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UNF Graduate Theses and Dissertations

Theses/Dissertations

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Full-Text Articles in Ecology and Evolutionary Biology

The Effect Of Environmental Factors On Movement Patterns And Habitat Use Of Young-Of-The-Year Scalloped Hammerhead Sharks (Sphyrna Lewini) In The Tolomato River Nursery, Matthew Bernanke Jan 2023

The Effect Of Environmental Factors On Movement Patterns And Habitat Use Of Young-Of-The-Year Scalloped Hammerhead Sharks (Sphyrna Lewini) In The Tolomato River Nursery, Matthew Bernanke

UNF Graduate Theses and Dissertations

Various shark populations on the southeastern coast of the United States experienced declines in the late 20th century, including the scalloped hammerhead shark (Sphyrna lewini). Improved management strategies, implemented in the late 1990s, have helped these populations to recover, but they are still under threat from fishing pressure and habitat loss. In continuing to strive towards population recovery and conservation, it is important to identify Essential Fish Habitat, or habitats that are necessary for the spawning, feeding, breeding, or growth of marine organisms. One such habitat is that of the shark nursery habitat. Nursery habitats are those …


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 …


Plant Physiological Responses To Environmental Change In A Marsh-Mangrove Ecotone, Matthew Sturchio Jan 2021

Plant Physiological Responses To Environmental Change In A Marsh-Mangrove Ecotone, Matthew Sturchio

UNF Graduate Theses and Dissertations

Globally, photosynthesis (A) and autotrophic respiration (R) are the two largest physiological processes responsible for CO2 flux. Coastal wetland ecosystems are responsible for some of the highest rates of C sequestration. Marsh grass and mangrove habitats responsible for this service are important in supporting biodiversity and preventing shoreline erosion, yet little is known about how this vegetation will respond physiologically to effects of climate and global change. In the first chapter a warming experiment was used to determine whether a C4 marsh grass (Spartina alterniflora) and a C3 mangrove (Avicennia …


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 …


Effects Of Abiotic Factors On Host Plant Quality And Community Structure Of The Parasitoid Guild That Attacks Asphondylia Borrichiae Midges On Borrichia Frutescens, Kevin Orta Jan 2020

Effects Of Abiotic Factors On Host Plant Quality And Community Structure Of The Parasitoid Guild That Attacks Asphondylia Borrichiae Midges On Borrichia Frutescens, Kevin Orta

UNF Graduate Theses and Dissertations

Asphondylia borrichiae is a gall-inducing insect that attacks its ancestral host plant Borrichia frutescens: through ovipositional mistakes it has acquired two additional hosts, Iva frutescens and Iva imbricata. Oviposition results in the formation of a gall, a tumor-like growth of plant tissue within which immature A. borrichiae develop. During development, immature A. borrichiae, are attacked by a suite of four generalist hymenopteran parasitoids. Of these, Galeopsomyia haemon and Torymus umbilicatus are facultative hyperparasitoids, more common and exhibit non-random attack patterns. In the present study, soil quality was manipulated through bi-weekly application of either ammonium nitrate fertilizer or sodium …


Molecular And Evolutionary Analysis Of Cyanobacterial Taxonomic Methods, Chelsea Denise Villanueva Jan 2018

Molecular And Evolutionary Analysis Of Cyanobacterial Taxonomic Methods, Chelsea Denise Villanueva

UNF Graduate Theses and Dissertations

Cyanobacteria are a group of photo-oxygenic bacteria found in nearly every ecosystem, but much cyanobacterial diversity, in various habitats, has yet to be explored. Cyanobacteria are often conspicuous components of photosynthetic flora, providing significant carbon and nitrogen inputs to surrounding systems. As possible primary colonizers of stone substrates not native to this region, cyanobacteria isolated from headstones may provide biogeographically informative data. An exploratory study of lichen-dominated microbial consortia, growing on headstones, was conducted to isolate and identify novel microaerophytic cyanobacteria, and resulted in the establishment of four novel cyanobacterial taxa. Phylogenetic analyses of photobionts in one tripartite lichen revealed …


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 …


The Soundscape Of The St. Johns River And Its Potential Impacts On The Habitat Use Patterns Of Bottlenose Dolphins, Carissa Deeann King Jan 2017

The Soundscape Of The St. Johns River And Its Potential Impacts On The Habitat Use Patterns Of Bottlenose Dolphins, Carissa Deeann King

UNF Graduate Theses and Dissertations

The development of effective management plans for animal populations relies on an understanding of how the population is utilizing the habitat as well as the identification of any critical habitat areas. The St. Johns River (SJR), an urban estuary with a high level of anthropogenic disturbance, is home to a resident population of bottlenose dolphins (Tursiops truncatus). In chapter one, SJR dolphin habitat use patterns, the factors that influenced these patterns, and the critical habitat areas were identified. Significant associations were found in most pair-wise comparisons between season, behavioral state, group size, water depth, and location, indicating that …


Tests Of Reproductive Isolation Between The Fishes Fundulus Heteroclitus And F. Grandis, Ruthie E. Barbas Jan 2016

Tests Of Reproductive Isolation Between The Fishes Fundulus Heteroclitus And F. Grandis, Ruthie E. Barbas

UNF Graduate Theses and Dissertations

The closely related killifishes Fundulus heteroclitus and F. grandis hybridize in a small region where their ranges overlap in coastal northeastern Florida. Hybrids of these species are rare in frequency within the contact zone, suggesting the presence of relatively strong reproductive isolation between these species. The objective of this study was to elucidate barriers to reproduction between F. heteroclitus and F. grandis in the lab, as well as to quantify the relative strengths and contributions of various isolating barriers. Pre-zygotic (mating and fertilization) and post-zygotic (hatching) barriers were investigated by performing a variety of choice and no-choice laboratory mating experiments. …


