SPCMSC scientists publish new paper on shoreline erosion and sediment deposition

Release Date:

Kathryn Smith and team publish a new paper, “Lateral shoreline erosion and shore-proximal sediment deposition on a coastal marsh from seasonal, storm and decadal measurements” in the journal Geomorphology. The study provides new information about sediment accumulation and marsh shoreline erosion at multiple time scales in the Grand Bay National Estuarine Research Reserve.

a person holds a square plate on a pole with sediment piled on top of it in front of a marsh shoreline

A net sedimentation tile (NST) is used by scientists to measure surface sediment deposition in wetlands over short time scales. Scientists installed several NSTs on the surface of the marsh to measure sediment deposition. The samples are retrieved and measured in the lab to identify short-term sediment deposition rates on the marsh surface. It is important to study sediment delivery since it is a critical process influencing marsh elevation and how the marsh will respond to changing sea level. (Credit: Joseph Terrano, USGS. Public domain.)

Salt marshes provide essential ecosystem services to communities and the environment including protecting infrastructure from storms, absorbing atmospheric carbon, and serving as wildlife habitat. These valuable ecosystems are under increasing threat of loss due to both natural and anthropogenic (human-influenced)  impacts. Marshes can experience a lot of wave action, and the sediments transported by these actions are either pushed up into the marsh or pulled away from the shore into the estuary. If sediments keep getting eroded away from the marsh system, the marsh may not be able to keep pace with future changes such as sea-level rise.

Research Ecologist Dr. Kathryn Smith and colleagues from the USGS St. Petersburg Coastal and Marine Science Center investigated marsh sediment budgets at seasonal, annual, episodic, and decadal time scales within the Grand Bay National Estuarine Research Reserve in Grand Bay, Mississippi. They evaluated sediment deposition and erosion by measuring how much sediment accumulated using experimental tiles and sediment cores near the marsh shoreline, and measured shoreline erosion rates by using Global Positioning System (GPS) and historic maps. They were also able to compare accumulation and erosion before and after a tropical storm (Hurricane Nate) made landfall in October 2017 during the study, providing an episodic perspective to the project. 

In addition to improving our understanding of marsh sediment dynamics, these data are useful for providing baseline information for marsh vulnerability analyses, carbon budgets, and impact assessment of restoration and mitigation plans.

To read the journal article, visit: https://doi.org/10.1016/j.geomorph.2021.107829.

Related Content

Filter Total Items: 1
Date published: May 28, 2020
Status: Active

Estuarine and MaRsh Geology Research Project

The goal of the Estuarine and MaRsh Geology (EMRG) Research Project is to study how and where short- and long-term marsh and estuarine coastal processes interact, how they influence coastal accretion or erosion, and how they pre-condition a marsh’s resiliency to storms, sea-level change, and human alterations along the northern Gulf of Mexico (Grand Bay and Point aux Chenes, Mississippi and St...