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The Analysis Of Volatile Organic Compounds In The Southern Chesapeake Bay, Virginia By Gas Chromatography/Mass Spectrometry, James D. Haluska

OES Theses and Dissertations

Sea-water samples from the Norfolk, Virginia area were analyzed for trace volatile organic compounds by helium sparging. Contents of the trap were injected into a gas chromatograph/mass spectrometer. Analysis of the trap contents indicated the presence of aliphatic and olef1nic hydrocarbons containing up to six carbon atoms and eight halogenated compounds of up to two carbon atoms in length. The halogenated compounds which were identified were dichlorofluoromethane, trichlorotrifluoroethane, carbon tetrachloride, chloroform, trichloroethane (2 isomers) bromodichloromethane, and chlorotrifluoroethylene. The

relative concentrations of volatile organic compounds generally tended to increase in samples collected from water prone to urban environmental pressures. All eight …

Quantitative And Qualitative Seasonal Analysis Of The Surface Zooplankton Of Magothy Bay, Virginia, Malcom E. Browne

OES Theses and Dissertations

No abstract provided.

Feeding And Food Preferences By Three Sympatric Species Of Cyprinodontid Fishes, Lawrence J. Baer

OES Theses and Dissertations

The feeding and food utilization by three sympatric species of cyprinodontid fishes was examined using a modified Ivlev Electivity Co-efficient. Results indicated that although Fundulus heteroalitus and Fundulus majalis are sympatric in the area examined,their usage of the available food source varied noticeably. The third investigated species, Cyprinodon variegatus, fed mainly upon a vegetal detritus food source varied by the consumption of invertebrate and vertebrate food items. Slight intra-specific variances of diet between crespuscular periods was also discussed.

Observations On The Distribution And Composition Of Zooplankton In Portions Of The Intracoastal Waterway, Virginia, O. Clair Hillard Jr.

Biological Sciences Theses & Dissertations

Five stations were established in the Southern Branch of the Elizabeth River, the Dismal Swamp Canal, the Albemarle and Chesapeake Canal and the North Landing River. Representative samples of zooplankton were taken from October 1971 to June 1972. A. total of 57 species were identified and discussions regarding seasonal distribution in relation to physical factors and circulation are presented.

The composition of the zooplankton was found to fluctuate greatly due to the variables characteristic of the study area. The combined effect of tidal flow with freshwater input in conjunction with drainage from the Great Dismal Swamp, results in isolated populations …

A Zooplankton Study Of Stumpy Lake, Virginia Beach, Virginia, Jose E. Hernandez

Biological Sciences Theses & Dissertations

A one year study was made of the zooplankton composition in Stumpy lake, a reservoir in the city of Virginia Beach, Virginia. Quantitative and qualitative -parameters were investigated under field conditions. The analysis of the data presents information on the monthly dynamics or the zooplankton and other fluctuations in the lake environment. It is the intention or this study to emphasize the seasonal changes in the zooplankton community and their relationship to the ecological factors responsible for these variations.

Phycosociology Of The Estuarine Eulittoral Of Smith Island Virginia: A Quantitative Approach To Seasonal Periodicity, William M. Willis

OES Theses and Dissertations

Seasonal periodicity of benthic algae of the estuarine eulittoral of Smith Island, Virginia, (37°07’55” N, 75°55’ W), has been investigated on a qualitative and quantitative basis. Forty-three taxa of benthic eucaryiotic algae were found to be present; of these, twenty-one were quantitatively significant at least once during the course of the study. Five species represent additions to the Virginia flora, and, at the same time, also represent southern extensions of the known U.S. east coast range. The range of three other species has been extended, though they are not new to Virginia.

Review of the literature suggests two models of …

Food And Feeding Of Fishes From Magothy Bay, Virginia, Joseph J. Kimmel

OES Theses and Dissertations

No abstract provided.

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 …

Investigation Of The Halocline Structure In Lower Chesapeake Bay, Samuel Bowen Heltzel

OES Theses and Dissertations

A portion of the Chesapeake Bay from 37°20’N latitude to the entrance was investigated to determine the halocline structure, the effects on this structure through the tidal sequence, and seasonal variations. A determination of the stage of slack water during which maximum extension of the halocline occurred was also made. This was accomplished by looking at the salinity distribution at the halocline upper limit, the mean depth to the halocline, and seasonal salinity contours drawn for tidal increments. By comparing salinity/depth gradients and salinity-depth vertical profiles, an attempt was made to relate seasonal and tidal variations to the halocline structure. …

Morphologic Time Series From A Submarine Sand Ridge On The South Virginia Coast, John F. Mchone Jr.

OES Theses and Dissertations

Submarine sand ridges several km long locally merge southward into the U. S. Atlantic coastline. Shallow (< 8m) observations of -such a ridge at False Cape, Virginia, favor a modern hydraulic origin. Time series maps show the ridge to be paralleled by a landward trough of approximately equal volume. Ridge flanks are usually steeper on the trough side.

Northeasterly winds and waves generate a coast-parallel current which funnels southward into the trough scouring it out and providing sediments for ridge aggradation. The current may be organized as a helical flow cell or cells. Bottom currents converge southward along the ridge crest causing landward transport of traction load along the crest. The trough current eventually breaches the confining ridge at the head of the trough, cutting saddles with steeper seaward slopes and producing outlying sediment fans.

The ridge and trough rest obliquely …

Phytoplankton Distribution In Waters Off The Northeastern Coast Of The United States, Sharon H. Craft

Biological Sciences Theses & Dissertations

Abstract unavailable.

