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Theses/Dissertations

2012

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Articles 1 - 30 of 47

Full-Text Articles in Marine Biology

Filtering Efficiency And Feeding Mechanisms Of Daphnia Pulex On Microcystis Aeruginosa And Nannochloropsis, Elizabeth Orlowicz Dec 2012

Filtering Efficiency And Feeding Mechanisms Of Daphnia Pulex On Microcystis Aeruginosa And Nannochloropsis, Elizabeth Orlowicz

Honors Theses and Capstones

The filtering and feeding rate of Daphnia pulex from the Old Durham Reservoir, Durham, NH, were measured to determine the feeding efficiency on different concentrations of non-toxic Nannochloropsis (Class Eustigmatophyceae) and toxigenic cyanobacteria Microcystis aeruginosa. Direct observations of thoracic appendage beats and post-abdominal rejections were also measured at 5*105 and 106 cells mL-1 concentrations of Nannochloropsis and M. aeruginosa to examine the feeding mechanisms of the D. pulex. In the presence of increasing Nannochloropsis concentrations, the filtering rates decreased and the feeding rates increased. When exposed to M. aeruginosa, both the filtering and feeding …


Population Dynamics Of The Sub-Arctic Copepod Calanus Finmarchicus In The Gulf Of Maine: Demography And Mortality Estimation, Cameron R. S. Thompson Dec 2012

Population Dynamics Of The Sub-Arctic Copepod Calanus Finmarchicus In The Gulf Of Maine: Demography And Mortality Estimation, Cameron R. S. Thompson

Electronic Theses and Dissertations

Calanus finmarchicus is a widely distributed copepod species that dominants the zooplankton community in the Gulf of Maine. It is of particular interest in its role as a major food source for the endangered northern right whale and stocks of herring, mackerel and cod. More accurate coupled models to predict its distribution requires better life history models. However, due to the difficulty in estimating it, mortality is often used as a closure term in those models; the value is justified mathematically rather than ecologically. Instantaneous mortality is difficult to measure, but the Vertical Life Table method (VLT) has gained some …


An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County, Grant Tyler Waltz Dec 2012

An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County, Grant Tyler Waltz

Master's Theses

ABSTRACT

An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County

Grant Tyler Waltz

The number of coastal areas open to public access in California and San Luis Obispo County is increasing due to the acquisition by California State Parks of land previously owned by private entities. For example, California State Parks acquired property from the Hearst Corporation in 2005, which included 18 miles of coastline. California State Parks is responsible for providing public access in these newly acquired areas and also for maintaining the health of the natural systems found on these properties. Part of …


Analysis Of Extracellular Proteins Expressed By Host, Crassostrea Virginica And Pathogen, Roseovarius Crassostreae In Roseovarius Oyster Disease, Erin Macro Dec 2012

Analysis Of Extracellular Proteins Expressed By Host, Crassostrea Virginica And Pathogen, Roseovarius Crassostreae In Roseovarius Oyster Disease, Erin Macro

Electronic Theses and Dissertations

Roseovarius Oyster Disease (ROD) involves the colonization of the inner shell of the Eastern Oyster (Crassostrea virginica) by the marine alpha-proteobacterium Roseovarius crassostreae. The ensuing disease can result in upwards of 90% mortality in hatchery-raised juvenile (< 25 mm shell length) oysters. Symptoms of ROD include heavy, brown ring deposits of conchiolin on the surface of the shell, as well as uneven valve growth and shell curvature. Although the bacterium does not invade oyster tissue or digestive tract, fluorescent localization of an R. crassostreae biofilm on the inner shells of ROD-affected oysters, and toxic effects of R. crassotreae extracellular products on hemocytes and larval oysters suggest that a chemical warfare takes place between the R. crassostreae biofilm and the oyster host. In this thesis, I cultured R. crassostreae under laboratory conditions and analyzed the affects of physical growth condition, temperature, culture volume, and iron limitation on bacterial growth and bacterial extracellular protein (ECP) production. Culture growth rate increased with increasing temperature. Iron limitation resulted in slower growth but had no affect on maximum culture density. Iron limited cells produced a greater volume of ECPs, especially at low cell density. ECPs from liquid and solid-phase cultures were analyzed by LC-tandem mass spectrometry. The resulting protein sequences had high similarity to proteins in other bacterial species that act as virulence factors in other hosts, including metal transporters (2), proteases (2) and a surface-associated GroEL chaperonin. I also exposed live oysters to ECPs of live R. crassostreae cells by embedding a filter capsule into the oyster shell. I sampled extrapallial fluid from oysters pre-exposure and post-exposure and analyzed the relative expression of the oyster defense protein dominin in addition to the extent of brown shell deposition as a function of bacterial presence. The injury response due to capsule embedment masked any potential response by oysters to R. crassostreae ECPs.


