Physical Sciences and Mathematics Commons^™

Gulf Sturgeon Mesohabitat Use And Movement In The Lower Pearl River Louisiana-Mississippi, Amanda Popovich

LSU Master's Theses

After spring migrations to natal rivers Gulf Sturgeon Acipenser oxyrinchus desotoi reside in freshwater holding areas prior to fall emigrations to nearby estuaries. Limited published information on the physical habitat characteristics of these holding areas is available, especially for juvenile fish in the western portion of the Gulf Sturgeon’s distribution. To further investigate freshwater occupancy and movement patterns, 32 acoustic receivers were deployed from late April to October of 2021 and 2022 in 1600-m reaches distributed throughout the lower Pearl River, Louisiana-Mississippi, the westernmost river within their distribution. Generalized linear mixed models and multi-state models were used to determine what …

Review Of Structural Color In The Genus Chrysochroa Dejean, 1833 (Coleoptera: Buprestidae), Able Chow

LSU Master's Theses

The jewel beetles, (Coleoptera: Buprestidae Leach, 1815), is the eighth most speciose coleopteran family, with the majority of its members possessing diverse bright, saturated structural coloration of multilayer origin. This study focuses on the genus Chrysochroa Dejean, 1833, which includes some of the most brilliantly and charismatically colored buprestid species. While members of Chrysochroa are prised by entomologists amateurs and professional and are well-represented in museum collections, the evolution and ecology of their structural color remain underexplored. Twenty-eight select taxa including exemplars from all 13 subgenera of Chrysochroa were investigated to provide an overview of the objective optical properties and …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

A New Insight Into Fungal Cell Wall Architecture By Functional Genomics And Solid-State Nmr Along With Recent Advancements In Dynamic Nuclear Polarization For Analyzing Biomolecules, Arnab Chakraborty

LSU Master's Theses

This dissertation summarizes the findings related to the way by which supramolecular architecture of fungal cell wall changes with genetic mutation, dispensing genes responsible for biosynthesis of cell wall polysaccharides. This is necessary because without perfect picture of how supramolecular assembly changes with genetic mutation it is hard to assess new anti-fungal targets. Alongside this we have highlighted how recent advancement into Dynamic Nuclear Polarization (DNP) methods improved characterization of biomolecules both in case of labeled and unlabeled samples.

First study utilized Solid-state NMR (SSNMR) which is a non-destructive technique hence enabled us for the first time to deduce how …

Regional Expansion And Evaluation Of Potential Chemical Control For Invasive Apple Snails (Pomacea Maculata) In Southwest Louisiana, Julian M. Lucero

LSU Master's Theses

The integration of monitoring and chemical control is an efficient strategy for managing invasive apple snails, Pomacea maculata, in the rice (Oryza sativa L.) and crawfish systems of southwest Louisiana. However, their current distribution, expansion rates, and susceptibility to chemical control methods in this area are not well known. This study evaluated the expansion of P. maculata in southwest Louisiana and assessed potential chemical control for P. maculata among toxicity assays using various application rates. The effects of potential chemical control were also assessed on a non-target species, the red swamp crawfish (Procambarus clarkii). P. maculata …

Blue Carbon In South Florida's Mangroves: The Role Of Large Roots And Necromass, Zoë I. Shribman

LSU Master's Theses

Blue carbon sequestration and storage in mangroves largely result from belowground biomass allocation in response to flooded anaerobic soil conditions and nutrient availability. Biomass allocation to belowground roots is a major driver of mangrove soil formation and organic matter accumulation leading to blue carbon storage potential. Belowground biomass sampling in mangroves is labor intensive, limiting data availability on biomass stocks, particularly for large roots (>20 mm diameter) and necromass (dead roots). The mangrove nutrient model (NUMAN) uses mostly literature values to parameterize a soil cohort approach to simulate depth distribution of root mass and organic carbon concentration. We evaluated …

Phragmites Australis Dieback In The Mississippi River Delta: Chemical Profiles Of Soil Types And Restoration Potential, Herie Lee

LSU Master's Theses

Since 2016, there has been widespread dieback of P. australis in the Lower Mississippi River Delta (hereafter referred to as Lower MRD, which is defined as the Birds Foot Delta) with relatively little to no signs of recovery. The cause of the current dieback is not fully understood. This thesis explores P. australis with emphasis on chemical profile characterization of different soil types and its effects on plant growth and the potential for restoration in the Lower MRD.

