Physical Sciences and Mathematics Commons^™

Assessment Of Changes Of Complex Shoreline From Medium‑Resolution Satellite Imagery, Nikolay P. Nezlin, Julie Herman, Jonathan Hodge, Stephen Sagar, Robbi Bishop-Taylor, Guangming Zheng, John M. Digiacomo

VIMS Articles

The imagery collected by medium-resolution earth-observing satellites is a powerful and cost-effective tool for the quantitative assessment of shoreline dynamics for water bodies of different spatial scales. In this study, we utilize imagery collected in 1984–2021 on the Middle Peninsula, Virginia, bordering the Chesapeake Bay, USA, by medium-resolution (10–30 m) satellites Landsat-5/7/8 and Sentinel-2A/B. The data was managed in the Earth Analytics Interoperability Lab (EAIL) Data Cube built and configured by the Commonwealth Scientific and Industrial Research Organization (CSIRO, Australia and Chile). The assessments of shoreline change demonstrate adequate agreement with assessments based on aerial photography collected during 1937–2009 by …

Sediment Metagenomics Reveals The Impacts Of Poultry Industry Wastewater On Antibiotic Resistance And Nitrogen Cycling Genes In Tidal Creek Ecosystems, Miguel Semedo, Bongkeun Song

VIMS Articles

The intensification of the poultry industry may lead to the increased spread of antibiotic resistance genes (ARGs) in the environment. However, the impacts of wastewater discharge from poultry processing plants on the sediment resistome are relatively unexplored. Furthermore, its relationships with important biogeochemical pathways, such as the N cycle, are virtually unknown. The overall objective of this study was to examine the abundance and diversity of antibiotic resistance and N cycling genes in sediment microbial communities impacted by poultry industry wastewater. We performed a metagenomic investigation of sediments in an impacted and a reference tidal creek. We also quantified the …

Nitrogen Reductions Have Decreased Hypoxia In The Chesapeake Bay: Evidence From Empirical And Numerical Modeling, Luke T. Frankel, Marjorie A.M. Friedrichs, Pierre St-Laurent, Aaron J. Bever, Rom Lipcius, Gopal Bhatt, Gary W. Shenk

VIMS Articles

Seasonal hypoxia is a characteristic feature of the Chesapeake Bay due to anthropogenic nutrient input from agriculture and urbanization throughout the watershed. Although coordinated management efforts since 1985 have reduced nutrient inputs to the Bay, oxygen concentrations at depth in the summer still frequently fail to meet water quality standards that have been set to protect critical estuarine living resources. To quantify the impact of watershed nitrogen reductions on Bay hypoxia during a recent period including both average discharge and extremely wet years (2016–2019), this study employed both statistical and three-dimensional (3-D) numerical modeling analyses. Numerical model results suggest that …

A Novel Antibody-Based Biosensor Method For The Rapid Measurement Of Pah Contamination In Oysters, Kristen M. Prossner, George G. Vadas, Ellen Harvey, Michael A. Unger

VIMS Articles

Conventional PAH analytical methods are time-consuming and expensive, limiting their utility in time sensitive events (i.e. oil spills and floods) or for widespread environmental monitoring. Unreliable and inefficient screening methods intended to prioritize samples for more extensive analyses exacerbate the issue. Antibody-based biosensor technology was implemented as a quantitative screening method to measure total PAH concentration in adult oysters (Crassostrea virginica) — a well-known bioindicator species with ecological and commercial significance. Individual oysters were analyzed throughout the historically polluted Elizabeth River watershed (Virginia, USA). Significant positive association was observed between biosensor and GC–MS measurements that persisted when the method was …

Long-Term Annual Aerial Surveys Of Submersed Aquatic Vegetation (Sav) Support Science, Management, And Restoration, Robert J. Orth, William C. Dennison, Cassie Gurbisz, (...), Kenneth A. Moore, Christopher J. Patrick, (..), David J. Wilcox, Richard A. Batiuk

VIMS Articles

Aerial surveys of coastal habitats can uniquely inform the science and management of shallow, coastal zones, and when repeated annually, they reveal changes that are otherwise difficult to assess from ground-based surveys. This paper reviews the utility of a long-term (1984–present) annual aerial monitoring program for submersed aquatic vegetation (SAV) in Chesapeake Bay, its tidal tributaries, and nearby Atlantic coastal bays, USA. We present a series of applications that highlight the program’s importance in assessing anthropogenic impacts, gauging water quality status and trends, establishing and evaluating restoration goals, and understanding the impact of commercial fishing practices on benthic habitats. These …

