Drivers And Impacts Of Water Level Fluctuations In The Mississippi River Delta: Implications For Delta Restoration,
2019
Louisiana State Univ, Dept Oceanog & Coastal Sci, Coll Coast & Environm
Drivers And Impacts Of Water Level Fluctuations In The Mississippi River Delta: Implications For Delta Restoration, Matthew Hiatt, John W. Day, Robert V. Rohli, John Andrew Nyman
Faculty Publications
This review synthesizes the knowledge regarding the environmental forces affecting water level variability in the coastal waters of the Mississippi River delta and relates these fluctuations to planned river diversions. Water level fluctuations vary significantly across temporal and spatial scales, and are subject to influences from river flow, tides, vegetation, atmospheric forcing, climate change, and anthropogenic activities. Human impacts have strongly affected water level variability in the Mississippi River delta and other deltas worldwide. Collectively, the research reviewed in this article is important for enhancing environmental, economic, and social resilience and sustainability by assessing, mitigating, and adapting to geophysical changes …
Sea Surface Roughness Observed By High Resolution Radar,
2019
University of Guam
Sea Surface Roughness Observed By High Resolution Radar, Atsushi G. Fujimura, Susanne Lehner, Alexander Soloviev, Xiaofeng Li
Marine & Environmental Sciences Faculty Articles
Changes in the sea surface roughness are usually associated with a change in the sea surface wind field. This interaction has been exploited to measure the sea surface wind speed by scatterometry. A number of features on the sea surface associated with changes in roughness can be observed by synthetic aperture radar (SAR) because of the change in Bragg backscatter of the radar signal by damping of the resonant ocean capillary waves. With various radar frequencies, resolutions, and modes of polarization, sea surface features have been analyzed in numerous campaigns, bringing various datasets together, thus allowing for new insights in …
Sub-Tidal Hydrodynamics Of The Multi-Inlet Lake Pontchartrain Estuary Influenced By Mississippi River Diversion And Wind Associated With Atmospheric Fronts,
2019
Louisiana State University and Agricultural and Mechanical College
Sub-Tidal Hydrodynamics Of The Multi-Inlet Lake Pontchartrain Estuary Influenced By Mississippi River Diversion And Wind Associated With Atmospheric Fronts, Wei Huang
LSU Doctoral Dissertations
In-situ observations and a Finite Volume Community Ocean Model (FVCOM) are used to investigate the cold front induced sub-tidal hydrodynamics of Lake Pontchartrain, a semi-enclosed low-salinity estuary with multiple inlets connecting to the open ocean. Observations show that the sub-tidal hydrodynamic responses are highly correlated with the meteorological parameters during cold front events. Model results indicate that, under barotropic conditions, the remote wind effect has the greatest contribution to the overall water level variation, while the local wind stress during cold front events determines the slope for the water level inside the estuary. An examination of a quasi-steady state force …
The Role Of A Permeable Sand Column In Modifying Tidal Creek Geochemistry And Land-Derived Inputs To The Coastal Ocean,
2019
Coastal Carolina University
The Role Of A Permeable Sand Column In Modifying Tidal Creek Geochemistry And Land-Derived Inputs To The Coastal Ocean, Nicholas Anthony Legut
Electronic Theses and Dissertations
The impairment of regional water quality in Long Bay is an episodic occurrence that has been documented for over a decade. According to one explanation, the occurrence of these events is hypothesized to be the combination of local, terrestrially derived inputs and water-column stratification in the nearshore zone. A portion of these inputs may discharge as surface run-off through estuaries ending in sandy transitional environments termed "swashes". An investigation into the fate of land-derived materials through swashes utilize a linear conservative mixing model to describe the non-conservative behavior of materials in the overlying water and pore-water. This model relies on …
The Effects Of Oil On Blue Crab And Periwinkle Snail Interactions: A Mesocosm Study,
2019
Louisiana State Univ, Dept Oceanog & Coastal Sci
The Effects Of Oil On Blue Crab And Periwinkle Snail Interactions: A Mesocosm Study, Elizabeth M. Robinson, Nancy N. Rabalais
Faculty Publications
We examined the sub-lethal effect of Macondo oil from the Deepwater Horizon oil spill on predator-prey interactions using blue crabs (Callinectes sapidus) and periwinkle snails (Littoraria irrorata). A 2 x 2 factorial mesocosm design determined the effect of oil (no oil vs. oil) and blue crabs (no blue crab predator vs. one blue crab predator) on periwinkle snail climbing and survival. Sixteen mesocosm tanks were used in the experiment, which were replicated three times. Each tank contained water, sand, and Spartina marsh stems. The sixteen tanks were divided between two, temperature-controlled chambers to separate oil treatments (no oil vs. oil). …
