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 …

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 …

Marine Heatwaves In The Chesapeake Bay, Piero L. F. Mazzini, Cassia Pianca

VIMS Articles

Prolonged events of anomalously warm sea water temperature, or marine heatwaves (MHWs), have major detrimental effects to marine ecosystems and the world's economy. While frequency, duration and intensity of MHWs have been observed to increase in the global oceans, little is known about their potential occurrence and variability in estuarine systems due to limited data in these environments. In the present study we analyzed a novel data set with over three decades of continuous in situ temperature records to investigate MHWs in the largest and most productive estuary in the US: the Chesapeake Bay. MHWs occurred on average twice per …

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 …

Restoration Of Seagrass Habitat Leads To Rapid Recovery Of Coastal Ecosystem Services, Robert J. Orth, Jonathan S. Lefcheck, Karen S. Mcglathery, Lillian Aoki, Mark Luckenbach, Kenneth A. Moore, Matthew P.J. Oreska, Richard A. Snyder, David J. Wilcox, Bo Lusk

VIMS Articles

There have been increasing attempts to reverse habitat degradation through active restoration, but few largescale successes are reported to guide these efforts. Here, we report outcomes from a unique and very successful seagrass restoration project: Since 1999, over 70 million seeds of a marine angiosperm, eelgrass (Zostera marina), have been broadcast into mid-western Atlantic coastal lagoons, leading to recovery of 3612 ha of seagrass. Well-developed meadows now foster productive and diverse animal communities, sequester substantial stocks of carbon and nitrogen, and have prompted a parallel restoration for bay scallops (Argopecten irradians). Restored ecosystem services are approaching historic levels, but we …

Estuarine Forecasts At Daily Weather To Subseasonal Time Scales, Andrew C. Ross, Charles A. Stock, Keith W. Dixon, Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Most present forecast systems for estuaries predict conditions for only a few days into the future. However, there are many reasons to expect that skillful estuarine forecasts are possible for longer time periods, including increasingly skillful extended atmospheric forecasts, the potential for lasting impacts of atmospheric forcing on estuarine conditions, and the predictability of tidal cycles. In this study, we test whether skillful estuarine forecasts are possible for up to 35 days into the future by combining an estuarine model of Chesapeake Bay with 35-day atmospheric forecasts from an operational weather model. When compared with both a hindcast simulation from …

Shoreline Hardening Affects Nekton Biomass, Size Structure,And Taxonomic Diversity In Nearshore Waters, With Responses Mediated By Functional Species Groups, Ms Kornis, Donna Marie Bilkovic, La Davias, S Giordano, Dl Brietburg

VIMS Articles

Coastal shoreline hardening is intensifying due to human population growth and sea level rise. Prior studies have emphasized shoreline-hardening effects on faunal abundance and diversity; few have examined effects on faunal biomass and size structure or described effects specific to different functional groups. We evaluated the biomass and size structure of mobile fish and crustacean assemblages within two nearshore zones (waters extending 3 and 16 m from shore) adjacent to natural (native wetland; beach) and hardened (bulkhead; riprap) shorelines. Within 3 m from shore, the total fish/crustacean biomass was greatest at hardened shorelines, driven by greater water depth that facilitated …

Massive Upland To Wetland Conversion Compensated For Historical Marsh Loss In Chesapeake Bay, Usa, Nathalie W. Schieder, David C. Walters, Matthew L. Kirwan

VIMS Articles

Sea level rise leads to coastal transgression, and the survival of ecosystems depends on their ability to migrate inland faster than they erode and submerge. We compared marsh extent between nineteenth-century maps and modern aerial photographs across the Chesapeake Bay, the largest estuary in North America, and found that Chesapeake marshes have maintained their spatial extent despite relative sea level rise rates that are among the fastest in the world. In the mapped region (i.e., 25% of modern Chesapeake Bay marshland),94 km2of marsh was lost primarily to shoreline erosion,whereas 101 km2of marsh was created by upland drowning.Simple projections over the …

Marsh Persistence Under Sea-Level Rise Is Controlled By Multiple, Geologically Variable Stressors, Molly Mitchell, Julie Herman, Donna M. Bilkovic, Carl Hershner

VIMS Articles

Introduction: Marshes contribute to habitat and water quality in estuaries and coastal bays. Their importance to continued ecosystem functioning has led to concerns about their persistence.

Outcomes: Concurrent with sea-level rise, marshes are eroding and appear to be disappearing through ponding in their interior; in addition, in many places, they are being replaced with shoreline stabilization structures. We examined the changes in marsh extent over the past 40 years within a subestuary of Chesapeake Bay, the largest estuary in the United States, to better understand the effects of sea-level rise and human pressure on marsh coverage.

Sea Level Driven Marsh Expansion In A Coupled Model Of Marsh Erosion And Migration, Matthew L. Kirwan, Dc Walters, W. G. Reay, Ja Carr

VIMS Articles

Coastal wetlands are among the most valuable ecosystems on Earth, where ecosystem services such as flood protection depend nonlinearly on wetland size and are threatened by sea level rise and coastal development. Here we propose a simple model of marsh migration into adjacent uplands and couple it with existing models of seaward edge erosion and vertical soil accretion to explore how ecosystem connectivity influences marsh size and response to sea level rise. We find that marsh loss is nearly inevitable where topographic and anthropogenic barriers limit migration. Where unconstrained by barriers, however, rates of marsh migration are much more sensitive …