Enhancing Assessments Of Blue Carbon Stocks In Marsh Soils Using Bayesian Mixed-Effects Modeling With Spatial Autocorrelation — Proof Of Concept Using Proxy Data, Grace S. Chiu, Molly Mitchell, Julie Herman, Christian Longo, Kate Davis

VIMS Articles

Our paper showcases the potential gain in scientific insights about blue carbon stocks (or total organic carbon) when additional rigor, in the form of a spatial autocorrelation component, is formally incorporated into the statistical model for assessing the variability in carbon stocks. Organic carbon stored in marsh soils, or blue carbon (BC), is important for sequestering carbon from the atmosphere. The potential for marshes to store carbon dioxide, mitigating anthropogenic contributions to the atmosphere, makes them a critical conservation target, but efforts have been hampered by the current lack of robust methods for assessing the variability of BC stocks at …

Impact Assessment And Management Challenges Of Key Rural Human Health Infrastructure Under Sea Level Rise, Molly Mitchell, Robert Isdell, Julie Herman, Christine Tombleson

VIMS Articles

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 …

Real-Time Environmental Forecasts Of The Chesapeake Bay: Model Setup, Improvements, And Online Visualization, Aaron Bever, Marjorie A.M. Friedrichs, Pierre St-Laurent

VIMS Articles

Daily real-time nowcasts (current conditions) and 2-day forecasts of environmental conditions in the Chesapeake Bay have been continuously available for 4 years. The forecasts use a 3-D hydrodynamic-biogeochemical model with 1–2 km resolution and 3-D output every 6 h that includes salinity, water temperature, pH, aragonite saturation state, alkalinity, dissolved oxygen, and hypoxic volume. Visualizations of the forecasts are available through a local institutional website (www.vims.edu/hypoxia) and the MARACOOS Oceans Map portal (https://oceansmap.maracoos.org/chesapeake-bay/). Modifications to real-time graphics on the local website are routinely made based on stakeholder input and are formatted for use on a mobile …

Advancing Estuarine Ecological Forecasts: Seasonal Hypoxia In Chesapeake Bay, Donald Scavia, Isabella Bertani, (...), Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Ecological forecasts are quantitative tools that can guide ecosystem management. The coemergence of extensive environmental monitoring and quantitative frameworks allows for widespread development and continued improvement of ecological forecasting systems. We use a relatively simple estuarine hypoxia model to demonstrate advances in addressing some of the most critical challenges and opportunities of contemporary ecological forecasting, including predictive accuracy, uncertainty characterization, and management relevance. We explore the impacts of different combinations of forecast metrics, drivers, and driver time windows on predictive performance. We also incorporate multiple sets of state-variable observations from different sources and separately quantify model prediction error and measurement …

Coastal Setting Determines Tidal Marsh Sustainability With Accelerating Sea-Level Rise, Karinna Nunez, Yinglong J. Zhang, Donna M. Bilkovic, Carl Hershner

VIMS Articles

There is an increasing concern over how accelerated rates of sea-level rise (SLR) will impact tidal marsh ecosystems. The present study evaluates the potential impacts of SLR on marsh sustainability using the Tidal Marsh Model (TMM) with the addition of a new vegetation algorithm within the SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) framework. This new functionality contributes to an improved understanding of how vegetation affects the mean flow velocity and turbulence, and consequently, the sedimentation processes. Using two SLR scenarios (intermediate and extreme SLR rates), we projected the changes in marsh extent over the next 50 years in two …

Evaluation Of A Rapid Biosensor Tool For Measuring Pah Availability In Petroleum-Impacted Sediment, Jason Conder, Mehregan Jalalizadeh, (...), Michael A. Unger

VIMS Articles

Decades of research have shown that the concentration of freely dissolved PAH (C_free) in sediment correlates with PAH bioavailability and toxicity to aquatic organisms. Passive sampling techniques and models have been used for measuring and predicting C_free, respectively, but these techniques require weeks for analytical chemical measurements and data evaluation. This study evaluated the performance of a portable, field-deployable antibody-based PAH biosensor method that can provide measurements of PAH C_free within a matter of minutes using a small volume of mechanically-extracted sediment porewater. Four sediments with a wide range of PAHs (ΣPAH 2.4 to 307 …

