Physical Sciences and Mathematics Commons^™

The Status Of Virginia's Public Oyster Resource 2015, Melissa Southworth, Roger L. Mann

Reports

This report summarizes data collected during 2015 in the Virginia portion of the Chesapeake Bay. The report is composed of two parts, part one, oyster recruitment (shell string) in Virginia and part two, dredge survey of selected oyster bars in Virginia.

Evaluating Recruitment Of American Eel, Anguilla Rostrata, In The Potomac River (Spring 2016), Troy D. Tuckey, Mary C. Fabrizio

Reports

American Eel (Anguilla rostrata) is a valuable commercial species along the Atlantic coast of North America from New Brunswick to Florida. Landings from Chesapeake Bay typically represent 60% of the annual United States commercial harvest (ASMFC 2012). American Eel is also important to the recreational fishery as it is often used live as bait for Striped Bass (Morone saxatilis) and Cobia (Rachycentron canadum). In 2012, Chesapeake Bay commercial landings of American Eel (771,536 lbs) were 72% of the U.S. landings (personal communication from the National Marine Fisheries Service, Fisheries Statistics Division). Since the 1980s, harvest along the U.S. Atlantic Coast …

Vertical One-Dimensional (1-D) Simulations Of Horizontal Velocity Profiles, Jerome P.Y. Maa, Jian Shen, Xiaoteng Shen, Shao Yuyang

Reports

Details of a vertical 1-D hydrodynamic model to simulate the horizontal velocity profiles for tidal estuarial flows with possible stratifications caused by salinity or Suspended Sediment Concentration (SSC) are presented. The standard 2nd order k-ε model was implemented to address the turbulent flow with possible stratification effects. Simulation results are verified with two field measurements for steady nonstratified flows and a field measurement for tidal estuary non-stratified flow. The stratification effect of salinity and suspended sediment concentration are also checked with the following descriptions: “Salinity stratification will change the typical logarithmic velocity profile to a linear profile for most of …

City Of Chesapeake, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Julie Bradshaw, David Stanhope, Karen Duhring, Kallie Brown, Jessica Hendricks, David Weiss, Carl Hershner

Reports

The 2016 Inventory for City of Chesapeake was generated using on-screen, digitizing techniques in ArcGIS® - ArcMap v10.2.2 while viewing conditions observed in Bing high resolution oblique imagery, Google Earth, and 2013 imagery from the Virginia Base Mapping Program (VBMP). Four GIS shapefiles are developed. The first describes land use and bank conditions (Chesapeake_lubc_2016). The second portrays the presence of beaches (Chesapeake_beaches_2016). The third reports shoreline structures that are described as arcs or lines (e.g. riprap) (Chesapeake_sstru_2016). The final shapefile includes all structures that are represented as points (e.g. piers) (Chesapeake_astru_2016). The metadata file accompanies the shapefiles and defines attribute …

2014 Chesapeake Bay Sav Coverage, Sav Data Administrator, Virginia Institute Of Marine Science

Data

Abstract: The 2014 Chesapeake Bay SAV Coverage was mapped from 1:24,000 black and white aerial photography and digital multispectral imagery with a 25cm GSD to assess water quality in the Bay. Each area of SAV was interpreted from the rectified photography and classified into one of four density classes by the percentage of cover. The SAV beds were entered into an SDE GIS fetaure class using the quality control procedures documented below. The dataset contains all SAV areas that were identified from the areas flown. Some areas that are presumed to contain no SAV were not flown. Some small beds, …

Two Nucleon Systems At M(Pi) Similar To 450 Mev From Lattice Qcd, Kostas Orginos, Assumpta Parreño, Martin J. Savage, Silas R. Beane, Et Al.

Arts & Sciences Articles

Nucleon-nucleon systems are studied with lattice quantum chromodynamics at a pion mass of m(pi) similar to 450 MeV in three spatial volumes using n(f) = 2 + 1 flavors of light quarks. At the quark masses employed in this work, the deuteron binding energy is calculated to be B-d = 14.4(-2.6)(+3.2) MeV, while the dineutron is bound by B-nn = 12.5(-5.0)(+3.0) MeV. Over the range of energies that are studied, the S-wave scattering phase shifts calculated in the S-1(0) and S-3(1)-D-3(1) channels are found to be similar to those in nature, and indicate repulsive short-range components of the interactions, consistent …

Lancaster County, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Julie Bradshaw, Kory Angstadt, David Stanhope, Christine Tombleson, Karen Duhring, Alexander D. Renaud, Robert Isdell, Pamela Braff, Benjamin P. Weissman, Carl Hershner

Reports

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. This assessment characterizes conditions that can be observed from a small boat navigating along the shoreline or by using observations made remotely at the desktop using high resolution imagery. The three tiered shoreline assessment approach divides the shorezone into three regions:

• the immediate riparian zone, evaluated for land use

• the bank, evaluated for height, cover and natural protection

• the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes.

