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Oceanography and Atmospheric Sciences and Meteorology

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LSU Master's Theses

Theses/Dissertations

2014

Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Assessment Of Habitat Quality For Red Snapper, Lutjanus Campechanus, In The Northwestern Gulf Of Mexico: Natural Vs. Artificial Reefs, Brittany Dawn Schwartzkopf Jan 2014

Assessment Of Habitat Quality For Red Snapper, Lutjanus Campechanus, In The Northwestern Gulf Of Mexico: Natural Vs. Artificial Reefs, Brittany Dawn Schwartzkopf

LSU Master's Theses

Habitat quality of natural and artificial reefs for red snapper (Lutjanus campechanus) in the northwestern Gulf of Mexico (Gulf) is important as this area is home to the majority of the Gulf’s artificial reef system, in the form of oil and gas platforms, in addition to the largest extent of high vertical relief natural habitat. This study sought to assess habitat quality of natural reefs of varying habitat complexity and an artificial reef complex located on the LA continental shelf. Habitat quality was assessed by comparing red snapper diets and foraging patterns, and nutritional condition using the liver-somatic index (LSI) …

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Legacy Phosphorus Implications In The Lake Pontchartrain Estuary Sediment Due To The 2011 Bonnet Carre Spillway Opening, Nhan Thanh Nguyen Jan 2014

Legacy Phosphorus Implications In The Lake Pontchartrain Estuary Sediment Due To The 2011 Bonnet Carre Spillway Opening, Nhan Thanh Nguyen

LSU Master's Theses

Phosphorus (P) is an essential nutrient for life and excess P in aquatic systems can trigger algal blooms. Nutrient-rich Mississippi River water is diverted into the Lake Pontchartrain estuary (LPE) periodically through the Bonnet Carré Spillway (BCS) to avoid downstream flooding to the city of New Orleans, Louisiana and can significantly increase the internal P load in the sediment. A sequential P fractionation procedure was performed on sediments collected before the opening and after the closing of the 2011 BCS operation to understand the role of these large river diversions on P dynamics. Before the 2011 BCS opening, 10,368 Mt …

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Effects Of Storm Surge And Nutrient Loading On Coastal Wetland Soil Processes: Implications For Ecosystem Function, Morgan Mckee Jan 2014

Effects Of Storm Surge And Nutrient Loading On Coastal Wetland Soil Processes: Implications For Ecosystem Function, Morgan Mckee

LSU Master's Theses

Coastal Louisiana is at risk from increases in salinity from storm surge and nutrient loading from the Mississippi River. Increased salinity causes plant death, decreases in microbial productivity, and shifts in biogeochemical processes. Eutrophication is linked to shifts in plant communities and changes in wetland biogeochemical properties. We hypothesized that 1) storm surge would increase soil porewater salinity and decrease extractable ammonium (NH4), and 2) long-term nutrient loading would decrease soil extracellular enzyme activity and increase total nutrients. Intact soil cores from two sites in the Wax Lake Delta were continually flooded with 35 g L-1 salt water for 1, …

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Nutrient And Sediment Effects On Oligohaline Marsh Plant Community In Mississippi River Delta, Sareh Poormahdi Jan 2014

Nutrient And Sediment Effects On Oligohaline Marsh Plant Community In Mississippi River Delta, Sareh Poormahdi

LSU Master's Theses

The Mississippi River Delta comprises approximately 40% of the coastal wetlands in the conterminous United States, but has experienced more than 80% of the wetland loss in part due to flood control levees that have hydrologically isolated the lower River from the adjacent wetlands for a century. Thus, reconnecting the River to the wetlands through diversions is one of the approaches being used to reduce the rate of wetland loss. However, the diversion structures were originally designed to deliver freshwater rather than sediment. Furthermore, nutrient concentrations in the River water have increased during the past half-century as a result of …

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Cdom Optical Properties Near Dwh Site, Gulf Of Mexico: Pot Oil Spill, Zhi Li Jan 2014

Cdom Optical Properties Near Dwh Site, Gulf Of Mexico: Pot Oil Spill, Zhi Li

LSU Master's Theses

The Deep Water Horizon (DWH) oil spill resulted in the largest accidental release of crude oil in U.S. waters with both short- and long-term effects on the marine environment. Extensive studies conducted immediately following the oil spill in the northern Gulf of Mexico provided greater understanding of the physical processes influencing the distribution of the released oil, including the use of optical detection of polycyclic aromatic hydrocarbons (PAHs), a toxic crude oil fraction in the northern Gulf of Mexico. In this study, the optical properties of chromophoric dissolved organic matter (CDOM) and the concentrations of dissolved organic carbon (DOC) were …

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Polonium-210 Dynamics In The Northern Gulf Of Mexico, Patrick Robert Jones Jan 2014

