Environmental Sciences Commons^™

Recent Wetland Elevation Dynamics In Coastal Louisiana, Usa, Elizabeth Harris

LSU Master's Theses

Coastal marshes globally are increasingly vulnerable to accelerating relative sea-level rise (RSLR), which threatens their capacity to maintain elevation through feedbacks among sediment supply, vegetation productivity, hydrology, and soil processes. Although many marshes can persist under moderate rates of sea-level rise through vertical accretion and belowground biomass production, this resilience is strongly constrained by sediment availability and subsurface processes such as autocompaction and organic matter decomposition. High accretion is often assumed to confer marsh resilience; however, subsurface processes, particularly autocompaction driven by surface loading, can substantially offset elevation gains. Coastal Louisiana experiences among the highest rates of RSLR worldwide due …

Establishing A Framework Of Best Management Practices For Sustainable Water Quality: Integration Of Technology And Remote Sensing, Mason L. Marcantel

LSU Master's Theses

Water quality security is a complex management issue that is constantly challenged by factors of seasonal variability in climate change, urban population growth, and agricultural intensification. These factors warrant the need for innovative technological adaptations to management practices that integrate remote monitoring, predictive modeling, and sustainable resource utilization. This study establishes a framework for sustainable water quality practices through the integration of remote sensing technology for urban wastewater treatment and agricultural irrigation systems. This dual-site research study explores seasonal water quality dynamics and technological interventions to create a more proactive approach to water quality security.

In the first study, water …

Effects Of Hydrological Connectivity On Created Marsh Sustainability, Katie Swann

LSU Master's Theses

While efforts are being made to curb the high rate of coastal land loss in Louisiana, and even to restore ecosystem services and functions, it is generally accepted that restoration of these areas and functions is not a one-to-one value. It may take decadal time scales to reach efficient functional processing of nutrients and carbon storage rates, which may never reach true capacity comparable to similar naturally-organized systems. Although it is imperative to preserve these areas, restoration of ecosystem services and biogeochemical processes of coastal wetlands are preferable to future without action scenarios. Effectively directing the use of the limited …

Increasing The Economic And Social Viability Of Carbon Capture Using Biomass Slurry Fracture Injection, Zachary G. Laird

LSU Master's Theses

The climate is changing. This is a fact not a statement, not a theory, and not a falsehood, this is a fact. At the current projections the world’s average temperature is expected to rise by at least 2°C from pre-industrial averages by 2050 (Emissions Pathways to 2100 - Climate Action Tracker, 2024). This temperature rise will be catastrophic for a vast number of communities. What is driving this changing climate? Humans. In particular the carbon emissions caused by human activities. As humans we consume large amounts of meat, causing the need for cattle to increase, generating large amounts …

Source Origins Of Hunter-Harvested Waterfowl In Arkansas And Louisiana, Shannon C. Stemaly

LSU Master's Theses

Understanding variability in breeding origins of harvested waterfowl is important for effective population management and regional conservation. Band-recovery data are often used to estimate harvest derivation and inform resource allocation for cross-seasonal conservation. However, uneven spatial and temporal banding effort across species' breeding ranges may result in an incomplete understanding of summer origins and recruitment, particularly if portions of the breeding range are inaccessible. Analysis of stable-hydrogen isotope ratios in duck feathers (δ²H_f) provides an alternative method for identifying source origins of unmarked populations since environmental deuterium values follow a predictable latitudinal gradient across North …

Global Ocean Bottom Temperature Observation Design: Observing System Simulation Experiments For Strategic Deployment Of Smart Subsea Cables, Karen E. Renninger-Rojas

LSU Master's Theses

Deep-ocean observations below 2000 meters remain limited, restricting our ability to model global ocean processes critical to climate prediction. This thesis evaluates the potential of SMART (Science Monitoring and Reliable Telecommunications) subsea cables to address these observational gaps by conducting Observing System Simulation Experiments (OSSEs) and adjoint sensitivity analyses using the MITgcm ocean model and ECCO outputs.

