Sediment budgets, estuarine sediment loads, and wetland sediment storage at watershed scales, York River watershed, Virginia

Three separate but related aspects of sediment allocation in a river/estuarine system were examined. The main purpose was to compare sediment budgets for a series of eleven nested sub-watersheds as a function of watershed size, ranging from 65 to 6900 km2. The approach quantified six budget components: upland erosion; stream bank erosion; colluvial storage; wetland storage; stream channel erosion and storage; and sediment flux at the outlets. Three budgets were developed for each sub-watershed to examine the relative proportions of budget components, budget sensitivity (the influence of individual components on the overall budget), and the uncertainty of budget components. The study area was the rural, forested, low relief York River watershed in southeastern Virginia. The relative proportions of budget components do not change with sub-watershed size. Budgets are more influenced by the tributary system than by the sub-watershed size. The budget is sensitive to most components because they are large in size and are highly variable. The uncertainties of budget components are proportional to the magnitude of the best estimates. Management efforts should focus on locally-derived sediment to improve water quality because little sediment from the upper parts of the watershed reaches the estuary. Sediment loads were needed in the sediment budgets for three estuarine sampling stations. The loads were estimated by separating the gravitational circulation, tidal pumping, and river input components of long-term total suspended solids data. The load for the station closest to the river mouth was somewhat larger than literature values. The contribution to the estuary of the two tributary stations was previously unknown. Tidal pumping, rather than gravitational circulation, is the dominant process moving suspended sediment up the estuary. The potential supply and storage of sediment in wetlands at the watershed level was examined by quantifying the areal extent of wetland type and location in the watershed, and surrounding land use, slope, and soil type. Results showed that these landscape characteristics are unevenly distributed within the York River watershed and its subdivisions. The differences in landscape characteristics between subdivisions suggest that wetland performance and its impact on water quality may vary within a watershed. Separate management approaches may be needed to accommodate these differences

Cellular uptake of soy-derived phytoestrogens in vitro and in human whole blood

Epidemiological studies comparing typical Western and traditional Eastern lifestyles indicate that dietary intake of soyderived phytoestrogens, including genistein, daidzein, and equol, may have significant health protective effects on hormone-dependent cancers, osteoporosis and cardiovascular diseases. Phytoestrogens have been demonstrated to exert varying effects depending on tissue, endogenous hormone concentrations, and receptor types. Thus, a detailed understanding of the biodistribution and bioavailability of specific phytoestrogens is required in order to predict the subsequent biologic activities. In this study we aimed to investigate the cellular uptake of these soy-derived phytoestrogens in different cell types, including the mammary MCF-7/6 and MDAB-MB 231 cell lines, the ovarian Ishikawa Var-I cell lines and in murine adipocyte clusters. Furthermore, the biodistribution between serum and cell fraction was also investigated in human whole blood. Equol generally shows a higher cellular uptake when compared with genistein and daidzein. Therefore, equol may be more potent with respect to its relative bioactivity, which is corroborated by the observations of specific health effects associated with the equol-producer phenotype

Migration of the Tidal Marsh Range Under Sea Level Rise for Coastal Virginia, with Land Cover Data

The layers in this geodatabase were intended to represent the land that is encompassed by the average tidal range as sea level rises in the Virginia coastal region, including Chesapeake Bay and tributaries, the Atlantic Ocean side of the Eastern Shore, and Virginia Beach. The data layers in this geodatabase represent each two foot range of elevation incremented by 0.5 ft (e.g. 0-2 ft, 0.5-2.5 ft, 1-3 ft, etc.) with the current land cover that exists in that range. ArcGIS metadata is included in the geodatabase. Further details are provided in the Geodatabase Information file located from the download tab

Estuarine Suspended Sediment Loads and Sediment Budgets in Tributaries of Chesapeake Bay Phase 1: York, Patuxent, and Potomac Rivers

Understanding the sources and sinks of suspended sediment in Chesapeake Bay tributaries is an important contribution to quantifying the Bay sediment budget, as well as an aid to management strategies. The purpose of the project was to identify estuarine sediment transport processes and estimate sediment loads and sediment budgets for the major tributaries of the Bay. The first phase included the York River, Va. and the Patuxent River, Md. Sediment transport processes, sediment loads, and a partial budget also were developed for the Potomac River, Md. The results of this study represent the most comprehensive calculations to date of sediment loads for Bay tributaries. The three rivers exhibit different magnitudes and transport directions of sediment loads at individual stations. Average sediment loads for the rivers as a whole show the York, Patuxent, and Potomac all importing sediment. Sediment budgets for the York and Patuxent show a sediment loss that is unaccounted for; i.e. more sediment is needed from sources, or sinks are too large. The York River is highly energetic, moving large amounts of sediment within the estuary. The Patuxent River is less energetic but more variable in redistributing sediment. Important future work for a more comprehensive understanding of suspended sediment transport in the Chesapeake Bay includes completion of the sediment budget for the Potomac River and calculation of estuarine transport processes, sediment loads, and sediment budgets for the James and Rappahannock Rivers, Va

