Physical Sciences and Mathematics Commons^™

Public Beach Assessment Report Gloucester Point Public Beach, Gloucester County, Virginia, Donna A. Milligan, C. Scott Hardaway Jr., George R. Thomas

Reports

Gloucester Point Public Beach is located at the southern end of Gloucester County, Virginia on the York River. It is a southeastward facing shoreline about 960 ft long and it is part of a larger stretch of moderately low shore between Sarah Creek and the George P. Coleman Bridge. While no shoreline improvement projects have taken place at the public beach, shore protection projects updrift and including the Virginia Institute of Marine Science (VIMS) affect it. In 1983, erosion along the shoreline at VIMS just updrift of the public beach led to the installation of a riprap revetment in front …

1996 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Effects Of Channel Geometry On Cross Sectional Variation In Along Channel Velocity In Partially Stratified Estuaries, Carl T. Friedrichs, John M. Hamrick

VIMS Books and Book Chapters

Analytic solutions for along‐channel velocity through an estuarine cross‐section with laterally varying depth are compared to observations from an array of current meters deployed over a nearly triangular cross‐section of the James River estuary. Analytic results suggest that the transverse structure of along‐channel velocity at this cross‐section is primarily due to simple density‐driven circulation modified by bathymetry. Comparisons of analytic solutions for the amplitude and phase of tidal velocity to observations suggest that linear models which include realistic lateral depth variation should also incorporate across‐channel variation in eddy viscosity. Solutions for various contributions to mean velocity are then derived which …

1996 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Effects Of Periodic Environmental Hypoxia On Predator Utilization Of Macrobenthic Infauna, Janet A. Nestlerode

Dissertations, Theses, and Masters Projects

Hypoxia and anoxia have significant deleterious ecological effects on living resources throughout many estuarine and marine ecosystems worldwide. Brief periods of low oxygen facilitate transfer of benthic production to higher trophic levels as many benthic infaunal species have shallower sediment depth distributions during hypoxic events. A baited time-lapse camera equipped with a water quality datalogger was used to document in situ exploitation of oxygen-stressed benthic invertebrate prey organisms by mobile fish and crustacean predators during alternating normoxia-hypoxia cycles in the York River. Based on photographic and diver observations, this hypoxiainduced benthic-pelagic transfer of production is more likely to occur when …

Perkinsus Marinus Extracellular Proteases: Modulation Of Production By Environmental Factors And Effects On The Host Defense Parameters Of The Eastern Oyster Crassostrea Virginica, Kathleen A. Garreis

Dissertations, Theses, and Masters Projects

No abstract provided.

Temporal Variablity Of The Pycnocline In The Mid-Chesapeake Bay, Linda Jane Frizzell-Makowski

Dissertations, Theses, and Masters Projects

Mixing and dispersion in a partially mixed estuary are driven by, among other processes, the gravitational circulation, wind-events and tides. These processes are important in the vertical and horizontal distribution and exchange of salinity, oxygen, nutrients, and organisms. The objective of this research was to examine the temporal variability of the pycnocline in the mid-Chesapeake Bay in response to forcing at subtidal and higher frequencies as observed in the spring of 1993. The largest change in the pycnocline was associated with meteorological forcing. Up-Bay wind stress and subsequent abatement of the wind stress produced a 5 meter displacement of the …

Growth Dynamics Of A York River Estuary Heterotrophic Dinoflagellate Grazing Katodinium Rotundatum, Angela Denise Smith

Dissertations, Theses, and Masters Projects

No abstract provided.

Variational Inverse Methods For Transport Problems, Zhaoqing Yang

Dissertations, Theses, and Masters Projects

Variational inverse data assimilation schemes are developed for three types of parameter identification problems in transport models: (1) the tracer inverse for the Lagrangian mean transport velocity in a long-term advection-diffusion transport model; (2) determination of inflow salinity open boundary condition in an intra-tidal salinity transport model; and (3) determination of settling velocity and resuspension rate for a cohesive sediment transport model. The gradient of the cost function with respect to the control variables is obtained by the adjoint model. A series of twin experiments are conducted to test the inverse models for the three types of problems. Results show …