Vertical decorrelation analysis showed that temperature and salinity in key regions decouple from the upper ocean beyond 2000 m. Over 60% of the proposed SMART cable sites exhibited decorrelation depths exceeding Argo’s maximum sampling depth, highlighting their strategic value for deployment.

A comparison …

Advancing Aerial Survey Techniques For Non-Breeding Waterfowl Populations: A Comprehensive Review And Application In Northeastern Louisiana, Victoria L. Drake

LSU Master's Theses

Aerial surveys play a crucial role in monitoring North America's waterfowl populations and habitat conditions, and consistency across geographies and years allows biologists to track trends through time. The goal of this project was to redesign the northeastern portion of the Louisiana wintering waterfowl survey to align with statistically robust transect surveys conducted in neighboring states within the Mississippi Alluvial Valley. To identify the optimal sampling method, we evaluated three transect weighting schemes: stratified random (unweighted), stratified by watershed, and stratified by expert opinion. Approximately 10% of the total sampling area was randomly selected for each survey period, adhering to …

Intraspecific Variation In Morphological And Biochemical Responses To Salinity And Flooding In Phragmites Australis, Olivia Hurley

LSU Master's Theses

Phragmites australis is a widespread wetland plant species with numerous haplotypes, several of which are highly invasive. In low-lying coastal marshes of Louisiana, the Delta-type (haplotype M1) dominates across a wide range of salinity and flooding environments. This suggests that Phragmites may be highly adaptable to diverse environmental conditions and that there may be a genetic component, as seen in other coastal wetland plant species. While non-native Phragmites haplotypes are targeted for control and removal in many areas, they are considered beneficial for marsh stabilization and contributing to elevation gain in coastal Louisiana, where several areas experience rapid land loss. …

Improving Rice Yield Using Sensor Based Nitrogen Application And Best Management Practices (Bmps) In Rice-Soybean And Rice-Crawfish Rotational Systems, Charles Darnall

LSU Master's Theses

Sustainable rice farming requires effective nutrient management and conservation practices to maintain high yields and minimize environmental impact. Implementing best management practices (BMPs) promotes lower fertilizer application rates, increased N use efficiency, improves soil health, and water quality. Demonstration fields established in two different rotational cropping systems (rice-soybean and rice-crawfish) in Kaplan, LA in 2023. In each rotation system, the benefits of BMPs (sensor based mid-season N management and cover cropping) compared to farmer’s practice (FP) were evaluated using yield, yield components, soil and water quality as metrics. The rice-soybean fields in 2023 and 2024 were both planted with PVL03 …

Examination Of The Effects Of Ultraviolet Radiation On The Toxicity Of An Array Of Pesticides, Polyaromatic Hydrocarbons, And Pharmaceuticals Via In-Vitro Bioassays, Jessica R. Stephens

LSU Master's Theses

Chemicals are often released via anthropogenic means both intentionally and unintentionally into aquatic environments. The chemical fate of these compounds can vary greatly depending on numerous factors that can include but are not limited to salinity, pH, dissolved oxygen, and exposure to ultraviolet radiation. The goal of this study was to investigate the effect of UV radiation on the level of toxicity of different chemicals over time. Chemicals were selected based on previous studies of the toxicity of both parent and metabolites formed as a result of photolysis. Anthracene, phenanthrene, anthraquinone, dicloran, chlorothalonil, hydroxy chlorothalonil, benzobicyclon hydrolysate, and sertraline were …

Quantification Of Belowground Biomass And Sediment Accretion In Mangroves Of Different Coastal Environmental Settings Of The Costa Rican Pacific Coast, Denise M. Poveda

LSU Master's Theses

The adaptation of intertidal ecosystems such as mangroves to anticipated accelerated relative sea level rise is dependent on net increase of sediment surface elevations and forest migration inland. Ecosystem models developed to simulate trajectories of ecosystem adaptations have determined that rates of soil formation are most sensitive to surface sediment (organic and inorganic) deposition and subsurface organic production by mangrove roots. Mangrove belowground biomass contributes to soil organic matter accumulation, while mangrove litter has minor contribution due to export and annual decay. In addition to belowground biomass production, inorganic sediment loading is also key contribution to soil formation and accretion. …

