Physical Sciences and Mathematics Commons^™

The Effects Of X-Irradiation On The Metamorphosis And Budding Of Aurelia Aurita, Michael John Prokopchak

OES Theses and Dissertations

With the aid of the Aurelia Metamorphosis Test System, the acute or subtle morphological and behavioral effects of irradiation on the Norfolk Aurelia aurita were described and the sensitivity to X-irradiation of those organisms receiving thyroxine and those not receiving thyroxine was compared. Levels of radiation were 0 (control), 5,000, 10,000, 15,000, 20,000 and 40,000 rads. Morphology of the ephyrae, statolith and rhopalia numbers were recorded using the light microscope, Developmental abnormalities of the scyphistomae and ephyrae were recorded with the scanning electron microscope and light microscope. Two major findings from this investigation were the absence of rhopalia and statoliths …

Numerical Experiments With The Quasigeostrophic Potential-Vorticity Equation, Peter L. Spence

OES Theses and Dissertations

A method is developed to model the circulation of a barotropic, 8-plane ocean under an imposed steady wind stress. The model includes the effect of both horizontal and vertical friction along with nonlinear advection of vorticity. Implementing the method involves solving the unsteady quasigeostrophic potential-vorticity equation using a compact finite difference scheme (Gatski, Grosch, and Rose, 1982).

Once developed, this model is used in four separate numerical experiments. In each experiment, a model ocean with an initial flow field is driven to a steady state solution. Vertical viscosity is held constant in the first three experiments while lateral viscosity is …

Fourier Series Analysis Of The Relationship Of Morphologic Variations And Bathymetry In Recent Bolivina (Foraminiferida) From The Northwestern Gulf Of Mexico, Anthony Cavedo Gary

OES Theses and Dissertations

Automated video digitization and closed-form Fourier series analysis were used to investigate the applicability of benthic foraminiferal test morphology for paleo-bathymetric/paleoenvironmental reconstructions. Sample relationships and harmonics with the greatest power for discriminating between samples were determined using canonical discriminant analysis. Samples were eleven short cores obtained from the northwestern Gulf of Mexico. Three species of Bolivina were analyzed, B. albatrossi, B. lowmani, and B. subspinescens.

Results show populations of Bolivina albatrossi from the upper bathyal and upper-middle bathyal zones to have more triangular tests and lobulate chambers than lower-middle and lower bathyal zone populations. Specimens of Bolivina subspinescens …

The Spatial And Temporal Distribution Of The Larvae Of Sympatric Pagurid Hermit Crabs (Decapoda, Anomura) In Virginian Estaurine And Coastal Waters, Philip Wesley Sadler

OES Theses and Dissertations

Thirteen stations were occupied at two - week intervals from May through September 1980 within the York River, lower Chesapeake Bay depths encompassing the entire water column.

Three species of pagurids were identified: Pagurus longicarpus, P. pollicaris, and P. annulipes. The larvae of P. annulipes had not been previously identified from Virginian waters. The shapes of the antennae of P. pollicaris and P. annulipes weredistinctive, allowing rapid identification of these larvae. The shapes of the uropods were found to be useful in distinguishingthe glaucothoe· of P. longicarpus from P. annulipes. The larvae of these species …

A Description And Analysis Of The Timing Of Virginia's Weakfish Fishery, Bruce William Hill

OES Theses and Dissertations

The seasonality of Virginia's weakfish fishery is quantitatively defined by providing a mean time of catch and variance of catch for the years 1960 - 1981. On the average. the central half of the population is available for harvest from mid-May through September in all of Virginia's waters and the mean date of harvest is July 20th • The 22 year average variance of catch for Virginia's waters is 3.97. In Virginia's Chesapeake Bay tributaries the mean date of harvest is July 17th and the 22 year average variance of catch is 2.50. There is evidence for an inverse relationship …

An Examination Of The Variability Of Migratory Timing Statistics Estimated From Catch And Effort Observations, Arthur J. Butt

