Digital Commons Network^™

Effects Of Environmental And Anthropogenic Factors On Loggerhead Sea Turtle (Caretta Caretta) False Crawl Rates On Jekyll Island, Ga, Brittany Byrd

UNF Graduate Theses and Dissertations

Loggerhead sea turtles (Caretta caretta) are currently listed as “vulnerable” on the IUCN Red List and are experiencing population declines across many parts of their range. These declines are caused by environmental and anthropogenic stressors which impact sea turtle ecology and behavior, including nesting behavior. One nesting behavior sea turtles exhibit is known as “false crawling,” which is when a female sea turtle ascends the beach in an attempt to nest and either abandons the attempt altogether or while in the middle of digging an egg chamber. False crawling, a largely understudied sea turtle behavior, can not only …

The Effect Of Visitor Density And Interaction On The Behavior Of Four Ray Species (Hypanus Sabina, Hypanus Say, Pseudobatos Lentiginosus, And Rhinoptera Bonasus) Housed In An Aquatic Touch Pool, Aimee Marie Little

UNF Graduate Theses and Dissertations

Human-Animal Interactions (HAI) in zoological institutions are thought to be important in helping visitors to establish a connection with animals and thus making them more likely to contribute to conservation efforts. However, animals can respond to visitor interaction in both negative and positive ways. The growing focus on animal welfare in zoological institutions emphasizes the need for assessing different environmental inputs, including visitor interaction, and how these inputs influence behavioral outputs associated with welfare. A touch pool exhibit presents a novel interactive experience that allows visitors to directly interact with various aquatic species, including elasmobranchs, whose conservation has important implications …

Revitalizing Conservation And Management Of The American Crocodile (Crocodylus Acutus) In The Dominican Republic, Robert Greco

UNF Graduate Theses and Dissertations

Crocodilian populations declined globally during the 20^th century because of overhunting and habitat loss. Some crocodilian populations have recovered recently through legal protections and habitat restoration, but the status of many crocodilian populations are still unknown because of a lack of recent data. The American crocodile (Crocodylus acutus) population in the Dominican Republic (DR) is one of these data-deficient populations, with country-wide surveys not carried out since the 1980s. From May through July 2021 we surveyed areas within DR where C. acutus is still likely residing. Our surveys yielded no crocodile sightings in Monte Cristi, suggesting that …

Evaluation Of The Use Of Alternative Biomarkers As Indicators Of Post-Release Mortality In Blacktip Sharks (Carcharhinus Limbatus), Casey L. Zender

UNF Graduate Theses and Dissertations

The release of sharks caught in recreational fisheries or as by-catch in non-target commercial fisheries is generally regarded as a sustainable fishing approach. However, post-release mortality can occur in these fish due to physiological damage sustained during capture. It is important to determine the amount of mortality specifically attributed to capture so losses can be accounted for in population management practices. Previous studies have used electronic tagging and/or measurement of secondary stress indicators in plasma (e.g., pH, levels of lactate, glucose, pCO₂) to estimate rates of post-release mortality. These methods may not always be the best approaches, as …

Implementing Welfare Science: Case Studies In Evidence-Based Zoo Management, Marisa Suzanne Spain

UNF Graduate Theses and Dissertations

Animal welfare science is a field that focuses on how we can improve the lives and well-being of animals in human care. Modern welfare science has moved away from simply preventing suffering and on to promoting positive welfare states, a concept that has been coined animal “wellness”. A process called evidence-based zoo management has been implemented in many zoos as a way to promote and ensure wellness. This is the idea that husbandry and housing standards should be evaluated and tested for their efficacy using data rather than relying on traditional best practices. In this manuscript we discuss an informal …

Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs

UNF Graduate Theses and Dissertations

Previous research regarding aquatic acidification has examined the protonation of the carbonate and does not consider calcium to be a limiting factor. This is the first study to suggest that pH may affect the uptake of calcium in crustacean gills. This project describes ion transport mechanisms present in the cell membranes of white river shrimp Litopenaeus setiferus gill epithelium, and the effects of pH on the uptake of calcium by these means. Partially purified membrane vesicles (PPMV) of shrimp gills were prepared through a homogenization process that has been used previously to define ion transport in crab and lobster gill …

Behavioral Assessment Of Social Structure And Guest Provisioning Program Participation Of Zoo-Housed Giraffes (Giraffa Camelopardalis) Under Varying Spatial Availability., Fatima Ramis

UNF Graduate Theses and Dissertations

Close encounters with animals are considered integral for visitors and are trademark components of traditional educational engagement in zoological parks. As capacity for up-close encounters continue to increase with a simultaneous development in the field of animal welfare science, behavioral assessments on the role of common close encounters is timely. Giraffes (Giraffa camelopardalis) visitor feeding programs are established in approximately 57% of institutions accredited by Association of Zoos and Aquariums. Due to successful breeding and capacity building for zoological giraffe populations, this percentage will likely continue to increase. There is a great deal of variation in the environmental …

Spatial Variation In Fishery Exploitation Of Mature Female Blue Crabs (C. Sapidus) In Chesapeake Bay, Corey Travis Corrick

UNF Graduate Theses and Dissertations

From 2008 to 2012, the total U.S. commercial landings of blue crabs (Callinectes sapidus Rathbun, 1896) averaged over 173 million lbs. Chesapeake Bay and its tributaries are important contributors to this fishery, providing greater than 30% of national commercial landings annually. In Chesapeake Bay, C. sapidus exhibits a complex life cycle in which mated females migrate to the saline waters of the Bay mouth to spawn. During migration, females can traverse multiple management jurisdictions, complicating effective management of this important fishery. Sustained declines in harvest have led to management strategies focused on protecting the female spawning stock in an …

Reproductive Biology Of The Tiger Shark In The Western Atlantic Ocean, Chelsea Shields

UNF Graduate Theses and Dissertations

Although tiger sharks are an important apex predator in many ecosystems, little is known about their reproduction. The goal of this study was to determine the size-at-maturity and the reproductive seasonality of tiger sharks in the western Atlantic Ocean. This was achieved using a combination of ultrasonography and measurements of plasma hormone concentrations; in particular, testosterone for males and estradiol and progesterone for females. Steroid hormone concentrations were measured using chemiluminescent assays (CLIA). Maturity was also examined through histology of reproductive organs in females and clasper calcification in males. Females were found to mature between 270 and 310 cm total …

Survey Gear Comparisons And Shark Nursery Habitat Use In Southeast Georgia Estuaries, Jeffrey Cohen Carpenter

UNF Graduate Theses and Dissertations

Gill nets and longlines were compared as shark nursery sampling methodologies in inshore waters of Georgia to (1) assess differences in gear selectivity, bias, and stress of capture and (2) determine potential relationships between habitat features and shark distribution and abundance. Gear selectivity varied between gears as a function of both species and life stage resulting in significantly different estimates of species and life stage compositions. Juvenile bonnetheads (Sphyrna tiburo) and young of the year blacktip sharks (Carcharhinus limbatus) experienced significantly higher stress from gill net capture than longline. Major sources of bias are thought to …

Behavioral And Physiological Assessment Of Zoo-Housed Heterosexual Gorilla (Gorilla Gorilla Gorilla) Troops With Multiple Silverbacks, Kaylin S. Tennant

UNF Graduate Theses and Dissertations

Based on recognized life history traits and ecology, zoos strive to house their gorillas (Gorilla gorilla gorilla) in mixed-sex groups with one mature male or silverback, multiple females, and their offspring. However, successful captive breeding programs and a nearly 50:50 birth sex ratio has created the need to house surplus males in solitary conditions or all-male groups. It is commonly believed that male western gorillas will not tolerate one another in the presence of females; however, multi-male, mixed-sex groups have been observed in the wild. For this reason, some zoos have begun experimenting with this scenario. At the …