Density And Diversity Of Penaeid Shrimp And Fish Species In Near-Shore Seagrass Beds Of Northern Biscayne Bay, Florida (Usa), Robin Cascioli Dec 2012

Density And Diversity Of Penaeid Shrimp And Fish Species In Near-Shore Seagrass Beds Of Northern Biscayne Bay, Florida (Usa), Robin Cascioli

HCNSO Student Theses and Dissertations

Seagrass beds serve critical functions in coastal Florida ecosystems. The beds serve as nursery habitat for many juvenile reef fish species and provide protection for many types of benthic organisms found in Biscayne Bay. They help stabilize sediment that would otherwise increase turbidity around coral reefs, filter the water of contaminants, and help support an entire food web. Three species of seagrass were found at the study sites in northern Biscayne Bay: Thalassia testudinum, Halodule wrightii, and Syringodium filiforme. This study focused on understanding the organism habitat interaction by determining the species diversity, seasonal densities, and the …


Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker Dec 2012

Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker

Dissertations

Marine fungi are an important but often overlooked component of marine ecosystems. Primarily saprotrophic, they are vital to coastal nutrient cycling processes and food webs. However, basic marine fungal distribution data are lacking in many parts of the world, as is knowledge of the sampling intensity required to characterize the biodiversity of these communities. The roles of substrate, season and latitude in shaping intertidal ascomycete community structure were examined for the U.S. Gulf of Mexico, and the role of sampling frequency on species richness estimates was also addressed. Best sampling practices were developed and 750 collections of beach detritus, sand …


Management Of Biological And Chemical Constituents For The Advancement Of Intensive, Minimal-Exchange, Biofloc-Based Shrimp (Litopenaeus Vannamei) Aquaculture, Andrew James Ray Dec 2012

Management Of Biological And Chemical Constituents For The Advancement Of Intensive, Minimal-Exchange, Biofloc-Based Shrimp (Litopenaeus Vannamei) Aquaculture, Andrew James Ray

Dissertations

Intensive, minimal-exchange, biofloc-based shrimp aquaculture systems may provide a sustainable alternative to traditional shrimp culture. Through a series of experiments, this document explores the effects of several key management strategies on water quality, isotopic distribution, and shrimp production.

An experiment evaluated the effects of managing suspended solids (biofloc) concentration at two levels. It was found that using a higher flow rate to larger settling chambers resulted in significantly lower biofloc and nitrate concentrations, and significantly improved shrimp growth rate. A second experiment compared systems with clear water and systems with biofloc. The filters in the clear water systems prevented biofloc …


Fluorescence And Size Characterization Of Dissolved Organic Matter In Riverine And Sea Waters In The Northern Gulf Of Mexico, Zhengzhen Zhou Dec 2012

Fluorescence And Size Characterization Of Dissolved Organic Matter In Riverine And Sea Waters In The Northern Gulf Of Mexico, Zhengzhen Zhou

Dissertations

Riverine export of dissolved organic matter (DOM) is an important component in marine carbon budget but the composition and phase partitioning are poorly quantified. Monthly water samples were collected from the lower Mississippi and Pearl rivers between January 2009 to August 2011 for DOM characterization using the fluorescence excitation emission matrix (FluoEEM) technique, coupled with parallel factor analysis (PARAFAC), and flow field-flow fractionation technique. DOM in the Pearl River showed higher dissolved organic carbon (DOC) concentration, temporal fluctuation, and aromaticity, reflecting instantaneous inputs of DOM from local soil and plant litter. In contrast, DOM in the Mississippi River exhibited lower …


Microbial Effects On The Production And Transformation Of Surfactants Within The Microlayer And Subsurface Waters In Application To Remote Sensing Techniques, Katie E. Vella Nov 2012