Biogeochemical Controls Of Surface Ocean Phosphate,
2019
Old Dominion University
Biogeochemical Controls Of Surface Ocean Phosphate, Adam C. Martiny, Michael W. Lomas, Weiwei Fu, Philip W. Boyd, Yuh-Ling L. Chen, Gregory A. Cutter, Michael J. Ellwood, Ken Furuya, Fuminori Hasshihama, Jota Kanda, David M. Karl, Taketoshi Kodama, Qian P. Li, Jian Ma, Thierry Moutin, E. Malcolm S. Woodward, J. Keith Moore
OES Faculty Publications
Surface ocean phosphate is commonly below the standard analytical detection limits, leading to an incomplete picture of the global variation and biogeochemical role of phosphate. A global compilation of phosphate measured using high-sensitivity methods revealed several previously unrecognized low-phosphate areas and clear regional differences. Both observational climatologies and Earth system models (ESMs) systematically overestimated surface phosphate. Furthermore, ESMs misrepresented the relationships between phosphate, phytoplankton biomass, and primary productivity. Atmospheric iron input and nitrogen fixation are known important controls on surface phosphate, but model simulations showed that differences in the iron-to-macronutrient ratio in the vertical nutrient supply and surface lateral transport …
Wide-Ranging Temporal Variation In Transoceanic Movement And Population Mixing Of Bluefin Tuna In The North Atlantic Ocean,
2019
Louisiana State Univ, Dept Oceanog & Coastal Sci
Wide-Ranging Temporal Variation In Transoceanic Movement And Population Mixing Of Bluefin Tuna In The North Atlantic Ocean, Michael A. Dance
Faculty Publications
Uncertainty regarding the movement and population exchange of Atlantic bluefin tuna (Thunnus thynnus) from the two primary spawning areas (Gulf of Mexico, Mediterranean Sea) is increasingly implicated as a major impediment for the conservation of this species. Here, two mixture methods were applied to natural chemical markers (delta O-18 and delta C-13) in otoliths (ear stones) to comprehensively investigate the nature and degree of transoceanic movement and mixing of eastern and western populations in several areas of the North Atlantic Ocean that potentially represent mixing hotspots. Areas investigated occurred on both sides of the 45 degrees W management boundary as …
Evaluating Fluid Fluxes From Deep-Sea Seepage Habitats,
2019
Coastal Carolina University
Evaluating Fluid Fluxes From Deep-Sea Seepage Habitats, Leigha E. Peterson
Electronic Theses and Dissertations
The permanently dark deep-sea, located at oceanic water depths greater than 200 m, represents the largest potential habitat space on Earth. The physicochemical conditions of the planet’s largest biome are tightly coupled to the exchange of matter and energy from terrestrial and sea-floor end-members. In fact, global ocean and climate systems are significantly impacted by deep-sea processes. Seafloor vents and seeps appear to act as geologic exchange conduits, returning recycled materials to the hydrosphere to sustain another generation of life. Despite submarine seepage having control on global elemental cycling, it is estimated that less than 1% of the deep-sea has …
Variations Of Global Ocean Salinity From Multiple Gridded Argo Products,
2019
University of South Florida
Variations Of Global Ocean Salinity From Multiple Gridded Argo Products, Chao Liu
USF Tampa Graduate Theses and Dissertations
Salinity is one of the fundamental ocean state variables. Variations of ocean salinity can be used to infer changes in the global water cycle and air-sea freshwater exchange. Many institutions have developed gridded Argo products of global coverage. However, the existing gridded salinity products have not yet been dedicatedly intercompare and assessed. In this study, the mean state, annual and interannual variabilities, and decadal changes of ocean salinity from five Argo-based gridded salinity products, available from UK Met Office, JAMSTEC, Scripps Institution of Oceanography, China Second Institute of Oceanography, and International Pacific Research Center, are examined and compared for their …
Lipid Biomarkers Of Bering And Chukchi Sea Euphausiids And Their Application To Diet History,
2019
Old Dominion University
Lipid Biomarkers Of Bering And Chukchi Sea Euphausiids And Their Application To Diet History, Rachel L. Pleuthner
OES Theses and Dissertations
