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The Effects Of Dredged Material (Suspended Solid Phase) On The Hatching Success Of Spot Eggs (Leiostomus Xanturus), Meryl A. Masters

OES Theses and Dissertations

A 24-hour static bioassay was performed with the suspended solid phase of bottom sediment from a highly industrialized river utilizing eggs of the spot, Leiostomus xanthurus. Hatching success was measured at four concentrations of elutriates prepared from sediment obtained from the confluence of the eastern and southern branches of the Elizabeth River adjacent to the Norfolk Shipbuilding and Drydock in Norfolk, Virginia. Test results indicated no significant effect on hatching success at any of the four test concentrations.

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 …

Analysis Of Heavy Minerals In Arenaceous Lutites From The Northern Canada Basin, Arctic Ocean, Kim Zauderer

OES Theses and Dissertations

Heavy minerals from arenaceous lutites in three widely spaced cores from the northern Canada Basin were analyzed for the first time to determine the provenance of these sediments. The abundant minerals (sp. gr. == 2.70) in decreasing order for most samples were detrital carbonate, micas, clinoamphibole, clinopyroxene, garnet, epidote, tourmaline, and chlorite. The majority of pyroxene grains were etched. Sedimentary sources dominated and metamorphic and igneous sources were important but secondary. The northern Canada Arctic Archipelago and northern Greenland is proposed as the provenance for the heavy minerals in the arenaceous lutites for at least the past three million years. …

Morphological Variation Of The Foraminifer Elphidium Excavatum (Terquem) On Crumps Bank And Willoughby Bank, Chesapeake Bay, Virginia, Pamela Kay Painter

OES Theses and Dissertations

Six variants of the highly variable foraminiferal species, Elphidium excavatum (Terquem) were recognized in the Crumps Bank and Willoughby Bank areas of the southern Chesapeake Bay. Measurements of the size of the test, the number of chambers, the number of umbilical bosses, and the number and average length of the sutural bridges on the last formed chamber, and opaqueness or translucence of the test were made on 30 specimens from each of 36 stations selected for differences in environmental parameters. The measurements were statistically analyzed by discriminant analysis to test the hypothesis that the variants are distinct morphotypes and to …

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 …

A Comparison Of Recruitment Strategies Among Brachyuran Crustacean Megalopae Of The York River, Lower Chesapeake Bay And Adjacent Shelf Waters, David Franklin Johnson

OES Theses and Dissertations

Twenty-one stations forming a transect of the Pamunkey River, York River, lower Chesapeake Bay and adjacent coastal waters were sampled from July through September 1980. The megalopa stages of 11 brachyuran species were sampled. Vertical and horizontal distributions are described for each species in relation to salinity and water column stratification. The megalopae are assigned to three apparent recruitment strategies: retained estuarine, expelled estuarine and retained coastal megalopae. the megalopa stages of estuarine adults, such as Hexapanopeus angustifrons, Neopanope sayi, Panopeus herbstii and Pinnotheres ostreum, are retained in estuarine epibenthic waters, while Rhithropanopeus harrisii are retained in slightly shallower …

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 …

A Capacitance Wavestaff And Measurements Of Wave Height Decay In The Surf Zone, David L. Timpy

OES Theses and Dissertations

A wavestaff system utilizing capacitance was developed to measure wave heights in the surf zone. Data were used to test the assumption that wave height decays linearly across the surf zone. The instrument system consisted of two wavestaffs and housing which contained the needed electronic circuits and a data recorder. Acceptable frequency response for waves of period greater than two seconds could not be obtained if sensor wires were greater than 0.35 mm in diameter. The size used was 0.35 mm.

A Laboratory Study Of Nongenetic Embryonic Adaptation To Salinity And Its Subsequent Effects Upon Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthius, Paul Jay Anninos

OES Theses and Dissertations

Fertilized embryos of the grass shrimp Palamonetes pugio Holthuis (Decapoda; Caridea) were exposed to two levels of salinity [5 ppt (exposed) and 20 ppt (control)] during incubation to determine the extent to which embryonic adaptation influences subsequent larval development. Larval response to embryonic exposure was measured at three salinities (5 ppt, 10 ppt, and 20 ppt) as the fraction of larvae surviving to metamorphosis and the duration (in days) of larval development. The survival rate of larvae hatched from control, or non-adapted, embryos was significantly influenced by rearing salinity. The differences in survival of pre-adapted larvae (exposed group), however, were …

The Geology Of The Oceanographer Transform Fault, Richard H. Moody Jr.

Geology Theses and Dissertations

A detailed survey of the Oceanographer transform fault and environs at 35º N, 35ºW has yielded detailed information with respect to the generation and evolution of seafloor at a slowly accreting plate margin. From this data detailed bathymetric maps and maps of depth to basement have been constructed for a swath of seafloor 1800 km long and 100-200 km wide centered about the offset region. This data was used to subdivide major phases of seafloor spreading during the Tertiary. The ridge crest and all major topographic features near the transform appear to be affected by their proximity to the transform. …

Wave Refraction By Warm Core Rings, George R. Mapp

Dissertations, Theses, and Masters Projects

No abstract provided.

