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Articles 91 - 120 of 168
Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology
Effect Of The Bp Deepwater Horizon Oil Spill On Critical Marsh Soil Microbial Functions, Jason Paul Pietroski
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 …
Polonium-210 Dynamics In The Northern Gulf Of Mexico, Patrick Robert Jones
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 …
Failed Agricultural Impoundments: An Interdisciplinary Assessment Of Community Structure And Social Resilience, Stacy Nicole Peterson
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 …
Effects Of Storm Surge And Nutrient Loading On Coastal Wetland Soil Processes: Implications For Ecosystem Function, Morgan Mckee
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, …
Temporal Variability Of Particulate Organic Carbon Fluxes In The Northern Gulf Of Mexico, Somiddho Bosu
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 …
The Feasibility Of Using Vanadium And Nickel To Track Oil Spills In Coastal Environments, Sean Patrick Kenny
The Feasibility Of Using Vanadium And Nickel To Track Oil Spills In Coastal Environments, Sean Patrick Kenny
LSU Master's Theses
Crude oil has been increasing in world demand over the past century. It is known that oil is resistant to weathering processes and if spilled, can cause serious environmental damage to an area, on land or sea. A complementary approach to current methods of tracking oil and identifying spill-impacted sediments may be to measure trace metals associated with crude oil. Trace metals, such a vanadium (V) and nickel (Ni) are known to be elevated in concentration in some oil sources, but little work has been done on this topic. This research explored less expensive and time-consuming methods to track or …
Characterization Of Epibenthic And Demersal Megafauan At Mississippi Canyon 252 Following The Deepwater Horizon Oil Spill, Marla Maxine Valentine
Characterization Of Epibenthic And Demersal Megafauan At Mississippi Canyon 252 Following The Deepwater Horizon Oil Spill, Marla Maxine Valentine
LSU Master's Theses
Increased demand for new sources of oil and gas has resulted in an expansion of drilling into deeper waters. With this exploratory drilling come increased risks, which were realized on April 20, 2010 when the blow out preventer on the Macondo Well failed, resulting in the release of a large quantity of oil and gas into the Northern Gulf of Mexico from a bathypelagic source. This unprecedented environmental disaster was coined the Deepwater Horizon Oil Spill by the popular news media. In the months that followed the spill, the lack of knowledge about the pre-spill condition of deep-sea communities in …
Acoustic Biomass Of Fish Associated With An Oil And Gas Platform Before, During, And After "Reefing" It In The Northern Gulf Of Mexico, Grace Elizabeth Harwell
Acoustic Biomass Of Fish Associated With An Oil And Gas Platform Before, During, And After "Reefing" It In The Northern Gulf Of Mexico, Grace Elizabeth Harwell
LSU Master's Theses
With over ~2600 oil and gas platforms (platforms) remaining in the northern Gulf of Mexico (Gulf), the Gulf States have access to one of the most unique fisheries in the world. Because of high abundances of game fishes around platform legs and the popular belief that platforms enhance fish stocks, both Louisiana and Texas have created artificial reef programs based upon the decommissioning of platforms. As oil and gas fields continue to be retired, oil and gas companies may find that “reefing” or toppling a platform may be a more economically viable alternative to complete removal of material. Questions remain …
Inertial Oscillations In The Gulf Of Mexico During 2005 Hurricane Season, Fan Zhang
Inertial Oscillations In The Gulf Of Mexico During 2005 Hurricane Season, Fan Zhang
LSU Master's Theses
Near Inertial Oscillations (NIOs) are widely observed in ocean current data after severe weather. In this work, we analyzed the NIOs in the Central Gulf of Mexico (GoM) associated with 6 hurricanes/tropical storms in 2005, including Katrina and Rita, based on the deep ocean mooring from Coastal Studies Institute (CSI), LSU. The basic characteristics of the NIOs, such as phase speed, group speed, frequency, energy were discussed. The phase speed ranged from 0.56 cm/s to 2 cm/s above the thermocline for the NIOs during Hurricane Katrina and Rita, while the group velocity varied from 0.047 cm/s above the thermocline to …
Impacts Of Artificial Reef Addition On The Nekton Community Of Louisiana Marsh Ponds: A Before-After-Control-Impact Analysis, Kari Elizabeth Klotzbach
Impacts Of Artificial Reef Addition On The Nekton Community Of Louisiana Marsh Ponds: A Before-After-Control-Impact Analysis, Kari Elizabeth Klotzbach
LSU Master's Theses
