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Full-Text Articles in Marine Biology

Horseshoe Crabs, Jessie M. Roncevic Oct 2025

Horseshoe Crabs, Jessie M. Roncevic

PANDION: The Osprey Journal of Research and Ideas

Horseshoe crabs (Limulus polyphemus) are fascinating animals known as “living fossils.” Older than dinosaurs, horseshoe crabs are arthropods, closely related to spiders and scorpions. Many shorebirds, including red knot, depend on the eggs of horseshoe crabs during migration. Horseshoe crabs are captured and bled alive for their blue blood. Rich in limulus amebocyte lysate (LAL), their blood is used for the Limulus Amebocyte Lysate (LAL) test, which is used worldwide to detect bacterial toxins in pharmaceuticals and medical devices.

Horseshoe crabs have an intricate anatomy, so I spent a lot of time researching it before I started drawing them. When …


Spatial And Temporal Patterns In Short-Term Surface Sediment Deposition And Accretion At The Guana Tolomato Matanzas National Estuarine Research Reserve: Implications For Resilience Of Coastal Wetlands To Sea-Level Rise, Jacob Michael Berna Jan 2025

Spatial And Temporal Patterns In Short-Term Surface Sediment Deposition And Accretion At The Guana Tolomato Matanzas National Estuarine Research Reserve: Implications For Resilience Of Coastal Wetlands To Sea-Level Rise, Jacob Michael Berna

UNF Graduate Theses and Dissertations

Coastal wetlands are at risk of drowning due to the increasing threat of rising sea levels. Wetlands will have to build in elevation vertically or migrate horizontally to survive. Previous research has demonstrated that some wetlands have the potential to naturally build in elevation over time if deposition and accretion rates from allochthonous sediment delivery are substantial, but work in this area has been limited, and many coastal wetlands remain understudied. Portions of Northeast Florida are especially lacking in short-term surface deposition and accretion data. Without surface rates it is difficult to determine the vulnerability of different wetlands to rising …


The Presence Of Mercury (Hg) And Perfluoroalkyl Substances (Pfas) In The Guana And Tolomato Rivers, Morgan E. Lattomus Jan 2025

The Presence Of Mercury (Hg) And Perfluoroalkyl Substances (Pfas) In The Guana And Tolomato Rivers, Morgan E. Lattomus

UNF Graduate Theses and Dissertations

The Guana and Tolomato Rivers provide essential habitat for several ecologically and economically important species and is a well-loved and recreated area. Spanning the northeastern Florida coast, the rivers are home to over 50 endangered or threatened species and host several habitat restoration projects due to their ecological significance and proximity to development along the coast. The effects of human influence and pollution, and specifically toxic metal mercury (Hg) and perfluoroalkyl substances (PFAS), are not well known within the system. Hg is known to biomagnify within food webs, and there is a considerable lack of literature concerning PFAS behavior within …


Use Of Coelomic Fluid As A Noninvasive Indicator Of Reproductive Status In Elasmobranchs, Emily Sapp Jan 2025

Use Of Coelomic Fluid As A Noninvasive Indicator Of Reproductive Status In Elasmobranchs, Emily Sapp

UNF Graduate Theses and Dissertations

Information on reproduction in elasmobranchs is important for the management and conservation of populations. However, the ability to obtain reliable data on elasmobranch reproduction without animal euthanasia is extremely limited. Therefore, there has been a call for nonlethal approaches for identifying reproductive status of elasmobranchs. Although useful, current techniques can be limited with respect to access to equipment and reliability of blood analyses. This study investigates whether a new noninvasive approach, the examination of coelomic fluid (CF), can provide a reliable indicator of reproductive status. CF is fluid that bathes the internal organs of the abdominal cavity, including ovaries, and …


Long-Term Abundance Estimates Of A Northeast Florida Estuarine Dolphin Community: Evaluating The Impacts Of The 2013–2015 Cetacean Morbillivirus Unusual Mortality Event, Allison L. Wilkins Jan 2025

