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New Insights Into The Paleovegetation Of The Ancient Underwater Forest Located In The Northern Gulf Of Mexico, Karla Lizarraga Garcia May 2023

New Insights Into The Paleovegetation Of The Ancient Underwater Forest Located In The Northern Gulf Of Mexico, Karla Lizarraga Garcia

Master's Theses

A well-preserved remnant of an ancient bald cypress forest (hereafter, Underwater Forest) constitutes the only known archive of a glacial refuge on the once exposed continental shelf of the Northern Gulf of Mexico. This forest existed around 41-72 yBP (MIS 3-5) according to the existing dating methods applied on previous studies. As the climate conditions and sea levels changed, the vegetation of this glacial refuge shifted from bald cypress forests to open marshes, altering the vegetation dynamics. The present research analyzed four new cores (21DF-5A, 21DF-5B, 15DF-6, and 16DF-3A), which provided additional insights into the vegetation that once existed in …


The Effects Of Vertical Diel Thermocline Movement On The Settling Of Marine Snow In A River Influenced Marine Environment, Nadine Doiron May 2021

The Effects Of Vertical Diel Thermocline Movement On The Settling Of Marine Snow In A River Influenced Marine Environment, Nadine Doiron

Master's Theses

To evaluate the role of diel heating and cooling cycles in the upper water column in marine snow settling processes, particle distribution data from 15 marine snow camera casts were analyzed to examine variations in aggregate abundance, ellipsoidal volume, and particle elongation with depth. Data were collected during two cruises aboard R/V Endeavor in the Gulf of Mexico (GoM), EN620 in 2018 and EN642 in 2019. To develop a deeper understanding of daily patterns in marine snow settling, data were collected at the beginning and end of daily heating cycles. Temperature data were obtained by camera mounted Seabird SBE19+ model …


Small-Scale Resuspension And Redistribution Of Surface Sediments In The Northeast Gulf Of Mexico, Austin Harris May 2021

Small-Scale Resuspension And Redistribution Of Surface Sediments In The Northeast Gulf Of Mexico, Austin Harris

Master's Theses

Following the release of ~4.9 million barrels of oil into the Gulf of Mexico from the Macondo wellhead, a vast area of the seafloor contained recently deposited marine sediments contaminated by the oil spill. The initial deposition of these contaminated marine sediments was likely not the end of the journey for the particles. Downslope gravitational processes and events of increased current speed in the deep ocean setting can result in recently deposited sediments to resuspend and be moved laterally with the current flow, increasing the area effected by the oil spill. Erosion experiments performed in a closed-loop resuspension flume were …


Development And Employment Of Environmental Dna Methods For The Detection Of Bull Sharks (Carcharhinus Leucas) In A Freshwater And Estuarine Interface In The Mobile-Tensaw Delta And Mobile Bay, Alabama, Katherine Schweiss Dec 2019

Development And Employment Of Environmental Dna Methods For The Detection Of Bull Sharks (Carcharhinus Leucas) In A Freshwater And Estuarine Interface In The Mobile-Tensaw Delta And Mobile Bay, Alabama, Katherine Schweiss

Master's Theses

Species conservation and management is influenced by the quality of monitoring methods employed, especially when targeting elusive, but ecologically significant species, like elasmobranchs. Bull Sharks (Carcharhinus leucas) are highly mobile predators that rely on estuaries and freshwater rivers for maturation, resources, and refuge; their ability to withstand changing environmental conditions may mean they are linking ecosystems through their habitat usage and movements. Rather than setting nets or attaching acoustic monitoring devices, which can be expensive, time-consuming, and invasive, the analysis of environmental DNA (eDNA) for tracing species presence was used to target C. leucasDNA. The present research …


The Variability Of High-Frequency Motions And Their Interactions With The Mesoscale On The Mississippi Shelf, Jordan Earls Dec 2019

The Variability Of High-Frequency Motions And Their Interactions With The Mesoscale On The Mississippi Shelf, Jordan Earls

