elevation differences between the ridge and slough landscape may be an important mechanism for increasing slough crayfish (Procambarus fallax) prey availability for the most abundant and seemingly depth-sensitive Everglades wading bird, the White Ibis (Eudocimus albus). I implemented a 2-year experimental study in four replicated manmade wetlands with controlled water recession rates in order to determine the effects of proximate deep water (akin to canals) on fish prey concentrations in the sloughs, as water levels receded similarly to a natural Everglades dry season. I also calculated average daily wading bird densities with game cameras (Reconyx PC800 Hyperfire) using timelapse imagery over 60 days to determine when and where wading birds responded to changing prey concentrations. I completed an additional observational study on White Ibis and slough crayfish prey from the first year of data (2017). Crayfish make up the majority of the diet for nesting White Ibis, and literature has suggested crayfish are most abundant at slough depths much deeper than previously proposed foraging depth limitations for White Ibis. This study specifically compared recent determinations about crayfish movement dynamics in the ridge and slough system with White Ibis foraging behavior and depth limits. Results from the first experimental study suggest that canals might be an attractive refuge for relatively large prey fishes (> 3 cm SL) in sloughs, but it is uncertain if the fencing blocked all prey fish movement. The second observational study determined White Ibis foraging activity was primarily driven by a down-gradient crayfish flux from ridge to slough, with the majority of foraging activity occurring at much deeper slough depths than previously suggested water depth limitations for White Ibis. Results from both of these studies support the importance of preserving the ridgeslough landscape of the Everglades to sustain high prey availability for wading birds. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Place theory examines the relationship between human identity and physical locations, asking how meaningful attachments are formed between people and the spots they visit or in which they live. Literature of place exhibits this relationship and the myriad ways humans connect to their environment through storytelling, both fictional and nonfictional. Florida literature, an emerging and dynamic genre, features characters, cultures, and histories heavily embedded in place. Florida’s places also abound with animal presences, and literature about Florida almost always illustrates significant human-animal interactions that drive plots and character development. Therefore, Florida literature invites consideration of how animals influence human attachment to the land in stories written by Florida authors. Scholarly attention has noted the important relationships formed by humans and animals in literature about Florida, but no extensive study incorporating place theory, ecocriticism, and close reading has been done on the literary representation of Florida animals or their contribution to the state’s diverse reputations. This dissertation brings together theories about place attachment, ecocriticism, and critical animal studies (CAS) to illustrate the roles of fictional and nonfictional animals in works by six Florida authors: William Bartram, Marjory Stoneman Douglas, Marjorie Kinnan Rawlings, Elizabeth Bishop, Rachel Carson, and John Henry Fleming. These works contain prominent animal characters that illuminate four ways of seeing Florida: idyllic Florida, wild Florida, opportunistic Florida, and mysterious Florida. These identities build off historical views about Florida as place: explorers, tourists, and developers projected their hopes for advancement onto the state based on its reputation as an exotic paradise, wild hinterland, or untouched beacon for industry and agriculture. Literature helped to produce these ideas about Florida through travel writing, but Florida stories also critique opportunistic ideologies responsible for harming animals and the environment. Literature can also preserve Florida’s mysteries and myths, offering narratives about nature and animals that challenge notions of human superiority. Thus, literature enacts a dynamic engagement with the four faces of Florida I discuss. Florida animals are vital to the construction of these four identities. For example, Henry Bunk, the protagonist of Douglas’s Alligator Crossings, sees the Everglades as an idyllic alternative to the city for its many birds and fish. Rawlings depicts Cross Creek as a wild host to deadly snakes, predatory big cats, and ubiquitous insects. Bishop captures through poetry the ordinary activity of Florida fishing in such a way that invites us to question the harm inflicted on animals for the opportunity of recreation. Fleming’s stories suggest that exploration, industry, and science have mostly erased the mysteries of Florida’s natural world, but his enigmatic and monstrous animals, along with their ties to the land, offer hope for reviving a meaningful attachment to the land. This dissertation connects literary representations of animals to real forms of violence occurring in Florida today, including fishing, caged hunting, and animal captivity. The works examined herein can prompt readers to rethink their own relationships to place and to nonhuman nature. As a cultural force, literature holds the potential for effecting change in our world. Beginning with the local is one way of witnessing this potential for the dynamic interplay between literature and place.