Long-Term Abundance Estimates Of A Northeast Florida Estuarine Dolphin Community: Evaluating The Impacts Of The 2013–2015 Cetacean Morbillivirus Unusual Mortality Event, Allison L. Wilkins

UNF Graduate Theses and Dissertations

Tamanend's bottlenose dolphins (Tursiops erebennus) in the St. Johns River (SJR), Jacksonville, FL, are subjected to substantial anthropogenic stressors (e.g., vessel traffic, dredging, fisheries interactions) and were heavily impacted by the 2013-2015 Mid-Atlantic cetacean morbillivirus unusual mortality event (UME). High prevalence of skin lesions and frequent sightings of emaciated dolphins suggest declining health and viability of the SJR dolphin community. Sighting data from Jul. 2011 to Oct. 2019 provided the rare opportunity to investigate long-term changes in dolphin abundance surrounding the UME. This study produced the first dolphin abundance estimate within the Jacksonville Estuarine System stock since 1997, …


The Moon Jelly, Adam Krogmann Oct 2024

The Moon Jelly, Adam Krogmann

PANDION: The Osprey Journal of Research and Ideas

Artist Statement

The Moon Jelly is a piece I created as a part of the Scientific Illustration course I participated in during the summer semester of 2023. This piece was inspired by the livestreams of the Monterey Bay Aquarium that film these moon jellies (Aurelia aurita) in their tank. The Moon Jelly is an ink drawing created as part of a collection focused on Monterey Bay Aquarium animals. Through this artwork I hoped to draw attention to smaller marine animals that may otherwise be overlooked even though they provide a vital role in the ecosystem. Moon jellyfish are important marine …


Turtlegrass (Thalassia Testudinum) Undergoes A Coordinated Hypersensitive Response When Challenged With Pathogenic Labyrinthula Sp., Ava Vasile Larson Jan 2024

Turtlegrass (Thalassia Testudinum) Undergoes A Coordinated Hypersensitive Response When Challenged With Pathogenic Labyrinthula Sp., Ava Vasile Larson

UNF Graduate Theses and Dissertations

Infection of the subtropical seagrass Thalassia testudinum Banks ex König by pathogenic Labyrinthula sp. was found to induce lesion progression, alterations to the host’s oxidative metabolism, and production of defense metabolites over the early stages of infection (monitored over a 72-hr time course). By 48-hrs post-infection, host oxygen consumption, internal reactive oxygen concentrations, and caspase-3 proteolytic activity reached their highest levels. The formation of reactive oxygen species (ROS) and nitric oxide (NO) were detected in T. testudinum lesions by use of redox-sensitive probes/substrates and fluorescent imaging. To our knowledge, this work represents the first time NO has been detected in …


Leafy Sea Dragon, Phycodurus Sp., Kennedi X. Light Sep 2023

Leafy Sea Dragon, Phycodurus Sp., Kennedi X. Light

PANDION: The Osprey Journal of Research and Ideas

Artist Statement

Leafy sea dragons, Phycodurus sp. are part of the Syngnathidae family. Syngnathidae is a genus made up of seahorses, pipefishes, and sea dragons. All three of the species are known to have beautiful patterning. However, leafy sea dragons got their name from their leafy appendages like their fins and limbs. The reason I chose to draw a leafy sea dragon is due to my own interest in astrobiology. Astrobiology is the study of life in the universe and astrobiologists look for signs of life within the universe. I would like to be an astrobiologist one day and focus …


River Report. State Of Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2023, Environmental Protection Board, Jacksonville Florida, University Of North Florida, Jacksonville University, Gerry Pinto, Brian P. Zoellner, Christopher Baynard, Gretchen Bielmyer-Fraser, Dale Casamatta, Charles Closmann, Nisse Goldberg, Ashley Johnson, Scott Jones, William Penwell, Radha Pyati, Adam Rosenblatt Jan 2023

River Report. State Of Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2023, Environmental Protection Board, Jacksonville Florida, University Of North Florida, Jacksonville University, Gerry Pinto, Brian P. Zoellner, Christopher Baynard, Gretchen Bielmyer-Fraser, Dale Casamatta, Charles Closmann, Nisse Goldberg, Ashley Johnson, Scott Jones, William Penwell, Radha Pyati, Adam Rosenblatt

State of the River Report

No abstract provided.


