Physical Sciences and Mathematics Commons^™

Rx For Success At Back Bay National Wildlife Refuge: Take Two Committed Partners-Add Water, Janet Taylor, Julia Herrick, Ben Mathias

V. Poster Abstracts

As part of a major effort to improve habitats for waterfowl and other wetland-dependent wildlife, Ducks Unlimited, Inc. is contributing $187,500 in matching funds to help the U.S. Fish and Wildlife Service rehabilitate wetland impoundments at Back Bay NWR.

The three-year project will increase Refuge management capabilities on existing wetland areas, create 300 acres of new marsh habitat and increase water management flexibility throughout the impoundment system. Components of the project include:

• Raising and re-sloping 8 miles of existing dikes
• Installing 13 new water control structures
• Constructing 6,000 feet of new dikes
• Creating two storage pools totalling 53 acres and …

Refuge Land Acquisition: Helping Preserve Back Bay's Wildlife Heritage, Julia Herrick, Ben Mathias, Janet Taylor

V. Poster Abstracts

The once-renowned waterfowl populations and bass fishery of Back Bay, Virginia have declined dramatically in recent years. Lands surrounding Back Bay are increasingly threatened by on-going and potential land development. These lands serve as an important filter for pollutant and sediment-laden runoff from adjacent areas. The boundary of the Back Bay National Wildlife Refuge was expanded in 1989 to include an additional 6,340 acres of brackish marsh, forested swamp, and "critical edge" upland habitat, important to a variety of wildlife species and for its natural filtering effect. Within the U.S. Fish and Wildlife Service's policy of working with willing sellers, …

Hydrogeology And Water Budget Analysis Of Two Interdunal Ponds Nags Head Woods Ecological Preserve, Dare County, North Carolina, Richard A. Hisert

OES Theses and Dissertations

Ground-water-fed interdunal ponds in Nags Head Woods Ecological Preserve lose as much as 7600 m³ yr^-1 of water through evaporation. This withdrawal of groundwater is sufficient to significantly alter flow patterns through the surficial aquifer on Bodie Island, N.C. Statistical analyses of evaporation estimates derived by various methods indicate a weak correlation, (r²=0.4-0.5) between pan evaporation data from Aurora, N.C. and pond evaporation at Nags Head Woods calculated by water budget analyses.

Results of stratigraphic and pedologic analyses in and around the ponds indicate that the ponds formed after development of multiple generations of dunes. This …

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White

OES Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. The mud crab Rhithropanopeus harrisii was exposed to varying concentrations of Nap or B[a]P to determine the effects on reproductive success, embryological development, larval physiology and mortality. Nap and B[a]P decreased hatching success and prolonged embryological development. Both pollutants produced high abnormality frequencies for egg exposed larvae. Molt frequency and respiratory rates of larvae from non-exposed eggs were more chronically affected by these pollutants than were egg exposed larvae. The EC₅₀ concentrations were determined for …

The Hydrogeology And Leachate Generation Of An Alum Sludge Lagoon Chesapeake Virginia, Charles M. Darling

OES Theses and Dissertations

In 1986 the City of Chesapeake, Virginia began to dig shallow ponds ("lagoons") to contain alum sludge, a waste generated by the City from the process of treating potable water. Borings at the disposal site reveal that the near-surface geologic units include a thin mud-rich facies which overlies a thick sandy facies, both of which are in the Lynnhaven Member of the Tabb Formation. At 7 meters depth, a clay-rich facies of the Yorktown Formation (Morgarts Beach Member?) underlies the sandy water table aquifer. Water levels from twenty observation wells and two monitoring wells installed into the water table aquifer …

The Effect On Earth's Surface-Temperature From Variations In Rotations Rate, Continent Formation, Solar Luminosity, And Carbon Dioxide, William R. Kuhn, J. C.G. Walker, Harold G. Marshall

Biological Sciences Faculty Publications

Proposed evolutionary histories of solar luminosity, atmospheric carbon dioxide amounts, Earth rotation rate, and continent formation have been used to generate a time evolution of Earth's surface temperature. While speculative because of uncertainties in the input parameters, such a study does help to prioritize the areas of most concern to paleoclimatic research while illustrating the relationships and mutual dependencies. The mean temperature averages about 5 K higher than today over most of geologic time; the overall variation is less than 15 K. The evolution of Earth's rotation rate makes a significant contribution to the surface temperature distribution as late as …

Reactions Of Organic N-Chloramines In The Gastric Fluid Of The Rat, Kathryn E. Mazina