Louisiana’s coastal estuaries are dynamic, highly variable environments that provide nursery areas for numerous recreationally and commercially important species. Louisiana’s coastline is constantly changing due to natural and anthropogenic processes, and it is important to know how nektonic species are impacted by such changes. This study sought to assess the effects of introducing a hard substrate artificial reef on the nekton community of a Louisiana estuary. A before-after-control-impact (BACI) design was used to assess the impacts of artificial reef addition on nektonic fishes and crustaceans in four shallow marsh ponds near Empire, Louisiana. Marsh ponds were sampled by purse seine …
Habitat- And Region-Specific Reproductive Biology Of Female Red Snapper (Lutjanus Campechanus) In The Gulf Of Mexico, Dannielle Helen Kulaw
Habitat- And Region-Specific Reproductive Biology Of Female Red Snapper (Lutjanus Campechanus) In The Gulf Of Mexico, Dannielle Helen Kulaw
LSU Master's Theses
This study compares reproductive biology estimates of female red snapper among three habitat types (natural shelf-edge banks, standing petroleum platforms and toppled petroleum platforms) and among six regions in the Gulf of Mexico (central Florida, northwest Florida, Alabama, Louisiana, north Texas and south Texas). In both studies, batch fecundity and spawning frequency increased with length, weight and age, and batch fecundity was best correlated with maternal length. Gulf-wide, 75% maturity was achieved by age-3 and 100% maturity was reached by age-8. Sizes- and ages-at-maturity differed among habitat types and regions. Females from natural habitat reached 50% maturity the slowest (age-5, …
Investigation Of Colored Dissolved Organic Matter And Dissolved Organic Carbon Using Combination Of Ocean Color Data And Numerical Model In The Northern Gulf Of Mexico, Nazanin Chaichitehrani
Investigation Of Colored Dissolved Organic Matter And Dissolved Organic Carbon Using Combination Of Ocean Color Data And Numerical Model In The Northern Gulf Of Mexico, Nazanin Chaichitehrani
LSU Master's Theses
The first part of this thesis includes evaluating and developing empirical band ratio algorithms for the estimation of colored dissolved organic matter (CDOM) and dissolved organic carbon (DOC) for SeaWiFS, MODIS and MERIS ocean color sensors for the northern Gulf of Mexico. For CDOM, matchup comparison between SeaWiFS-derived CDOM absorption coefficients and in situ absorption measurements at 412 nm (aCDOM(412)) were examined using the D’Sa et al. (2006) and the Mannino et al. (2008) algorithms. These reflectance band ratio algorithms were also assessed to retrieve aCDOM(412) from MODIS and MERIS data using the Rrs(488)/Rrs(555) and Rrs(510)/Rrs(560) band ratios, respectively. Since …
Biomass And Mass Balance Isotope Content Of Mussel Seep Populations, Philip Martin Riekenberg
Biomass And Mass Balance Isotope Content Of Mussel Seep Populations, Philip Martin Riekenberg
LSU Master's Theses
Cold seep mussels, Bathymodiolus childressi, are common cold seep constituents that form large populations at upper continental slope (500-1000 m) cold seep sites in the Northern Gulf of Mexico. These mussels utilize methane present through symbiotic relationships with methanotrophic bacteria. This study uses a coupled isotope technique to determine the relative incorporation of respiratory carbon in the shell as a measure of the availability of methane between different seep sites. This method indicates a higher abundance of methane at the Brine Pool site than at the Bush Hill site which appears significantly more resource limited and that changes in methane …
The Effects Of Carbon On Nitrogen Transformations In Restored Wetland And Wastewater Soils, Jared M. Theriot
The Effects Of Carbon On Nitrogen Transformations In Restored Wetland And Wastewater Soils, Jared M. Theriot
LSU Master's Theses
Since the industrialization of the Haber-Bosch process in the 1940’s, anthropogenic activity has nearly doubled the Earth’s nitrogen fixation. Furthermore, nitrate has become the number one groundwater contaminant in the United States and has harmful effects such as eutrophication, algal blooms, and pollution of drinking water. Soils from two sites influenced by high nitrate loading were examined to determine their biogeochemical integrity. First, the Loosahatchie Bar, located northwest of Memphis, Tennessee, is influenced by excess surface water nitrate loading by the Mississippi River. The Loosahatchie Bar is a newly restored wetland that now has similar hydrologic influence to an upstream …
Nitrogen Biogeochemistry In A Restored Mississippi River Delta: A Modeling Approach, Benjamin Lee Branoff
Nitrogen Biogeochemistry In A Restored Mississippi River Delta: A Modeling Approach, Benjamin Lee Branoff
LSU Master's Theses