Microbial Effects On The Production And Transformation Of Surfactants Within The Microlayer And Subsurface Waters In Application To Remote Sensing Techniques, Katie E. Vella

HCNSO Student Theses and Dissertations

The sea surface microlayer is a millimeter-scale interfacial layer between the atmosphere and the ocean. A number of studies have suggested that there is a unique ecosystem for marine bacteria in the sea surface microlayer, but little information exists on the microbial community composition of this ecosystem due to sampling complexities. In this work, we present an improved method to sample and compare the bacterial diversity of the sea surface microlayer with that of subsurface water at the same site. Bacterial samples were collected from the sea surface microlayer with a sampling method, which minimized sample contamination from the research …


Spatial And Oceanographic Factors Affecting Black-Legged Kittiwake And Thick-Billed Murre Distributions In The Southeastern Bering Sea, Brian Hoover Oct 2012

Spatial And Oceanographic Factors Affecting Black-Legged Kittiwake And Thick-Billed Murre Distributions In The Southeastern Bering Sea, Brian Hoover

Capstone Projects and Master's Theses

The distribution patterns of Thick-billed Murres (Uria lomvia) and Black-legged Kittiwakes (Rissa tridactyla) in the southeastern Bering Sea were documented at sea during vessel-based surveys in July-August of 2008 and 2009. The relationships of murre and kittiwake densities with environmental variables were investigated using binomial generalized additive models (GAMs) to model the presence or absence of birds, and Gamma-error distribution GAMs to model the positive densities of birds. Environmental variables included oceanographic factors (Chlorophyll, Chlorophyll anomalies, Daily SST, Monthly SST), spatial factors (Distance to nearest colony, Distance to 300m shelf break, Depth), and a temporal factor (Year). Nocturnal surveys were …


Life History Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Virginia, Margaret Cook Lynott Oct 2012

Life History Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Virginia, Margaret Cook Lynott

Biological Sciences Theses & Dissertations

Little is known about the life history and overall ecology of bottlenose dolphins that strand in Virginia. In this study, I examined archived life history samples and stranding data from bottlenose dolphins found in Virginia waters to (1) develop growth curves based on ages from sectioned teeth, (2) document characteristics of male and female reproductive organs, and (3) define the relationship between age/length and presence of neonatal characteristics during the first year of life. The Gompertz growth model provided the best fit of growth data for stranded T. truncatus in Virginia. Length at birth and asymptotic length for males were …


Phase Speciation Of Carbohydrates And Dioxins In Rivers And Coastal Waters In The Northern Gulf Of Mexico, Kusumica Mitra Aug 2012

Phase Speciation Of Carbohydrates And Dioxins In Rivers And Coastal Waters In The Northern Gulf Of Mexico, Kusumica Mitra

Master's Theses

Dissolved carbohydrates (d-CHO), including monosaccharide (MCHO) and polysaccharides (PCHO), and particulate carbohydrates (p-CHO) are major components of natural organic matter and play an important role in biogeochemical cycles of carbon and other trace elements in marine environments. This study aimed to examine the abundance and partitioning of CHO between dissolved and particulate phases and their seasonal variations in the Mississippi Sound/Bight and Lake Pontchartrain. Laboratory mixing experiments were also carried out to examine the behaviour of CHO species along a salinity gradient. The phase partitioning of dioxin among three different phases, i.e., colloidal organic matter, particulate organic matter and sediments, …


Determining The Trophic Role Of Gulf Menhaden (Brevoortia Patronus) Using Carbon And Nitrogen Stable Isotopes, Zachary Olsen Aug 2012

Determining The Trophic Role Of Gulf Menhaden (Brevoortia Patronus) Using Carbon And Nitrogen Stable Isotopes, Zachary Olsen

Master's Theses

Gulf menhaden (Brevoortia patronus) play multiple roles in the Gulf of Mexico coastal ecosystem as filter feeders and as an important food source for many recreationally and economically important finfish. Gulf menhaden also support a large commercial fishery, and little is known about the impact of fishing on the role of this species as a filter feeder in the food web. This study examines the spatial, temporal and ontogenetic dynamics of food selectivity and trophic role observed in Gulf menhaden. The most important dietary item for juvenile fish was found to be phytoplankton (75.7% dietary composition) while that of subadults …


Anode Material Testing For Marine Sediment Microbial Fuel Cells, Andrew John Quaid Aug 2012