Otoliths Through Time: A Multidecadal Characterization Of Fish Otoliths In A Changing Climate, Jordan M. Waldron Jan 2023

Otoliths Through Time: A Multidecadal Characterization Of Fish Otoliths In A Changing Climate, Jordan M. Waldron

UNF Graduate Theses and Dissertations

There is a lack of research describing how widespread environmental changes in marine ecosystems affect wild adult teleost otoliths, limiting our ability to understand the impacts that alterations to otoliths can have on fish physiology and ecology. In this study, morphological and microstructural changes in wild adult fish otoliths were traced over 3 decades among species common in Tampa Bay, Florida – red drum Sciaenops ocellatus and common snook Centropomus undecimalis. Optical microscopy and scanning electron microscopy were used to characterize otolith morphology and microstructure, respectively, to then pair with fluctuations in environmental variables – water temperature, pH, dissolved …


Field Assessment Of The Pervious Oyster Shell Habitat: Enhancement Of Intertidal Habitat For The Eastern Oyster And Associated Nekton In Northeast Florida, Hunter Mathews Jan 2023

Field Assessment Of The Pervious Oyster Shell Habitat: Enhancement Of Intertidal Habitat For The Eastern Oyster And Associated Nekton In Northeast Florida, Hunter Mathews

UNF Graduate Theses and Dissertations

A dramatic global decline in oyster reef habitat has led to widespread deployment of oyster restoration projects. Efforts are underway to move away from polluting methods like plastic mesh bags in oyster deployments. Additionally, increasing pressure on our estuaries from recreational boat wakes and intensified storms requires more robust structures for shoreline protection. The “Pervious Oyster Shell Habitat” (POSH) is a novel artificial reef structure composed of oyster shell bound by a thin layer of Portland cement, into the shape of a dome. The structure’s makeup greatly reduces its environmental impact, while providing quality substrate for provision of oyster reef …


River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2022., Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Gretchen Bielmyer-Fraser, John Burr, Dale Casamatta, Charles Closmann, Brian P. Zoellner, Ashley Johnson, An-Phong Le, William Penwell, Radha Pyati Jan 2022

River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2022., Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Gretchen Bielmyer-Fraser, John Burr, Dale Casamatta, Charles Closmann, Brian P. Zoellner, Ashley Johnson, An-Phong Le, William Penwell, Radha Pyati

State of the River Report

No abstract provided.


It's A Small World After All: Insights, Interferences, And Implications Of In Situ Chlorophyll Fluorescence Monitoring In Estuaries, James Silas Tanner Jan 2022

It's A Small World After All: Insights, Interferences, And Implications Of In Situ Chlorophyll Fluorescence Monitoring In Estuaries, James Silas Tanner

UNF Graduate Theses and Dissertations

Concentrations of the photosynthetic pigment chlorophyll a are used as a proxy for phytoplankton biomass by estuarine scientists to study eutrophication, food web dynamics, and harmful algal blooms. Coastal managers use chlorophyll as an indicator of nutrient pollution and for assessments to meet Clean Water Act standards. Chlorophyll a, as measured in the laboratory by extraction from monthly discrete water samples, is a core component of the National Estuarine Research Reserve (NERR) System-Wide Monitoring Program (SWMP). Field-deployable sensors based on the excitation and emission spectra of in situ chlorophyll have not been incorporated into SWMP to date because past …