There is evidence that significant reductions (about 50%) in surface water nitrate concentrations within coastal deltaic wetlands receiving diverted Mississippi River water can be contributed to denitrification. Yet there is also contrasting evidence that other processes could be responsible for this nitrate reduction. As Louisiana plans the implementation of major Mississippi River sediment diversions, a thorough understanding of nitrogen dynamics is necessary to reduce risks of coastal eutrophication and offshore hypoxia. A mechanistic numerical computer model has been developed to simulate nitrogen biogeochemistry within the wetlands of the prograding Wax Lake Delta. This model is calibrated to observed fluxes within …
Effect Of Hurricane Forward Speed And Approach Angle On Coastal Storm Surge, Chenguang Zhang
Effect Of Hurricane Forward Speed And Approach Angle On Coastal Storm Surge, Chenguang Zhang
LSU Master's Theses
Hurricane induced storm surges can be destructive and can pose great threats to coastal communities. There are many factors affecting storm surges, including the hurricane’s intensity and movement, the bathymetry and coastline of affected area, rainfall, tide, and river stage. This thesis focuses on the effects of hurricane approach angle (θ) and forward speed (U), which together describe the hurricane’s motion. The problem is approached through several numerical experiments with increasing complexity. First are some process studies of long wave propagations near the coast, followed by examination of the generation of long waves by a traveling wind field. The central …
Effects Of Mimic Artificial Oyster Reefs On The Ecology Of Juvenile Fishes In Marsh Ponds: A Before-After-Control-Impact Analysis, Steven B. Garner
Effects Of Mimic Artificial Oyster Reefs On The Ecology Of Juvenile Fishes In Marsh Ponds: A Before-After-Control-Impact Analysis, Steven B. Garner
LSU Master's Theses
I sought to assess the enhancement potential of mimic artificial oyster reefs (MAORs) on trophic dynamics of juvenile estuarine fishes in marsh ponds. Tropic dynamics were investigated by determining the impacts of MAOR addition on meiofauna and macrofauna and then comparing these results to the gut contents and condition of four abundant estuarine fishes: Atlantic croaker (Micropogonias undulatus), bay whiff (Citharichthys spilopterus), sand seatrout (Cynoscion arenarius), and pinfish (Lagodon rhomboides). Samples were collected every other month for two years (March 2009 – 11) employing a Before-After-Control-Impact (BACI) design. Halfway through the experiment (March 2010), two mud sites in two marsh …
Hurricane Induced Land And Vegetation Changes In The Breton Sound Estuary And Chandeleur Islands Using Landsat 5 Tm, Vandana Varshini Raghunathan
Hurricane Induced Land And Vegetation Changes In The Breton Sound Estuary And Chandeleur Islands Using Landsat 5 Tm, Vandana Varshini Raghunathan
LSU Master's Theses
This study focuses on hurricane-induced changes in land and vegetation primarily in two study areas, the Breton Sound Estuary and the Chandeleur Islands, southeast of New Orleans, Louisiana. Breton Sound Estuary consists of the Caernarvon Diversion, a fresh water diversion of the Mississippi River that supplies this region with managed pulses of fresh water and sediments. The Chandeleur Islands are a chain of barrier islands that are uninhabited and transgressive in nature. A sequence of hurricanes in the past two decades has greatly altered both areas significantly. Satellite data were analyzed for a period of 24 years (1987-2011) of Breton …
Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren
Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren
LSU Master's Theses
The Caernarvon Diversion meters Mississippi River water into coastal marshes of Breton Sound. Elevated levels of nitrogen in river water have sparked concerns that nutrient loading may affect marsh resilience and belowground biomass, as evidence from several marsh fertilization studies. These concerns resulted from observation that fresh and brackish Breton Sound marshes suffered extensive damage from Hurricane Katrina. The goal of this study is to determine the fate of nitrate (the dominant inorganic nitrogen form in the Mississippi River) in Breton Sound Estuary marshes. We hypothesized that most nitrate would be removed by denitrification and that nitrate loading would not …
Comparison Of The Age And Growth Of Red Snapper (Lutjanus Campechanus) Amongst Habitats And Regions In The Gulf Of Mexico, Courtney Rose Saari
Comparison Of The Age And Growth Of Red Snapper (Lutjanus Campechanus) Amongst Habitats And Regions In The Gulf Of Mexico, Courtney Rose Saari
LSU Master's Theses
The Gulf of Mexico (GOM) red snapper stock has been exploited since the mid 1800s; yet it is still one of the most economically important fisheries in the GOM. Red snapper have been managed as a unit stock and are currently overfished, but perhaps no longer undergoing overfishing. Habitat varies greatly throughout the GOM and while numerous studies have aged red snapper, none have simultaneously compared the age and size structure and growth rates among standing and toppled oil and gas platforms with natural habitats. The objectives of this study were to examine the size and age structure and growth …
Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico, Sean Brandon Creekmore
Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico, Sean Brandon Creekmore
LSU Master's Theses
The northwestern Gulf of Mexico currently experiences a large hypoxic area (“dead zone”) during the summer. While the local effects of hypoxia on organisms have been documented, the population-level effects are largely unknown. I developed a spatially-explicit, individual-based model to analyze how hypoxia effects on Atlantic croaker reproduction, growth, and mortality in the northwestern Gulf of Mexico could lead to population-level responses. The model follows the hourly growth, mortality, reproduction, and movement of individuals on a 300 x 800 spatial grid of 1 km2 cells for 100 years. Chlorophyll-a concentration, water temperature, and dissolved oxygen were specified daily for each …
The Effects Of Salinity On Nitrogen Cycling In Wetland Soils And Sediments Of The Breton Sound Estuary, La, Brett Whitfield Marks
The Effects Of Salinity On Nitrogen Cycling In Wetland Soils And Sediments Of The Breton Sound Estuary, La, Brett Whitfield Marks
LSU Master's Theses
Wetlands in the coastal zone are slowly becoming more saline under rising sea level over the long-term. However, there are a number of events in the coastal environment which lead to quick and temporary changes in the salinity of coastal marshes. Seawater driven inland from storm surge can significantly increase salinity in oligohaline wetlands over the short-term (weeks). Recent large-scale efforts to restore coastal wetlands in Louisiana have utilized Mississippi River surface water diversions to re-introduce freshwater into coastal marshes, decreasing the salinity of coastal marshes. We examined the effect of salinity changes on two important nitrogen cycling processes, potential …
Geological Analysis And Hydrodynamic Modeling Of Tropical Cyclone Influence: Northeastern Gulf Of Mexico Inner Shelf, Amy Lynn Spaziani
Geological Analysis And Hydrodynamic Modeling Of Tropical Cyclone Influence: Northeastern Gulf Of Mexico Inner Shelf, Amy Lynn Spaziani
LSU Master's Theses
The need to characterize offshore resources as borrow areas for beach restoration has initiated interest of the impact of storms to the inner continental shelf. While numerous studies have investigated the response of coastal systems to major storms, very little is known about the geological response of inner shelves to frequent and intense storms. This approach integrated a geological study with modeling of hydrodynamics during recent storms, in order to relate trends in the geological signature to physical forcing mechanisms during storms. First, waves and hydrodynamic conditions were modeled during two major recent storms that made landfall in the northeastern …
Hepatotoxic Cyanobacterial Blooms In Louisiana's Estuaries: Analysis Of Risk To Blue Crab (Callinectes Sapidus) Following Exposure To Microcystins, Ana Cristina Garcia
Hepatotoxic Cyanobacterial Blooms In Louisiana's Estuaries: Analysis Of Risk To Blue Crab (Callinectes Sapidus) Following Exposure To Microcystins, Ana Cristina Garcia
LSU Master's Theses
The most common toxins detected following freshwater harmful algal blooms are microcystins, a group of hepatotoxins produced by cyanobacteria (e.g., Microcystis and Anabaena spp.). Preference for filter-feeding prey, including bivalves, makes the blue crab, Callinectes sapidus, vulnerable to microcystin contamination and makes the commercially important crab a potential vector of microcystins. I used a combination of field and laboratory studies to determine blue crab vulnerability to microcystin contamination and consequent impacts on crab physiology. Samples collected from a hyper-eutrophic freshwater lake, Lac des Allemands, Louisiana, were analyzed for cyanobacterial abundances and microcystins in surface water and blue crabs using light-microscopy …
Estuarine Phytoplankton Response To Annual And Manipulated River Inputs, Jessica Czubakowski
Estuarine Phytoplankton Response To Annual And Manipulated River Inputs, Jessica Czubakowski
LSU Master's Theses
River water entering estuaries affects the physical and chemical environment at irregular intervals creating a highly dynamic aquatic habitat. Phytoplankton are important primary producers in estuaries that respond quickly to their changing environment. Since 1991, Breton Sound estuary in southeast Louisiana has been directly influenced by Mississippi River water through the Caernarvon Freshwater Diversion structure. Over a 12 month period, the phytoplankton response was examined, in terms of biomass, abundance, community composition and potential phycotoxin production to seasonal changes in river input into the estuary. Within this 12 month period, a short pulse study was also carried out to examine …