In chapter 2, I characterized the chemical profiles of soils collected from healthy and dieback stands of Phragmites, and from newly …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Incorporating Life Into Living Shorelines: Can Gulf Ribbed Mussels Reduce Shoreline Erosion And Enhance Restoration Practices?, Jordan Logarbo

LSU Master's Theses

The gulf ribbed mussel (Geukensia granosissima) exists throughout the Gulf of Mexico and influences biotic and abiotic environmental attributes as an ecosystem engineer. Ribbed mussels are an important component of marsh ecosystems providing services including filtering particulate matter, depositing and transforming nutrients in the system, increasing soil strength via byssal threads and providing structure via their shells.

The spatial distribution of mussels along the marsh edge of Sister Lake, LA was investigated via a broad survey of 150 sites, in relation to elevation, exposure and vegetation percent cover. This survey was followed by a second survey at a …

Mosquito Distribution And Stoichiometric Analysis Between Open And Closed Canopies In New Orleans Cemeteries, Rachel Rogers

LSU Master's Theses

Cemetery vases represent an important container habitat for mosquito larvae. Some species, like, Aedes albopictus and Aedes aegypti, prefer container habitats, whereas others, like Culex quinquefasciatus, will opportunistically use containers. In New Orleans, these three medically important vector species (Ae. albopictus Ae. aegypti, and Cx. quinquefasciatus) co-occur, despite a demonstrated competitive advantage of Ae. albopictus to the other two. Here we test the hypothesis that canopy cover from trees could be a mediating factor in driving mosquito assemblages in New Orleans, by influencing food sources, and the microclimate experienced by mosquito larvae. Samples from seven …

Plant Community Response To The Combined Effects Of Elevation, And Simulated Nutrient And Sediment Loading In Sagittaria Lancifolia-Dominated Wetlands, Donnie Day

LSU Master's Theses

Coastal wetlands are experiencing threats to their long-term sustainability brought about by the combined effects of relative sea-level rise and human modifications to hydrology, sediment delivery and nutrient loading. Restoration and management strategies can include adding sediment to the surface of deteriorating marshes to facilitate positive feedbacks among elevation, plant productivity, sediment trapping, and accretion; however, if delivered using nitrate-enriched river waters, belowground biomass and soil organic matter pools may be negatively affected, resulting in the acceleration of wetland loss. Overall, there is limited information on the combined effects of nutrient loading, sedimentation, and flooding dynamics in regulating feedbacks among …

The Life History And Population Dynamics Of Southern Flounder, Kenneth A. Erickson

LSU Master's Theses

Southern Flounder, Paralichthys lethostigma, are a coastal, estuarine-dependent flatfish species that inhabits the Southeastern US Atlantic Ocean and Gulf of Mexico. Throughout their range, Southern Flounder are exploited by both commercial and recreational fisheries. Recently, numerous sources have expressed concerns about Southern Flounder populations, with stock assessments indicating declines in spawning stock biomass and recruitment. To estimate life history traits needed for informed management, such as age, growth, and maturity, I collected 327 Southern Flounder from Louisiana and obtained 14,184 historical records from the Louisiana Department of Wildlife and Fisheries. Using a von Bertalanffy growth equation in a Bayesian …

Reproductive Effort Of Montastraea Cavernosa Across Depth In The Context Of Both Climate Change Refugia And Emergent Disease, Jeanne Bloomberg

LSU Master's Theses

As coral populations on shallow reefs decline globally, mesophotic coral ecosystems (MCE) have been suggested as potential coral refugia in the face of climate changes, leading to the development of a comprehensive deep reef refugia hypothesis. The current study assesses the climate and disease refuge potential of MCEs in the U.S. Virgin Islands (USVI) for the gonochoric, broadcast-spawning species Montastraea cavernosa. Polyp, population, and total habitat fecundities were estimated across the species’ depth range, and changes to population oocyte production over time due to recent ecosystem disturbances were considered. The number of gonads producing oocytes in each polyp and oocyte …