Current And Future Remote Sensing Of Harmful Algal Blooms In The Chesapeake Bay To Support The Shellfish Industry, Jl Wolny, Mc Tomlinson, S Schollaert Uz, Ta Egerton, Jr Mckay, A Meredith, Ks Reece, Gp Scott, Rp Stumpf

VIMS Articles

Harmful algal bloom (HAB) species in the Chesapeake Bay can negatively impact fish, shellfish, and human health via the production of toxins and the degradation of water quality. Due to the deleterious effects of HAB species on economically and environmentally important resources, such as oyster reef systems, Bay area resource managers are seeking ways to monitor HABs and water quality at large spatial and fine temporal scales. The use of satellite ocean color imagery has proven to be a beneficial tool for resource management in other locations around the world where high-biomass, nearly monospecific HABs occur. However, remotely monitoring HABs …

Long-Term Annual Aerial Surveys Of Submersed Aquatic Vegetation (Sav) Support Science, Management, And Restoration, Robert J. Orth, William C. Dennison, Cassie Gurbisz, Michael Hannam, Jeni Keisman, J. Brooke Landry, Jonathan S. Lefcheck, Kenneth A. Moore, Rebecca R. Murphy, Christopher J. Patrick, Jeremy Testa, Donald E. Weller, David J. Wilcox, Richard A. Batiuk

VIMS Articles

Aerial surveys of coastal habitats can uniquely inform the science and management of shallow, coastal zones, and when repeated annually, they reveal changes that are otherwise difficult to assess from ground-based surveys. This paper reviews the utility of a long-term (1984–present) annual aerial monitoring program for submersed aquatic vegetation (SAV) in Chesapeake Bay, its tidal tributaries, and nearby Atlantic coastal bays, USA. We present a series of applications that highlight the program’s importance in assessing anthropogenic impacts, gauging water quality status and trends, establishing and evaluating restoration goals, and understanding the impact of commercial fishing practices on benthic habitats. These …

Validating An Operational Flood Forecast Model Using Citizen Science In Hampton Roads, Va, Usa, Jon Derek Loftis, Molly Mitchell, Daniel Schatt, David R. Forrest, Harry V. Wang, David Mayfield, William A. Stiles

VIMS Articles

Changes in the eustatic sea level have enhanced the impact of inundation events in the coastal zone, ranging in significance from tropical storm surges to pervasive nuisance flooding events. The increased frequency of these inundation events has stimulated the production of interactive web-map tracking tools to cope with changes in our changing coastal environment. Tidewatch Maps, developed by the Virginia Institute of Marine Science (VIMS), is an effective example of an emerging street-level inundation mapping tool. Leveraging the Semi-implicit Cross-scale Hydro-science Integrated System Model (SCHISM) as the engine, Tidewatch operationally disseminates 36-h inundation forecast maps with a 12-h update frequency. …

Toward A Coordinated Global Observing System For Seagrasses And Marine Macroalgae, J. Emmett Duffy, L. Benedetti-Cecchi, Et Al, Robert J. Orth, Et Al

VIMS Articles

In coastal waters around the world, the dominant primary producers are benthic macrophytes, including seagrasses and macroalgae, that provide habitat structure and food for diverse and abundant biological communities and drive ecosystem processes. Seagrass meadows and macroalgal forests play key roles for coastal societies, contributing to fishery yields, storm protection, biogeochemical cycling and storage, and important cultural values. These socio-economically valuable services are threatened worldwide by human activities, with substantial areas of seagrass and macroalgal forests lost over the last half-century. Tracking the status and trends in marine macrophyte cover and quality is an emerging priority for ocean and coastal …

Treading Water: Tools To Help Us Coastal Communities Plan For Sea Level Rise Impacts, E A. Smith, W Sweet, Molly Mitchell, R Domingues, C P. Weaver, M Baringer, G Goni, J Haines, Jon Derek Loftis, John D. Boon, David L. Malmquist

VIMS Articles

As communities grapple with rising seas and more frequent flooding events, they need improved projections of future rising and flooding over multiple time horizons, to assist in a multitude of planning efforts. There are currently a few different tools available that communities can use to plan, including the Sea Level Report Card and products generated by a United States. Federal interagency task force on sea level rise. These tools are a start, but it is recognized that they are not necessarily enough at present to provide communities with the type of information needed to support decisions that range from seasonal …