In the eastern Bering Sea, Thysanoessa raschii are the most abundant krill species and a keystone trophic member that serve as both an important grazer and link to upper level consumers. In this system krill experience large annual variation in food resources, especially during ice advance and retreat; multiple lipid classes are used to temper the effects of those fluctuations, as well as to fuel reproduction and growth. Two shipboard feeding experiments that occurred during late spring and early summer of 2010, respectively, monitored the lipid retention in adult T. raschii and examined the fluctuation of specific lipid biomarkers under …
Nutrient Controls Over Cyanobacterial Synthesis Of The Neurotoxin Β-N-Methylamino-L-Alanine (Bmaa) And Its Potential Accumulation In The Blue Crab (Callinectes Sapidus),
2019
Old Dominion University
Nutrient Controls Over Cyanobacterial Synthesis Of The Neurotoxin Β-N-Methylamino-L-Alanine (Bmaa) And Its Potential Accumulation In The Blue Crab (Callinectes Sapidus), Madeline M. Hummel
OES Theses and Dissertations
Cyanobacteria are known to produce a variety of toxins that negatively impact both aquatic and terrestrial organisms. One putative neurotoxic compound is the non-protein amino acid β-N-methylamino-L-alanine (BMAA), which has epidemiological linkages to the development of several human neurological diseases. Three cyanobacterial species thought to produce BMAA —Microcystis aeruginosa, Synechococcus bacillaris, and Nostoc sp. —were grown in nutrient replete cultures to examine its synthesis and cellular distribution over a growth cycle. Production of BMAA was also examined in nutrient (nitrogen and phosphorus) deplete cultures of Microcystis aeruginosa. In addition, natural assemblages of phytoplankton dominated by …
Coupling Ocean Currents And Waves With Wind Stress Over The Gulf Stream,
2019
Michigan Technological University
Coupling Ocean Currents And Waves With Wind Stress Over The Gulf Stream, Qi Shi, Mark A. Bourassa
Michigan Tech Publications, Part 1
This study provides the first detailed analysis of oceanic and atmospheric responses to the current-stress, wave-stress, and wave-current-stress interactions around the Gulf Stream using a high-resolution three-way coupled regional modeling system. In general, our results highlight the substantial impact of coupling currents and/or waves with wind stress on the air–sea fluxes over the Gulf Stream. The stress and the curl of the stress are crucial to mixed-layer energy budgets and sea surface temperature. In the wave-current-stress coupled experiment, wind stress increased by 15% over the Gulf Stream. Alternating positive and negative bands of changes of Ekman-related vertical velocity appeared in …
Species Determination Of Ulvoid Algae Through Genotyping; What Are The Environmental Implications?,
2019
Seattle Pacific University
Species Determination Of Ulvoid Algae Through Genotyping; What Are The Environmental Implications?, Kora S. Krumm
Honors Projects
Ulva is a genus of marine green algae native to many of the world’s coastlines and is especially difficult to identify via traditional methods such as dichotomous keying. This project aims to streamline taxonomic classification of Ulva species through DNA sequence analysis. Local samples of Ulva were obtained from Puget Sound, Seattle, WA, and two target genes (rbcL and its1) were amplified via PCR and sequenced for comparative analysis between samples. Ulvoids have a detrimental impact on marine ecosystems in the Pacific Northwest due to their role in eutrophication-caused algal blooms, and reliable identification can help inform conservation …
Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss,
2019
California Polytechnic State University, San Luis Obispo
Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins
Master's Theses
Estuaries are dynamic environments that are strongly affected by natural variability, as well as direct and indirect anthropogenic impacts. A better understanding of the drivers of carbon fluxes and biogeochemical variability in estuarine systems is needed, particularly with the increasing threat of ocean acidification. Morro Bay in Central California is a small nationally protected estuary, with seasonally low freshwater inputs. Since 2007, the bay has experienced a significant loss of native seagrass, Zostera marina, which is an important component of the marine ecosystem. Because seagrass photosynthesis decreases carbon dioxide and increases oxygen in the water column, the loss of seagrass …
Estuarine Dissolved Organic Carbon Flux From Space: With Application To Chesapeake And Delaware Bays,
2019
Old Dominion University
Estuarine Dissolved Organic Carbon Flux From Space: With Application To Chesapeake And Delaware Bays, Sergio R. Signorini, Antonio Mannino, Marjorie A.M. Friedrichs, Pierre St-Laurent, John Wilkin, Aboozar Tabatabai, Raymond G. Najjar, Eileen E. Hofmann, Fei Da, Hanqin Tian, Yuanzhi Yao
CCPO Publications
This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large flux variability with highest fluxes in spring and lowest in fall as well as interannual flux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by …