Chemistry & Biochemistry Theses & Dissertations

Using chlorine as a drinking water disinfectant may have potential health effects due to its reactivity with organic amino nitrogen compounds found in the stomach. Organic N-chloramines have been shown to form in the stomachs of laboratory rats. The possible reactions of N-chloramines in the stomach fluid were examined in this study using a model radiolabeled N-chloramine. ³⁶Cl-N-Chloropiperidine, was synthesized and purified to remove ³⁶Cl-chloride. Stomach fluid was obtained from Sprague-Dawley rats which had been first fasted for 24 or 48 hours and then administered 3 mL of deionized water. Different concentrations of radiolabeled chloramine were reacted with …

Determination Of Amino Acids And Chloramino Acids In Municipal Wastewater, Jeffrey Taylor Jewell

Chemistry & Biochemistry Theses & Dissertations

It is well known that unchlorinated municipal wastewater contains high levels of organic and inorganic amino nitrogen compounds, the single most abundant amino-N species being ammonia. Upon chlorination, these compounds are transformed almost instantaneously and quantitatively into N-chloramino derivatives. The organic chloramines have been shown to

interfere with disinfection and have lower disinfection capacities than their inorganic counterpart monochloramine. The environmental effects imposed by the discharge of these compounds into natural receiving waters is unknown. This study has shown that amino acid precursors for N-chloramino acids range in concentration from 1.4 X 10^-7 M to 9.0 X 10^{-7 …}

Acceleration Of Nutrient Uptake By Phytoplankton In A Coastal Upwelling Ecosystem: A Modeling Analysis, Richard C. Zimmerman, James N. Kremer, Richard C. Dugdale

OES Faculty Publications

Studies of upwelling centers in the eastern Pacific suggest that maximum rates of nitrate uptake (light and nutrient saturated) increase, or shift-up, as newly upwelled water moves downstream. The rate of shift-up appears to be related to irradiance and the ambient concentration of limiting nutrient at the time of upwelling. A mathematical model was developed to evaluate effects of irradiance and initial nitrate concentration on temporal patterns of shift-up and subsequent time scales of nutrient utilization over a range of simulated upwelling conditions. When rates consistent with field studies were used, complete shift-up was possible only under certain conditions, and …

Fracture Detection In A Volcanic Oil Reservoir Using Discriminant Analysis Of Well Log Data, Joseph William Cross

OES Theses and Dissertations

A new method of detecting fractures using well logs is presented. The technique uses discriminant analysis to distinguish fractured from unfractured reservoir rock and was developed for the volcanic pay zone of Jatibarang oilfield, West Java, Indonesia.

The a priori information required to derive the discriminant function was provided by 22 wells known to penetrate intervals of either fractured or unfractured volcanics. The samples consisted of these 22 intervals digitized in one-meter increments (1256 meters total thickness). The discriminating variables were the petrophysical measurements made by 10 different types of well logs.

Discriminant analysis correctly classified 94.2% of the total …

Leachate Monitoring In Naturally Saline Groundwater Chesapeake Landfill Chesapeake Virginia, T. Britt Mcmillan

OES Theses and Dissertations

Groundwater chemistry around the Chesapeake municipal landfill was monitored over a one year period. Ten sample sites as well as two surface water sites were used to monitor water quality. Two wells, one at 3 m and the other at 10 m were located at each site. Surface water samples were taken from the Elizabeth River, north of the landfill, and a tidal channel, west of the landfill. Seven groundwater sites were downgradient of the landfill and three sites were upgradient (control sites).

The landfill overlies a tidal marsh, approximately 100 m south of the intracoastal waterway (Elizabeth River). Dredge …

Community Ecology, Robert K. Rose, Elmer C. Birney

Biological Sciences Faculty Publications

COMMUNITIES with Microtus tend to be structurally simple, usually grasslands or tundra, and to have no more than two species of Microtus and rarely more than six species of small mammals. Microtus often dominates both numerically and in total small mammal biomass, especially at higher latitudes. The small mammal community is most influenced by Microtus through its fluctuations in density, and thus also in biomass, by its relatively high level of diurnal activity, and by its year-round activity. Other species of small mammals may be adversely affected because Microtus usually is larger and behaviorally dominant and also because the mere …

Effects Of El Nino On Local Hydrography And Growth Of The Giant Kelp, Macrocystis Pyrifera, At Santa Catalina Island, California, Richard C. Zimmerman, Deborah L. Robertson

OES Faculty Publications

Deepened isotherms associated with El Niño resulted in severe nutrient limitation and very low kelp productivity during the last half of 1983. Frond growth rates were so low that terminal blades formed before reaching the surface, eliminating the canopy. Frond initiation rates were also extremely low, resulting in significant reductions in mean plant size. Plants growing above 10m were more severely affected than plants at 20m. Nutrient pulses associated with internal waves are thus critical for survival of Macrocystis pyrifera in nutritionally marginal habitats in Southern California.