Spatial and temporal heterogeneity of water and nutrient pools is closely associated with the existence of different plant communities in hydrologically-controlled ecosystems such as the Everglades. These various communities differ in their flooding and fire tolerances as well as nutrient requirements. Upland plant communities are of particular ecological significance since they have high biodiversity and provide habitat to terrestrial fauna, yet comprise less than 10 % of the total area. Restoration and maintenance of such communities requires an understanding of their water and nutrient requirements. Chapter 2 compares water source utilization in hammocks and pine rocklands on the Miami Rock Ridge using stable isotopes of water. Hammocks do not flood, while adjacent pinelands may flood between 2-3 months. In the wet season, hammocks were found to use phosphorus (P) rich soilwater, a local pool of water and nutrients while pineland plants primarily relied upon groundwater, the regional pool. Access to a rich pool of P in the oligotrophic Everglades was associated with higher community-level foliar P concentration in hammocks. However in the dry season, hammocks utilized groundwater, which suggests sensitivity to extended droughts. Chapter 3 compares the hammock (upland or head) and swamp forests (lowland or tail) on tree islands in the Shark River Slough. Uplands were associated with P-rich soilwater uptake in the wet season, with regional water uptake in the dry season. Accordingly, tree island heads are rich in foliar P and thereby P-hotspots in the Everglades. Foliar nutrient concentrations can thus indicate limiting nutrient availability in the Everglades. Chapter 4 looks at how leaf phenology patterns are tied to water and nutrient pools. Leaf fall in ridge hammocks is associated with high foliar carbon isotope values over the dry season, which is not the case for tree island hammocks. However, in some species, high levels of foliar nitrogen are also associated with high foliar C13 values indicating stomatal limitation of photosynthesis. Growing season for most hammock species is the wet season coinciding with high availability of P, as reflected in high foliar P in this season. Linking water sources to foliar nutrients elucidates roles of water and nutrient pools in leading to different plant communities within an ecosystem.

Salmonellosis or “food poisoning” is a foodborne infection brought on by the pathogen Salmonella from the ingestion of the bacterium on contaminated foods such as vegetables. Infection from Salmonella leads to the highest incidence of hospitalizations and deaths each year, compared to any other bacterial foodborne illness. South Florida is the second largest agricultural winter vegetable producer in the United States, and contamination of vegetables is often observed in preharvest practices. A hardy bacterium, Salmonella, has been shown to live up to 6 weeks in soil and water up to 42°C without a host. The Florida Everglades is a tropical wetland that plays a large role in South Florida’s watershed. It can be divided into agricultural, conservation, and urban areas that connect Lake Okeechobee to Florida Bay by canals, swamps, and rivers. Inland canals tightly regulate water levels in South Florida as a means of flood control for residential and agricultural land. With the influences of anthropomorphic run off from agricultural and urban use, we hypothesized that microbial communities would significantly differ between three select sites in western (Collier county) versus three sites in more urban eastern Florida (Broward county): natural standing water, manmade drainage canal in agricultural areas, and manmade drainage canals in urban areas. We also hypothesized that pathogenic like Salmonella would be present in these habitats. Deep sequencing and ecological genetics analyses of the 16s rRNA V4 region yielded a total of 163,320 unique bacterial OTUs from a total of 139 samples collected monthly for one year in 2015 and part of 2016. Salmonella is not considered an abundant taxon within the microbial population. With the knowledge that Salmonella resides within the microbial population isolates were cultured from soil and water samples that were taken monthly from each site using a modified version of the Food and Drug Administration Bacterial Analytical Methods manual (FDA-BAM). The culturing resulted in 234 isolates obtained and 31 different serovars of Salmonella. Culturing showed that Salmonella favored months with high standing water and high-water temperatures that would lead to the ideal environment for survival. The most commonly occurring isolates within the sample set are those associated with agricultural animals. Though Salmonella may be a rare taxon within the microbial population given the correct environmental conditions such as warm temperatures it is possible to observe Salmonella year round within the South Florida environment.

Human exposure to methylmercury (MeHg) through diets (e.g., fish and rice) is a global health concern. Although MeHg exposure through fish consumption has long been considered the major route of mercury health risks, studies concerning the long-term changes in MeHg exposure from fish remain lacking. In sharply contrast to the fish MeHg issue, the presence of MeHg in rice has only been reported recently and its implications on MeHg exposure, albeit probably important, are still in infancy. Focusing on the discrepancies in the studies of MeHg exposure through fish and rice consumption, this study was aimed to assess the MeHg exposure of human infants through consumption of rice cereals and to evaluate the long-term changes in fish MeHg. The presence of MeHg in rice prompted the studies on MeHg concentrations and bioaccessibility in rice cereals and potential infant dietary exposure to MeHg through cereal consumption, which is believed to be the first of its kind. The analysis of a variety of infant cereals sampled from the common markets in the United States and China showed that the concentrations of MeHg in the cereals ranged from 0.07 to 13.9 µg/kg with a mean of 1.61 µg/kg. On the basis of these MeHg concentrations, the daily intake of MeHg through rice cereal consumption for infants was estimated to be 4-122% of the reference dose (RfD). The MeHg bioaccessibility in the cereals, determined using an in vitro digestion method, ranged from 25 to 74% with a mean of 48±16%. A further examination on these results, however, revealed the occurrence of MeHg re-adsorption during extraction steps, which leads to the underestimation of MeHg bioaccessibility and warrants cautions to be exercised when using these procedures to evaluate bioaccessibility in general. The long-term changes in fish MeHg were investigated through conducting a comprehensive data analysis on datasets for the Everglades, a well-studied aquatic ecosystem for Hg contamination. The results showed a clear decline of MeHg in mosquitofish in the Everglades during the past two decades, which was probably related to changes in environmental conditions (e.g., periphyton, dissolve organic matter, and sulfate) instead of mercury deposition.