OES Theses and Dissertations

The estimate of the mean arrival time based on catch or CPUE of fishes migrating into a fixed harvest area is a function of the number of days fished. Simulation studies using chinook salmon catch and effort data from the Yukon River delta, Alaska indicate that fishing effort concentrated at the tails of the migratory distribution which would tend to erroneously weigh the estimated mean arrival time in the direction of the sample, away from the true mean, is only a significant problem when the number of days open to fishing is small, covering less than 12% of the total …

Determinants For The Timing Of Escapement From The Sockeye Salmon Fishery Of The Copper River, Alaska: A Simulation Model, Howard A. Schaller

OES Theses and Dissertations

A model to estimate determinants for migratory timing of catch and escapement in a terminal salmon fishery is presented. A method was developed to estimate average seasonal migration rates of salmon through a harvest area from catch and escapement data. The time series for the total population of Copper River sockeye salmon (Oncorhynchus nerka) was reconstructed in the reference frame of the commercial harvest area from catch and escapement data.

The catchability coefficients (q), derived from the reconstructed populations were found to vary within season and between seasons. The relation between q and effort was attributed to a …

An Intraseason Forecasting System For Commercial Marine Fisheries, Erik J. Barth

OES Theses and Dissertations

The reliability of an intraseason yield estimation technique which is commonly used by Pacific salmon harvest managers is evaluated for applicability to a variety of commercial finfish and crustacean fisheries. The estimation technique is known as the average timing or the average performance model. The method is not easily related to standard statistical models, but does show some similarity to both a single parameter linear regression model and the ratio estimator of sampling theory. A comparison of these models, a two parameter linear model, and a regression estimator is made to determine if the precision of forecasts of performance can …

A Method For Determining Creosote Contamination Of Sediment From The Elizabeth River, Norfolk, Va, Elizabeth G. Merrill

OES Theses and Dissertations

Hydrocarbon input sources to the Elizabeth River were investigated. Carbonized coal products (creosote, coal tar, and roof tar), petroleum products (Kuwait Crude Oil, No. 2 Fuel Oil, and a fuel oil spill sample) and soot (woodstove and diesel engine) have unique hydrocarbon distributions. Elizabeth River sediment hydrocarbon distributions indicate that they are contaminated with both carbonized coal and petroleum products. Using a simple two member mixing model, greater than 65 percent of Elizabeth River sediments' resolved aromatic compounds were determined to originate from carbonized coal products. These aromatic hydrocarbons include the EPA priority pollutant polynuclear aromatic hydrocarbons which are known …

Timing Of The Blue Crab Fisheries Of Virginia And Its Application To Harvest Management, J. Dale Shively

OES Theses and Dissertations

The timing of a fishery is a quantitative expression of the composite behaviors of harvesters, markets, animals and climatic events. A quantitative description of the timing of the blue crab (Callinectes sapidus) fisheries of Virginia was established using the time density model of Mundy (1979). Blue crab catch statistics supplied by the National Marine Fisheries Service and the Virginia Marine Resource Commission were divided into two fisheries based on gear type; the summer and winter fisheries. Average performance curves were then constructed using average cumulative proportions of catch. Annual yield estimates were also made and timing in five …

Analysis Of Central Equatorial Pacific Water Masses By Method Of Principal Components, Ross Tuxhorn

OES Theses and Dissertations

The distribution of Antarctic Intermediate Water at the extent of dispersion in the equatorial Pacific Ocean was investigated by means of multivariate analysis. Interrelationships among the upper intermediate water masses at this location are proposed.