Breeding Birds In Cedar Stands In The Great Dismal Swamp, Karen A. Terwilliger, Robert K. Rose

Biological Sciences Faculty Publications

The Great Dismal Swamp located in the coastal plain on the Virginia- North Carolina border, has long been recognized as a vegetationally distinctive region with many unusual geological and biological features. Formerly at least twice the currently estimated size of 85,000 hectares (Carter 1979), the Great Dismal Swamp is still shrinking because of a dropping water table caused by more than 200 years of logging, ditching, and other human activities. In 1973, the Union Camp Corporation donated a 19,871-hectare tract located near Suffolk, Virginia. to The Nature Conservancy, which transferred the land to the U.S. Fish and Wildlife Service. This …

Changes In The Lower Chesapeake Bay Food-Chain In Presence Of The Sea Nettle Chrysaora-Quinquecirrha (Scyphomedusa), David Feigenbaum, Michael Kelly

OES Faculty Publications

The abundance of 4 levels of the lower Chesapeake Bay food chain (Chlorophyll a, herbivores, ctenophore Mnemiopsis leidyi, and Scyphomedusa Chrysaora quinquecirrha) were moni­tored twice weekly at 4 stations from May 10 through Sep 30, 1982 in the Lafayette and Elizabeth Rivers (Virginia). The herbivore standing stock, largely copepods, declined sharply in late May when M. Jeidyi appeared, but rebounded a month later when C. quinquecirrha medusae reduced the ctenophore population. Despite the additional presence of Aurelia aurita (Scyphomedusa) from Jul onward, herbivore abundance remained at moderate levels until the end of the study period. Phytoplankton abundance fluctuated …

The Effects Of Dredged Materials On The Copeod, Acartia Tonsa, Renee Suzanne Crouch

Biological Sciences Theses & Dissertations

A study was conducted to determine the potential impact of open ocean disposal of sediments dredged from a highly industrialized seaport. Sediments from three potential dredge sites along the Southern Branch of the Elizabeth River, Hampton Roads, Virginia were evaluated for acute toxicity. The suspended particulate fractions of dredged materials were tested in a series of 96-hour, static bioassays using the calanoid copepod, Acartia tonsa Dana. Significant mortalities were observed for all three sites with the sediments from the most heavily industrialized site producing immediate and severe mortality. Analysis of results indicates that mortality was highly related to the volatile …

Polychlorinated Biphenyl Levels In The Ocean Scallop (Placopecten Magellanicus) Gmelin From The Philadelphia Sewage Sludge Disposal Site, Guy Jeffrey Hall

OES Theses and Dissertations

Ocean Scallops (Placopecten magellanicus) were sampled from stations in and around the Philadelphia Disposal Site. Each sample was dissected and aliquots of adductor muscle and reproductive tissue were chemically extracted for Polychlorinated Biphenyls (PCBs). A perchlorinated procedure outlined by Diosady et al., 1972, Aromour, 1973 and Crist et al., 1977 was employed to increase detection levels and simplify quantitation of PCBs. PCB levels were reported in dry weight and lipid weight of both adductor muscle and reproductive tissue. Findings indicated residual levels or PCB/lipid weight increased as lipid levels decreased in both tissue types. Levels detected in all adductor muscle …

Input And Distribution Of Sewage Derived Sedimentary Material Adjacent To Chesapeake-Elizabeth Sewage Outfall, Virginia Beach, Virginia, Robert Carroll Brown

OES Theses and Dissertations

The concentrations of coprostanol and hydrocarbons were measured in the effluent from the Chesapeake-Elizabeth sewage treatment plant and surface sediments from the area surrounding the effluent discharge site. Most of the coprostanol (>84%) and hydrocarbons (>91%) were associated with particulates in the effluent. Some of these particles were incorporated into the sedimentary column within the study area, while some may have escaped from the area.

