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Full-Text Articles in Physical Sciences and Mathematics
Influence Of Salinity, Sunlight, And Sediment On The Toxicity Of Pesticides In Three Non-Target Organisms, Emily Noelle Vebrosky
Influence Of Salinity, Sunlight, And Sediment On The Toxicity Of Pesticides In Three Non-Target Organisms, Emily Noelle Vebrosky
LSU Doctoral Dissertations
Pesticides used in the United States must undergo registration by the United States Environmental Protection Agency (USEPA), after a multitude of analyses ranging from environmental fate to aquatic toxicological impacts to human risk exposure. Testing varies for each chemical, some requiring more testing than others. In many cases, environmental factors are restricted in the analysis of chemical behavior and organismal testing is limited to larvae. Many pesticides are formulated to breakdown in the environment by means of photolysis, hydrolysis, or oxidation, either to ensure low-persistence, limited transport, or to form the active ingredient (pro-pesticides). Environmental influences on chemical behaviors include …
Variations In Salinity And Temperature On The Flank Of An Offshore Louisiana Salt Structure, Candice M. Mccollum
Variations In Salinity And Temperature On The Flank Of An Offshore Louisiana Salt Structure, Candice M. Mccollum
LSU Master's Theses
Sediments located in the vicinity of salt structures in the northern Gulf of Mexico have highly complex structures and fluid dynamics associated with the dissolution and diapirism of salt. Past studies (Lin and Nunn, 1997; Bruno and Hanor, 2003; Richards, 2013) have shown that faults associated with salt structures can act both as migration pathways and barriers to the flow of formation waters. Bruno and Hanor (2003), Steen et al. (2011), and Richards (2013) also demonstrated that lithology was a controlling factor in the flow of formation waters. In this study, two sets of wireline logs, one used in salinity …
Population Ecology Of The Ribbed Mussel In Southeastern Louisiana, Aaron Jacob Honig
Population Ecology Of The Ribbed Mussel In Southeastern Louisiana, Aaron Jacob Honig
LSU Master's Theses
Benthic intertidal bivalves play an essential role in estuarine ecosystems by contributing to habitat provision, water filtration, and promoting productivity. As such, ecosystem level changes that impact population distributions and persistence of local bivalve populations may have large ecosystem level consequences, making it important to better understand the population distribution and ecology of native bivalve populations. Gametogenesis, recruitment, growth, mortality, size structure and density of the ribbed mussel, Geukensia demissa, were examined across a salinity gradient in southeastern Louisiana. In summer 2012, 100-m transects were placed at interior and edge marsh plots to collect data on mussel density, and vegetation …
Evaluation Of Pleistocene To Holocene (Mis 5 To 1) Climatic Changes In Southwestern Black Sea: A Palynological Study Of Dsdp Site 380, Shannon Ferguson
Evaluation Of Pleistocene To Holocene (Mis 5 To 1) Climatic Changes In Southwestern Black Sea: A Palynological Study Of Dsdp Site 380, Shannon Ferguson
LSU Master's Theses
Site 380 of the Deep Sea Drilling Program [DSDP] is located in the southwestern region of the Black Sea (42°05.94’, 29°36.82’E). The location of this site is important due to its proximity to the narrow Bosphorus strait, the only present-day connection between the Black Sea and the Aegean Sea. Drops in eustatic sea level during extensive Pleistocene glacial episodes disconnected the Black Sea from the Aegean Sea at the Bosphorus strait, creating a change from brackish to freshwater within the Black Sea during these intervals. Organic-walled phytoplankton (dinoflagellate cysts, acritarchs, and fresh-water algae) are investigated to better constrain these glacio-eustatic …
Spatial Variation Analysis Of Salinity To Determine Fluid Flow Pathways And Reservoir Compartmentalization In A Deepwater Gulf Of Mexico Field, William Jacob Daugherty
Spatial Variation Analysis Of Salinity To Determine Fluid Flow Pathways And Reservoir Compartmentalization In A Deepwater Gulf Of Mexico Field, William Jacob Daugherty
LSU Master's Theses
Variations in salinity have been documented in previous studies onshore Louisiana in the Wilcox group (Funayama and Hanor 1995) as well as offshore Louisiana on the continental shelf (Bruno and Hanor 2003 and Steen et al. 2011). These studies were conducted using various methods to estimate pore water salinity and make inferences about possible fluid flow pathways and compartmentalization of reservoirs in order to better understand the complex hydrogeology of the Gulf of Mexico. Similar variations in salinity were documented in this study located in a deepwater salt withdrawal minibasin located on the upper slope of the Gulf of Mexico. …