The 2015 Inventory for Lancaster County was generated using on-screen, digitizing …

City Of Portsmouth, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Julie Bradshaw, Kory Angstadt, Karen Duhring, David Weiss, Carl Hershner

Reports

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. This assessment characterizes conditions that can be observed from a small boat navigating along the shoreline or by using observations made remotely at the desktop using high resolution imagery. The three tiered shoreline assessment approach divides the shorezone into three regions:

1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes.

The 2015 Inventory for the City of …

Piecewisesem: Piecewise Structural Equation Modelling In R For Ecology, Evolution, And Systematics, Jonathan S. Lefcheck

VIMS Articles

Summary

1. Ecologists and evolutionary biologists rely on an increasingly sophisticated set of statistical tools to describe complex natural systems. One such tool that has gained significant traction in the biological sciences is structural equation models (SEM), a form of path analysis that resolves complex multivariate relationships among a suite of interrelated variables.

2. Evaluation of SEMs has historically relied on covariances among variables, rather than the values of the data points themselves. While this approach permits a wide variety of model forms, it limits the incorporation of detailed specifications. Recent developments have allowed for the simultaneous implementation of non‐normal distributions, random …

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Climate Change As Migration Driver From Rural And Urban Mexico, Raphael J. Nawrotzki, Lori M. Hunter, Daniel Runfola, Fernando Riosmena

Arts & Sciences Articles

Studies investigating migration as a response to climate variability have largely focused on rural locations to the exclusion of urban areas. This lack of urban focus is unfortunate given the sheer numbers of urban residents and continuing high levels of urbanization. To begin filling this empirical gap, this study investigates climate change impacts on US-bound migration from rural and urban Mexico, 1986–1999. We employ geostatistical interpolation methods to construct two climate change indices, capturing warm and wet spell duration, based on daily temperature and precipitation readings for 214 weather stations across Mexico. In combination with detailed migration histories obtained from …

Street-Level Predictive Modeling Of Nuisance Flooding Verified Via Crowdsourced App Data In Norfolk, Va, J. D. Loftis, H. V. Wang, D R. Forrest

Presentations

No abstract provided.

Particle Transport In Low-Collisionality H-Mode Plasmas On Diii-D, Saskia Mordijck, X. Wang, E. J. Doyle, T. L. Rhodes, Et Al.

Arts & Sciences Articles

In this paper we show that changing from an ion temperature gradient (ITG) to a trapped electron mode (TEM) dominant turbulence regime (based on linear gyrokinetic simulations) results experimentally in a strong density pump-out (defined as a reduction in line-averaged density) in low collisionality, low power H-mode plasmas. We vary the turbulence drive by changing the heating from predominantly ion heated using neutral beam injection to electron heated using electron cyclotron heating, which changes the T-e/T-i ratio and the temperature gradients. Perturbed gas puff experiments show an increase in transport outside rho = 0.6, through a strong increase in the …

Molybdenum Complexes Of Chiral C2-Symmetric Picchxn-Type Ligands: Synthesis, Characterization, And Structural Studies, Rachel R. Bennov, David A. Berko, Samantha A. Burgess, John L. Dimeglio, Et Al., Robert D. Pike

Arts & Sciences Articles

A series of molybdenum complexes based on chiral C2-symmetric picchxn-type ligands (N4 ligands, defined as trans-N,N′-bis(heterocycl-2-ylmethyl)-1,2-diaminocyclohexanes) has been synthesized and characterized. Reported and novel picchxn-type ligands form (κ3-N4)Mo(CO)3, [(κ4-N4)Mo(NO)(CO)]PF6, and [(κ4-N4)Mo(NO)X]PF6 (X = Br, I) compounds. Multiple tridentate (κ3) and tetradentate (κ4) ligand configurations were observed, and the favored κ4 configuration was found to vary with N4 heterocycle identity. Heterocycle variation allowed for directed modification of the molybdenum electronic characteristics, but none of the studied {(κ4-N4)Mo(NO)}+ fragments was found to be a suitable …

Stafford County Shoreline Management Plan, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Marcia Berman, Tamia Rudnicky, Karinna Nunez, Sharon Kileen

Reports

With approximately 85 percent of the Chesapeake Bay shoreline privately owned, a critical need exists to increase awareness of erosion potential and the choices available for shore stabilization that maintains ecosystem services at the land-water interface. The National Academy of Science published a report that spotlights the need to develop a shoreline management framework (NRC, 2007). It suggests that improving awareness of the choices available for erosion control, considering cumulative consequences of erosion mitigation approaches, and improving shoreline management planning are key elements to minimizing adverse environmental impacts associated with mitigating shore erosion. Actions taken by waterfront property owners to …

Estuarine Sediment Dynamics, C. T. Friedrichs

Presentations

No abstract provided.