The study area is found to be a dynamic area where changes in the percentage and distribution of fine-grained sediments occur over periods of months. The movement of fine-grained sediments is an important …

Environmental Influence On The Migratory Behavior Of The Brown Shrimp In Pamlico Sound North Carolina, Michael Andrew Matylewich

OES Theses and Dissertations

Environmental conditions in the nursery areas during times of development affect the migratory behavior of the brown shrimp (Penaeus aztecus) by influencing growth and natural mortality. A linearized logistic model and a multiple linear model are used to relate environmental factors (week number, water temperature, salinity, air temperature, precipitation, net heating degree days, river discharge) to the cumulative proportion of catch and catch-per-unit-effort, respectively. Multiple regression analysis yielded equations containing the week number, the water temperature and an interaction term as the independent variables. Predictions of total annual yield and total annual catch-per-unit-effort are made using the migratory …

Some Effects Of The Polychaete Nereis Succinea Frey And Leukart 1847 On The Distribution Of Copper Cadmium And Zinc In Sediments And Water, Gabriela Kitzig August

OES Theses and Dissertations

Two laboratory experiments, each lasting 216 hours, were conducted in order to determine the effects of a burrowing polychaete, Nereis succinea Frey and Leukart, 1847, on the distribution of copper, cadmium, and zinc in sediments and water in environmentally controlled microcosms. Dissolved metal concentrations in microcosms containing worms (experimental) decreased more rapidly than in microcosms without worms (controls). From 72 hours to 216 hours, suspended metal concentrations in experimental microcosms increased while concentrations in controls remained relatively constant. Sediment cadmium concentrations in experimental microcosms increased more over time than in controls. Polychaetes accumulated significant amounts of all three metals. These …

The Effects Of Kepone On The Estuarine Copepod Acartia Tonsa, Judith Marie Wilson

Biological Sciences Theses & Dissertations

Due to the contamination of a 113 km reach of the James River, Kepone poses a serious environmental threat to the Chesapeake Bay. The purpose of the study is to determine the acutely toxic and sublethal levels of kepone for the copepod Acartia tonsa, and to investigate what effects those levels may have on filtration rates.

Kepone was determined to be acutely toxic to A. tonsa, with a 96 hour LC50 of 4.96 ug/1. Dunaliella tertiolecta was selected as the food source for the grazing experiments. Kepone concentrations of 0.046 ug/1 significantly (0.05 level) reduced the flltering rate …

Analysis Of Organic N-Chloramines In Chlorinated Drinking Water, John Po Wen Yang

Chemistry & Biochemistry Theses & Dissertations

This thesis describes the development of a sensitive method for the separation and quantitation of organic N-chloramines in chlorinated tap water. 5-Dimethylaminonaphthalene- l-sulfinic acid has been synthesized and characterized. It yields highly fluorescent dansyl derivatives on reaction with N-chloramines. Conditions of the derivatization were optimized for the detection of N-chloropiperidine at concentrations in aqueous solution of 10^-7 M. The technique gives a quantity of derivative which is proportional to the concentration of chloramine present over the range examined (10^-7 M to 10^-4 M). High pressure liquid chromatographic separation of dansyl derivatives of amines and amino acids has …

The Temporal And Spatial Distribution Of Hydrocarbons In Atmospheric Deposition From Stations Surrounding Lower Chesapeake Bay, David Benjamin Webber

OES Theses and Dissertations

Hydrocarbon concentrations were determined in bulk, wet, and dry deposition samples from urban and non-urban locations surrounding lower Chesapeake Bay. Mean hydrocarbon concentrations in bulk deposition samples were over three times greater at the urban station indicating a localized source. The major hydrocarbons present were n-alkanes, polycyclic aromatic hydrocarbons (PAH), and the unresolved complex mixture (UCM). The PAH and the UCM were an indication of significant anthropogenic inputs while the odd/even distribution of the n-alkanes was an indication of biogenic sources. These findings indicated seasonal trends of highest biogenic hydrocarbon inputs in the spring and summer months and highest anthropogenic …

Petroleum-Utilizing Bacteria: The Biological Line Defense Against Oil Pollution, Steven W. Sokolowski

Biological Sciences Theses & Dissertations

A silica gel-petroleum (SGP) medium was developed which is reliable, approximately the same cost as that of the corresponding agar-based petroleum medium, and can be made sufficiently firm to use in streaking or the spread-plate technique. Advantages of the medium include: the incorporation of all of the major ions of seawater in accordance with Dittmar's Law (the salinity of which can easily be varied from 0 to 35 parts per thousand); a wide workable pH range (5.5 to 11.6); negligable pH drift(~ 0.2 pH units after 166 days); the elimination of all but negligable amounts of syneresis, the ability to …