Estimating The Onset And Extent Of Dieback Of Phragmites Australis Using The Normalized Difference Vegetation Index And Remotely Sensed Land Cover Classifications, Aimee M. Beaudette

LSU Master's Theses

Phragmites australis is cosmopolitan plant species with an invasive variety present throughout most of North America. In the Balize Delta, Louisiana, USA, P. australis plays an important role in combatting subsidence, maintaining navigation channels, and protecting interior fish and wildlife habitat from waves and storm surge. In 2016 a dieback of P. australis was reported by wetland managers, coinciding with the appearance of an invasive Asian scale insect (Nipponaclerda biwakoensis), though the specific cause is still unknown. Two previous efforts attempted to identify the onset of dieback conditions met with limited success. Using Landsat images from 1985 to …

An Ecopath With Ecosim Analysis On Offshore Petroleum Platform Influences On Gulf Of Mexico Red Snapper, Valentin Gomez

LSU Master's Theses

Offshore oil and gas platforms have had a significant presence in the Gulf of Mexico since the 1950s. An important secondary function of these structures is that they provide artificial habitat to fisheries, most notably Red snapper. Policy changes intended to reduce the risk associated with aging infrastructure have reduced the number of standing platforms from 4044 to 1867 from 2001 to 2018. The effect this loss of habitat has on Red snapper was tested by creating three scenarios of platform changes and modeling the perturbation from 2005 to 2050. The simulation was accomplished using the ecological model Ecopath with …

Role Of Coastal Environmental Conditions During Austral Winter On Plankton Community Dynamics And The Occurrence Of Pseudo-Nitzschia Spp. And Domoic Acid In Inhambane Province, Mozambique, Holly Kelchner

LSU Master's Theses

Harmful algal blooms (HABs) are increasing globally in frequency, persistence, and geographic extent. HABs pose a threat to economic stability, and ecosystem and human health. To date no incidences of marine toxins produced by phytoplankton have been recorded in Mozambique, which may be due to the absence of a monitoring program and general awareness of the potential threat. This study is the first documentation of the occurrence of a neurotoxin, domoic acid (DA), produced by the diatom genus Pseudo-nitzschia spp. along the east coast of Africa. The coast of Inhambane Province is a biodiversity hotspot where year-round Rhincodon typus (whale …

Reproductive Biology And Trophic Niche Of Hardhead Catfish In The Northern Gulf Of Mexico, Lucas G. Pensinger

LSU Master's Theses

Generally, marine fishes have very high fecundity with each female producing many small eggs which hatch into small larvae. However, Ariopsis felis, a species of marine catfish common to coastal Louisiana, has low fecundity and produces the largest eggs of the teleost fishes. Despite wide range and generally high abundance, we know very little of A. felis biology and population. The few existing studies of A. felis are older and often have questionable or unclear methodology.

I examined four aspects of A. felis reproductive biology: 1) reproductive timing,

2) fecundity, 3) length at first maturity, and 4) mouth brooding. …

Reproductive Parameters And Female Breeding Season Survival Of Rio Grande Wild Turkeys In South Central Texas, Jacob White

LSU Master's Theses

Historically, Rio Grande wild turkeys in south central Texas have been at lower densities than other portions of the state. Within the Oak-Prairie Wildlife District of Texas, Rio Grande wild turkey regulatory restrictions are different for counties in the eastern and western portions of the ecoregion. Due to perceived increases in turkey density in the eastern portion of the ecoregion (hereafter 1-bird zone), Texas Parks and Wildlife Department (TPWD) considered increasing the bag limit to match counties in the western portion of the district (hereafter 4-bird zone) in order to increase hunting opportunities. However, if regulatory changes are to be …

Cogongrass (Imperata Cylindrica (L.) Beauv.) In Louisiana: Cause And Consequence, Lorissa A. Radunzel-Davis