Suspended Particulate Matter Longitudinal Survey – Currituck Sound, Nc; Oct 13-15, 2015, Cruise: Cs151013-15, Chsd Stations: S5566-5587, Grace M. Massey, Kelsey A. Fall

Data

Dataset consists of water column and bottom burst data, PICS, and light attenuation data collected as part of a 21 station longitudinal survey of the Currituck Sound, NC along a ~60 km transect northward from the Wright Memorial Bridge.

Re-Emergence Of The Harmful Algal Bloom Species Alexandrium Monilatum In The Chesapeake Bay: Assessing Bloom Dynamics And Potential Health Impacts, Sarah K.D. Pease, Kimberly S. Reece, Wolfgang K. Vogelbein

Presentations

Effective management of harmful algal blooms (HABs) within a region requires an understanding of species-specific HAB spatial and temporal distributions, bloom dynamics, as well as potential health impacts. In 2007, the southern Chesapeake Bay witnessed its first blooms of the HAB species Alexandrium monilatum. Since then, A. monilatum has bloomed in the region almost annually. A. monilatum produces the toxin ‘goniodomin A’ and is suspected in local mass mortalities of oyster larvae (Crassostrea virginica) grown for aquaculture and restoration projects. Representatives from Virginia’s multimillion dollar oyster aquaculture industry recently expressed great concern over A. monilatum impacts to their businesses; field …

Diel Vertical Distribution Patterns Of Zooplankton Along The Western Antarctic Peninsula, Patricia S. Thibodeau, John A. Conroy, Deborah K. Steinberg

Presentations

The Western Antarctic Peninsula (WAP) is a region that has undergone significant change over the past several decades due to unprecedented increases sea surface temperature and decreases in sea ice cover. The ongoing Palmer Antarctica Long-Term Ecological Research (PAL LTER) study shows that these environmental changes are significantly affecting the marine pelagic ecosystem along the WAP. The goal of this study was to analyze diel vertical distribution patterns of zooplankton along the WAP.

Efficacy Of Sediment Remediation Efforts On Pah Contaminant Flux Via Porewater Advection At The Sediment-Surface Water Interface, Julie L. Krask, Michael A. Unger, George G. Vadas, Michele A. Cochran, Aaron J. Beck

Presentations

Groundwater advection at the sediment-surface water interface is an important biogeochemical mechanism controlling the transport and bioavailability of contaminants in estuaries. At sites along the Elizabeth River (VA, USA) where the subterranean environment is heavily contaminated with polycyclic aromatic hydrocarbon (PAH)-rich dense non-aqueous phase liquid (DNAPL), consideration of groundwater-surface water dynamics and associated chemical exchange is critical for effective remediation. Preliminary data suggest that porewater advection in permeable sediments at this location is controlled by a host of physical forcing mechanisms that correspond with total flow estimates of up to 15,000 centimeters/year. Here, the efficacy of sediment remediation strategies, including …

Effects Of Commercial Clam Aquaculture On Biogeochemical Cycling In Shallow Coastal Ecosystems, Annie E. Murphy, Iris C. Anderson, Mark W. Luckenbach

Presentations

The bivalve aquaculture industry is expanding worldwide; sustainability requires improved understanding of its interactions with the environment. As suspension feeders, bivalves, such as clams, reduce primary production through feeding, and thus dampen eutrophication. Additionally, enhanced rates of denitrification, the microbial removal of reactive nitrogen, have been reported in bivalve sediments due to increased organic matter supply through biodeposition; another potential, yet indirect, control on eutrophication. Simultaneously, bivalves can influence local ‘bottom-up’ effects on production by enhancing nutrient regeneration through excretion and microbial mineralization of biodeposits. At clam aquaculture sediments, respiration and nutrient regeneration rates were significantly higher compared to uncultivated …

Informing Social Decision Making: Physical Vulnerability To Sea Level Rise, Alexander D. Renaud, Karinna Nunez, Molly Mitchell, Carl Hershner

Presentations

Social indices on census tract and other geopolitical levels are increasingly being considered to inform decision making. In a flooding and sea level rise context, the likelihood of an area flooding is an important component of adaptation and the decision-making framework, however it is frequently modeled on a continuous scale. In our work, we have developed an index of physical vulnerability to flooding on a census tract scale, specifically designed to complement social vulnerability indices.

