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Gregg Snedden, Ph.D.

Gregg Snedden is a research ecologist with the Wetland and Aquatic Research Center.

Gregg is broadly trained in aquatic ecology, fisheries, wetland plant ecology, and coastal physical oceanography.  Gregg’s research interests include fluvial and physical oceanographic drivers of coastal wetland hydrology, impacts of hydrology to wetland plant performance and soil dynamics, effects of Mississippi River diversions on receiving basin wetlands, and most recently, teleconnections between coastal sea-level variability and global-scale climate dynamics and the implications these linkages may impart to coastal wetland landscape sustainability.

EDUCATION

 

Ph.D.,  Oceanography and Coastal Sciences, Louisiana State University, 2006

M.S., Fisheries Science, Louisiana State University, 1997

B.S., Aquatic Ecology, University of Illinois, 1993

BACKGROUND

2007 - Present, Research Ecologist, USGS Wetland and Aquatic Research Center (formerly National Wetlands Research Center)

2005 - 2007, Post-Doctoral Research Fellow, UNC-Wilmington Center for Marine Science

2000 - 2005, Research Associate, Coastal Ecology Institute, Louisiana State University

1993 - 1997, Research Assistant, School of Forestry, Wildlife and Fisheries, Louisiana State University

Science and Products

Filter Total Items: 13
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Coastal marsh, Mississippi River Delta Plain

Long-Term Carbon Burial in Marshes of the Mississippi River Delta

Wetlands along the Gulf of Mexico coast play an important role in the global carbon cycle, but as they rapidly convert to open water, their potential for carbon storage is declining. USGS is working to provide accurate, long-term marsh soil carbon sequestration rates.
By
Ecosystems Mission Area, Land Management Research Program, Wetland and Aquatic Research Center
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Long-Term Carbon Burial in Marshes of the Mississippi River Delta

Wetlands along the Gulf of Mexico coast play an important role in the global carbon cycle, but as they rapidly convert to open water, their potential for carbon storage is declining. USGS is working to provide accurate, long-term marsh soil carbon sequestration rates.
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Filter Total Items: 32

Assessment of wave attenuation, current patterns, and sediment deposition and erosion during winter storms by living shoreline structures in Gandys Beach, New Jersey

This study was conducted by the U.S. Geological Survey and Northeastern University in cooperation with the U.S. Fish and Wildlife Service and The Nature Conservancy. This report summarizes field investigation and analysis of waves, current patterns, and sediment deposition and erosion along the Gandys Beach, New Jersey, salt marsh vegetated shoreline and mudflat, where living shoreline structures
Authors
H. Wang, William D. Capurso, Q. Chen, Ling Zhu, L.M. Niemoczynski, Gregg Snedden
By
Ecosystems Mission Area, Water Resources Mission Area, New Jersey Water Science Center, Wetland and Aquatic Research Center

2023 Coastal master plan: Model improvement plan, ICM-wetlands, vegetation, and soil

As part of the model improvement effort for the 2023 Coastal Master Plan, the wetland processes captured by the morphology and vegetation models used during previous master plans were reevaluated to assess how Integrated Compartment Model (ICM) subroutines could be improved. This process considered technical reviews, comments, and suggested improvements provided by model developers, advisory group
Authors
Melissa M. Baustian, Denise Reed, Jenneke Visser, Scott M. Duke-Sylvester, Gregg Snedden, Hongqing Wang, Kristin DeMarco, Madeline R. Foster-Martinez, Leigh Anne Sharp, Tommy E. McGinnis, Elizabeth Jarrell
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Ecosystems Mission Area, Land Management Research Program, Wetland and Aquatic Research Center

Field observations of wind waves in Upper Delaware Bay with living shorelines

Constructed oyster reefs (CORs) provide shore protections and habitats for fish and shellfish communities via wave energy attenuation. However, the processes and mechanism of CORs on wave attenuation remain unclear, thus limiting the effective assessment of CORs for shoreline protection. This paper presents results of a field investigation on wave characteristics and wave spectral variations along
Authors
Ling Zhu, Q. Chen, Hongqing Wang, William D. Capurso, L.M. Niemoczynski, Kelin Hu, Gregg Snedden
By
Ecosystems Mission Area, Water Resources Mission Area, Wetland and Aquatic Research Center , New York Water Science Center, New Jersey Water Science Center

Drivers and impacts of water level fluctuations in the Mississippi River delta: Implications for delta restoration

This review synthesizes the knowledge regarding the environmental forces affecting water level variability in the coastal waters of the Mississippi River delta and relates these fluctuations to planned river diversions. Water level fluctuations vary significantly across temporal and spatial scales, and are subject to influences from river flow, tides, vegetation, atmospheric forcing, climate chang
Authors
Matthew R. Hiatt, Gregg Snedden, John W. Day, Robert V. Rohli, John A. Nyman, Robert R. Lane, Leigh A. Sharp
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Mississippi river sediment diversions and coastal wetland sustainability: Synthesis of responses to freshwater, sediment, and nutrient inputs