Port Everglades Inlet is one of the busiest ports in the country and is a point source of pollution to surrounding beaches and offshore corals from heavy boat traffic and urban runoff. Understanding fluctuations of bacterioplankton communities in major port inlets is important due to their impacts on surrounding marine environments. To understand annual microbial fluctuations, the 16s rRNA V4 hypervariable region was sequenced using Illumina high-throughput DNA sequencing technology. Surface samples were taken weekly for one year to generate baseline fluctuations in the microbial community. Total reads of 1.4 million were generated with a final count of 16,384 Operational Taxonomic Units. The dominant phyla were Proteobacteria, Cyanobacteria, Bacteroidetes, and Actinobacteria. Pathogenic genera were detected at low abundances during peak shipping and tourist months (November –April). Results indicate significant differences in alpha diversity when comparing microbial communities in August with other times. This was likely caused by low community richness and abundance, and below-average August rainfall levels. Differences in beta diversity were significant when comparing monthly and seasonal changes. Rainfall, temperature, and nutrient trends may have affected microbial composition, specifically during the dry season that was warmer and wetter than historical averages for 2013-2014. Increased nitrogen and phosphorous concentrations were observed in the dry season months of October, December, and January potentially creating optimal bacterial growth conditions. These results can be compared with historical and future data regarding inlet microbial communities to determine underlying baselines of bacterioplankton communities and monitor the health of marine and recreational environments they impact. This study represents the first to characterize at this scale and use Illumina MiSeq technology to analyze water samples from Port Everglades.

The assembly mechanisms underlying microbial community abundance, biotic interactions, and diversity over space and time are unresolved, particularly in benthic microbial mats distributed along environmental gradients. Experimental enrichment of nutrient-limited microbial mats from the Florida Everglades along a nutrient subsidy-salinity stress gradient stimulated autotrophic and heterotrophic metabolism, growth, and diversity independent of autotroph-heterotroph interactions across treatments and space. These results suggest spatial segregation of autotrophic and heterotrophic components within mats. Considering only the diatom component of Everglades mats over space and time, the subsidy-stress gradient controlled diatom compositional turnover at broad spatial scales while environmental and dispersal-based processes structured diatom communities at the regional scale and environmental processes independent of the environmental gradient at the temporal scale. These results indicate environmental gradients may not necessarily increase connectivity and dispersal across space, and temporal microbial diversity is driven at the local and regional scales by environmental heterogeneity in benthic microbial communities.

Vertebrate populations are subjected to novel anthropogenic stressors that are expected to multiply exponentially in the future. Introductions of nonnative species and human-altered hydrology are among these stressors to native species communities. The Rocky Glades, located in Everglades National Park, may serve as a population sink for native species that typically do not survive the altered hydrology of the dry season, and as a source of nonnative species that may be better adapted to chronically stressful conditions. In the seasonally-flooded Everglades, the nonnative African Jewelfish invaded in the 1960s and has since shown rapid range expansion. African Jewelfish are aggressive and territorial, thus they are predicted to be more successful at acquiring space and resources, and may displace native Sunfishes. I monitored assemblages of fish across time in experimental mesocosms and solution holes and quantified survivorship and body condition of both natives and nonnatives. Overall, native Sunfish did poorly while nonnatives had higher survivorship over the course of the dry season. Unexpectedly, no evidence indicated that Jewelfish reduced survival of native Sunfish. I compared aggressive interactions between native Dollar Sunfish and nonnative African Jewelfish in Sunfish populations either sympatric or allopatric with Jewelfish. Sympatric Dollar Sunfish were twice as likely to approach African Jewelfish as allopatric ones. My study suggests native species can survive invasion through behavioral adaptation to nonnative competitors. Characterizing interactions between native and nonnative species and identifying their niche use can assist in understanding the challenges of native species conservation in the face of species invasions.