The Role Of Oyster In Nitrous Oxide Emissions From Oyster Reefs, Anne Arfkin, Ashley Smyth, Bongkeun Song

Presentations

Oyster microbiomes may play a significant role in the biogeochemical N cycle and N2O emissions in estuarine and coastal ecosystems. Rates of denitrification and N2O production were measured from live oysters and oyster shells collected at a coastal lagoon and a tidal estuary in the Chesapeake Bay. Live oysters had the highest rates of denitrification and N2O production in both study sites. This indicates that oysters are an import N remover and a N2O source in coastal ecosystems.

Quantifying Finfish And Blue Crab Use Of Created Oyster Reefs In The Lower Chesapeake Bay, Bruce W. Pfirrmann, Rochelle D. Seitz

Presentations

Structurally complex reefs created by the eastern oyster Crassostrea virginica provide a host of ecosystem services yet have experienced significant declines, prompting extensive restoration efforts. We investigate the use of created oyster reefs in the lower Bay by mobile finfish and blue crabs with field surveys and diet analysis. The results of this study provide insight into how restoration activities influence estuarine community dynamics and the provision of ecosystem services.

Structural Complexity And Location Affect The Habitat Value Of Restored Oyster Reefs, Melissa Karp, Rochelle Seitz

Presentations

Oyster reefs provide a suite of valuable ecosystem services, such as water filtration, nitrogen sequestration, and provision of habitat and foraging grounds. The global decline of these habitats has had negative economic and ecological impacts to coastal waters worldwide. In the Chesapeake Bay, < 1% of the historic oyster population remains and efforts to restore oyster populations and the services they provide have been increasing. Building reefs that successfully provide specific ecosystem services may require different techniques then previously used, and success may depend on reef morphology, location, and environmental conditions. Settling trays were embedded into previously restored oyster reefs that varied in their structural complexity (rugosity) in multiple rivers in the lower Chesapeake Bay. Trays were collected after 7-weeks, sorted, and species identified and weighed (ash-free dry weight) to obtain species diversity, abundance, and biomass. Species composition data was analyzed using nMDS plots, which showed that salinity was an important driver of differences in species composition. Results of an ANOVA analysis found that species diversity was significantly greater on reefs in the high-salinity rivers compared to reefs in low-salinity rivers. Total organism abundance and biomass were positively correlated with reef structural complexity measures, such as rugosity, oyster clump volume, and oyster biomass. These results suggest that more complex oyster reefs in higher salinity locations may support more diverse and productive benthic communities. This study provides insight into the driving factors that structure oyster reef communities and has important implications for oyster reef restoration design and management.

The Relationship Between Reproduction And Mortality In Triploid Crassostrea Virginica: A Matter Of Economic Importance, Joseph L. Matt, Standish K. Allen

Presentations

The goal of this project is to maximize survival for commercially produced triploid Crassostrea virginica oysters in Virginia. Over the last few years, commercial oyster growers in Virginia have reported significant mortality events of triploid oysters during the spring and summer months. The summer of 2014 was the worst yet, as growers across the state reported summer mortality, most severe on the Eastern shore and in some cases as high as 85% of the crop (Karen Hudson, personal communication). Surviving oysters from some of these mortality events were sent to the Virginia Institute of Marine Science and several of the …

Modeling Continental Shelf Formation In The Adriatic Sea And Elsewhere, Lincoln Pratson, John Swenson

VIMS Articles

No abstract provided.

Wallops Assateague Chincoteague Inlet (Waci) Geologic And Coastal Management Summary Report, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Curtis Smith

Reports

No abstract provided.

James City County Shoreline Management Plan, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Marcia Berman, Tamia Rudnicky, Karinna Nunez, Sharon A. Killeen

Reports

Actions taken by waterfront property owners to stabilize the shoreline can affect the health of the Bay as well as adjacent properties for decades. With these long-term implications, managers at the local level should have a more proactive role in how shorelines are managed. James City County recognizes that its natural environment is one of its most valuable assets as well as its most vulnerable (James City County, 2015). The shores of James City range from exposed open river to very sheltered creeks, and the nature of shoreline change varies accordingly (Figure 1-1). This shoreline management plan is useful for …

Tidal Flat Morphodynamics: A Synthesis, C. T. Friedrichs

Presentations

No abstract provided.

Controls On Suspended Particle Properties And Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Usa, K. A. Fall, C. T. Friedrichs, G. M. Cartwright, D. G. Bowers

Presentations

The Chesapeake Bay and its associated tidal tributaries, which together form one of the United States’ largest and most important estuaries, are among the many coastal systems where degraded water clarity is a major concern. Despite long-term decreases in sediment input, water clarity over the last 20 years has continued to deteriorate in the Bay and its tributaries (Williams et al., 2010). Analysis of long-term monitoring data (Wang et al., 2010) found that the concentration of total suspended solids (TSS), the regulatory indicator of ‘suspended sediment pollution’, is about as likely to be positively or negatively correlated to sediment loads …