Temporal And Spatial Patterns In The Ross Sea: Phytoplankton Biomass, Elemental Composition, Productivity And Growth Rates, Walker O. Smith Jr., David Nelson, Giacomo R. Ditullio, Amy R. Leventer

VIMS Articles

The temporal and spatial patterns of phytoplankton biomass, productivity, and particulate matter composition in the Ross Sea were assessed during cruises in January 1990 and February 1992. Biomass and primary productivity in the southern Ross Sea were greatest during mid-January, with surface chlorophyll concentrations, particulate organic carbon levels, and integrated primary productivity averaging 4.9 Ixg L 'l, 0.54 mg L-•, and 2.63 g C m"• d '•, respectively. Comparable mean concentrations and rates for February were 1.1 Ixg L 'l, 0.29 mg L 'l, and 0.78 g C m '•- d '• (decreases of 76, 46, and 70%, respectively), indicative …

Linking Sediment Transport And Stratigraphy On The Continental Shelf, Pl Wilberg, Da Cacchione, Rw Sternberg, L. Donelson Wright

VIMS Articles

The goal of the shelf sediment dynamics component of STRATAFORM is to link sediment transport processes active on the continental shelf to the formation and preservation of event beds in shelf sediment deposits. An approach combining shelf sediment-transport models with high-resolution measurements of water-column and bed properties over periods from several months to several years allows us to make quantitative estimates of bed modification caused by sediment resuspension during episodic transport events. These modifications include erosion and deposition of bed material, formation of graded storm beds, and changes in small-scale bed surface morphology. The characteristics of the resulting “event bed” …

Contributions To The Life History Of Juvenile Blueback Herring (Alosa Aestivalis): Phototactic Behavior And Population Dynamics, Douglas A. Dixon

Dissertations, Theses, and Masters Projects

This research investigated the relationship between juvenile abundance indexes (JAIs) for anadromous blueback herring (Alosa aestivalis) and abiotic factors (river flow and temperature) during the spawning and nursery period in the tidal freshwater areas of James, Pamunkey, Mattaponi, and Rappahannock Rivers in Virginia. Accomplishing this objective required the evaluation of the JAI methodology, specifically the effect of phototactic behavior on diel changes in the surface availability to the pushnet sampling gear, and obtaining population dynamics information (hatch dates, growth, natural mortality) during early life history from otolith microstructure of samples collected in 1991 and 1992. Mean catch-per-unit effort (CPUE) at …

Demersal Predator Exposure To Toxic Organic Contaminants: Direct Effects Of Macrofauna In Trophic Transfer, Patrick Winfield Lay

Dissertations, Theses, and Masters Projects

The bioaccumulation and metabolism of organic contaminants (PAH, PCB) by three estuarine polychaetes, Nereis succinea (Frey and Leuckart 1847), Paraprionospio pinnata (Ehlers 1901) and Polydora ligni (Webster 1879), and by the fish predator, spot (Leiostomus xanthurus Lacepede 1802), were examined in laboratory experiments. Variations in trophic transfer of these contaminants resulting from differences in prey and contaminant type were also investigated. Toxicokinetic modeling reveals that metabolism of organic contaminants by invertebrate species result in variations in uptake, metabolism and elimination rate constants. Incorporation of prey metabolism potential in kinetic models increases the latter's predictability of biota-sediment accumulation factors (BSAFs), or …

Fate And Transport Processes For Polycyclic Aromatic Hydrocarbons In The Surface Microlayer Of Southern Chesapeake Bay, Kewen Liu

Dissertations, Theses, and Masters Projects

Surface microlayer (SM) samples were collected with a rotating cylinder sampler from the York and Elizabeth River estuaries of southern Chesapeake Bay every other month from May 1994 through June 1995. Total suspended particle concentration (TSP) concentrations in the SM were found to be up to 1000 times higher than in the corresponding subsurface water, and to be exponentially associated with the wind speed at sampling. A relatively larger POC/TN ratio in the Elizabeth River SM compared with that in the York River SM was also observed. No seasonal trends were noticed in the SM characteristics; however, TSP, POC, and …

The Role Of Microbial Food Webs In Benthic-Pelagic Coupling In Freshwater And Marine Ecosystems, Adele J. Pile