Surface Water Turbidity In The Entrance To Chesapeake Bay, Virginia, James R. Melchor

OES Theses and Dissertations

Seasonal and spatial variations in the surface water turbidity across the entrance to Chesapeake Bay, Virginia, have been monitored with an optical transmissometer for one year. The data indicate a suspended-sediment gradient across the entrance with higher turbidity on the south side. This condition suggests that the flooding and ebbing tidal currents are influenced by Coriolis force. Clearer ocean water is introduced into the bay on the north side; whereas highly turbid water from the major drainage systems exits on the south side. A salinity gradient with18 0/00 on the south side of the bay and approximately 32 0/00 on …

Determination Of Nutrient Levels And Proposed Predictive Models For Phosphate In The Lafayette River, Norfolk, Virginia, John R. Montgomery

OES Theses and Dissertations

The Lafayette River, an Urban, well-mixed estuarine embayment, was sampled from October, 1970 to January, 1972 for phosphate, nitrate, nitrite, oxygen, water temperature and salinity. The mean values found for these samples were: oxygen saturation from 69% to 106% nitrate from 0 to 4 microgram-atoms per liter, and salinity from 13 ‰ to 24 ‰. The mouth of the Elizabeth River to Hampton Roads as also sampled from May, 1971 to August, 1971. The Lafayette and Elizabeth Rivers were also sampled over a 24 hour period in the summer of 1971 and the Lafayette River again in the winter of …

The Influence Of The Summer Thermocline On Estuarine Classification In The Chesapeake Bay Entrance, William G. Weiss Jr.

OES Theses and Dissertations

The temperature, salinity, and sigma-t of 397 oceanographic stations taken in the entrance to Chesapeake Bay were plotted using a simple interpolation formula by the lBM 1130 computer. Each station was catalogued by position, tidal stage, season, and estuarine classification. Results indicated increased stratification during the ebb phase of all entrance stations regardless of season. Partially mixed conditions predominate. The influence of the summer thermocline on the stratification caused a slight increase in the summer stratification mean. However, statistical tests showed this summer increase to be insignificant at the 95% level. Detailed classification of tidal stage by estuarine type for …

A Physical Hydrographic Study Of The Lafayette River, E. Glenn White

OES Theses and Dissertations

A basic investigation of the physical ~properties, temperature, density and current velocity, in the Lafayette River is presented. Graphs of the observations indicata a difference in salinity, density and current velocity- distributions after moderate to heavy rains from the graphs during a dry period. The changes in distribution indicate a change in the classification of the estuary from a type B/C, partially mixed estuary, to a type D, sectionally homogeneous estuary. The estuary is predominantly a well-mixed or sectionally homogeneous estuary.

Changes in salinity, temperature, density and current velocity over tidal cycles are discussed as well as tidal height data. …

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 …

Phytoplankton Composition At Lake Drummond In The Dismal Swamp, Virginia, William Howard Poore Jr.

Biological Sciences Theses & Dissertations

Abstract unavailable.

Analysis Of Littoral Transport By Wave Energy: Cape Henry, Virginia To The Virginia, North Carolina Border, Zvi Henry Weinman

OES Theses and Dissertations

An investigation of the rate of littoral transport by an analysis of wave energy for the area from Cape Henry, Virginia to the Virginia, North Carolina border is made. Wave refraction diagrams are done by digital computer. Total upcoast (northerly) transport is determined to be 2.05 x 10⁶ yds³/year. Total downcoast (southerly) transport is determined to be 1.07 x 10⁶ yds³/year. Net transport is determined to be 9.8 x 10⁵ yds³/year in an upcoast (northerly) direction. The values obtained are compared with those of similar areas. The general efficacy of the …

Observations On The Hydraulic Regime Of The Ridge And Swale Topography Of The Inner Virginia Shelf, Barry W. Holliday

OES Theses and Dissertations

The Virginia inner shelf is dominated by southwest-trending sand ridges. Wavelengths are 2 to 4 km; amplitudes are up to 10 m; crests can be traced for up to 10 cm, Nearshore ridges trend southwest into the shore face and merge with it at depths as shoal as 5 m. The ridges have been examined by bathymetric mapping, grab sampling, coring, seismic profiling, SCUBA diving, and current monitoring. They are hemi-cylindrical sand bodies of recent age, resting on a pre-recent substrate. In troughs a thin, medium- to coarse-gained, pebbly lag veneers the substrate. Crests consist of a better sorted, medium- …

An Evaluation Of An Electromagnetic Current Meter For Study Of Water Particle Motion, George Milton Hecker

OES Theses and Dissertations

A new sophisticated electromagnetic current meter was laboratory and field tested in a wide variety of applications, ranging from measurement of net bottom currents (primarily tidal origin) on the continental shelf, to horizontal and vertical components of wave induced orbital motion of waves with periods as small as one second.

These tests indicate that this instrument is capable of performing to at least the following specifications, subject to the comments which follow:

Speed range: Accuracy: Threshold: 0 to + 5 knots + 0.2 knots + 0.02 knots Response time: 0.25 sec. Direction: -+ 7 degrees Depth: '0 to 42 feet …

Erasure Of Sediment Surface Features By Mellita Quinquiesperforata (Leske), Walter Richard Boehmer

OES Theses and Dissertations

Erasure of sediment surface features by individuals of the species, Mellita guinguiesperforata, observed in this study suggests that all members of the sub-order, Scutellina, are able to erase sediment surface features. Sweep time, the time needed to erase the surface features of an area, depends on the population density, individual size, and speed of movement of the sand dollars. Assuming their pattern of movement as random, the following equation can be used to determine sand dollar sweep time,

T - 3.2 N^-0.76 (W / S) (A/ W² )^1.21

where T is sweep time, N is the …