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 Jan 2022

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 …


Effects Of Environmental And Anthropogenic Factors On Loggerhead Sea Turtle (Caretta Caretta) False Crawl Rates On Jekyll Island, Ga, Brittany Byrd Jan 2022

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 …


An Analysis Of The Spatial Genetic Structure Of A Hybrid Zone Between Two Species Of Killifish, Fundulus Heteroclitus And F. Grandis, Andrew Lee Hardy Jan 2022

An Analysis Of The Spatial Genetic Structure Of A Hybrid Zone Between Two Species Of Killifish, Fundulus Heteroclitus And F. Grandis, Andrew Lee Hardy

UNF Graduate Theses and Dissertations

Hybridization offers unique insight into the evolutionary process of speciation and the forces that maintain barriers to reproduction. In northeast Florida, a hybrid zone between two species of killifish, Fundulus heteroclitus and F. grandis, has been identified near Flagler Beach, FL, although the exact boundaries of the hybrid zone remain unknown (Gonzalez et al. 2009). This study aims to determine the fine-scale spatial genetic patterns of the hybrid zone and test the hypothesis that species ranges are influenced by changes in dominant vegetation. Results from an ADMIXTURE analysis and FST data indicated the boundary of the area of …


Histological Comparison Of Shark Dermis Across Various Ecomorphologies, Olivia Schuitema Jan 2022

Histological Comparison Of Shark Dermis Across Various Ecomorphologies, Olivia Schuitema

UNF Graduate Theses and Dissertations

The integument plays essential roles in the structural support, protection, and hydrodynamic capability among fishes. Most shark skin research has been done on the external epidermal layer containing the dermal denticles, while the larger dermis layer has been mostly ignored. The dermis layer in sharks is composed of two layers, the upper stratum laxum and the lower stratum compactum, holding supportive collagen and elastin fibers. There may be morphological and compositional differences in the dermis layers across various species of sharks, although the extent of such is unknown. These potential differences may be represented by various dermal thicknesses and different …


Bycatch Reduction Devices As A Method To Reduce Mortality Rates Of Malaclemys Terrapin In Crab Pots, Benjamin Lowstuter, Leslie Delong, Corey Hymel Apr 2021

Bycatch Reduction Devices As A Method To Reduce Mortality Rates Of Malaclemys Terrapin In Crab Pots, Benjamin Lowstuter, Leslie Delong, Corey Hymel

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Diamondback terrapins (Malaclemys terrapin) currently face population loss along their broad coastal North American range, spanning from Massachusetts down to Texas. This species is suggested to be an important indicator of environmental change within the limited brackish water habitat along the coastlines. Terrapin mortality predominantly stems from human activities, such as commercial and recreational blue crab (Callinectes sapidus) trapping. Once caught in one of many crab pots littered throughout their aquatic habitat, terrapins can easily drown in several hours upon capture. In reviewing published research, the use of bycatch reduction devices (BRDs) have been shown to reduce the number of …


Why Are You So Slimy?, Lindsay Dillman, James Gelsleichter, Laura Habegger Apr 2021

Why Are You So Slimy?, Lindsay Dillman, James Gelsleichter, Laura Habegger

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The epithelium of vertebrates is a complex tissue that houses a large variety of cells with different functions. One of its most important functions is protection and in many cases this function is achieved by exuding copious amounts of mucous that fight off diseases, harmful toxins and overall protect the species from external invaders. Mucous, made of mucin, is produced by specialized epithelial cells called goblet cells. Among vertebrates’, fishes are perhaps one of the major groups known to produce mucous, particularly stingrays. The Atlantic stingray, Dasyatis sabina is one of the few cartilaginous fishes known to inhabit both freshwater …


The Relative Contribution Of The Blue Crab (Callinectes Sapidus) To Periwinkle Snail (Littoraria Irrorata) Predation Mortality In The Lower Salt Marsh Intertidal Of Northeast Florida, Amanda Paige Small Jan 2021