Anode Material Testing For Marine Sediment Microbial Fuel Cells, Andrew John Quaid

Master's Theses

Research on the power production of the microbial fuel cell has increased in the past decade. The sediment microbial fuel cell is a type of fuel cell that uses the environment of submerged sediments to provide a natural voltage difference. The fuel cell is comprised of an anode buried in the sediment and a cathode that is held in the overlying water column. The process of electron transfer to the anode is catalyzed by anaerobic bacteria in the sediment. The anaerobic bacteria have that are able to catalyze the electron transfer have been termed exoelectrogenic. The increase in scientific research …


Evaluating Macrobenthic Indicators Of Organic Enrichment And Hypoxia Within The Coastal Mississippi Hypoxic Zone, Daneen P. Menke Aug 2012

Evaluating Macrobenthic Indicators Of Organic Enrichment And Hypoxia Within The Coastal Mississippi Hypoxic Zone, Daneen P. Menke

Master's Theses

Macrobenthic communities offer effective indicators of biotic integrity, but their use for distinguishing anthropogenic from natural stress is tricky because coastal taxa are eurytolerant. Effective coastal management calls for benthic indicators that respond to specific stressors, apply across different habitats, and reflect ecosystem function. Macrobenthic process metrics based on body-size descriptors should reflect ecosystem function and be useful for assessing the effects of eutrophication. Functional trait analysis should reflect the functional diversity of the community. Coastal Mississippi experienced widespread and sustained hypoxia throughout summer 2008. Site 6 located on the 10-m isobath in the center of the 2008 hypoxic zone …


Post-Release Survival And Habitat Utilization Of Juvenile Swordfish In The Florida Straits, Jenny Fenton Jul 2012

Post-Release Survival And Habitat Utilization Of Juvenile Swordfish In The Florida Straits, Jenny Fenton

HCNSO Student Theses and Dissertations

The use of pop-up satellite archival tags (PSATs) eliminates many of the limitations associated with acoustic and conventional tags by using fishery-independent data collection and retrieval. Previous research techniques have provided information on longer-term movements, migrations, and behavior patterns, but there is still a need for additional tagging studies using tags with depth and light data and increased memory that will further define the short-duration activity patterns and habitat utilization of juvenile swordfish in the western North Atlantic. PSATs have been successfully used on other large pelagic fishes, but have yet to be used on juvenile swordfish. This study investigated …


The Effects Of A New Bridge On Manatee (Trichechus Manatus Latirostris) Use Of The Fpl Discharge Canal At Port Everglades, Florida, Brea Viragh Jul 2012

The Effects Of A New Bridge On Manatee (Trichechus Manatus Latirostris) Use Of The Fpl Discharge Canal At Port Everglades, Florida, Brea Viragh

HCNSO Student Theses and Dissertations

The Florida manatee (Trichechus manatus latirostris) is an endangered species that migrates to warm water refuges such as natural springs or power plant effluents during the winter months to escape cold water. The Florida Power and Light (FPL) discharge canal in Port Everglades, Ft. Lauderdale, FL., is utilized as a refuge by overwintering manatees. Construction of a new bridge over the FPL effluent canal had a potential effect on manatee usage of the canal. Discharge is often 10-15° C warmer in the winter season than the surrounding waters of the Intracoastal Waterway. Previous data, including age class and …


Assessing Movement Of Fish Through Spectral Analysis Of Otolith Life History Scans, Renee Reilly Hoover Jul 2012

Assessing Movement Of Fish Through Spectral Analysis Of Otolith Life History Scans, Renee Reilly Hoover

OES Theses and Dissertations

The ability to accurately measure movement timing across environmental gradients is fundamental for testing hypotheses in marine ecology that deal with ingress, egress, and migration of fish. Timing and patterns of movement have been estimated using life-history scans of the chemical signatures encoded in fish otoliths (ear stones). I provide a quantitative approach to examining life history scan data using spectral analysis, which retrospectively measures the movement timing for individual fish. Sagittal otoliths from juvenile Atlantic croaker (Micropogonias undulates) and adult black sea bass (Centropristis striata) were sampled using laser ablation inductively coupled plasma mass spectrometry …


Fish Assemblage Dynamics And Red Drum Habitat Selection In Bayou St. John And Associated Urban Waterways Located Within The City Of New Orleans, Louisiana, Patrick W. Smith Mr. May 2012

Fish Assemblage Dynamics And Red Drum Habitat Selection In Bayou St. John And Associated Urban Waterways Located Within The City Of New Orleans, Louisiana, Patrick W. Smith Mr.