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh

LSU Master's Theses

The marine cyanobacterium Synechococcus sp. CCMP 1334 was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nitrate availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21°C, 24°C, 28°C, 32°C, and 35°C. The maximum median nutrient-replete growth rate was ~1.15 d−1 at 32 –35°C. Median growth rates at 1000 ppmv pCO2 were higher than those at 400 ppmv at all temperatures, but most of the differences were statistically insignificant. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate but decreased with …

Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent

LSU Master's Theses

Submarine pipelines and cables are vital for transmitting physical and digital resources across bodies of water, necessitating regular inspection to assess maintenance needs. The safety of subsea pipelines and cables is paramount for sustaining industries such as telecommunications, power transmission, water supply, waste management, and oil and gas. Incidents like those involving the Nord Stream subsea pipeline and the SEA-ME-WE 4 subsea communications cable exemplify the severe economic and environmental consequences of damage to these critical infrastructures. Existing inspection methods often fail to meet accuracy requirements, emphasizing the need for advancements in inspection technologies. This comprehensive survey covers the sensors …

The Impacts Of Nature-Based Sediment Restoration Practices On Coastal Wetland Soil Biogeochemistry, Jacob Z. Cheng

LSU Master's Theses

Coastal marshes provide many valuable ecosystem services. However, these wetlands are threatened worldwide, being subject to sea level rise, sediment starvation, subsidence, coastal edge erosion, etc. Many efforts are being made to counteract this wetland loss and preserve the ecosystem services. Two such methods are sediment diversion and the thin layer placement (TLP) of dredged sediment.

Sediment diversion involves reconnecting the main channel of a river body to disconnected wetlands, supplying much needed soil-building materials. However, this method affects the salinity of the waters, introducing large amounts of freshwater into the system. Salinity changes can affect marsh biogeochemistry. Most ecological …

If You Build It, Will They Come? Assessing Habitat Quality For Marsh Birds At Created Marshes In Southeastern Louisiana, Katherine Aylett Lipford

LSU Master's Theses

Wetland loss occurs at an alarming pace globally, with extremely high rates along the northern Gulf of Mexico. Louisiana loses a football field of wetland every 100 minutes: that is 77,000 m² of wetland bird habitat lost daily. In Louisiana, marsh creation projects combat wetland loss, and while wildlife habitat is often used as a justification for restoration, wildlife receives little to no consideration during and after construction. Habitat characteristics such as site-specific hydrology, vegetation composition, and habitat structure affect the abundance of wetland birds and understanding these features is crucial to creating habitat that will benefit birds. My …

Vegetation And Habitat Classification Of Created And Natural Brackish Marshes Via Unoccupied Aerial Systems And Potential Monitoring Applications, Seth T. Chapman

LSU Master's Theses

Louisiana’s coastal marshes are some of the most valuable natural, economic, and cultural state resources that however, have been severely deteriorating over the last century. Federal and state agencies have pooled billions of dollars into coastal restoration projects in Louisiana of which marsh creation is a primary focus. Traditional monitoring of created marshes involves in-situ vegetation sampling and aerial imagery from fixed-wing occupied aircraft, but these methods have limitations and/or can negatively impact sites. My thesis explores the use of Unoccupied Aerial Systems (UAS; i.e., drones) to classify vegetation and habitat in coastal marsh systems, compare habitat and vegetation cover …

Uavs And Deep Neural Networks: An Alternative Approach To Monitoring Waterfowl At The Site Level, Zachary J. Loken

LSU Master's Theses

Understanding how waterfowl respond to habitat restoration and management activities is crucial for evaluating and refining conservation delivery programs. However, site-specific waterfowl monitoring is challenging, especially in heavily forested systems such as the Mississippi Alluvial Valley (MAV)—a primary wintering region for ducks in North America. I hypothesized that using uncrewed aerial vehicles (UAVs) coupled with deep learning-based methods for object detection would provide an efficient and effective means for surveying non-breeding waterfowl on difficult-to-access restored wetland sites. Accordingly, during the winters of 2021 and 2022, I surveyed wetland restoration easements in the MAV using a UAV equipped with a dual …