Citizen-Science For The Future: Advisory Case Studies From Around The Globe, C Simoniello, J Jencks, Fm Lauro, Jon Derek Loftis, K Deja, David R. Forrest, Et At

VIMS Articles

The democratization of ocean observation has the potential to add millions of observations every day. Though not a solution for all ocean monitoring needs, citizen scientists offer compelling examples showcasing their ability to augment and enhance traditional research and monitoring. Information they are providing is increasing the spatial and temporal frequency and duration of sampling, reducing time and labor costs for academic and government monitoring programs, providing hands-on STEM learning related to real-world issues and increasing public awareness and support for the scientific process. Examples provided here demonstrate the wide range of people who are already dramatically reducing gaps in …

Shorescape-Level Factors Drive Distribution And Condition Of A Salt Marsh Facilitator (Geukensia Demissa), Robert E. Isdell, Donna M. Bilkovic, Carl Hershner

VIMS Articles

Ribbed mussels (Geukensia demissa) are a highly abundant bivalve filter feeder throughout the salt marshes of the U.S. Atlantic Coast. These mussels form a mutualistic relationship with smooth cordgrass Spartina alterniflora wherein the grass provides habitat and shade to the mussels, and the mussels stabilize the sediment and fertilize the grass. Salt marshes are, however, rapidly changing and eroding as humans modify the coast, and the rate of sea level rise is accelerating. In order to understand how ribbed mussels may respond to their changing habitat, we collected mussel density and distribution data from 30 marshes covering the range of …

Projecting Shifts In Thermal Habitat For 686 Species On The North American Continental Shelf, J. W. Morley, R. L. Selden, Robert J. Latour, T. L. Frolicher, R. J. Seagraves, M. L. Pinsky

VIMS Articles

Recent shifts in the geographic distribution of marine species have been linked to shifts in preferred thermal habitats. These shifts in distribution have already posed challenges for living marine resource management, and there is a strong need for projections of how species might be impacted by future changes in ocean temperatures during the 21st century. We modeled thermal habitat for 686 marine species in the Atlantic and Pacific oceans using long-term ecological survey data from the North American continental shelves. These habitat models were coupled to output from sixteen general circulation models that were run under high (RCP 8.5) and …

Consequences Of Drift And Carcass Decomposition For Estimating Sea Turtle Mortality Hotspots, Bianca Santos, David M. Kaplan, Marjorie A.M. Friedrichs, Susan G. Barco, Katherine L. Mansfield, James P. Manning

VIMS Articles

Sea turtle strandings provide important mortality information, yet knowledge of turtle carcass at-sea drift and decomposition characteristics are needed to better understand and manage where these mortalities occur. We used empirical sea turtle carcass decomposition and drift experiments in the Chesapeake Bay, Virginia, USA to estimate probable carcass oceanic drift times and quantify the impact of direct wind forcing on carcass drift. Based on the time period during which free-floating turtle carcasses tethered nearshore were buoyant, we determined that oceanic drift duration of turtle carcasses was highly dependent on water temperature and varied from 2 to 15 days during typical …

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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Effects Of The June 1995 Freshet On The Main Virginia Tributaries To The Chesapeake Bay, Herbert M. Austin, Christopher F. Bonzek

VIMS Articles

Environmental conditions in the Virginian waters of the Chesapeake Bay area during the summerof 1995 have been characterized as a severe drought. This drought was punctuated on 27 June with a headwater (James and Rappahannock River) rain storm that produced a "freshet". Although it did not rain in the Tidewater area of Virginia, surface salinities were depressed by the run-off, and main-stem bottom ox}'gen levels dropped to z.ero in the James and Rappahannock rivers. The effects of the reduced oxygen were apparent on the James River oyster stock, particularly the reduction in spatfall, and to a lesser degree on the …

Tracing Kepone Contamination In James Estuary Sediments, Maynard M. Nichols, Norman H. Cutshall

VIMS Articles

The escape of Kepone into the James River estuary, Virginia, for more than nine years produced widespread contamination of the sediments with important ecological consequences. The pollutant extended seaward more than 100 km from its source and contaminated an estimated 31 million tonnes of sediment to depths of more than 60 cm. Kepone spread through the food chain and to every segment of the environment from marshes to the channel floor.

Kepone escaped mainly during high river inflow from a point source in freshwater tributaries. Near the source Kepone is associated with organic material but in the low er estuary …