University of New Orleans Theses and Dissertations

Bayou St. John (BSJ) and City Park Lakes and Lagoons (CPLL) are urban waterways in New Orleans, Louisiana. I studied habitat selection of red drum in BSJ, and fish assemblage change in BSJ and CPLL over 40 years. Temperature was found to be the best predictor of red drum habitat selection in Bayou St. John, while salinity and change in depth also were found to be good predictors for certain sites. Potential prey item abundance did not appear to influence habitat selection. Using data from 1971 – 2010, nearshore habitats in CPLL were affected by Hurricane Katrina, but have sense …


An Approach For Use Of Dual Frequency Identification Sonar (Didson) To Quantify Behavioral Aspects Of Piscivory At Ecologically Relevant Time And Space Scales, Victoria E. Price May 2012

An Approach For Use Of Dual Frequency Identification Sonar (Didson) To Quantify Behavioral Aspects Of Piscivory At Ecologically Relevant Time And Space Scales, Victoria E. Price

Master's Theses

Predator-prey interactions of large vagile fishes are difficult to study in the ocean due to limitations in the space and time requirements for observations. Small-scale direct underwater observations by divers (<10m >radius) and large-scale hydroacoustic surveys (10s - 100s km2) are traditional approaches. However, large piscivorous predators identify and attack prey at the scale of meters to tens of meters. Dual- Frequency Identification Sonar, or DIDSON, is a high-resolution acoustic camera operating in the MHz range that provides detailed continuous video-like imaging of objects out to 30 m range. This technology can be used to observe predator-prey interactions at ecologically …


Diversity And Activity Of Roseobacters And Roseophage, Charles Ryan Budinoff May 2012

Diversity And Activity Of Roseobacters And Roseophage, Charles Ryan Budinoff

Doctoral Dissertations

Bacteria of the Roseobacter lineage are dominant bacterioplankton in coastal systems and contribute significantly to secondary production in oceanic environments. Generalities of Roseobacter ecology, diversity, and distributions are known, but the intraspecific differences between species and their dynamics over short temporal periods is not well understood. Bacteriophage that infect Roseobacters (‘roseophage’) have the potential to shunt secondary production into the dissolved carbon pool and through the process of infection alter Roseobacter physiology. Despite their significance, little effort was made prior to the onset of this study to characterize roseophage. Using culture dependent and independent approaches, I describe the diversity and …


Investigating The Roles Of Lhx1a, Lhx1b, And Lhx5 In Zebrafish Spinal Cord Interneuron Specification And Function, Samantha Balakirsky May 2012

Investigating The Roles Of Lhx1a, Lhx1b, And Lhx5 In Zebrafish Spinal Cord Interneuron Specification And Function, Samantha Balakirsky

Honors Capstone Projects - All

Located in the vertebral column, the human spine is responsible for regulating body movements and receiving sensory input about pain and touch. Currently, few treatments for neurological diseases and spinal cord injuries exist, partly because we know little about how a fully functioning spinal cord is constructed. As such, studying spinal cord development, specifically neuronal specification and patterning, should be useful for developing better treatments for people with spinal cord injuries and diseases. Zebrafish are a prime model organism for studying neuronal specification because their transparent embryos develop outside the mother, allowing us to easily examine gene expression, cell movements …


Genetic Variation In Potentially Virulent Vibrio Parahaemolyticus From The Northern Gulf Of Mexico, Nicholas Felix Noriea Iii May 2012

Genetic Variation In Potentially Virulent Vibrio Parahaemolyticus From The Northern Gulf Of Mexico, Nicholas Felix Noriea Iii

Dissertations

Vibrio parahaemolyticus (Vp) is a gram-negative bacterium found naturally in marine and estuarine environments. Vp is found in oysters including those which are later consumed by the public. Sub-populations of potentially virulent Vp contain specific virulence factors and are relevant human pathogens capable of causing gastroenteritis, wound infection, and death. The tdh and trh genes, both encoding hemolysins, have been correlated with the majority of clinical Vp isolates but have not been shown to be the definitive virulence factors.