Master's Theses

In this study, we examine the spatial and temporal variability of high-frequency and low-frequency motions across the Mississippi Shelf and how the high-frequency motions are modulated by low-frequency mesoscale motions. For this purpose, we use Acoustic Doppler Current Profiler (ADCP) measurements collected at nearshore (23 m), mid-shelf (60 m), and shelf break (88 m) stations. High-frequency motions are defined as motions with periods less than 36 hours, whereas mesoscale motions have larger periods. The collected datasets are analyzed through bandpass filtering, least square harmonic analysis, spectral analysis, and empirical orthogonal functions (EOF). We find that along-shelf barotropic mesoscale motions contain …


Environmentally-Driven Variation In The Population Dynamics Of Gulf Menhaden (Brevoortia Patronus), Grant D. Adams Aug 2017

Environmentally-Driven Variation In The Population Dynamics Of Gulf Menhaden (Brevoortia Patronus), Grant D. Adams

Master's Theses

Gulf Menhaden (Brevoortia patronus) is an abundant forage fish distributed throughout the Northern Gulf of Mexico (NGOM). Gulf Menhaden support the second largest fishery, by weight, in the United States and represent a key linkage between upper and lower trophic levels. Variation in the population dynamics can, therefore, pose consequences for the ecology and economy in the NGOM. Here we aim to understand variation in the individual and population dynamics of Gulf Menhaden throughout ontogeny and how such variation relates to environmental processes. We utilized a suite of fishery-dependent and –independent, remote sensing, modeled, and in situ data …


Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg May 2017

Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg

Master's Theses

Invasive Red Lionfish (Pterois volitans) were first detected in the northern Gulf of Mexico (nGOM) in 2010 and since then their numbers have increased dramatically. From 2010 to 2015, more than 15,000 Red Lionfish were collected opportunistically from the nGOM for this study. Length and weight relationships differed significantly among ecoregions by sex and there was clear sexual dimorphism in size with males being larger and heavier. Red Lionfish age ranged from 0-4.5 years old and males achieved greater growth rate (K) and asymptotic maximum lengths (Linf) compared to females and these parameters were also different …


Determining The Viability Of Recent Storms As Modern Analogues For North-Central Gulf Of Mexico Paleotempestology Through Sedimentary Analysis And Storm Surge Reconstruction, Joshua Caleb Bregy Aug 2016

Determining The Viability Of Recent Storms As Modern Analogues For North-Central Gulf Of Mexico Paleotempestology Through Sedimentary Analysis And Storm Surge Reconstruction, Joshua Caleb Bregy

Master's Theses

The northern Gulf of Mexico has been devastated by recent intense storms. Camille (1969) and Katrina (2005) are two notable hurricanes that made landfall in virtually the same location in Mississippi. However, fully understanding the risks and processes associated with hurricane impacts is impeded by a short and fragmented instrumental record. Paleotempestology could potentially use modern analogues from intense storms in this region to extend the hurricane record back to pre-observational time. Existing empirically based models can back-calculate surge heights over coastal systems as a function of transport distance, particle settling velocity, and gravitational acceleration. We collected cores in a …


Age, Growth, Reproduction, And Diet Of The Finetooth Shark, Carcharhinus Isodon, In The Northern Gulf Of Mexico, Jeremy Michael Higgs May 2016

Age, Growth, Reproduction, And Diet Of The Finetooth Shark, Carcharhinus Isodon, In The Northern Gulf Of Mexico, Jeremy Michael Higgs

Master's Theses

The current study examined life history parameters of the finetooth shark, Carcharhinus isodon, in the northern Gulf of Mexico (nGOM) to provide an accurate description of the species’ reproductive biology, age, growth and diet composition. A total of 1,489 finetooth sharks (830 female; 659 male) were collected from coastal waters of the nGOM between Apalachicola Bay, Florida (29.873° N and 84.514° W) and East Bay, Louisiana (28.959° N and 89.279° W) from June 2006 through October 2013. Peak reproductive development occurred during May/June for both males and females, which was followed by mating and an 11-12 month gestation period. …


Fishery And Population Dynamics Of Mississippi’S Spotted Seatrout, David Arthur Dippold May 2016

Fishery And Population Dynamics Of Mississippi’S Spotted Seatrout, David Arthur Dippold

Master's Theses

Spotted Seatrout (Cynoscion nebulosus) is the most popular recreational inshore fishery in Mississippi coastal waters. Because of the popularity of Spotted Seatrout in Mississippi as a recreational target and the magnitude of harvest, quantitative approaches to describe the population and fishery dynamics of the Mississippi stock are needed to continue the sustainability of the stock. Quantitative approaches to describing stock dynamics are useful because they can help describe population characteristics, assess the current status of the stock, and be used to evaluate alternative management strategies. In this thesis, I use a suite of quantitative methods to describe, evaluate, …


