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Full-Text Articles in Physical Sciences and Mathematics

Impact Of Seabed Resuspension On Oxygen And Nitrogen Dynamics In The Northern Gulf Of Mexico: A Numerical Modeling Study, Julia M. Moriarty, Courtney K. Harris, Marjorie A.M. Friedrichs, Katja Fennel, Kehui Xu Oct 2018

Impact Of Seabed Resuspension On Oxygen And Nitrogen Dynamics In The Northern Gulf Of Mexico: A Numerical Modeling Study, Julia M. Moriarty, Courtney K. Harris, Marjorie A.M. Friedrichs, Katja Fennel, Kehui Xu

VIMS Articles

Resuspension affects water quality in coastal environments by entraining seabed organic matter into the water column, which can increase remineralization, alter seabed fluxes, decrease water clarity, and affect oxygen and nutrient dynamics. Nearly all numerical models of water column biogeochemistry, however, simplify seabed and bottom boundary layer processes and neglect resuspension. Here we implemented HydroBioSed, a coupled hydrodynamic-sediment transport-biogeochemical model to examine the role of resuspension in regulating oxygen and nitrogen dynamics on timescales of a day to a month. The model was implemented for the northern Gulf of Mexico, where the extent of summertime hypoxia is sensitive to seabed …


Restoring The Eastern Oyster: How Much Progress Has Been Made In 53 Years?, Ab Hernandez, Rochelle Brumbaugh, P Fredrick, R Grizzle, Mark Luckenbach, Ch Peterson, C Angelini Oct 2018

Restoring The Eastern Oyster: How Much Progress Has Been Made In 53 Years?, Ab Hernandez, Rochelle Brumbaugh, P Fredrick, R Grizzle, Mark Luckenbach, Ch Peterson, C Angelini

VIMS Articles

Coastal ecosystem restoration is accelerating globally as a means of enhancing shoreline protection, carbon storage, water quality, fisheries, and biodiversity. Among the most substantial of these efforts have been those focused on re-establishing oyster reefs across the US Atlantic and Gulf coasts. Despite considerable investment, it is unclear how the scale of and approaches toward oyster restoration have evolved. A synthesis of 1768 projects undertaken since 1964 reveals that oyster substrate restoration efforts have primarily been concentrated in the Chesapeake Bay and the Gulf Coast, have been heavily reliant on oyster shell, and have re-established 4.5% of the reef area …


Living Shorelines Support Nearshore Benthic Communities In Upper And Lower Chesapeake Bay, Tm Davenport, Rochelle D. Seitz, Ke Knick, N Jackson Sep 2018

Living Shorelines Support Nearshore Benthic Communities In Upper And Lower Chesapeake Bay, Tm Davenport, Rochelle D. Seitz, Ke Knick, N Jackson

VIMS Articles

Human population growth and sea-level rise are increasing the demand for protection of coastal property against shoreline erosion. Living shorelines are designed to provide shoreline protection and are constructed or reinforced using natural elements. While living shorelines are gaining popularity with homeowners, their ability to provide ecological services (e.g., habitat provision and trophic transfer) is not well understood, and information is needed to improve coastal and resource management decision-making. We examined benthic community responses to living shorelines in two case-study subestuaries of Chesapeake Bay using a before-after control-impact study design. At Windy Hill, a bulkhead was removed and replaced by …


Estimating Hypoxic Volume In The Chesapeake Bay Using Two Continuously Sampled Oxygen Profiles, Aaron J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, Malcolm E. Scully Aug 2018

Estimating Hypoxic Volume In The Chesapeake Bay Using Two Continuously Sampled Oxygen Profiles, Aaron J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, Malcolm E. Scully

VIMS Articles

Low levels of dissolved oxygen (DO) occur in many embayments throughout the world and have numerous detrimental effects on biota. Although measurement of in situ DO is straightforward with modern instrumentation, quantifying the volume of water in a given embayment that is hypoxic (hypoxic volume (HV)) is a more difficult task; however, this information is critical for determining whether management efforts to increase DO are having an overall impact. This paper uses output from a three‐dimensional numerical model to demonstrate that HV in Chesapeake Bay can be estimated well with as few as two vertical profiles. In addition, the cumulative …


Impacts Of Atmospheric Nitrogen Deposition And Coastal Nitrogen Fluxes On Oxygen Concentrations In Chesapeake Bay, Fei Da, Marjorie A.M. Friedrichs, Pierre St-Laurent Jul 2018

Impacts Of Atmospheric Nitrogen Deposition And Coastal Nitrogen Fluxes On Oxygen Concentrations In Chesapeake Bay, Fei Da, Marjorie A.M. Friedrichs, Pierre St-Laurent

VIMS Articles

Although rivers are the primary source of dissolved inorganic nitrogen (DIN) inputs to the Chesapeake Bay, direct atmospheric DIN deposition and coastal DIN concentrations on the continental shelf can also significantly influence hypoxia; however, the relative impact of these additional sources of DIN on Chesapeake Bay hypoxia has not previously been quantified. In this study, the estuarine‐carbon‐biogeochemistry model embedded in the Regional‐Ocean‐Modeling‐System (ChesROMS‐ECB) is used to examine the relative impact of these three DIN sources. Model simulations highlight that DIN from the atmosphere has roughly the same impact on hypoxia as the same gram‐for‐gram change in riverine DIN …