A total of 146 Vp isolates from the northern Gulf of Mexico were collected and probed …


Application Of A Hybrid 3d-Var Data Assimilation System In The Monterey Bay To Study Regional Dynamics Of The California Current System, Chudong Pan May 2012

Application Of A Hybrid 3d-Var Data Assimilation System In The Monterey Bay To Study Regional Dynamics Of The California Current System, Chudong Pan

Dissertations

A data assimilation system combining 3-dimensional variational scheme and Navy Coastal Ocean Model was applied to the Monterey Bay area to assimilate temperature and salinity glider data collected in August 2003. The hybrid background error covariance model in the present 3-dimensional variational system incorporates both the static and the flow-dependent background error covariance. To explore the impact of high temporal resolution on the overall skill of the assimilation system, the intended data assimilation interval was set to 1 hour in the present study. A Floating Temporal Window approach is designed to keep the computational efficiency of the scheme and to …


Effects Of Hypoxia And 4-Tert-Octylphenol On Gene Expression Profiles Of The Sheepshead Minnow (Cyprinodon Variegatus), Arthur Alan Karels May 2012

Effects Of Hypoxia And 4-Tert-Octylphenol On Gene Expression Profiles Of The Sheepshead Minnow (Cyprinodon Variegatus), Arthur Alan Karels

Dissertations

Hypoxia occurs in estuaries of northern Gulf of Mexico and world-wide, with increasing frequency/severity via eutrophication and anthropogenic influences. Hypoxia inducible factors (HIFs) form transcriptional complex and bind DNA at hypoxia responsive elements (HREs) in promoter regions of genes needed for systemic and cellular adaptation of fish to low dissolved oxygen (hypoxia, DO <2.0 mg/ml). Hypoxia-induced activation of HIF-αs can lead to a cascade of downstream activation, such as erythropoietin (EPO). Return to normal DO levels (normoxia), prolyl hydroxylases (PHDs) are activated to degrade HIF-αs back to baseline. Fish are affected by environmental estrogen mimics, like 4-tert-octylphenol (4tOP), binding estrogen receptor alpha (ERα) at estrogen responsive elements (EREs) and activating genes vitellogenin (VTG). Previous research showed overlap or crosstalk between these two mechanistic pathways. Hypoxia triggers unknown factors regulating ERE-mediated ERα signaling pathway, and stressor combinations could increase/decrease hypoxic or endocrine pathway. Research examined molecular/physiological effects of hypoxia (acute and chronic, moderate and severe) and 4tOP (~60μg/L)on adult male and/or female sheepshead minnow (Cyprinodon variegatus). Three genes identified, cloned, and sequenced (HIF-1α, HIF-2α, and PHD3), plus previously identified genes EPO and VTG, were examined in liver/testes exposed to hypoxia and/or 4tOP for cellular/physiological changes. Endpoints examined included mRNA expression from real-time PCR of HIF-1α, HIF-2α, PHD3, EPO, and VTG using cDNA from total RNA extracts, and microarray analyses of genes expressed during the transition from hypoxia back to normoxia. Phylogenetic analyses confirmed isolation of two HIF-α isofoms (HIF-1α and HIF-2α) and the PHD3 isoform. Significant up-regulation of PHD3 occurred within 10 hrs of chronic hypoxia, and persisted when severe (1.5 mg/L) and declined when moderate (~2.5mg/L). Significant up-regulation of HIF-1α and EPO occurred within 30 minutes to 2 hours of onset of acute severe and very severe (~1.08mg/L) hypoxia. Hypoxia acted similar to an estrogen mimic, with huge up-regulation of VTG gene expression in males, and increased VTG levels (additive effect) when hypoxia was combined with 4tOP. Microarray analyses showed 125 genes with significant transcriptional change, with up- or down-regulation from transitions of: (1) hypoxia (72 hrs) to normoxia (74 hrs) and (2) hypoxia+4tOP (72 hrs) to normoxia+4tOP (74 hrs).