LSU Master's Theses

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive species from East Asia, is found worldwide and is problematic in several countries. In the United States, it grows primarily in the Southeast, reducing biodiversity by growing in dense patches and potentially causing mortality and reducing value of native and planted pinelands due to a high burning temperature. Using Lee Memorial Forest, a Louisiana State University AgCenter property in Washington Parish as a study site, this thesis explores cogongrass in Louisiana with emphasis on soil microbes and soil legacy effects on native plant species. Cogongrass populations at Lee Memorial Forest were more …

Spatiotemporal Impact Of Snow On Underwater Photosynthetically Active Radiation In Taylor Valley, East Antarctica, Madeline E. Myers

LSU Master's Theses

The role of snow on underwater photosynthetically active radiation (UW PAR) in the McMurdo Dry Valleys (MDVs) has been understudied due to lack of a detailed snowfall record. Research has shown that a relationship between snow cover and UW PAR exists, but the extent has never been evaluated in great detail. Although annual snowfall values in the MDVs are low (3 to 50 mm water equivalent annually), trends of increasing snowfall on the continent under future warming conditions could lead to an increased role for snow in regulating UW PAR (and associated primary productivity). Here, I discuss evidence from the …

Matrix Recharge In A Shrink-Swell Floodplain Forest Soil, Savannah R. Morales

LSU Master's Theses

Despite the global distribution of fine-grained Vertisols, the hydrology of these floodplain soils is still not well understood. Vertisols shrink and swell depending on soil moisture leading to a range of soil pore sizes, from large macropore cracks to smaller micropores, and consequently a range of hydraulic conductivities. Despite the plethora of research indicating the importance of both flooding and soil moisture in floodplain ecosystems, the specific role that flooding plays in soil moisture recharge has been less widely studied and remains of interest. Blue food dye and deuterated water were used as tracers to determine the role of the …

Maximizing And Modeling Malonyl-Coa Production In Escherichia Coli, Tatiana Thompson Silveira Mello

LSU Master's Theses

In E. coli, fatty acid synthesis is catalyzed by the enzyme acetyl-CoA carboxylase (ACC), which converts acetyl-CoA into malonyl-CoA. Malonyl-CoA is a major building block for numerous of bioproducts. Multiple parameters regulate the homeostatic cellular concentration of malonyl-CoA, keeping it at a very low level. Understanding how these parameters affect the bacterial production of malonyl-CoA is fundamental to maximizing it and its bioproducts. To this end, competing pathways consuming malonyl-CoA can be eliminated, and optimal nutritional and environmental conditions can be provided to the fermentation broth. Most previous studies utilized genetic modifications, expensive consumables, and high-cost quantification methods, making …

Building A Better Batture: A Regional Recreational Enhancement Around The Morganza To The Gulf Levee, Taylor N. Fehmel

LSU Master's Theses

Twenty-five years ago, the existing flood protection levees along the Louisiana coastline were removed and construction was started by Terrebonne Levee and Conservation District on a new project called ‘Morganza to the Gulf’ or MTG. This project was undertaken to construct a new flood protection levee system around Louisiana in the communities in Terrebonne and Lafourche Parish. The MTG Levee is one of the first coastal projects in Louisiana to incorporate a risk-based analysis for a double levee system containing both local parish drainage levees and future storm surge levees of MTG. It was designed to protect approximately 250,000 people …

Mosquito Image Classification Using Convolutional Neural Networks, Sumanth Vissamsetty

LSU Master's Theses

Human life has always been affected by insects, especially mosquitoes, since it's early beginnings. This pesky insect acts as a vector that transmit pathogens through feeding on our blood, spreading life-threatening diseases like Zika Virus, Malaria, Dengue fever, Chikungunya and more. It is important to prevent these mosquitoes from harming humans and one way to do so is to control the mosquito population, or mosquito abatement as it is commonly known. It is important to note that not all mosquitoes are the same and each of them live, reproduce and attack in their own unique way. Hence it is crucial …