The Relative Contribution Of The Blue Crab (Callinectes Sapidus) To Periwinkle Snail (Littoraria Irrorata) Predation Mortality In The Lower Salt Marsh Intertidal Of Northeast Florida, Amanda Paige Small

UNF Graduate Theses and Dissertations

In top-down regulation of ecological communities, predation of grazers is critical for maintaining the presence and growth of essential vegetation. The periwinkle snail (Littoraria irrorata) is a ubiquitous grazer in Atlantic salt marshes that can defoliate patches of Spartina alterniflora when populations are extremely dense. On the east coast of Florida, multiple predators could contribute to periwinkle population control maintaining this critical habitat. This study aimed to determine if the blue crab (Callinectes sapidus) is the primary predator of periwinkle snails in the salt marsh lower intertidal. Tethering was utilized to assess if periwinkle mortality is …


Benthic Microalgae Response To A Warming Climate And Shift In Foundational Vegetation Species In A Saltmarsh-Mangrove Ecotone, Gabriela Canas Jan 2021

Benthic Microalgae Response To A Warming Climate And Shift In Foundational Vegetation Species In A Saltmarsh-Mangrove Ecotone, Gabriela Canas

UNF Graduate Theses and Dissertations

The ecotone in Northeast Florida is experiencing rapid change as mangroves begin to encroach northward into saltmarsh dominated coastal wetlands. This is especially prevalent within the boundaries of the Guana Tolomato Matanzas National Estuarine Research Reserve where studies are attempting to understand the consequences of more mangroves. Although we are beginning to understand some of the implications of this shift in dominant vegetation, the true effects and the accompanying sustained climatic warming effects on the resilience of wetland habitats and their associated communities remains unknown. Primary producers such as benthic microalgae (BMA) are important food sources in both mangrove and …


Reproductive Biology Of The Spinner Shark Carcharhinus Brevipinna, Off The Southeast U.S. Coast, Kristin K. Palmrose Jan 2021

Reproductive Biology Of The Spinner Shark Carcharhinus Brevipinna, Off The Southeast U.S. Coast, Kristin K. Palmrose

UNF Graduate Theses and Dissertations

The spinner shark, Carcharhinus brevipinna, is a large coastal shark species that is common on the U.S. southeast coast and caught in both commercial and recreational fisheries. Little research has been conducted on the life history of C. brevipinna in the Northwestern Atlantic, presenting challenges for fishery management. This is especially true for reproductive biology, warranting a need to determine how rapidly individuals are reproducing and contributing to the population. This study aimed to characterize reproduction in C. brevipinna by determining size-at-maturity, reproductive seasonality, periodicity, and fecundity. This was accomplished by analyzing changes in reproductive tract morphology and histology, …


Estimating The Heritability Of Plasticity Of Thermal Tolerance And Its Application In The Restoration Of Endangered Caribbean Coral, Matz O. Indergard Jan 2020

Estimating The Heritability Of Plasticity Of Thermal Tolerance And Its Application In The Restoration Of Endangered Caribbean Coral, Matz O. Indergard

UNF Graduate Theses and Dissertations

Abstract

Over the last two centuries anthropogenic activity has elevated atmospheric CO2, creating a greenhouse effect that is predicted to elevate global temperatures 1-4o C within the century. Increases in surface temperature pose a threat to the world’s coral reefs and have been the cause of many mass bleaching events. To combat this new threat, corals must migrate, acclimate, or evolve to rising temperatures. Phenotypic plasticity, or the ability of an individual to express different phenotypes to survive in different environments, is crucial for sessile organisms since it can increase survivability in species incapable of moving to …


River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2019, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Brian P. Zoellner, Christopher Baynard, Charles Closmann, Nisse Goldberg, Scott F. Jones, William Penwell, Radha Pyati, Adam E. Rosenblatt, Gretchen Bielmyer-Fraser Jan 2019

River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2019, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Brian P. Zoellner, Christopher Baynard, Charles Closmann, Nisse Goldberg, Scott F. Jones, William Penwell, Radha Pyati, Adam E. Rosenblatt, Gretchen Bielmyer-Fraser

State of the River Report

No abstract provided.


Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs Jan 2019

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 …


River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2018, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Gretchen Bielmyer-Fraser, Nisse Goldberg, Anthony Ouellette, An-Phong Le, Radha Pyati, Charles Closmann, Brian P. Zoellner Jan 2018

River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2018, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Gretchen Bielmyer-Fraser, Nisse Goldberg, Anthony Ouellette, An-Phong Le, Radha Pyati, Charles Closmann, Brian P. Zoellner

State of the River Report

No abstract provided.


Characterization Of Vitellogenesis In The Bonnethead Shark Sphyrna Tiburo, Adrien Kathleen Mowle Jan 2018

Characterization Of Vitellogenesis In The Bonnethead Shark Sphyrna Tiburo, Adrien Kathleen Mowle

UNF Graduate Theses and Dissertations

Vitellogenin (Vtg) is a precursor to yolk-proteins produced in the liver of many invertebrates and non-mammalian vertebrates; its synthesis is stimulated by the hormone estradiol (E2). This study is the first to characterize vitellogenin synthesis in a placental viviparous elasmobranch, the yolk-sac placental bonnethead shark, Sphyrna tiburo. This study focused on determining where and when Vtg is produced, as well as what hormonal factors regulate Vtg production. The liver was confirmed as the site of Vtg production via immunohistochemistry. Immunoreactivity was also observed within granulosa cells of ovarian follicles; further experimentation is needed to determine if this is indicative …


Establishing Relationships Among Environmental Stressors, Host Immune Status, And Wasting Disease Susceptibility In The Dominant Seagrass Species Thalassia Testudinum, Paige Joy Duffin Jan 2018

Establishing Relationships Among Environmental Stressors, Host Immune Status, And Wasting Disease Susceptibility In The Dominant Seagrass Species Thalassia Testudinum, Paige Joy Duffin

UNF Graduate Theses and Dissertations

A growing body of evidence supports the observation that marine disease outbreaks, especially those caused by opportunistic pathogens, are increasing in frequency and severity. One genus of such pathogens, Labyrinthula, has been identified as the causative agent of seagrass wasting disease, an epidemic that has historically plagued seagrass beds around the world. It is suspected that pathogenicity is intimately linked to the ability of the host to initiate defense responses, but a lack of compelling evidence prevents any meaningful application of preliminary observations. This body of work investigated the roles of host genotype, host immune status, and environmental stressors …


Reproductive Biology Of The Tiger Shark In The Western Atlantic Ocean, Chelsea Shields Jan 2018

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 …


The Effects Of The Red Tide Producing Dinoflagellate, Karenia Brevis, And Associated Brevetoxins On Viability And Sublethal Stress Responses In Scleractinian Coral: A Potential Regional Stressor To Coral Reefs, David A. Reynolds Jan 2018

The Effects Of The Red Tide Producing Dinoflagellate, Karenia Brevis, And Associated Brevetoxins On Viability And Sublethal Stress Responses In Scleractinian Coral: A Potential Regional Stressor To Coral Reefs, David A. Reynolds

UNF Graduate Theses and Dissertations

Coral cover is in decline on a global scale, with increased mortality events being attributed to a number of global and regional stressors. While the impacts of global stressors (e.g. sea surface temperature rise, ocean acidification) are well documented, there is growing interest in identifying and understanding the impacts of regional stressors. The reason for this change in focus is that regional stressors can often work in combination, sometimes synergistically, with global stressors and that stressors on a regional scale tend to be more easily mitigated by management practices. One regional stressor that impacts a myriad of marine organisms in …