Management and restoration of coastal wetlands require insight into how inundation, salinity, and the availability of mineral sediment and nutrients interact to influence ecosystem functions that control sustainability. The Mississippi River Delta, which ranks among the world's largest and most productive coastal wetland complexes, has experienced extensive deterioration over the last century due,
Authors
Tracy Elsey-Quirk, Sean A. Graham, Irving A. Mendelssohn, Gregg Snedden, John W. Day, Gary P. Shaffer, Leigh Anne Sharp, Robert R. Twilley, James Pahl, R.R. Lane
By
Ecosystems Mission Area, Wetland and Aquatic Research Center , Gulf of Mexico

Hydrodynamic controls on sediment retention in an emerging diversion-fed delta

The morphodynamics of river-dominated deltas are largely controlled by the supply and retention of sediment within deltaic wetlands and the rate of relative sea-level rise. Yet, sediment budgets for deltas are often poorly constrained. In the Mississippi River Delta, a system rapidly losing land due to natural and anthropogenic causes, restoration efforts seek to build new land through the use of
Authors
Molly E. Keogh, Alexander S. Kolker, G.A. Snedden, Alisha A. Renfro
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Patterning emergent marsh vegetation assemblages in coastal Louisiana, USA, with unsupervised artificial neural networks

QuestionAre self‐organizing maps (SOMs) useful for patterning coastal wetland vegetation communities? Do SOMs provide robust alternatives to traditional classification methods, particularly when underlying species response functions are unknown or difficult to approximate, or when a need exists to continuously classify new samples obtained under ongoing long‐term ecosystem monitoring programs as t
Authors
G.A. Snedden
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Numerical modeling of the effects of Hurricane Sandy and potential future hurricanes on spatial patterns of salt marsh morphology in Jamaica Bay, New York City

The salt marshes of Jamaica Bay, managed by the New York City Department of Parks & Recreation and the Gateway National Recreation Area of the National Park Service, serve as a recreational outlet for New York City residents, mitigate flooding, and provide habitat for critical wildlife species. Hurricanes and extra-tropical storms have been recognized as one of the critical drivers of coastal wetl
Authors
Hongqing Wang, Q. Chen, Kelin Hu, Gregg A. Snedden, Ellen K. Hartig, Brady R. Couvillion, Cody L. Johnson, Philip M. Orton
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Ecosystems Mission Area, Wetland and Aquatic Research Center , Hurricane Sandy, Hurricanes

A landscape-scale assessment of above- and belowground primary production in coastal wetlands: Implications for climate change-induced community shifts

Above- and belowground production in coastal wetlands are important contributors to carbon accumulation and ecosystem sustainability. As sea level rises, we can expect shifts to more salt-tolerant communities, which may alter these ecosystem functions and services. Although the direct influence of salinity on species-level primary production has been documented, we lack an understanding of the lan
Authors
Camille L. Stagg, Donald R. Schoolmaster, Sarai C. Piazza, Gregg Snedden, Gregory D. Steyer, Craig J Fischenich, Robert W. McComas
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Drivers of barotropic and baroclinic exchange through an estuarine navigation channel in the Mississippi River Delta Plain

Estuarine navigation channels have long been recognized as conduits for saltwater intrusion into coastal wetlands. Salt flux decomposition and time series measurements of velocity and salinity were used to examine salt flux components and drivers of baroclinic and barotropic exchange in the Houma Navigation Channel, an estuarine channel located in the Mississippi River delta plain that receives su
Authors
Gregg Snedden
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

What role do hurricanes play in sediment delivery to subsiding river deltas?

The Mississippi River Delta (MRD) has undergone tremendous land loss over the past century due to natural and anthropogenic influences, a fate shared by many river deltas globally. A globally unprecedented effort to restore and sustain the remaining subaerial portions of the delta is now underway, an endeavor that is expected to cost $50–100B over the next 50 yr. Success of this effort requires a
Authors
James E. Smith, Samuel J. Bentley, Gregg Snedden, Crawford White
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Inundation and salinity impacts to above- and belowground productivity in Spartina patens and Spartina alterniflora in the Mississippi River Deltaic Plain: implications for using river diversions as restoration tools

Inundation and salinity directly affect plant productivity and processes that regulate vertical accretion in coastal wetlands, and are expected to increase as sea level continues to rise. In the Mississippi River deltaic plain, river diversions, which are being implemented as ecosystem restoration tools, can also strongly increase inundation in coastal wetlands. We used an in situ mesocosm approac
Authors
Gregg A. Snedden, Kari Foster Cretini, Brett Patton
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

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