Role Of Gulf Stream Frontal Eddies In Forming Phytoplankton Patches On The Outer Southeastern Shelf, James A. Yoder, Larry P. Atkinson, Thomas N. Lee, Hongsuk H. Kim, Charles R. Mcclain

CCPO Publications

Continuous surface mapping of temperature, salinity, and chlorophyll along a 300-km segment of the Gulf Stream cyclonic front defined the spatial scales of a large diatom patch that persisted throughout a 10-day study. The patch was localized in the upwelled cold core of a Gulf Stream frontal eddy centered over the 200-m isobaths off Jacksonville, Florida, in April 1979. The µ g liter^-1 surface chlorophyll isopleth enclosed an area >1,000km² with an alongshore dimension of 130km. Surface chlorophyll exceeded 5µg liter^-1 within the upwelled cold core of the eddy, 10-100X higher than concentrations in Gulf Stream or …

Litter Production And Nutrient Content Of Litter In The Seasonally Flooded Dismal Swamp, Marta M. Gomez

Biological Sciences Theses & Dissertations

Litter production was studied in four plant communities in the Great Dismal Swamp, Virginia, that differ primarily in species composition and flooding regime. Greatest leaf deposition occurred in the more flooded communities, maple-gum (Acer-Nyssa) with 536 g m^-2 yr^-1 and cypress (Taxodium distichum (L.) Richard) with 528 g m^-2 yr^-1, followed by the cedar (Chamaecyparis thyoides (L.) BSP) and mixed hardwood (Quercus-Acer-Nyssa-Liquidambar) communities with 506 g m^-2 yr^-1 and 455 g m^-2 yr^-1, respectively. Litter nutrient concentrations were generally higher in the cypress and maple-gum stands, indicating greater nutrient availability …

Phytoplankton Studies Within The Virginia Barrier Islands I. Seasonal Study Of Phytoplankton In Goose Lake, Parramore Island, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton of Goose Lake, an oligohaline lake on Parramore Island, was studied for one year. The populations consisted primarily of ultraplankton and nanoplankton-sized forms with diatoms and chlorophyceans dominant most of the year. A general pattern of seasonally higher cell concentrations in early summer and fall was noted, with an unidentified ultraplankton-sized component prominent throughout the collection period. A list of 154 species is given.

Additional Comments On Reproductive Strategies And Population Fluctuations In Microtine Rodents, Michael S. Gaines, William M. Schaffer, Robert K. Rose

Biological Sciences Faculty Publications

Recently, Schaffer and Tamarin (1973) proposed a model relating changes in reproductive effort (RE) to fluctuating densities in microtine rodents (lemmings and voles). They assumed (and presented data supporting this assumption) that the major effect of increased crowding would be a reduction in survival among prereproductives, thereby lowering the effective fecundity (Schaffer and Rosenzweig 1977) of their parents. As a consequence, Schaffer and Tamarin argued that the optimal reproductive expenditure, E(N), should decline with increasing population size, N. They also deduced the shape of the zero-growth isocline, N*(E), for differing levels of RE and plotted both E(N) and N*(E) on …

Conservation According To The Pure Theory Of Exhaustible Resources, George Lymbouris

Economics Theses & Dissertations

The objective of this thesis is to develop a theory for defining optimal conservation and applying definition to the prevailing rate of domestic petroleum production. Optimal conservation is defined as action designed to achieve or to maintain, from the point of view of society as a whole, the maximum present value of natural resources (or of a natural resource). The proper "action" is defined according to the pure theory of exhaustible resources. The literature survey is a chronological series of articles concerning this theory.

Through building a model which shows that optimal conservation occurs when the marginal internal rate of …

A Seasonal Study Of Phytoplankton Composition Abundance And Productivity In Back Bay, Virginia, Robert Ringgold Comegys

Biological Sciences Theses & Dissertations

Phytoplankton samples were collected monthly (August 1974-June 1975) at two stations in the Back Bay system of southeastern Virginia. Measurements of phytoplankton productivity and potentially influencing environmental parameters (water and air temperature, turbidity, depth, pH, salinity, dissolved oxygen) accompanied sample collections. A total of 106 phytoplankton species, representing six algal divisions and 54 genera were identified. Cyanophyta species were dominant at both stations in the warmer months of August, September, October, and June, and in April at one station only. In all remaining months, Chlorophyta species were dominant, indicating a seasonal shift in phytoplankton composition during winter and spring. The …