Non-Lethal Methods For Assessing Reproductive Status In Bonnethead Sharks (Sphyrna Tiburo), Brenda Carol Anderson

UNF Graduate Theses and Dissertations

Reproductive biology is a necessary element for the management of elasmobranch fisheries. Traditionally, characterization of elasmobranch reproduction has involved lethal sampling to examine gross reproductive structures and development of embryos. However, this method is counterproductive to the conservation of shark populations. One non-lethal alternative is the measurement of serum hormones, which often vary according to reproductive events. Radioimmunoassay (RIA) has been used to measure hormone concentrations in reproductive endocrinology, but can be problematic for researchers. Alternatively, chemiluminescence immunoassays (CLIA) are routinely used for measuring circulating hormone concentrations in low-volume, non-extracted human serum samples. However these assays have not been previously …

The Reproductive Biology Of The Finetooth Shark, Carcharhinus Isodon, In The Northwest Atlantic Ocean, Amanda N. Brown

UNF Graduate Theses and Dissertations

Shark fisheries are a multimillion dollar industry in the United States and have significant contributions both recreationally and commercially. In order to maintain this industry, fisheries must be properly managed. An understanding of life history and reproduction is crucial in order to adequately manage shark fisheries. The finetooth shark, Carcharhinus isodon, is a member of the small coastal shark (SCS) fishery complex. It is found in Atlantic waters from South Carolina to Florida and throughout the Gulf of Mexico. This species has recently come under increased fishing pressure and has previously been overfished. New data is needed in order …

Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino

UNF Graduate Theses and Dissertations

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its …

Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey

UNF Graduate Theses and Dissertations

Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning …

Nutrient Transport By Shrimp Hepatopancreas, Tamla A. Simmons

UNF Graduate Theses and Dissertations

Purified brush border membrane vesicles (BBMV) were isolated to characterize primary cellular transport mechanisms for white shrimp. The ultimate goal is to determine the effective components of a shrimp’s diet, thereby enhancing growth, as well as nutrient content. Juvenile shrimp are dependent on plant material as a food source. Potassium is a key component of plants, thus it may play a role in nutrient transport. In addition, divalent metals have been shown to act as co-transporters in several other organisms, thus they may serve as a transport mechanism for shrimp.

Fresh, live, white or brown shrimp were obtained, and from …

The Effect Of Zinc On L-Leucine Transport In Lobster Intestine, Anna Lynn Mullins

UNF Graduate Theses and Dissertations

The current study is a characterization of L-leucine absorption across the American lobster intestine in order to determine the likelihood of a bis-complex formation with zinc ([Leu]-Zn-[Leu]) as a possible substrate for PEPT1. This study required isolated lobster intestines to be mounted in a perfusion chamber in order to quantify 3H-L-leucine transport. It was hypothesized that an apical dipeptide transporter, PEPT1, was responsible for uptake of L-leucine via formation of a bis-complex with zinc ([Leu]-Zn-[Leu]) in the form of molecular mimicry, where the bis-complex mimics the normal dipeptide substrate of the proposed carrier system. It was found that L-leucine transport …

Physical And Health Assessment Of A Population Of Raccoon (Procyon Lotor) In Northeastern Florida, Eric C. Munscher

UNF Graduate Theses and Dissertations

The purpose of this research was to study the potential negative effects that mesopredators have on their environment and to promote control of mesopredator populations. Overabundant predatory species such as the raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana) can have significant pernicious effects on populations of autochthonous prey species, particularly when super predators such as the red wolf (Canis rufus) and Florida panther (Felis concolor coryii) are absent. These overabundant species, coined as mesopredators, are often responsible for extreme levels of predation on prey species and/or their young. The mesopredator release hypothesis involves the "release" or increased density of …