Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Entire DC Network

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa Dec 2017

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa

Dissertations

Leatherback turtles (Dermochelys coriacea) are a wide-ranging, oceanic species that feed exclusively on gelatinous zooplankton. Leatherback have been spotted in the Gulf of Mexico (GoM) for several decades and consistently had a high level of interactions with longline fisheries. However, no quantitative studies have been performed to address the spatiotemporal distribution of these turtles in the GoM. This research determines 1) leatherback movements and high-use areas in the GoM, 2) their association with oceanographic features, 3) the distribution and density of two abundant medusae in the northern GoM and any association with biophysical parameters, and 4) the body …


Effects Of Trophic Relationships On Oyster Reef Restoration Success In The Mississippi Sound, Virginia Robin Fleer Dec 2017

Effects Of Trophic Relationships On Oyster Reef Restoration Success In The Mississippi Sound, Virginia Robin Fleer

Dissertations

Natural and anthropogenic changes resulting from altered hydrology, hurricanes, variable precipitation, and the BP oil spill have all taken their toll on oyster reefs in Mississippi. In response, oyster reef restoration efforts are currently underway within the Northern Gulf of Mexico. In order to understand why these efforts succeed or fail, it is crucial to consider predator-prey relationships within the context of the trophic dynamics of oyster reefs. Thus, for this dissertation study I integrated a multidisciplinary approach to understanding key trophic interactions affecting oyster recruitment, growth and survival, comprising field sampling, manipulative lab experiments, and individual-based modeling. Spat settlement …


Effects Of Wave Action On The Structure Of Fish Assemblages Across An Exposure Gradient, Lauren Liddon Aug 2017

Effects Of Wave Action On The Structure Of Fish Assemblages Across An Exposure Gradient, Lauren Liddon

Master's Theses

Disturbance affects the function and diversity of ecosystems. Increased wave exposure to salt marsh can disturb sediments and cause a loss of habitat. The purpose of this study was to explore the effects of increased wave exposure on diversity, abundance, and functional ecology of estuarine fishes. If increased wave exposure is acting as a disturbance to these habitats, ecological theory (Intermediate Disturbance Hypothesis) predicts that diversity will peak at intermediate frequencies and intensities of disturbance. Fish were sampled from 10 sites monthly for 6 years. The sites were assigned to different exposure categories (Open, Intermediate, and Sheltered) using an exposure …


An Ecological Examination Of Johnson Bayou (Pass Christian, Ms) With A Reproductive Histological Analysis Of Rangia Cuneata, And A Comparative Morphological Study Of The Foot And Shell Of Rangia Cuneata And Polymesoda Caroliniana, Brandon Drescher Aug 2017

An Ecological Examination Of Johnson Bayou (Pass Christian, Ms) With A Reproductive Histological Analysis Of Rangia Cuneata, And A Comparative Morphological Study Of The Foot And Shell Of Rangia Cuneata And Polymesoda Caroliniana, Brandon Drescher

Dissertations

Johnson Bayou is an estuarine system located in Pass Christian, MS. Research involved a biotic and abiotic examination of Johnson Bayou, resulting in the identification of numerous species of plants and animals, including Rangia cuneata (Mactridae) and Polymesoda caroliniana (Cyrenidae), sympatric species of infaunal bivalves. Environmental factors (e.g., water temperature, salinity) were measured over three years to describe the system from an abiotic standpoint, and used in a qualitative and quantitative reproductive histological study on R. cuneata. Results revealed differences in timing of gamete production and spawning between three subpopulations of this species. Sediment samples taken from the study …


Solution Of Pdes For First-Order Photobleaching Kinetics Using Krylov Subspace Spectral Methods, Somayyeh Sheikholeslami Aug 2017

Solution Of Pdes For First-Order Photobleaching Kinetics Using Krylov Subspace Spectral Methods, Somayyeh Sheikholeslami

Dissertations

We solve the first order reaction-diffusion equations which describe binding-diffusion kinetics using a photobleaching scanning profile of a confocal laser scanning microscope approximated by a Gaussian laser profile. We show how to solve these equations with prebleach steady-state initial conditions using a time-domain method known as a Krylov Subspace Spectral (KSS) method. KSS methods are explicit methods for solving time- dependent variable-coefficient partial differential equations (PDEs). KSS methods are advantageous compared to other methods because of their stability and their superior scalability. These advantages are obtained by applying Gaussian quadrature rules in the spectral domain developed by Golub and Meurant. …


Effects Of Marsh Fragmentation And Patch Area On Fish And Nekton Assemblages In Mississippi, Jennifer R. Main May 2017

Effects Of Marsh Fragmentation And Patch Area On Fish And Nekton Assemblages In Mississippi, Jennifer R. Main

Honors Theses

Fragmentation divides continuous habitat into smaller patches. Fragmentation can also produce smaller populations of species, because fragmentation can split a population into smaller groups. Both terrestrial and aquatic ecosystems suffer from fragmentation. There are a variety of fishes that live along marsh, each depending upon the marsh for protection, food, and sometimes even competition. Species richness of fishes can be altered due to marsh fragmentation. I predict islands with a larger patch index should have a higher species richness of fishes. For this study, fish assemblages at 20 islands of marsh were sampled in the months of June and July …