Physical And Microbial Responses Of Dredged Sediment To Two-Soil-Stabilizing Amendments, Xanthan Gum And Guar Gum, For Use In Coastal Wetland Restoration, Lauren Land
LSU Master's Theses
In wetland sediments, organic matter provides a substrate for microbial activity. During metabolism, microbes release extracellular polymeric substances, which accumulate to bind soil particles. A similar concept can be implemented on a large scale to reduce wetland loss in Louisiana. Hypothetically, hydraulically dredged sediment can be amended with polymer and deposited on subsiding marshes as a restoration method where the polymer increases sediment stabilization until plants become established. This lab study focused on investigating the influence of natural polymer additions on particle aggregation to increase sediment stability and the effects on microbial activity. Sediments from three sites (i.e. freshwater, intermediate, …
Patterns Of Habitat Suitability And Abundance Trends Of Current And Candidate Coastal Fish Species Of Concern In Louisiana, Elin Rose Sandy
Patterns Of Habitat Suitability And Abundance Trends Of Current And Candidate Coastal Fish Species Of Concern In Louisiana, Elin Rose Sandy
LSU Master's Theses
Louisiana’s estuaries and coastal waters play an important role in providing habitat for several estuarine-dependent species and also serve as a nursery for the juveniles of several other species. The current rate of land loss in Louisiana and the decline of estuarine-dependent species force us to improve our understanding of the recruitment of these species into Louisiana’s estuaries. Habitat suitabilities were developed for several fish species of concern (SOC) and other estuarine-dependent species across three environmental gradients, abundance patterns were developed for seasons, five-year intervals, and coastal study areas (CSAs). Chi-square analyses and ANOVAs were then used to test for …
Neurotoxin In A Louisiana Estuary: Quantitative Analysis Of Domoic Acid In Gulf Menhaden (Brevoortia Patronus) And Qualitative Modeling Of Links In A Shark Nursery, Ross Del Rio
LSU Master's Theses
Harmful algal blooms are an increasing problem for coastal waters world-wide. The diatom genus, Pseudo-nitzschia, is of particular concern in Louisiana, due to the potential for several species to produce the neurotoxin domoic acid (DA). While trophic transfer of DA to consumers has repeatedly occurred along the California coast, little is known about trophic transfer of recently detected DA in the Gulf of Mexico. In this study, the presence of DA in gulf menhaden (Brevoortia patronus) and the potential for trophic transfer to higher order consumers was investigated. In addition, the effects of this transfer and other algal toxins that …
Applying The Isotope Pairing Technique To Evaluate How Water Temperature And Habitat Type Influence Denitrification Estimates In Breton Sound, Louisiana, Peter L. Lenaker
Applying The Isotope Pairing Technique To Evaluate How Water Temperature And Habitat Type Influence Denitrification Estimates In Breton Sound, Louisiana, Peter L. Lenaker
LSU Master's Theses
The upper Breton Sound estuary was hydrologically reconnected to the Mississippi River via the Caernarvon freshwater diversion structure in 1991. The Caernarvon structure can provide controlled freshwater pulses to the upper Breton Sound estuarine ecosystem, replicating historic freshwater pulsed events, although the original authorization was to control salinity isohalines at specific locations in the estuary. However, unlike historic freshwater pulsed events prior to the construction of levees, the current freshwater pulse contains an unprecedented amount of inorganic nitrogen, predominately as nitrate (annual average 71.4 µM NO3-). Denitrification is a microbial process, which can potentially remove excess nitrate entering coastal Louisiana …
Seasonal Variability In Absorption And Fluorescence Properties Of Chromophoric Dissolved Organic Matter In The Barataria Basin, Louisiana, Usa, Shatrughan Singh
Seasonal Variability In Absorption And Fluorescence Properties Of Chromophoric Dissolved Organic Matter In The Barataria Basin, Louisiana, Usa, Shatrughan Singh
LSU Master's Theses
Absorption and fluorescence measurements of chromophoric dissolved organic matter (CDOM) were examined along a transect containing 36 sampling stations in the Barataria Basin during high and low conditions to observe seasonal variation in these optical properties. The objectives of this study were (i) to observe CDOM variability in Barataria Basin in variable flow (high and low) conditions, and to characterize the CDOM, (ii) to identify the constituents of CDOM and to model CDOM compositional variability in the Barataria Basin using parallel factor analysis (PARAFAC). CDOM–salinity relationships were non-conservative in lower and upper part of the transect; however a conservative inverse …