Are We There Yet?, Marion S. Freistadt

LSU Master's Theses

To solve the Climate Crisis, a global Energy Transition is required. The primary contemporary tool for tackling these two massive problems is modeling, both biophysical climate models and IAMS (Integrated Assessment Models) which combine socioeconomic and technological progress with Climate Change. However, the proliferation and complexity of modeling systems make it difficult for most people to contribute substantively to solutions. In particular, stakeholders, policymakers, nonspecialists and activists require sufficient understanding of modeling to impact outcomes.

In this thesis, after summarizing the Climate Crisis and potential Energy Transition solutions, I review current modeling approaches. Models can be considered in terms of …

Can Gulf Ribbed Mussels Enhance Coastal Restoration Projects In A Future With Climate Change?, Skylar Liner

LSU Master's Theses

Living shorelines present one restoration approach using biotic elements (via ecosystem engineers) to stabilize shorelines and increase valuable habitat. Gulf ribbed mussels (Geukensia granosissima) are important ecosystem engineers within brackish and salt marshes in the northern Gulf of Mexico, and can increase nutrient availability, enhance marsh vegetation production, and potentially improve shoreline stability. It is unknown whether mussels will maintain these functions as future climate change predicts increases in temperature and water level, which may exceed the mussel’s tolerance. A field survey conducted during the summer of 2022 identified the daily maximum temperature at the marsh surface, where mussels naturally …

Interactive Effects Of The Partial Pressure Of Co2, Temperature, And Nutrient-Limitation On The Physiology And Growth Of The Coccolithophore E. Huxleyi Grown On A 12:12 L:D Cycle Of Illumination, James Bradley

LSU Master's Theses

I studied the interactive effects of pCO2, temperature, and nutrient limitation on the growth and physiology of the marine coccolithophore, Emiliania huxleyi. This was done to look at the effect of climate change factors on the widespread and abundant calcifying marine organism as a predictor of what the future has to hold. The strain of E. huxleyi (PnB 272 B10) was grown on a 12:12 L:D cycle of illumination and exposed to either high or low pCO2 under nutrient-replete or nitrate-limited conditions across a temperature range of 10–28C. I examined the direct and interactive effects of temperature, pCO2, and nutrient …

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 …

Assessing Turgor Loss Point In Bottomland Hardwood Trees Using Leaf Spectroscopy, Alexandra M. Eisley

LSU Master's Theses

Climate change is expected to radically alter our planet’s forests, with higher frequencies of drought- and flood-induced mortality events posing a challenge for forest managers and biologists. Research into the factors underlying plant tolerance to environmental stressors is therefore gaining popularity for incorporation into projective and earth system modeling using remote sensing measures. Leaf turgor loss point (TLP) is a key trait associated with drought tolerance among plants and is defined as the water potential at which leaf turgor pressure reaches zero, causing wilting. Here, I investigated patterns of TLP across the landscape and its role as an indicator of …

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 …

Local And State Climate Initiatives In Louisiana Since 2005: Content And Thematic Analyses, Jessie F. Parrott

LSU Master's Theses

Louisiana is uniquely exposed to severe weather because of its geography and climate. Louisiana’s extreme weather is exacerbated by anthropogenic climate change, which will worsen in the future. The risks its population and environment are exposed to has generated several policies and planning documents, nine of which are analyzed in this thesis. Three plans are from the state level, three are from the parish level, and three are from the urban (New Orleans) level. These planning documents pose various adaptation and mitigation actions to ameliorate and address multiple climate issues. These actions utilize specific mitigation strategies. The content and thematic …

Impact Of Oil And A Tropical Cyclone On An Omnivore And Herbivore Population In Salt Marshes Of Louisiana, Hannah K. Gordon