Dissertations, Theses, and Masters Projects

A majority of carbon in freshwater and marine ecosystems is in the form of ultraplankton, heterotrophic and autotrophic plankton &<&5 &\mu&m including heterotrophic bacteria, Prochlorococcus, cyanobacteria, and autotrophic eucaryotes. However, ultraplankton and subsequently microbial food webs have yet to be incorporated into models of benthic-pelagic coupling despite the preponderance of macroinvertebrates with the capacity to feed on ultraplankton. I have examined the role of microbial food webs in benthic-pelagic coupling in three ecosystems: Lake Baikal, Siberia, Russia; Gulf of Maine, Northwest Atlantic Ocean; and Conch Reef, Florida Keys, USA. Using sponges as a model organism and in situ measurements, I have quantified (1) suspension feeding on ultraplankton and (2) release of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) resulting in direct evidence that benthic macroinvertebrates do occupy the level of primary consumer within the microbial food web. Dual-beam flow cytometry was employed to quantified sponge suspension feeding on five types of ultraplankton: heterotrophic bacteria, Synechococcus-type cyanobacteria, autotrophic picoplankton &<&3 &\mu&m, autotrophic eucaryotes 3-10 &\mu&m, and in marine ecosystems Prochlorococcus. Grazing by the freshwater sponges Baikalospongia intermedia and B. bacilliferia and the boreal marine sponge, Mycale lingua, was unselective for all types of ultraplankton with efficiencies ranging from 63-99%. This is the first time that grazing on Synechococcus-type cyanobacteria and Prochlorococcus by macroinvertebrates has been quantified in freshwater and marine ecosystems. Conversely, the coral reef sponges Ircinia felix and I. strobilina release significant amounts of DIN and DIP as a result of grazing on procaryotic plankton. Using a general model for organism-mediated fluxes, it is conservatively estimated that through active suspension feeding sponges in Lake Baikal retain 1.97 g C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and M. lingua retains 29 mg C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& while at Conch Reef sponges released 204 &\mu&mol DIN day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and 48 &\mu&mol DIP day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}&. A majority of the carbon retained at all three locations was from procaryotic cell types suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.

Gaseous Flux And Distribution Of Polycyclic Aromatic Hydrocarbons Across The Air-Water Interface Of Southern Chesapeake Bay, Kurt E. Gustafson

Dissertations, Theses, and Masters Projects

Gaseous fluxes of polycyclic aromatic hydrocarbons (PAHs) across the air-water interface of Southern Chesapeake Bay were calculated for the period January 1994 through May 1995 using a modified two-film model. Additionally, the distributions of PAHs between the vapor and aerosol phase in the atmosphere, and between the freely dissolved and suspended particulate phase in the water column were investigated. Net instantaneous gaseous fluxes of PAHs were determined to vary in direction and magnitude both spatially and temporally across the air-water interface of Southern Chesapeake Bay at four sites ranging from remote to urban and highly industrialized. The magnitude of gas …

Modeling Storm-Induced Sediment Transport On The Inner Shelf: Effects Of Bed Microstratigraphy, Baeck Oon Kim

Dissertations, Theses, and Masters Projects

Sediment transport during a storm event on the inner continental shelf was detailed through the development of models based on field experiments conducted at Duck, North Carolina in October 1994. A vertical one-dimensional model (1DV model) was developed by coupling the Grant and Madsen (1986) model with bed stratigraphy to consider real seabeds. Sediment was divided into seven size classes and fractional transport was estimated. Mixing depth and total depth from a simplified sediment conservation equation provided the basis for changing bottom sediment, sediment availability for transport, and armoring processes. These processes involve a feedback between hydrodynamics and bed stratigraphy. …

Age, Growth, And Reproductive Biology Of Blackcheek Tonguefish, Symphurus Plagiusa (Cynoglossidae: Pleuronectiformes), In Chesapeake Bay, Virginia, Mark Richard Terwilliger

Dissertations, Theses, and Masters Projects

No abstract provided.

Habitat Complexity As A Determinant Of Juvenile Blue Crab Survival, Jessica L. Schulman

Dissertations, Theses, and Masters Projects

No abstract provided.

The Development Of Affinity Maturation In Rainbow Trout Oncorhynchus Mykiss, Ing Wei Khor

Dissertations, Theses, and Masters Projects

No abstract provided.