The Effects Of Nutrient Limitation And Cyanophage On Heterotrophic Microbial Diversity, Claire Elyse Campbell May 2012

The Effects Of Nutrient Limitation And Cyanophage On Heterotrophic Microbial Diversity, Claire Elyse Campbell

Masters Theses

Marine viruses are critically important in the regulation of biogeochemical cycles and host microbial communities. In this study, we tested whether the indirect effects of virus predation on a phototroph (i.e., Synechococcus) affected the composition of co-occurring heterotrophic bacteria under nitrogen and phosphorus limitation in long-term chemostat experiments. Using 454 Titanium barcoded pyrosequencing of the 16S rRNA gene, microbial diversity and technical (i.e., sequencing) reproducibility were assessed for nine individual chemostats across five different time points. A total of 325,142 reads were obtained; 194,778 high-quality, non-cyanobacterial sequences were assigned to 110 OTUs. Our results show high reproducibility …


Assessing The Variability In Distribution Of Four Shark Species Within The Mississippi Sound, Daniel Crear Apr 2012

Assessing The Variability In Distribution Of Four Shark Species Within The Mississippi Sound, Daniel Crear

All Theses And Dissertations

Global declines in shark populations have been observed, including several species indigenous to the northwest Atlantic Ocean and the Gulf of Mexico (GOM). Attributing to these declines is a lack of abundance and distribution data of early life stages, particularly within essential habitats such as nursery grounds. Previous research has defined the Mississippi Sound as a multispecies shark nursery, therefore determining how abundance and distribution patterns change will aid in verifying where these species are throughout the year within this shark nursery. Thus, the objectives of the current study were to describe the variability in distributions of four shark species …


Two- And Three-Dimensional Photogrammetric Mass Estimation Techniques For Two Phocid Species: Halichoerus Grypus And Phoca Vitulina Concolor, Jennifer Harris Apr 2012

Two- And Three-Dimensional Photogrammetric Mass Estimation Techniques For Two Phocid Species: Halichoerus Grypus And Phoca Vitulina Concolor, Jennifer Harris

All Theses And Dissertations

Collecting mass measurements of seals is a common technique used to determine health. To determine the mass of Western North Atlantic Grey seal (Halichoerus grypus) and Atlantic Harbor seal (Phoca vitulina concolor) pups, a researcher must physically measure each animal. This produces stress for both pups and their mothers. Photogrammetric analysis (PGA) (evaluating photographs to obtain characteristics of a subject) has been used to determine physical measurements in a number of marine mammals. The purpose of this study was to develop a nonintrusive method for determining the mass of grey and harbor seal pups. Through this …


Effects Of The Parasitic Dinoflagellate Hematodinium Sp. On Blue Crab (Callinectes Sapidus) Activity Predation And Habitat Selection, John M. Tiggelaar Ii Apr 2012

Effects Of The Parasitic Dinoflagellate Hematodinium Sp. On Blue Crab (Callinectes Sapidus) Activity Predation And Habitat Selection, John M. Tiggelaar Ii

Biological Sciences Theses & Dissertations

The blue crab Callinectes sapidus occurs along the Atlantic and Gulf coasts of the United States, and in high salinity regions, they are subject to lethal infection by the parasitic dinoflagellate Hematodinium. In Virginia's seaside estuaries, the prevalence of Hematodinium infection of C. sapidus can sometimes exceed 50%, threatening the commercial fishery for this species. Indeed, other commercially important crustacean fisheries have approached collapse due to Hematodinium infections. Most studies of this host-parasite interaction have focused on epidemiology, host-pathogen dynamics, and pathogen transmission, and little is known about the impact of the parasite on host behavior and population dynamics. …


Non-Lethal Determination Of Heavy Metals In Spiny Dogfish (Squalus Suckleyi) Spines Using La-Icp-Ms, Clayton L. (Clayton Louis) Bailes Jan 2012

Non-Lethal Determination Of Heavy Metals In Spiny Dogfish (Squalus Suckleyi) Spines Using La-Icp-Ms, Clayton L. (Clayton Louis) Bailes

WWU Graduate School Collection

Biological structures that develop incremental growth patterns over time present a unique opportunity to study chronological aspects of the organism's chemical environment. Spiny Dogfish (Squalus suckleyi), an abundant shark species, develop two dorsal spines that exhibit this type of growth pattern. The growth patterns on these spines have been used extensively as indicators of age. However, the chronological patterns of trace metal deposits in these spines have yet to be assessed. The main goals of this study were to develop the methods for analyzing this chronology and to explore techniques to analyze these data. Laser ablation inductively coupled plasma mass …