Developmental Responses To Abiotic Conditions During Aquatic And Air Incubatoin Of The Gulf Killifish (Fundulus Grandis): Subtitle, Charles Alexander Brown
Developmental Responses To Abiotic Conditions During Aquatic And Air Incubatoin Of The Gulf Killifish (Fundulus Grandis): Subtitle, Charles Alexander Brown
LSU Master's Theses
The Gulf killifish (Fundulus grandis) is a topminnow native to the tidal marshes of the Gulf of Mexico. The species is prized by anglers as effective bait for catching popular sportfish and is of interest to aquaculturists and bait dealers due to its hardy nature. Limited seasonal availability and aquaculture of this species due to low fecundity and larval cannibalism of fry has led to increased incentive to improve cultural techniques. The purpose of this study is to determine the influences of temperature, salinity, and air incubation on embryogenesis of the Gulf killifish. Temperature was found to have a negative …
Geomicrobiology Of Louisiana Coastal Marshes Before And After The Deepwater Horizon Oil Spill, Chang Liu
Geomicrobiology Of Louisiana Coastal Marshes Before And After The Deepwater Horizon Oil Spill, Chang Liu
LSU Master's Theses
The 2010 Deepwater Horizon oil spill in the Gulf of Mexico not only impacted open ocean and shoreline geochemical and ecological environments, but it served to promote research of microbial ecosystems in poorly studied habitats, such as Louisiana marshes. Sediment and water samples from four main marshes in southern Louisiana were collected in May 2010 (pre-oil), September 2010 (oiled), and June 2011 (post-oil). Sites near the Mississippi River had exceptionally low salinity in the immediate months following the oil spill due to freshwater diversion efforts; salinity increased by an order of magnitude one year later. Microbial diversity was evaluated from …
Spatial Variations Of Salinity, Temperature And Pressure On The Flank Of A Salt Dome, Offshore Louisiana: Implications For Mechanisms Of Fluid Flow, Andrew Kevin Steen
Spatial Variations Of Salinity, Temperature And Pressure On The Flank Of A Salt Dome, Offshore Louisiana: Implications For Mechanisms Of Fluid Flow, Andrew Kevin Steen
LSU Master's Theses
Salt dome dissolution in the Gulf of Mexico sedimentary basin is a primary cause for elevated pore water salinities in the subsurface. Temperature, pressure, salinity, lithology and fluid density are parameters often used to identify preferential conduits and driving forces for fluid migration. These parameters were calculated using 20 wireline logs covering 40 km² on the south flank of a salt dome on the continental shelf, offshore Louisiana. 3-D seismic has been utilized to determine location of faults, to aid in sand correlation, and to provide a structural overview of the dome. Vertical and lateral variations in lithology, salinity, temperature, …
The Effects Of A Freshwater Diversion Of Nekton Species Biomass Distributions, Food Web Pathways, And Community Structure In A Louisiana Estuary, Kim De Mutsert
The Effects Of A Freshwater Diversion Of Nekton Species Biomass Distributions, Food Web Pathways, And Community Structure In A Louisiana Estuary, Kim De Mutsert
LSU Doctoral Dissertations
A current method to restore Louisiana’s estuaries includes reintroducing freshwater and sediments to wetlands that are hydrologically isolated from the Mississippi River due to the construction of levees. In this dissertation, I examined effects of the second largest freshwater diversion in Louisiana, the Caernarvon Freshwater Diversion (CFD), on estuarine nekton in Breton Sound. Before focusing on Breton Sound, I examined the status of nekton communities in the northern Gulf of Mexico (GOM), and Louisiana wetlands in particular, using the mean trophic level index (MTLI). I demonstrated that commercial targeting caused the previously reported low and declining MTLI from the GOM. …
Developing Tools To Identify Factors That Limit Production In Coastal Marshes, Vanessa Danielle Tobias
Developing Tools To Identify Factors That Limit Production In Coastal Marshes, Vanessa Danielle Tobias
LSU Doctoral Dissertations
Marsh loss is a problem in many areas around the world. In Louisiana’s coastal marshes, where Spartina patens is the most common plant, restoration and management seek to slow wetland loss rates that average approximately 77.4 km2/year. To combat the problem, scientists and managers require tools to determine local causes and evaluate the effectiveness of management techniques. Current methods for identifying factors that limit productivity in marshes are too time-consuming or expensive for wide-spread, regular use. Critical values of elemental concentrations in plant tissue are widely used to diagnose mineral deficiencies and toxicities in agricultural crops, however. I used the …