Environmental Controls On Dissolved Carbon Export And River Geochemistry - A Case Study In The Mississippi-Atchafalaya System, Jeremy Reiman

LSU Master's Theses

Rivers serve as an important medium for the exchange of elements between land, ocean, and atmosphere. This thesis consists of three interconnected studies with the overarching goal of analyzing the environmental factors influencing dissolved carbon dynamics and river geochemistry in large rivers. These studies utilized river water samples and in-stream measurements collected from the Mississippi and Atchafalaya Rivers at hourly to monthly intervals between 2013 to 2018, along with ambient river and meteorological data downloaded from public-access databases. Results indicate substantially higher dissolved organic carbon concentrations (DOC, 611 ±181 µmol L^-1) but lower concentrations of dissolved inorganic carbon …

Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning

LSU Master's Theses

I coupled fine-scale environmental data with observed behavior and group composition data to examine overall distribution within the bay system and to characterize the habitat associated with foraging and the presence of calves. Semi-isolated populations of bottlenose dolphins (Tursiops truncatus) along Louisiana’s coast are undergoing increased risks from boat traffic, oil spills, land subsidence, and planned water diversions (CPRA 2017). Characterizing the habitat use of bottlenose dolphins in Terrebonne and Timbalier bays, Louisiana, is important given the likely high site fidelity, small home ranges, and low exchange of individuals with nearby coastal populations (Lane et al. 2015, McDonald …

Using Local Fishery Monitoring To Understand Small-Scale Coastal Fisheries In Tanzania, Matthew Robertson

LSU Master's Theses

Nearshore marine fisheries provide the main source of protein for nearly 9 million people in the coastal villages of Tanzania, yet for decades the fisheries have shown signs of overexploitation. These fisheries are small-scale and co-managed by local coastal communities in groups known as Beach Management Units (BMUs). BMUs monitor individual fishing trip data (e.g. gear, vessel, taxa); however, these data have only been analyzed in nationally aggregated statistics and to our knowledge, are not presently used in management decision making. The present thesis aimed to identify the forms of data and information that local fishery monitoring can record about …

Effects Of Enhanced Efficiency Nitrogen Fertilizers On Agronomic Parameters And Loss Pathways In The Subtropical Mississippi Delta Region, Scott Michael Pensky

LSU Master's Theses

Minimizing nitrogen (N) loss is critical for improving N use efficiency (NUE) in crop production and reducing its effects on the environment. Management practices such as seasonal application timing of N fertilizers and the addition of enhanced efficiency N fertilizers (EENFs) were investigated for the high N requirement of the two most common cereal crops globally, corn (Zea mays L.) and wheat (Triticum aestivum L.), in the subtropical climate of Louisiana. Field research was established during the 2016 and 2017 seasons at the LSU Agricultural Center’s Dean Lee and Central research stations to examine the effect of different EENFs and …

Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye

LSU Master's Theses

Sugarcane (Saccharum spp) production is an integral part of Louisiana's economy. Proper fertilizer management, particularly nitrogen (N) and potassium (K), optimizes sugarcane production. An experiment was established in 2015 at the LSU AgCenter Sugar Research Station in St. Gabriel, Louisiana to: (1) assess the effect of N and K fertilizer sources on sugarcane yield and quality parameters, and (2) monitor the changes in inorganic N and K levels in the soil at different sugarcane growth stages. The experiment was arranged in a randomized complete block design on a Sharkey clay soil and complete randomized design on a Commerce …

A Study Of The Urban Red Fox (Vulpes Vulpes) Population In Baton Rouge, Louisiana Using Social Media, Ahsennur Soysal

LSU Master's Theses

Foxes are timid yet resourceful animals that are integrated into many urban environments. Because they are elusive, collecting information about the number of urban foxes, their diet and spatial distribution, their interactions with the ecological community in their urban habitat, as well as residents’ response to them, is difficult. Involving stakeholders to participate in the data collection on wildlife via citizen science on social media is one way to overcome this complication, while simultaneously engaging residents in the ecology happening around them. Therefore, we used social media as the platform to engage the public to document and map the foxes …