A Study Of Nutritional Requirements Of The Larvae Of The American Oyster (Crassostrea Virginica), Fu-Lin E. Chu

Dissertations, Theses, and Masters Projects

The purpose of this study is to obtain information for the formulation of artificial diets for larvae of the American oyster (Crassostrea virginica) and to test procedures related to presenting these diets to the oyster larvae. In order to determine the nutrient components usually provided in larval diets, biochemical analyses of lipids and fatty acids, proteins and amino acids and polysaccharide carbohydrates were performed on five algae species used as a food source for oyster larvae. These algae are Chlorella sp., Pyramimonas virginica, Pseudoisochrysis paradoxa, Pavlova (Monochrysis) lutheri and Isochrysis galbana. The biochemical analyses indicate that the nutritional value of …

The Distribution And Ecology Of Gammaridean Amphipods In The Plankton Of The Middle Atlantic Bight, Cathy J. Womack

Dissertations, Theses, and Masters Projects

No abstract provided.

Effects Of Disruptive Grazing By The Mud Snail Ilyanassa Obsoleta On Mudflat Nematode Populations, David Ludwig

Dissertations, Theses, and Masters Projects

Population densities of the mud snail Ilyanassa obsoleta were manipulated in caging experiments on a salt marsh mudflat and in laboratory microcosms. Mud snails outcompete nematodes for food resources, but may increase resources available to deposit feeding groups. Mud snails reduce annelid (polychaete and oligochaete) populations by substrate disruption. Reduced annelid densities provide the nematode community with some release from predation and competition. In mudflat sediments, the nematode community responds to both primary (predation) and secondary (envirorm1ental release, food competition) interactions. Multiple levels of interactive coupling should be considered in any systems level investigation in this habitat.

Zooplankton Communities In Chesapeake Bay Seagrass Systems, Cathy Elizabeth Meyer

Dissertations, Theses, and Masters Projects

No abstract provided.

Waterfowl Utilization Of A Submerged Vegetation (Zostera Marina And Ruppia Maritima) Bed In The Lower Chesapeake Bay, Elizabeth W. Wilkins

Dissertations, Theses, and Masters Projects

No abstract provided.

The Distribution Of Dissolved Silica And Particulate Biogenic Silica In The James, York And Rappahannock Estuaries, Virginia, Gary F. Anderson

Dissertations, Theses, and Masters Projects

No abstract provided.

Life History And Management Of Spiny Dogfish, Squalus Acanthias, Off The Northeastern United States, Marta Nammack

Dissertations, Theses, and Masters Projects

No abstract provided.

Utilization Of A Zostera Marina And Ruppia Maritima Habitat By Four Decapods With Emphasis On Callinectes Sapidus, Deborah L. Penry

Dissertations, Theses, and Masters Projects

No abstract provided.

Analysis Of Population And Price Aspects Of The Virginia Hard Clam (Mercenaria Mercenaria) Fishery, Andre C. Kvaternik

Dissertations, Theses, and Masters Projects

No abstract provided.

Two-Dimensional, Intratidal Model Study Of Salinity Intrusion Structure And Motion In Partially-Mixed Estuaries (Virginia), Carl F. Cerco

Dissertations, Theses, and Masters Projects

A two-dimensional, longitudinal-vertical model for partially-mixed estuaries has been developed. The model provides intratidal predictions of surface level, velocity, and salinity through a semi-implicit finite-difference solution to the continuity and momentum equations and an explicit finite-difference solution to the salinity equation. The model was verified through comparison with analytical solutions, laboratory data, and prototype data. Following verification, the model was used to simulate the destratification-stratification cycle which occurs in the James River Estuary, Virginia, coincident with the spring-neap tidal cycle. In a second application to the James, a simulation of the movement of the salinity intrusion following a storm-generated freshwater …

Influence Of Temperature On The Immune Response Of Juvenile Summer Flounder, Paralichthys Dentatus, And Its Role In The Elimination Of Trypanoplasma Bullocki Infections, Joseph P. Sypek

Dissertations, Theses, and Masters Projects

Two groups of juvenile summer flounder maintained at 5�C were experimentally infected with the hemoflagellate Trypanoplasma bullocki. Another group maintained at 5�C was not infected. The water temperature of one infected group was raised stepwise to 12�C, 18�C, and 24�C for 2 to 3 weeks at each level. The other infected group was maintained at 5�C for 12 weeks, the duration of the experiment. In addition, juvenile flounder were collected over a temperature range of 6�C to 22�C from February to June, 1982 to monitor natural infections. Live T. bullocki were incubated in plasma from fish at each temperature to …