Physical Sciences and Mathematics Commons^™

Effects Of Meteorologic Events On Wave Climate And Current Regime In A Shallow, Microtidal Bay, Jay S. Merrill

LSU Master's Theses

Along coastal Louisiana and within the shallow microtidal Barataria Bay estuary, meteorological events can play a primary role in influencing wave climate and circulation patterns. Understanding the effects of hurricanes and smaller tropical storms on hydrodynamic processes is important for constraining and predicting hydrodynamic variation in Barataria Bay, which, largely due to impacts from wave energy, is currently experiencing rapid wetland loss and is a major focus of coastal restoration efforts. Two bottom-mounted upward-facing Acoustic Current Doppler Profilers and wave, temperature, and depth recorders were installed in the lower portions of Barataria Bay to measure the wave climate and three-dimensional …

Iron Geochemistry Across An Estuary-To-Coastal Gradient, Lissett G. Diaz

Honors Theses

Iron is a ubiquitous earth element that participates in biogeochemical processes that occur in marine sediments. Microorganisms utilize iron for many purposes, including cell growth, conserving energy, and for maintaining metabolic activity. In coastal sedimentary settings, understanding the redox reactions involving ferric iron, Fe³⁺, and ferrous iron, Fe²⁺, in its solid phase and pore-water phases, respectively, enable an appreciation of biogeochemical transformations occurring in the coastal zone. In this study, iron concentrations in sediment of ranging permeability were determined at four stations marking an estuary-coast transition zone in Singleton Swash in Myrtle Beach, South Carolina. The …

From River To Sea: Improving Carbon System Measurement Methods For Use In Rivers, Estuaries, And Oceans, Ellie Hudson-Heck

USF Tampa Graduate Theses and Dissertations

Over the last 30 years, spectrophotometric methodologies have been developed, with increasing rigor, to accurately measure all four carbon system parameters: total alkalinity (A_T), total carbon (C_T), partial pressure of CO₂ (pCO₂), and pH. Spectrophotometric measurements of carbon system parameters rely on quantitative characterizations of the response of sulfonephthalein indicator dyes (e.g., meta-cresol purple (mCP), thymol blue (TB), and bromocresol purple (BCP)) to changing solution pH, as well the response of indicator physical-chemical characteristics to key environmental variables (salinity (S_P), temperature (T), and pressure). Until recently, the physical-chemical properties …

Algal Coverage Detection And Classification Using Envi: Correlation With Dissolved Oxygen Levels In Elkhorn Slough, Ca, Jason Dawson

All HCAS Student Capstones, Theses, and Dissertations

Estuaries are exposed to varying stressors, whether they be physical, chemical, or environmental. The most notable of stressors is eutrophication of coastal and inland ecosystems. This is a result of increased supply of nutrients fueling production within the system. One outcome of this increased nutrient load to the system is that of algal blooms. These blooms can impact the aesthetic appearance and degrade the quality of health of the system. Many of these coastal zones and waterways are critical habitats for many biological (some endangered) species and serve as recreational areas for human populations. Elkhorn Slough, California is one of …

Improved Estimates Of Tributary Nitrogen Load To Casco Bay, Maine, Whitley J. Gray

Electronic Theses and Dissertations

Over the past two decades, total nitrogen (TN) concentrations have increased in Casco Bay (CBEP 2015). The sources of the increased nitrogen are poorly understood but occur with simultaneous population growth and land use changes. The total riverine nitrogen load to Casco Bay was previously estimated by Liebman and Milstead (2012) using the United States Geologic Survey’s (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model. The SPARROW model uses watershed characteristics, regional monitoring data and nitrogen source data to estimate nitrogen loading but was not validated using measurements of nitrogen in the Casco Bay watershed. This study attempts to …

Ecophysiology Of Lionfish Metabolic And Visual Systems: Are There Physiological Limits To Inshore Invasion?, Aaron Hasenei

HCNSO Student Theses and Dissertations

Lionfish (Pterois spp.), an invasive species native to the Indo-Pacific, have permanently established themselves throughout the greater Caribbean, Gulf of Mexico, and regions of the Western Atlantic ranging from as far north as North Carolina to central Brazil. As their fundamental range expands, lionfish threaten to migrate into estuarine environments as they have been found to tolerate low salinities and an eclectic range of temperatures. The physiological capacity of invasion was assessed by quantifying the visual ecology of lionfish utilizing corneal electroretinography (ERG) as well as their metabolic scope and hypoxia tolerances under various temperature-oxygen-regimes utilizing intermittent-flow respirometry. Seasonal …

Cyanobacteria Harmful Algal Blooms In South Louisiana Estuaries : A Synthesis Of Field Research, Management Implications, And Outreach, Emily Anne Smith

LSU Doctoral Dissertations

Estuaries are biologically productive and important habitats for several fisheries. However, human intervention has separated many estuaries from their needed freshwater source and the commonly used solution is to use diversions to regulate the flow. This episodic increase in nutrients into estuaries has sometimes led to the formation of freshwater cyanobacteria HABs (CyanoHABs). The goal of this dissertation was to look at a field research study of phytoplankton bloom dynamics; management implications for cyanobacteria entering estuaries; and an outreach effort in relation to residents knowledge about cyanobacteria and algae. The first study compared the phytoplankton bloom dynamics, specifically CyanoHABs, in …

Optical Detection And Classification Of Phytoplankton Taxa Through Spectral Analysis, Daniel Tyler Sensi

USF Tampa Graduate Theses and Dissertations

Phytoplankton serve as the bottom of the marine food web and therefore play an essential role in marine ecosystems. On the other hand, coastal phytoplankton communities can adversely affect the marine ecosystem and humans. A variety of techniques have been developed to measure and study phytoplankton, including in situ methods (e.g., flow cytometry) and laboratory methods (e.g., microscopic taxonomy). These provide accurate measurements of phytoplankton taxa and concentrations, yet they are limited in space and time, and synoptic information is difficult to obtain with these techniques.