Effects Of The Exotic Red Imported Fire Ant (Solenopsis Invicta) On The Growth And Survival Of The Threatened Hooded Pitcher Plant (Sarracenia Minor), Edward Marques Jan 2015

Effects Of The Exotic Red Imported Fire Ant (Solenopsis Invicta) On The Growth And Survival Of The Threatened Hooded Pitcher Plant (Sarracenia Minor), Edward Marques

UNF Graduate Theses and Dissertations

Plants and insects are some of the most biodiverse groups in the world and are constantly interacting. One unique interaction that has been observed occurs between carnivorous plants and insects; some plant species are capable of capturing and digesting insects for nutrients. Despite preying on these insects, there are cases where such interactions can been viewed as mutualistic. For instance, a nectar reward is produced by the plant to attract insects, and during visitation insects may fall prey to these plants. Additionally, carnivorous myrmecophytic plants may receive an added indirect benefit in the form of reduced herbivory, since ants have …


Reproductive Biology Of The Bonnethead (Sphyrna Tiburo) From The Southeastern U.S. Atlantic Coast, Melissa I. Gonzalez De Acevedo Jan 2014

Reproductive Biology Of The Bonnethead (Sphyrna Tiburo) From The Southeastern U.S. Atlantic Coast, Melissa I. Gonzalez De Acevedo

UNF Graduate Theses and Dissertations

Understanding the life history of marine wildlife is essential for the management of both commercial and recreational fisheries. Bonnetheads (Sphyrna tiburo) are a component of the small coastal shark (SCS) fishery complex, and are caught regularly in both types of fisheries. Despite being well studied in the Gulf of Mexico, little is known about bonnetheads from the U.S. Atlantic coast. The goal of the first component of this study was to provide new, key information on their life history to improve management of U.S. Atlantic populations, particularly by identifying reproductive seasonality, periodicity and fecundity. This was accomplished by examining sexually …


The Performance Of Simple Artificial Floating Wetland Communities And Their Effects On Aquatic Nutrient Levels And Algal Abundance, Bradley L. Sleeth Jan 2014

The Performance Of Simple Artificial Floating Wetland Communities And Their Effects On Aquatic Nutrient Levels And Algal Abundance, Bradley L. Sleeth

UNF Graduate Theses and Dissertations

Harmful algal blooms are exponential increases in autotrophic microorganisms that proliferate in such a way that the surrounding environment, the local economy and the health of regional populations are negatively affected. Among the causes of these blooms are anthropogenic inputs of excess nitrogen and phosphorus into the environment through overfertilization. Floating treatment wetlands (FTW) have emerged as a novel method of reducing the negative impacts of these nutrient inputs by using artificial rafts to float normally emergent wetland plants on the surface of water bodies to assimilate excess nutrients. Because their use is so new, only limited research has been …


Effects Of Elevated Salinity And Oxidative Stress On The Physiology Of The Toxigenic Cyanobacterium Microcystis Aeruginosa, Billy Christopher Warhurst Jan 2014

Effects Of Elevated Salinity And Oxidative Stress On The Physiology Of The Toxigenic Cyanobacterium Microcystis Aeruginosa, Billy Christopher Warhurst

UNF Graduate Theses and Dissertations

Harmful algal blooms (HABs) are found worldwide, particularly in places where warm, well-lit, and stagnant waters are common. HABs can have negative effects on aquatic plants and wildlife due to the reduction in light availability associated with turbidity, decrease in O2 availability, and the production of secondary metabolites that can harm or even prove lethal. Aquatic ecosystems are regularly being affected by elevated salinity because of recent water management strategies, episodes of drought, and salt water intrusion. This research focused on how salinity levels ranging from 0-10ppt affected physiological attributes such as cellular growth and abundance, cell mortality, toxin …


Physiology And Biochemistry Of The Tropical Seagrass Thalassia Testudinum In Response To Hypersalinity Stress And Labyrinthula Sp. Infection, Stacey Marie Trevathan-Tackett Jan 2011

Physiology And Biochemistry Of The Tropical Seagrass Thalassia Testudinum In Response To Hypersalinity Stress And Labyrinthula Sp. Infection, Stacey Marie Trevathan-Tackett

UNF Graduate Theses and Dissertations

Seagrass meadows are essential to coastal ecosystems and have experienced declines in abundance due to a series of environmental stressors including elevated salinity and incidence of disease caused by the pathogen Labyrinthula sp. This thesis evaluated the dynamics between T. testudinum and Labyrinthula concerning the impacts of short term elevated salinity stress on the early stages of infection in Thalassia testudinum (Chapter 2) as well as the presence of anti-labyrinthulid secondary metabolites produced by the tropical seagrass (Chapter 3). The results showed that short term exposure to hypersalinity alters some cellular processes but does not necessarily lead to an immediate …


Vegetation Response To Restoration Treatments In A Former Pine Plantation In North Florida, Ryan C. Meyer Jan 2009

Vegetation Response To Restoration Treatments In A Former Pine Plantation In North Florida, Ryan C. Meyer

UNF Graduate Theses and Dissertations

As the human population in Florida continues to expand, development follows, and tree farms give way to homes and businesses. As parks are established, restoration of these semi-natural plantations may provide critical habitat for species conservation. This study evaluates vegetation response to restoration treatments at two study sites, formerly tree farms, now preserves in NE Florida. Treatments included thinning, clearing, or control (no treatment) within 10m^2 plots. Thinning reduced tree canopy to 20% (2-3 pines/plot) and removed all other vegetation; clearing treatments removed all biomass to bare soil; no herbicides were used. Within these plots richness and abundance was assessed …