36 Years After The Species' Mass-Mortality: Diadema Antillarum Test Sizes, Population Densities, And Substrate Preferences In Three Guna Yala Reefs Near Wichub Wala Island,
2019
SIT Study Abroad
36 Years After The Species' Mass-Mortality: Diadema Antillarum Test Sizes, Population Densities, And Substrate Preferences In Three Guna Yala Reefs Near Wichub Wala Island, Bimini Horstmann
Independent Study Project (ISP) Collection
In January 1983, a waterborne pathogen beginning near the Atlantic Panama Canal entrance caused history's largest recorded marine animal die-off, wiping out 95-99% of Diadema antillarum populations throughout the Caribbean. D. antillarum, the long-spined sea urchin, is a keystone herbivore in coral reefs and its decreased densities have caused many reefs to suffer macroalgal phase shifts. Modest recovery of this species has been documented in some Caribbean locations, but reefs in Guna Yala, Panama continued to experience population decline. This study investigates density, test size, and substrate preferences of D. antillarum in three shallow coral reef areas to update the …
Coastal Stream Salinity And Its Impacts On Pemba Agriculture,
2019
SIT Study Abroad
Coastal Stream Salinity And Its Impacts On Pemba Agriculture, Sara Mccormack
Independent Study Project (ISP) Collection
The extent of saltwater inundation of coastal streams was assessed on Pemba Island near agricultural areas in northeastern and northwestern regions of the island. Conductivity and pH were measured from water samples collected at various distances along the stream to determine the extent of salinity at different points in the tidal cycle. This salinity data, as well as the context of recent weather events, runoff, and geological characteristics of the region were used to determine the primary factors that influence changes in surface water salinity. The primary factor that influences surface water salinity was determined to be changes in stream …
Sediment Resuspension In A Microtidal Estuary: Causative Forces And Links With Algal Blooms,
2019
Old Dominion University
Sediment Resuspension In A Microtidal Estuary: Causative Forces And Links With Algal Blooms, Samantha C. Mcgill
OES Theses and Dissertations
After years of efforts to restore the Chesapeake Bay, bacterial levels are down and species diversity has increased, however, algal blooms (primarily dinoflagellates) persist, occurring nearly every summer. Dinoflagellates produce resting cysts that accumulate in the bottom sediments and are thought to provide seed populations for future algal blooms when they are resuspended. When estuarine sediments are advected from a bed, other materials, such as pollutants, nutrients, and organic matter are also released into the water column. Thus, resuspended sediments can contribute to the degradation of water quality, habitat, and aquatic life, and impart negative impacts on local ecosystems and …
Pacts 1.0: A Crowdsourced Reporting Standard For Paleoclimate Data,
2019
Old Dominion University
Pacts 1.0: A Crowdsourced Reporting Standard For Paleoclimate Data, D. Khider, J. Emile-Geay, N. P. Mckay, Y. Gil, D. Garijo, V. Ratnakar, M. Alonso-Garcia, S. Bertrand, O. Bothe, P. Brewer, A. Bunn, M. Chevalier, L. Comas-Bru, J. Hertzberg, Y. Zhou
OES Faculty Publications
The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on the data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efforts to standardize the format and terminology of paleoclimate data, this article describes the Paleoclimate Community reporTing Standard (PaCTS), a crowdsourced reporting standard for such data. PaCTS captures which information should be included when reporting paleoclimate data, with the goal of …
Improving Thorium-230 Determination In Marine Sediment,
2019
SIT Study Abroad
Improving Thorium-230 Determination In Marine Sediment, Katherine Mateos
Independent Study Project (ISP) Collection
Our oceans are intimately related to the climate of our planet. Paleoceanographic approaches aim to study oceans through geologic time to improve models of future climate. Radioisotopes provide us with chemical tracers that help us understand change through time. The uraniumseries decay chain contains thorium-230, a decay product of uranium-234. This isotope is useful to paleoceanographers in its disequilibrium to its parent isotope and in determining the flux of sediment falling to the ocean floor. In order to use 230Th to study oceans, we must be able to accurately measure the amount of thorium in sediment samples. Thorium is found …
Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors,
2019
SIT Study Abroad
Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors, Sophie Coppieters ‘T Wallant
Independent Study Project (ISP) Collection
Currently, less than 5% of our oceans are comprehensively monitored and much more ocean data is needed to facilitate understanding of ocean physics, carbon cycling, and ocean ecosystems. Today, most autonomous ocean sensors are powered by primary battery, which have both limited capacity and lifetime. The goal of this research is to design a small, accessible renewable wave energy device to power autonomous free-floating ocean sensors. By designing a cheap, accessible, and simple wave energy converter, this work hopes to make ocean sensor deployment easier and cheaper for researchers, increase the lifetime of autonomous ocean sensors, and reduce the reliance …
The Tensile Root Strength Of Spartina Patens Varies With Soil Texture And Atrazine Concentration,
2019
Louisiana State Univ, Dept Oceanog & Coastal Sci
The Tensile Root Strength Of Spartina Patens Varies With Soil Texture And Atrazine Concentration, Lauris O. Hollis, R. Eugene Turner
Faculty Publications
The widely used agricultural herbicide atrazine enters wetlands and may potentially affect wetland plants that provide critical reinforcement of soil strength and contribute to ecosystem stability in ways that may vary among soil types. We conducted greenhouse experiments using four levels of atrazine doses and three different soil textures to test for differences between control and experimental treatments and interactive effects of soil texture and atrazine exposure by using the tensile root strength of the coastal wetland emergent macrophyte Spartina patens as the response variable. The tensile root strength of S. patens was not affected after 50days of atrazine exposure …
The Distribution, Fractionation, And Application Of The 210po/210pb System: Insights From Three Geotraces Transects,
2019
CUNY Graduate Center
The Distribution, Fractionation, And Application Of The 210po/210pb System: Insights From Three Geotraces Transects, Yi Tang
Dissertations, Theses, and Capstone Projects
The sinking flux of particles is an important pathway for the removal of carbon and other elements from the surface ocean via the biological pump. The 210Po/210Pb disequilibrium method can be used to study particle export at high spatial resolution over the time scale of months. The distribution of 210Po and 210Pb activity was measured during two GEOTRACES transects of the North Atlantic and one GEOTRACES transect of the eastern tropical South Pacific. This dissertation aimed to advance the knowledge and improve methods of the application of the 210Po/210Pb pair to quantify …
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 …
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 …
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 …
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 …