LSU Master's Theses

Terrestrial arthropods are the ideal ecological indicators for the health of a salt marsh. Salt marshes are under extreme continuous stressors including climate change, land loss, oil spills, and tropical cyclones. Such stressors impact trophic and species level interactions, food resources, dispersal and population size of insects. In the present study, we collected terrestrial arthropods from eleven sites around Barataria Bay, five sites were oiled and five sites were unoiled, to determine the impact of the redistribution of oil from the Deepwater Horizon oil spill. Site C6 was excluded from the oiled and unoiled data because it was in close …

Effects Of Hypoxia And High Temperature On Eastern Oysters: Investigating Differential Tolerance In Populations And Ploidies, Nicholas C. Coxe

LSU Master's Theses

Increasing prevalence of hypoxia in estuarine waters can pose a serious threat to eastern oysters (Crassostrea virginica). While oysters are considered more tolerant to hypoxia than many other bivalves, their tolerance at temperatures of 28 °C and above, typical in northern Gulf of Mexico estuaries in the summer, is not well characterized. Moreover, it is unknown whether differences in hypoxia tolerance exist among oyster populations or between diploid and triploid oysters. To investigate population differences, wild oysters were collected from four estuaries in the northern and northwestern Gulf of Mexico and spawned. In a series of studies, the …

Changes In Heat Metrics Following A Major Hurricane And Implications On Heat Stress, Cade Reesman

LSU Master's Theses

Tropical cyclones modify surface-atmosphere interactions in several ways, including the destruction of patches of tree canopy, increasing the direct and diffuse (shortwave) radiation reaching the surface. This addition of radiation at the surface impacts the sensible, latent, and substrate heat (energy) fluxes, generating heat anomalies along the hurricane’s track, which, among other effects, contributes to the higher post-hurricane surface air temperatures. This study consists of a case study on Hurricane Laura (2020) to examine hurricane defoliation impacts on heat stress metrics. Normalized difference vegetation index (NDVI) data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) identified the spatial extent of defoliation …

Sediment Buffering And Recycling On An Annual To Centennial Scale Along The Mississippi River, Nikki E. Neubeck

LSU Master's Theses

Although the Mississippi River and its tributaries have been investigated for many years, the alteration of the river through dams, levees, and diversions has affected how sediment is transported from source to sink (>10³ y). Previous provenance research using detrital zircon U-Pb dating indicates a slow transport time from source-to-sink, but recent anthropogenic alterations of the river may potentially diminish the transportation time of heavy minerals due to an increase in flow efficiency. The objective of this study is to analyze the degree of buffering and recycling of Mississippi River sediment over a range of short time scales, …

Bat Habitat Use And Activity In Forests Of Central Louisiana, Jane M. Kunberger

LSU Master's Theses

In the southeastern U.S., where forests are the primary land cover type and trees are often harvested for production purposes, understanding how forestry practices influence bat distributions is critical for bat conservation and management. It is also important for researchers to quantify and report variation in the performance of automated recordings units (ARUs) used to survey for bats because several key features of ARUs (e.g., microphone sensitivity, triggering thresholds) can influence an ARUs ability to detect bat calls. My goals were (1) to examine the influence of forest management practices on seasonal bat species occurrence and activity in central Louisiana, …

Application Of Gravity Data For Hydrocarbon Exploration Using Machine Learning Assisted Workflow, Oluwafemi Temidayo Alaofin

LSU Master's Theses

Gravity survey has played an essential role in many geoscience fields ever since it was conducted, especially as an early screening tool for subsurface hydrocarbon exploration. With continued improvement in data processing techniques and gravity survey accuracy, in-depth gravity anomaly studies, such as characterization of Bouguer and isostatic residual anomalies, have the potential to delineate prolific regional structures and hydrocarbon basins. In this study, we focus on developing a cost-effective, quick, and computationally efficient screening tool for hydrocarbon exploration using gravity data employing machine learning techniques. Since land-based gravity surveys are often expensive and difficult to obtain in remote places, …