Categorization of shellfish TMDL sites Final Report

There were two important goals for this project, including the assembly and compilation of digital data for the Coastal Plain and tidal waters of Virginia, and the categorization of the Division of Shellfish Sanitation (DSS) shellfish growing areas to determine if some are similar enough for water quality models to be effectively transferred from the modeled growing areas to other areas. This report summarizes the data and statistical analyses and discusses the results. Note: The digital data has a very fine resolution. The maps displayed in this report cannot convey this information on 8.5x11 paper. All digital data layers (shape files and grids), digital maps (jpgs), data files (excel files) and a digital copy of this report (pdf format) are included on 3 cdroms that accompany this report. The cdroms include a text file (called Readme.txt) that provides an explanation of each of the data layers and pertinent information in the tables contained in the data layers

Evolution of Tidal Marsh Distribution under Accelerating Sea Level Rise

Tidal marshes are important ecological systems that are responding to sea level rise-driven changes in tidal regimes. Human development along the coastline creates barriers to marsh migration, moderating tidal marsh distributions. This study shows that in the Chesapeake Bay, USA an estuarine system with geographic and development variability, overall estuarine tidal marshes are projected to decline by approximately half over the next century. Tidal freshwater and oligohaline habitats, which are found in the upper reaches of the estuary and are typically backed by high elevation shorelines are particularly vulnerable. Due to their geological setting, losses of large extents of tidal freshwater habitat seem inevitable under sea level rise. However, in the meso/poly/euhaline zones that (in passive margin estuaries) are typically low relief areas, tidal marshes are capable of undergoing expansion. These areas should be prime management targets to maximize future tidal marsh extent. Redirecting new development to areas above 3 m in elevation and actively removing impervious surfaces as they become tidally inundated results in the maximum sustainability of natural coastal habitats. Under increasing sea levels and flooding, the future of tidal marshes will rely heavily on the policy decisions made, and the balance of human and natural landscapes in the consideration of future development

Impact Assessment and Management Challenges of Key Rural Human Health Infrastructure Under Sea Level Rise

Accelerating sea level rise in Virginia, United States, will significantly increase the flooding threat to low-lying roads, residences, and critical infrastructure as well as raise the water table, allowing saltwater intrusion into well water and threatening the function of septic fields. Although most of the adaptation work in Virginia has focused on urban economic centers, the majority of the coastline is rural and faces different threats and opportunities to address them compared to urban areas due to their reduced economic assets and their reliance on private infrastructure. In this case study, we assess the potential for geospatially quantifying impact to septic systems and adjacent water ways due to sea level rise. The case study found that the data necessary to reliably quantify these impacts on a state-wide scale are lacking and collection of that information needs to be prioritized given the potential for extensive sea level impacts

Synthesis of Shoreline, Sea Level Rise, and Marsh Migration Data for Wetland Restoration Targeting Final Report

Coastal marsh loss is a significant issue globally, due in part to rising sea levels and high levels of coastal human activity. Marshes have natural mechanisms to allow them to adapt to rising sea levels, however, migration across the landscape is one of those mechanisms and is frequently in conflict with human use of the shoreline. Ensuring the persistence of marshes into the future requires an understanding of where marshes are likely to migrate under sea level rise and targeting those areas for conservation and preservation activities. The goal of this project was to 1) compile existing datasets and information related to marsh migration under sea level rise-driven inundation due to forecasted climate change, topography of bay shorelines, shoreline condition (e.g., erosion rates, hardening, existing natural resources), existing wetland area and potential migration corridors, and other relevant data from around the Chesapeake Bay and 2) develop a methodology that synthesizes the information in a format that can be used to assist with marsh conservation and restoration decisions under multiple sea level rise scenarios (see associated report). This dataset is the resulting data from the methodology development

VIMS Marsh Migration final report + metadata sheets

Coastal marsh loss is a significant issue globally, due in part to rising sea levels and high levels of coastal human activity. Marshes have natural mechanisms to allow them to adapt to rising sea levels, however, migration across the landscape is one of those mechanisms and is frequently in conflict with human use of the shoreline. Ensuring the persistence of marshes into the future requires an understanding of where marshes are likely to migrate under sea level rise and targeting those areas for conservation and preservation activities. The goal of this project was to 1) compile existing datasets and information related to marsh migration under sea level rise-driven inundation due to forecasted climate change, topography of bay shorelines, shoreline condition (e.g., erosion rates, hardening, existing natural resources), existing wetland area and potential migration corridors, and other relevant data from around the Chesapeake Bay and 2) develop a methodology that synthesizes the information in a format that can be used to assist with marsh conservation and restoration decisions under multiple sea level rise scenarios (see associated report). This dataset is the resulting data from the methodology development