Polonium-210 Dynamics In The Northern Gulf Of Mexico, Patrick Robert Jones

LSU Master's Theses

Polonium-210 (t1/2=138 d) is the most common among the 33 known radioisotopes of Polonium found in the natural environment. It is produced by the radioactive decay of its long-lived grandparent Lead-210(t1/2=22.3 d) via Bismuth-210 (t1/2=5.012 d) and forms as part of the natural Uranium-238 decay series. The primary hazard associated with Polonium-210 is its radioactivity, as an alpha particle emitter. Marine organisms receive their maximum radioactive dose in the natural environment from Polonium-210. Polonium has been known to bioaccumulate in the marine food web and can be potentially harmful to humans via the intake of certain marine organisms. Thus it …

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Hurricane-Induced Geologic Change And Palynological Assessment Of A Rapidly Subsiding Deltaic Environment In Coastal Louisiana, James Dustin Naquin Jan 2014

Hurricane-Induced Geologic Change And Palynological Assessment Of A Rapidly Subsiding Deltaic Environment In Coastal Louisiana, James Dustin Naquin

LSU Master's Theses

This study is focused on a paleoenvironmental history of a backbarrier coastal lagoon situated on the seaward margin of the Lafourche delta lobe in coastal Louisiana. A 2.2 meter long sediment core (Core BC 53) was collected from a mangrove-covered land strip on the northern margin of Bay Champagne, and was studied using pollen analysis, Loss-on-ignition (LOI), X-ray Fluorescence (XRF) analysis, and Cesium-137 and radiocarbon dating techniques to establish sediment stratigraphy and core chronology. Bay Champagne, a backbarrier lagoon formed during the evolution of Bayou Lafourche, has shown to be highly sensitive to geomorphological and vegetation changes induced by sea-level …

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Failed Agricultural Impoundments: An Interdisciplinary Assessment Of Community Structure And Social Resilience, Stacy Nicole Peterson Jan 2014

Failed Agricultural Impoundments: An Interdisciplinary Assessment Of Community Structure And Social Resilience, Stacy Nicole Peterson

LSU Master's Theses

The remnants of the wetland reclamation era of the early 1900s are visible in the leveed, drained, and failed impoundments across the United States, and especially in coastal regions. The common themes of their history are flooding, restoration, and – sometimes - community resilience. The physical changes occurring during and after impoundment, and after failure includes subsidence, erosion, and flooding are well-documented. Here I construct an environmental history that integrates data on these physical changes with archival records, historical documents, site visits and personal interviews. The primary region of focus is ‘Delta Farms’ - a failed agricultural impoundment in Lafourche …

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Temporal Variability Of Particulate Organic Carbon Fluxes In The Northern Gulf Of Mexico, Somiddho Bosu Jan 2014

Temporal Variability Of Particulate Organic Carbon Fluxes In The Northern Gulf Of Mexico, Somiddho Bosu

LSU Master's Theses

There is limited data of Particulate Organic Carbon (POC) export from the Northern Gulf of Mexico and this work presents the first estimation of the efficiency of the “biological pump” in this region. In oligotrophic oceans like the Gulf of Mexico, POC is the main source of particles and POC flux is the key mechanism for the removal of particle reactive contaminants and pollutants from upper ocean water column. Particle-reactive, the naturally occurring radionuclides are useful tracers of the sinking flux of organic matter from the surface to the deep ocean. The disequilibrium between natural radioisotope pair 238U-234Th as well …

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Does Reproductive Potential Of Red Snapper In The Northern Gulf Of Mexico Differ Among Natural And Artificial Habitats?, Hilary Day Glenn Jan 2014

Does Reproductive Potential Of Red Snapper In The Northern Gulf Of Mexico Differ Among Natural And Artificial Habitats?, Hilary Day Glenn

LSU Master's Theses

This study compares the reproductive potential of red snapper (Lutjanus campechanus) at artificial and natural habitats. Natural habitats are areas of vertical relief created from biogenic/geologic processes that are thought to be the historical centers of abundance for red snapper in the northern Gulf of Mexico. Red snapper were collected from 2011 to 2013 at three natural habitat sites and two artificial habitat oil and gas platform sites. The mean gonadosomatic indices (GSI), maturity at size and age, spawning indicators, batch fecundity, spawning frequency, and annual fecundity for red snapper at each habitat were analyzed to examine reproductive potential among …

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Effect Of The Bp Deepwater Horizon Oil Spill On Critical Marsh Soil Microbial Functions, Jason Paul Pietroski Jan 2014

Effect Of The Bp Deepwater Horizon Oil Spill On Critical Marsh Soil Microbial Functions, Jason Paul Pietroski

LSU Master's Theses

On April 20, 2010, the BP Deepwater Horizon (DWH) offshore oil platform exploded releasing ~ 795 million L of southern Louisiana (LA) light sweet crude oil into the Gulf of Mexico. Approximately 7.9 million liters of dispersant, Corexit EC9500A, were applied for remediation. The effect of BP DWH crude oil and Corexit EC9500A on two marsh soil microbial processes, (mineralizable nitrogen and denitrification), were examined in the laboratory. Surface soil samples were collected from an unimpacted salt marsh site proximal to areas that suffered light to heavily oiling in Barataria Bay, LA. Additions of oil were at a ratio of …

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