A 3d Unstructured-Grid Model For Chesapeake Bay: Importance Of Bathymetry, Fei Ye, Yinglong J. Zhang, Harry V. Wang, Marjorie A.M. Friedrichs, Isaac D. Irby, Eli Alteljevich, Arnaldo Valle-Levinson, Zhengui Wang, Hai Huang, Jian Shen, Jiabi Du Jul 2018

A 3d Unstructured-Grid Model For Chesapeake Bay: Importance Of Bathymetry, Fei Ye, Yinglong J. Zhang, Harry V. Wang, Marjorie A.M. Friedrichs, Isaac D. Irby, Eli Alteljevich, Arnaldo Valle-Levinson, Zhengui Wang, Hai Huang, Jian Shen, Jiabi Du

VIMS Articles

We extend the 3D unstructured-grid model previously developed for the Upper Chesapeake Bay to cover the entire Bay and its adjacent shelf, and assess its skill in simulating saltwater intrusion and the coastal plume. Recently developed techniques, including a flexible vertical grid system and a 2nd-order, monotone and implicit transport solver are critical in successfully capturing the baroclinic responses. Most importantly, good accuracy is achieved through an accurate representation of the underlying bathymetry, without any smoothing. The model in general exhibits a good skill for all hydrodynamic variables: the averaged root-mean-square errors (RMSE‟s) in the Bay are 9 cm for …


Host And Symbionts In Pocillopora Damicornis Larvae Display Different Transcriptomic Responses To Ocean Acidification And Warming, Emily B. Rivest, Morgan B. Kelly, Melissa B. Debiasse, Gretchen E. Hofmann May 2018

Host And Symbionts In Pocillopora Damicornis Larvae Display Different Transcriptomic Responses To Ocean Acidification And Warming, Emily B. Rivest, Morgan B. Kelly, Melissa B. Debiasse, Gretchen E. Hofmann

VIMS Articles

As global ocean change progresses, reef-building corals and their early life history stages will rely on physiological plasticity to tolerate new environmental conditions. Larvae from brooding coral species contain algal symbionts upon release, which assist with the energy requirements of dispersal and metamorphosis. Global ocean change threatens the success of larval dispersal and settlement by challenging the performance of the larvae and of the symbiosis. In this study, larvae of the reef-building coral Pocillopora damicornis were exposed to elevated pCO2 and temperature to examine the performance of the coral and its symbionts in situ and better understand the mechanisms of …


Carbon Budget Of Tidal Wetlands, Estuaries, And Shelf Waters Of Eastern North America, Rg Najjar, M Herrmann, R Alexander, Ew Boyer, Dj Burdige, D Butman, W-J Cai, Elizabeth A. Canuel, Rf Chen, Marjorie A.M. Friedrichs, Et Al Mar 2018

Carbon Budget Of Tidal Wetlands, Estuaries, And Shelf Waters Of Eastern North America, Rg Najjar, M Herrmann, R Alexander, Ew Boyer, Dj Burdige, D Butman, W-J Cai, Elizabeth A. Canuel, Rf Chen, Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Carbon cycling in the coastal zone affects global carbon budgets and is critical for understanding the urgent issues of hypoxia, acidification, and tidal wetland loss. However, there are no regional carbon budgets spanning the three main ecosystems in coastal waters: tidal wetlands, estuaries, and shelf waters. Here we construct such a budget for eastern North America using historical data, empirical models, remote sensing algorithms, and process‐based models. Considering the net fluxes of total carbon at the domain boundaries, 59 ± 12% (± 2 standard errors) of the carbon entering is from rivers and 41 ± 12% is from the atmosphere, …


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 Jan 2018

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 …


Effects Of Projected Changes In Wind, Atmospheric Temperature, And Freshwater Inflow On The Ross Sea, Ms Dinniman, Jm Klinck, Ee Hofmann, Walker O. Smith Jr. Jan 2018

Effects Of Projected Changes In Wind, Atmospheric Temperature, And Freshwater Inflow On The Ross Sea, Ms Dinniman, Jm Klinck, Ee Hofmann, Walker O. Smith Jr.

VIMS Articles

A 5-km horizontal resolution regional ocean-sea ice-ice shelf model of the Ross Sea is used to examine the effects of changes in wind strength, air temperature, and increased meltwater input on the formation of high-salinity shelf water (HSSW), on-shelf transport and vertical mixing of Circumpolar Deep Water (CDW) and its transformation into modified CDW (MCDW), and basal melt of the Ross Ice Shelf (RIS). A 20% increase in wind speed, with no other atmospheric changes, reduced summer sea ice minimum area by 20%, opposite the observed trend of the past three decades. Increased winds with spatially uniform, reduced atmospheric temperatures …