Lipid Class Composition Of Oysters, Crassostrea Virginica, Exposed To Sediment-Associated Pahs, Tong Li

Dissertations, Theses, and Masters Projects

No abstract provided.

A Comparison Of Natural And Laboratory Diets For The Culture Of Marine Invertebrate Larvae American Oyster, Crassostrea Virginica, Queen Conch, Strombus Gigas, And Milk Conch, Strombus Costatus, Sandra Dawn Brooke

Dissertations, Theses, and Masters Projects

No abstract provided.

Autoecology Of Paraprionospio Pinnata (Polychaeta: Spionide) Along An Estuarine Gradient, Elizabeth K. Hinchey

Dissertations, Theses, and Masters Projects

No abstract provided.

The Influence Of Location, Seagrass Species And Water Depth On The Settlement And Distribution Of Early Stage Blue Crabs, Renee A. Pardieck

Dissertations, Theses, and Masters Projects

No abstract provided.

The Effects Of A Regulatory Gear Restriction On The Harvest Of The Recruiting Year Class In The Offshore Sea Scallop, Placopecten Magellanicus, Fishery, Jeffrey C. Brust

Dissertations, Theses, and Masters Projects

No abstract provided.

Exchanges Of Dissolved Inorganic Nitrogen And Dissolved Organic Carbon Between Salt Marsh Sediments And Overlying Tidal Water, Betty Berry Neikirk

Dissertations, Theses, and Masters Projects

No abstract provided.

An Analysis Of The Effects Of Sea Level Rise On The Salt Marshes Of Cape Hatteras National Seashore, North Carolina, Christopher Robert Perle

Dissertations, Theses, and Masters Projects

No abstract provided.

Hydrodynamics Of Sediment Suspensions In The Littoral Zone Of The Lower York River - Phase Ii, John D. Boon

Reports

This report covers the second year (Phase II) of a two-year study. An earlier contract report (Boon,1996) was submitted in January, 1996, to the Virginia Coastal Resources Management Program covering the first year (Phase I) results of a wave , current and suspended sediment monitoring study conducted at the mouth of the York River (Figure 1).

The purpose of the monitoring study , as originally planned , was to investigate processes governing sediment suspension within the shallow waters of the littoral zone (depths< 2m) in coastal estuaries. These are regions in which bottom sediment, in the absence of vegetative cover and depending on sediment grain sizes present, has the potential to be actively eroded and entrained in the water column by wind waves and/or currents. Suspended sediment has the further potential to impact water quality and promote eutrophication through nutrient enrichment processes (Kemp et al., 1983; Orth and Moore, 1983). High sediment loadings also lead to light reduction in the photic zone which can impact the growth or survival of submerged aquatic vegetation (De Groot and de Jonge, 1990) .

The Role Of Epibenthic Predators In Structuring Marine Soft-Bottom Communities Along An Estuarine Gradient, Rochelle D. Seitz

Dissertations, Theses, and Masters Projects

A unifying theory of community regulation in soft-bottom systems remains elusive, despite extensive field studies on factors controlling community structure. Here, I have (1) reviewed models of community regulation, (2) examined the role of predation in controlling benthic diversity along a salinity gradient, (3) examined effects of predation upon an abundant bivalve, Macoma balthica, and (4) revised a model of community regulation in an estuarine soft-bottom system. The Menge and Sutherland (MS) "consumer stress model" posits that consumers feed ineffectively in harsh environments, and the importance of physical disturbance, competition and predation varies with recruitment, environmental conditions, and trophic position. …

Water Quality Modeling As An Inverse Problem, Jian Shen

Dissertations, Theses, and Masters Projects

An inverse mathematical estuarine eutrophication model has been developed. The model provides a framework to estimate unknown parameters by assimilation of the concentration data of those state variables. The inverse model developed is a laterally integrated, two-dimensional, real-time model which consists of a hydrodynamic model, an eutrophication model and an adjoint model. The hydrodynamic model provides the dynamic fields for both the eutrophication model and the adjoint model. The eutrophication model simulates eight water quality state variables which are phytoplankton, organic nitrogen, ammonium nitrogen, nitrite-nitrate nitrogen, organic phosphorus, inorganic (ortho) phosphorus, carbonaceous biochemical oxygen demand and dissolved oxygen. The adjoint …