Numerical Modeling Of Wave Dynamics And Sediment Transport Near The Mississippi Birdfoot Delta And Barataria Estuary,
2019
Louisiana State University and Agricultural and Mechanical College
Numerical Modeling Of Wave Dynamics And Sediment Transport Near The Mississippi Birdfoot Delta And Barataria Estuary, Soroush Sorourian
LSU Doctoral Dissertations
The Barataria Basin is a large estuarine system in Southeastern Louisiana, connected to the Gulf of Mexico through a number of inlets, the most important of which is the Barataria Pass. This research examines, during April-June 2010 including both cold front passage and calm summer-time wind regimes, the wave dynamics in this basin and in its major inlets, morphological evolution near the Barataria Pass, and the budgeting and dispersal of the Mississippi River sediment in the birdfoot delta region. An unstructured grid, terrain following, high resolution coupled FVCOM-SWAVE-SED model is employed and validated in this study. The numerical model results …
A Fishy Problem: Effects Of Atlantic Salmon Farming In The Pacific Ocean,
2019
Fordham University
A Fishy Problem: Effects Of Atlantic Salmon Farming In The Pacific Ocean, Madeleine A. Griffith
Student Theses 2015-Present
In this report, I explore the historical, climatological, economic, and ethical issues created by the contemporary industrial salmon farming practices off Pacific coast of the United States and Canada. Chapter 1 utilizes a variety of sources from Stephen Hume’s A Stain upon the Sea to Miller’s Living in the Environment, to examine the integral part salmon plays in both freshwater and marine ecosystems, the ecosystem services salmon contribute in wild and farmed settings, and the trends in salmon consumption around the world. Chapter 2 examines the historically relevant role salmon held among indigenous societies and how that role has changed …
Bias Reduction In Machine Learning Classifiers For Spatiotemporal Analysis Of Coral Reefs Using Remote Sensing Images,
2019
Chapman University
Bias Reduction In Machine Learning Classifiers For Spatiotemporal Analysis Of Coral Reefs Using Remote Sensing Images, Justin J. Gapper
Computational and Data Sciences (PhD) Dissertations
This dissertation is an evaluation of the generalization characteristics of machine learning classifiers as applied to the detection of coral reefs using remote sensing images. Three scientific studies have been conducted as part of this research: 1) Evaluation of Spatial Generalization Characteristics of a Robust Classifier as Applied to Coral Reef Habitats in Remote Islands of the Pacific Ocean 2) Coral Reef Change Detection in Remote Pacific Islands using Support Vector Machine Classifiers 3) A Generalized Machine Learning Classifier for Spatiotemporal Analysis of Coral Reefs in the Red Sea. The aim of this dissertation is to propose and evaluate a …
An Objective Procedure For Delineating The Circumpolar Vortex,
2019
Louisiana State Univ, Coll Coast & Environm, Dept Oceanog & Coastal Sci
An Objective Procedure For Delineating The Circumpolar Vortex, Nazla Bushra, Robert V. Rohli
Faculty Publications
The broad-scale, steering atmospheric circulation in the Northern Hemisphere, represented by the tropospheric circumpolar vortex (CPV), is an important driver of environmental processes. The area and circularity of the CPV are analyzed hereby delineating the leading edge of the CPV at the steepest 500-hPa geopotential height gradient globally. The daily CPV area and circularity were aggregated to monthly averages for contrast with measurements identified in previous research for the overlapping period of record (1979-2001). Accuracy of representation of the CPV is assessed through correlations to air-sea teleconnections known to be associated with broad-scale, extratropical steering circulation. Correlation to monthly teleconnection …
Spatial Variations In Chlorophyll A, C, N, And P In A Louisiana Estuary From 1994 To 2016,
2019
Louisiana State Univ, Dept Oceanog & Coastal Sci
Spatial Variations In Chlorophyll A, C, N, And P In A Louisiana Estuary From 1994 To 2016, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee
Faculty Publications
Intense sampling of an estuary can reveal relative spatial changes that are significant irrespective of whether or not the estuary is eutrophic, micro- or meso-tidal, disturbed, or restored. This waterscape' perspective is analogous to a landscape perspective. We collected monthly water samples in the Barataria Basin watershed from 1994 to 2016 at 37 stations along a 129km transect from 1km offshore to a freshwater stream. The average Chlorophyll a (Chl) concentration from 267 trips was supported from both nitrogen-fixing cyanobacteria in a freshwater lake and partially from nutrients in seaward sources. Estuarine salinity was correlated with the discharge of the …