Assemblage Comparisons Of Living Benthic Foraminifera At Bathyal Sites Oiled And Un-Oiled By The Deepwater Horizon Blowout In The Northeastern Gulf Of Mexico, Valerie Joanna Cruz Aug 2014

Assemblage Comparisons Of Living Benthic Foraminifera At Bathyal Sites Oiled And Un-Oiled By The Deepwater Horizon Blowout In The Northeastern Gulf Of Mexico, Valerie Joanna Cruz

Master's Theses

Live benthic foraminiferal assemblages were studied at contaminated and uncontaminated bathyal sites around the wellhead of the Deepwater Horizon oil spill. Samples collected in October of 2010 and 2011 and summer of 2012 were divided into uncontaminated (GIP 12, 21, K, and 25 and Obs0), moderately oiled (GIP 16 and 17) and heavily oiled groups (GIP 15), in which the TPAH concentrations ranged from 29 to 7,553 ng/g in 2010. Metric multidimensional scaling (MDS) and cluster analyses were conducted to compare all surface samples. Additionally, the heavily oiled site (GIP 15) and an uncontaminated site (GIP 25) were studied downcore …


Exploration Of Biophysical Interactions Associated With Mesoscale Variability In The Central Gulf Of Mexico, Katharine Celeste Woodard May 2014

Exploration Of Biophysical Interactions Associated With Mesoscale Variability In The Central Gulf Of Mexico, Katharine Celeste Woodard

Master's Theses

Bio-physical coupling in the Gulf of Mexico (GMx) is explored in this research using an integrated satellite sensor approach. Physical features are identified using Sea Level Anomaly (SLa) produced by Archiving, Validation, and Interpretation of Satellite Oceanographic data (AVISO). Biological characteristics of the GMx have been recognized as ocean color identified by the satellites SeaWiFS and MODISA. A climatology data set and a chlorophyll anomaly (CLa) was made using the 14-year mean determined from the ocean color files. The hypotheses are that there will be an inverse relationship between SLa and CLa, that mesoscale SLa features will significantly modulate local …


Taxonomy, Diversity, And Distribution Patterns Of Portunid Crab Megalopae In The Northern Gulf Of Mexico During Fall Of 2003, Carley Rain Knight May 2014

Taxonomy, Diversity, And Distribution Patterns Of Portunid Crab Megalopae In The Northern Gulf Of Mexico During Fall Of 2003, Carley Rain Knight

Master's Theses

The field of zooplankton biology contributes to more accurate stock assessments as well as to a greater understanding of the marine food web. However, adequate information for the invertebrate component of zooplankton is lacking compared to the ichthyoplankton component. In this thesis, identification of Portunidae (Crustacea: Decapoda) megalopae collected during the fall of 2003 from a NOAA SEAMAP cruise revealed 7 species and 11 morphs with 90% of the total density comprised of Callinectes sapidus, Achelous gibbesii, Callinectes similis, Achelous spinicarpus, and Achelous sp.I. Keys and detailed descriptions are provided along with photographs and morphological drawings for each morph to …


Thermal Tolerance Of Age-0 Gulf Of Mexico Striped Bass (Morone Saxatilis): Ontogenetic And Genetic Effects, Corey Robert Anderson Dec 2011

Thermal Tolerance Of Age-0 Gulf Of Mexico Striped Bass (Morone Saxatilis): Ontogenetic And Genetic Effects, Corey Robert Anderson

Master's Theses

Striped bass, Morone saxatilis, were historically abundant in the Gulf of Mexico region but were largely extirpated from most Gulf rivers by the early 1960s. Since 1967 hatchery stocking has supported populations in Mississippi rivers and to date there is no evidence of natural reproduction. Intolerance of striped bass to high water temperature is a potential factor negatively impacting Gulf striped bass survival and reproductive fitness, and may be a limiting factor to reintroduction of the species in Mississippi. This work contributed to restoration efforts by establishing molecular tools necessary for genetic monitoring of striped bass restoration, and evaluating …