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Full-Text Articles in Physical Sciences and Mathematics

Early Flotant Establishment And Growth Dynamics In A Nutrient Amended Wetland In The Lower Mississippi River Delta, Caleb W. Izdepski Jan 2007

Early Flotant Establishment And Growth Dynamics In A Nutrient Amended Wetland In The Lower Mississippi River Delta, Caleb W. Izdepski

LSU Master's Theses

Nutrient dynamics and seasonal marsh growth were examined in a newly formed Panicum virgatum floating marsh at Thibodaux LA. The floating marsh formed in a cleared area of forested wetland receiving secondarily treated effluent. Net Areal Primary Productivity (NAPP), total belowground biomass, NO3, and δ15N ratios varied significantly (P <0.05) along a 75m marsh transect while mean δ13C varied between plant species. The upland end of the transect had the highest NAPP (3876 g m-2y-1), total belowground biomass (4079.0 ± 298.5 g m-2), and mean NO3 (5.4 ± 2.9 mg l-1). The mean floating-marsh …


The Anatomy Of A Coastal Bay/Lake System, Michelle Greene Jan 2007

The Anatomy Of A Coastal Bay/Lake System, Michelle Greene

LSU Master's Theses

A comprehensive and integrated approach involving sedimentology, shallow surface geophysics and radio-chemistry was used to understand lakebed sediment dynamics in Little Lake. This methodology attempted to (1) define the morphology and origin of the lake, (2) understand the variability in lake-bottom sediments, (3) assess short-term and long-term sediment accumulation rates, and (4) image lakebed features. Subbottom chirp, single beam echo sounder, and side scan sonar data were collected to define hydrographic depths, lateral variability in seabed sediment type, lakebed features, and shallow subsurface structure. Sediment samples were taken at representative locations throughout the lake and particle size distributions were determined. …


Rna:Dna As An Indicator Of Nutritional Condition And Growth In Larval Naked Goby, Gobiosoma Bosc, Michelle C. Satterwhite Jan 2007

Rna:Dna As An Indicator Of Nutritional Condition And Growth In Larval Naked Goby, Gobiosoma Bosc, Michelle C. Satterwhite

LSU Master's Theses

Developing organism-based metrics for assessing habitat quality is an important tool in conservation and restoration of aquatic habitats. The use of the RNA:DNA ratio as an early indicator of habitat effects on growth of nekton species has been suggested, but requires species-specific laboratory assessment prior to field application. We used food availability in laboratory treatments to simulate differences in habitat quality. Wild Gobiosoma bosc eggs were collected using nest-traps constructed of PVC pipe. Eggs from several different nests collected in the field were hatched in the lab, yielding larvae that were randomly assigned to three feeding treatments in two replicate …


Assessment And Analysis Of Quikscat And Coamps Model Vector Wind Products For The Gulf Of Mexico: A Long-Term And Hurricane Perspective, Neha Sharma Jan 2007

Assessment And Analysis Of Quikscat And Coamps Model Vector Wind Products For The Gulf Of Mexico: A Long-Term And Hurricane Perspective, Neha Sharma

LSU Master's Theses

Global weather changes have become a matter of grave concern in hurricane prone areas as intensities of hurricanes are observed to be increasing every year, necessitating improved monitoring capabilities. NASA’s QuikSCAT satellite sensor has provided significant support in analyzing and forecasting winds for the past 8 years. In this study, the performance of QuikSCAT products, including JPL’s latest L2B 12.5km swath winds, was evaluated against buoy-measured winds in the Gulf of Mexico. The long-term study period was 1/2005 – 2/2007. The Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) was also assessed. The regression analyses showed very good results for QuikSCAT products, …


Ecosystem Effects Of Expanding Populations Of Avicennia Germinans In A Southeastern Louisiana Spartina Alterniflora Saltmarsh, Carey Lynn Perry Jan 2007

Ecosystem Effects Of Expanding Populations Of Avicennia Germinans In A Southeastern Louisiana Spartina Alterniflora Saltmarsh, Carey Lynn Perry

LSU Master's Theses

Although the Earth may be in the early stages of the projected trends of global warming, several ecological responses to recent warming are already evident. The timing of seasonal activities of plants and animals has begun to shift, and the advancement of species poleward is occurring in several regions of the world. One unique distributional shift is the movement of Avicennia germinans (black mangrove) northward into temperate salt marshes dominated by the marsh grass, Spartina alterniflora. In Louisiana, black mangroves were historically restricted to the southernmost barrier islands and beaches; however, in recent years a noticeable expansion of Avicennia northward …


Sediment Flux And Fate In The Mississippi River Diversion At West Bay: Observation Study, Thomas Mitchell Andrus Jan 2007

Sediment Flux And Fate In The Mississippi River Diversion At West Bay: Observation Study, Thomas Mitchell Andrus

LSU Master's Theses

Land-building sediment diversions, such as the Mississippi River Diversion at West Bay, can be used as important building blocks in the conservation and restoration of Mississippi Delta wetlands. Sediment deposition and retention patterns were studied in the West Bay diversion outfall area through analyses of sediment cores, hydrodynamics, and bathymetry. Cores and x-ray samples were collected at twenty stations in March 2004, August 2004, November 2005, and April 2006. Cores were analyzed for grain-size distributions and 7Be activities, in order to examine patterns of recent sediment deposition. In comparing ratios of total 7Be inventory to atmospheric 7Be …


Disturbance Effects On Nekton Communities Of Seagrasses And Bare Substrates In Biloxi Marsh, Louisiana, Jamie Lynn Maiaro Jan 2007

Disturbance Effects On Nekton Communities Of Seagrasses And Bare Substrates In Biloxi Marsh, Louisiana, Jamie Lynn Maiaro

LSU Master's Theses

With marshes deteriorating rapidly across the Louisiana coast, the role of seagrasses in sustaining fisheries has come into question. Seagrasses are known to shelter small fish from larger predators. Seagrasses also act as a foraging ground for commercially important species, including spotted seatrout. Thirty samples, fifteen from seagrass habitats and fifteen from bare substrate habitats, were collected inside Biloxi Marsh using a drop sampler in May 2005. After the passage of Hurricanes Cindy and Katrina on July 6, 2005 and August 29, 2005, respectively, the seagrasses in Biloxi Marsh were either uprooted, buried, or both. The May 2005 sites were …