Optical remote sensing may provide complementary information for its synoptic nature, as demonstrated by …

Quantification Of Nitrate Sources And Sinks Using A Water Quality Network In Morro Bay Estuary, California, Johanna Nadia Jean Weston

Master's Theses

Using an instrumented water quality network in Morro Bay Estuary, California from 2007 to 2010 (15 min sampling frequency), this study addressed the two objectives of constructing a nitrate budget and assessing the influence of sampling frequency on water quality parameters. These two objectives led to the submission of an original report of research (Appendix A) and a note (Appendix B) to peer-reviewed journals.

The first objective was to characterize the high spatial and temporal variation in physical parameters and nitrate concentrations and to construct a nitrate budget quantifying sources and sinks of nitrate from the ocean, streams, and groundwater, …

Export Of Terrestrial Dissolved Organic Matter Along A River To Ocean Transect Of The Lower Chesapeake Bay Investigated By Advanced Analytical Techniques, Rachel Leigh Sleighter

Chemistry & Biochemistry Theses & Dissertations

Ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) has proved essential for the complete separation of the thousands of peaks present in natural organic matter (NOM), a complex assemblage of organic molecules present in water, soils, and sediments. An improved understanding of its composition is crucial to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles.

Optimizing the acquisition and handling of the FTICR mass spectra is the first step to obtaining high quality data. A simple method to internally calibrate the peaks in the complex spectra, using naturally present fatty …

Exchange Hydrodynamics Between A Subestuary And Its Adjacent Estuary, Diego A. Narváez

OES Theses and Dissertations

Four oceanographic surveys and two periods of moored data were analyzed to describe the subtidal exchange hydrodynamics between a subestuary (Nansemond River) and its adjacent estuary (James River) in the lower Chesapeake Bay. The surveys were carried out during two semidiurnal periods (~25 hrs), which included two spring and two neap tides. Velocity profiles and hydrographic data were recorded over an area ~4 km long and ~1 km wide allowing a spatial resolution rarely obtained with observational data. The results obtained in the surveys were extended with instruments deployed at the entrance to the subestuary during winter and summer time …

Fortnightly Variability At The Transition Between Two Sub-Estuaries, Mayra Lorena Riveron Enzastiga

OES Theses and Dissertations

Profiles of current velocity from an Acoustic Doppler Current Profiler (ADCP) and of water salinity, temperature and density from a Conductivity-Temperature-Depth (CTD) recorder, were combined with surface salinity, temperature and density from a Conductivity-Temperature (CT) recorder to elucidate the fortnightly variability at the Lafayette River entrance. The Lafayette River connects at its mouth with the Elizabeth River, which is a tributary to the James River in the Chesapeake Bay. Data were collected in four experiments during consecutive spring and neap tides in the autumn of 2000, and in the spring of 2001. Each experiment was carried out for -25 hours …

Interannual Variation Of Stratification In Lower Chesapeake Bay, Christopher S. Katzenmiller

OES Theses and Dissertations

Stratification in the water column can prove to be an important indicator to the state of the water column and ecosystem. The focus of this research is to evaluate trends in stratification in the Lower Chesapeake Bay. Detailed analysis was performed on a 14 year data set to study interannual variation in the region of study. Potential energy anomaly was used to quantify stratification. Potential energy anomaly is the amount of energy required to mix a water column. It is determined from the vertical density structure of density. Potential energy anomaly is the departure of potential energy from climate conditions. …

Wind-Induced Exchange In Semi-Enclosed Basins, Rosario Sanay

OES Theses and Dissertations

The wind-induced circulation over laterally varying bathymetry was investigated in homogeneous and in stratified systems using the three-dimensional Regional Ocean Model (ROMS). For homogeneous systems, the focus was to describe the influence of the earth's rotation on the lateral distribution of the flow with particular emphasis on the transverse circulation. Along-basin wind-stress with no rotation caused a circulation dominated by an axially symmetric transverse structure consisting of downwind flow over the shoals and upwind flow in the channel along the whole domain. Transverse circulation was important only at the head of the system where the water sank and reversed direction …

Morphostatic Long-Term Hypsometric Analysis Of Coastal Bay Environments: Hog Island Bay, Virginia, Kathleen Marie Overman

OES Theses and Dissertations

Sea level has been rising at a variable rate since the end of the last glaciation approximately 18,000 years ago. As the transgressing sea inundates the shore areas a series of landform state changes occur in coastal regions. One such change of state in a coastal paleo-river channel is from an estuary into a coastal lagoon. At large temporal intervals (thousands of years) the hypsometry of a coastal lagoon varies as a result of sea level rise due to these changes of state. Using a morphostatic technique, the time period in which an estuary transforms into a coastal lagoon can …

Processes Affecting The Behavior Of Redox-Sensitive Elements In Chesapeake Bay, Maria Lourdes San Diego-Mcglone

OES Theses and Dissertations

Several processes can affect variations in the chemical composition of an estuary, including (1) biogeochemical reactions in the water column, (2) advective transport, and (3) diffusion from underlying sediments.

The purpose of the study was to establish whether estuarine redox reactions are controlled by a complex interaction of processes 1 to 3. Short-term and long-term studies were conducted in Chesapeake Bay. Redox species involved in redox cycling include oxygen, iron, manganese, hydrogen sulfide, nitrogen species, arsenic and antimony species, while phosphate is indirectly involved in redox cycles. Silicate was used as a non-redox tracer.

For the short-term study, a Lagrangian …