Salinity Variation As An Indicator Of Fluid Flow In The Lower Ellesmerian Sequence, North Slope, Alaska, Jacob Scott Dehamer
Salinity Variation As An Indicator Of Fluid Flow In The Lower Ellesmerian Sequence, North Slope, Alaska, Jacob Scott Dehamer
LSU Master's Theses
Previous studies have shown the existence of a topographically driven recharge system in the North Slope foreland basin, Alaska. The Lower Ellesmerian Sequence represents the lowest most flow pathway in the stratigraphic sequence. Limestones and dolomites of the Lisburne Group and sands and shales of the Endicott Group represent laterally extensive pathways for flow. Salinities calculated from spontaneous potential response in the Lower Ellesmerian range from less than 10 gL-1 to over 150 gL-1. Low salinities calculated for the Lower Ellesmerian indicate the displacement of connate marine waters throughout the history of the North Slope foreland basin. Flushing of connate …
Comments On Buzan Et Al. “Positive Relationships Between Freshwater Inflow And Oyster Abundance In Galveston Bay, Texas”, R. Eugene Turner
Comments On Buzan Et Al. “Positive Relationships Between Freshwater Inflow And Oyster Abundance In Galveston Bay, Texas”, R. Eugene Turner
Faculty Publications
Buzan et al. critique Turner’s (Estuaries and Coasts 29:345–352, 2006) analysis of the relationship between freshwater inflow and oyster productivity in the Gulf of Mexico, using 16 years of fisheries-independent data for Galveston Bay. They conclude that the catch-per-unit effort (CPUE; number h−1) of marketable oysters increase 1 to 2 years after years with increased freshwater inflows, and they express concerns that water supply managers may mis-apply the results of Turner (Estuaries and Coasts 29:345–352, 2006) to justify a reduced freshwater inflow to Galveston Bay. I find no relationship between the CPUE of oyster spat or marketable oyster density and …
Fluid Flow In The Central North Slope Foreland Basin, Alaska, Anna Marie Bélanger
Fluid Flow In The Central North Slope Foreland Basin, Alaska, Anna Marie Bélanger
LSU Master's Theses
Previous studies of the areal variations in heat flow and spatial variations in formation water salinity and hydraulic head are consistent with the existence of a currently active, topographically-driven regional fluid flow regime in the National Petroleum Reserve Alaska (NPRA) portion of the western North Slope foreland basin. This conclusion is also supported by the results of numerical modeling of fluid flow and heat transport in the area. This work has now been extended to the east. The results of this study demonstrate that the Permian though Cenozoic age sediments of the central North Slope foreland basin have been significantly …
Compositional Systematics Of Deep, Low Salinity Formation Waters In The Upper Wilcox Of Southeastern Texas, Kathleen (Kt) Moran
Compositional Systematics Of Deep, Low Salinity Formation Waters In The Upper Wilcox Of Southeastern Texas, Kathleen (Kt) Moran
LSU Master's Theses
Overpressured Eocene Wilcox sandstones in the Newton County, Texas Sabine Tram field contain water with salinities ranging from 14 to 28 g/L. The solutes appear to fall loosely into three groups. Na, Ca, and Mg follow systematics previously known globally for saline formation waters whereby their concentrations are controlled by fluid-mineral equilibrium. Cl, Br, I, and B are conservatively diluted constituents of some saline endmember that is not solely connate marine. Potassium does not follow any known basinal systematic, and the formation water is supersaturated with respect to SiO2 by an order of magnitude. Meteoric water is not a probable …
An Investigation Of A Salt-Dome Environment At South Timbalier 54, Gulf Of Mexico, Robert E. Little, Jr
An Investigation Of A Salt-Dome Environment At South Timbalier 54, Gulf Of Mexico, Robert E. Little, Jr
LSU Master's Theses
Salt domes have been studied in the Gulf Coast region to look at how, why, and where saline waters are located within these field areas. Fluid flow model and pathway studies can be helpful to the research of saline water migration because it can be correlated to hydrocarbon migration in petroleum exploration. The South Timbalier 54 field occurs over a salt dome that sits at approximately 3,048 meters beneath the seafloor. Two major faults were found originating from the salt dome up into the shallow section of the field. The sands were deposited in fluvial, deltaic, or marine environments. The …