Physical Sciences and Mathematics Commons^™

Sodium-Calcium Ratios In The Planktic Foraminifera Trilobatus Sacculifer As A Proxy For Sea Surface Salinity, Colton Steele Watkins

OES Theses and Dissertations

Recent culture and field studies have found a significant positive correlation between seawater salinity and the incorporation of sodium into foraminiferal calcite, suggesting a potential new proxy for reconstructing past changes in sea surface salinity (SSS) (Mezger et al., 2016 and Bertlich et al., 2018). In order to test the applicability of this new proxy in an open-ocean setting, Na/Ca ratios in the planktic foraminifera Trilobatus sacculifer (T. sacculifer Na/Ca) were measured from a suite of sediment core tops spanning a natural salinity gradient from the North Atlantic subtropical gyre to the South Atlantic subtropical gyre. Initial results from …

Salt Fluxes At The Chesapeake Bay Entrance, Ruth Lane

OES Theses and Dissertations

Underway measurements of salinity and flow profiles were used to compute salt fluxes at the mouth of the Chesapeake Bay in spring and summer. Waters were sampled along a cross-bay transect over four tidal cycles in 1997: at the end of April, during neap tides, and in mid-July, during spring tides. Data were interpolated onto a uniform grid along the transect area. A least squares regression with semidiurnal and diurnal harmonics was fit on both salinity and flow at each point of the grid to separate tidal from non-tidal influences. The results of the least squares fit were used to …

Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski

Biological Sciences Theses & Dissertations

The present research compared and contrasted the physical structure of floating and rooted marshes, their differing responses to open-water salinities and inundation, as well as the nutrient distribution in the porewaters and sediment. The effects of the physical differences in the two marsh types on the ocurrence of the dominant emergent vegetation was discussed.

The main difference in physical structure of the two marsh types was the presence of a mineral, non-buoyant layer at 25-45 cm depth in the rooted marsh, which could serve as an anchor for the overlying highly organic mat layer found in both marsh types. Porewater …

Distribution Of Suspended Particulate Matter, Patuxent River Estuary, Maryland, Christopher W. Frye

OES Theses and Dissertations

Physical processes which may affect estuarine circulation in a coastal plain estuary were monitored to determine their relative importance on temporal and spatial variability of the concentration, composition, and particle-size of suspended particulate matter (SPM) in Patuxent River estuary, MD, during 1985-86. Discharge rates from Patuxent River determined the character of fresh and estuarine water mixing, and magnitude of SPM concentration in the upper estuary. The mixing zone between fresh and estuarine water, defined as 0 - 1.5 °‰, and turbidity maximum were geographically separated during most of the study period. This suggests that two-layer circulation may be less important …

The Effects Of Varying Fresh Water Discharge On Dispersion In An Estuarine Hydraulic Model Of The Lafayette River, Norfolk, Virginia, Michael J. Jugan

OES Theses and Dissertations

Three experimental tests were conducted in the Lafayette River branch of the Chesapeake Bay Hydraulic Model, each successive test with an increase in the amount of fresh water discharged into the head of the river. This was done to study the response from varying river discharge on mixing parameters including the longitudinal dispersion coefficient (E).

The model generated a tide of constant range and period. Batch releases of Rhodamine WT dye were made in the model and sampled throughout the river for ten tidal cycles. Samples were taken simultaneously at selected high and low water slack.

The calculation of the …

Temperature And Salinity Tolerance Of The Larvae Of The Sand Shrimp, Crangon Septemspinosa (Say), Karen Lyttle Hinsman

OES Theses and Dissertations

The effects of temperature and salinity on the larval development of the sand shrimp, Crangon septemspinosa, were investigated in the laboratory using 30 combinations of temperature and salinity in a five by six factorial experiment. The five temperatures were 5°c, 10°c, 15°c, 20°c, and 25°c and the six salinities were 10°/oo, 15°/oo, 20°/oo, 25°/oo, 30°/oo and 35°/oo. Thirty-six larvae were used for each temperature-salinity combination. Temperature and salinity produced significant differences (1% level) in survival and the duration of larval development. Highest survival occurred at 15°c and 20°/oo. At optimum temperatures (15°c to 20°c) larvae exhibited the broadest tolerance …

A Seasonal Distributional Survey Of The Epiphytic Diatoms Of The Outer Banks Region Of North Carolina With Respect To Temperature And Salinity, Charles Welles Belin Jr.

OES Theses and Dissertations

This study was initiated to investigate epiphytic diatoms at selected stations along the North Carolina coast and bay region. The relationships between these organisms and the season of the year and salinity and temperature of the water in which they were found are considered. The special affinity between the epiphytic diatoms and their host plants is also discussed. The specific data were analyzed statistically via linear correlation coefficients, graphs of least squares-best fit, and multiple linear regression analysis.

From the statistical tests, it was found that the mean number of epiphytic diatoms shows a significant multiple linear regression with respect …

A Graphic Analysis Of Current Velocity Salinity Density And Temperature During Periods Of Ebb And Flood In The Entrance To Thimble Shoals Channel, Stanley Hecker

OES Theses and Dissertations

A graphic analysis is presented of the observed patterns of longitudinal current velocity, salinity, density and temperature through a group of tidal cycles in Thimble Shoals Channel. Graphs of the properties indicate that this estuary passes through a sequence of estuarine types during a tidal cycle. In spite of this observation, the net non-tidal profiles of salinity are patterns of a partially mixed estuary.

The most noteworthy observation in this study was that longitudinal velocity was essentially constant throughout the water column at any increment of a tidal cycle as well as in the net non-tidal profile of the water …