Oceanographic data contained in seven cruise legs measured during the 1979-80 Hawaii to Tahiti Shuttle Experiment formed the basis of this study. Six parameters -- temperature, salinity, dissolved oxygen, phosphate, silicate and nitrate -- were used in the method of principal component analysis to classify water masses between the sea surface and 1000m. The derived water masses were compatible with previously described oceanographic features of …

Fission Track Dating Of Detrital Zircons From The Scotland Sandstones, Barbados, West Indies, Suzanne Louise Baldwin

Geology Theses and Dissertations

Results of fission track dating of detrital zircons from the Scotland sandstones, Barbados, yield a mixture of ages with several strong groupings from 20-80 Ma, 200-350 Ma, and greater than 500 Ma. Metamict grains were assumed to fall into the greater than 500 Ma population.
The youngest population indicates that the Scotland beds, previously dated by paleontologic methods as Eocene, may actually be as young as late Oligocene. These ages better constrain the timing of deposition for these sediments and support the proposal that the late middle Eocene - early Oligocene Oceanic Fm has overthrust the Scotland beds. This population …

The Influence Of Oceanic Transform Boundaries On The Generation And Evolution Of Oceanic Lithosphere, David G. Gallo

Geology Theses and Dissertations

The first-order geologic and morphologic relationships at, along and proximal to ridge-transform-ridge plate boundaries are used to construct an empirical and speculative tectonic model. The geometry of a ridge-transform intersection necessitates the juxtaposition of relatively cold, thick lithosphere against the truncated end of an accreting plate boundary. The cold face of lithosphere cools the adjacent wedge of asthenosphere rising beneath the axis of accretion and restricts the amount of partial melting thus attenuating the amount of basaltic melt segregated from the asthenosphere per unit time. The manifestation of this cold edge effect is a thinner oceanic crust. At depth, upper …

The Distribution And Abundance Of The Bottlenose Dolphin, Tursiops Truncatus In Virginia, Robert A. Blaylock

Dissertations, Theses, and Masters Projects

No abstract provided.

Non-Tidal Sea Level Variations Across The Lower Chesapeake Bay, Richard Leo Garfield

Dissertations, Theses, and Masters Projects

No abstract provided.

Electrophoretic Stock Identification Of Summer Flounder, Paralichthys Dentatus, Garret Van Housen

Dissertations, Theses, and Masters Projects

No abstract provided.

Anatomical Observations On The Ampullae Of Lorenzini From Selected Skates And Galeoid Sharks Of The Western North, William Raschi

Dissertations, Theses, and Masters Projects

The gross structure of the ampullae of Lorenzini and its distribution on the body of 40 species of skates (Rajoidei) and 5 species of sharks (Galeomorphii) were compared in an attempt to investigate correlations within this system to feeding mechanisms. Three general lines of morphological change are observed. A larger proportion of the ampullary pores are associated with the ventral surface of the dorsoventrally flattened skates than the more conically shaped sharks. The relative proportion of ventral pores is significantly reduced on those species inhabiting aphotic waters. Secondly, the more piscivorous rajoids possess an array of ventral pores which covers …

Antibody Production In Spot (Leiostomus Xanthurus Lacepede): A Model To Test The Impact Of Elizabeth River Sediments On The Humoral Immune System Of Fish, Catherine Nancy Pourreau

Dissertations, Theses, and Masters Projects

No abstract provided.

Nanoplankton Dynamics In A Salt Marsh-Mudflat Ecosystem, Helena Maria Galvaeo

Dissertations, Theses, and Masters Projects

No abstract provided.

Lower Chesapeake Bay Surface Turbidity Variations As Detected From Landsat Images, Michael S. Fedosh

Dissertations, Theses, and Masters Projects

Landsat images are analyzed to investigate the causes of turbidity variations in lower Chesapeake Bay surface water. Visual analysis and image enhancement are used in association with optical film density data obtained along selected Bay transects. The optical density data of all images, inversely related to surface turbidity, are used to produce residual turbidity profiles showing turbidity above and below average conditions. meteorological conditions have Images with similar tidal or their residual optical density data averaged to identify probable causes of above average turbidity levels. Freshwater discharge does not directly contribute suspended sediment to Chesapeake Bay, except from the Potomac …

The Response Of Benthic Respiration To Nutrient Levels, Laurence E. Gadbois

Dissertations, Theses, and Masters Projects

No abstract provided.