Water level data for four sites in the coastal marsh at Grand Bay National Estuarine Research Reserve, Mississippi, from October 2018 through January 2020
To better understand sediment deposition in marsh environments, scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center (USGS-SPCMSC) selected four study sites (Sites 5, 6, 7, and 8) along the Point Aux Chenes Bay shoreline of the Grand Bay National Estuarine Research Reserve (GNDNERR), Mississippi. These datasets were collected to serve as baseline data prior to the installation of a living shoreline (a subtidal sill). Each site consisted of five plots located along a transect perpendicular to the marsh-estuary shoreline at 5-meter (m) increments (5, 10, 15, 20, and 25 m from the shoreline). Each plot contained six net sedimentation tiles (NST) that were secured flush to the marsh surface using polyvinyl chloride (PVC) pipe. NST are an inexpensive and simple tool to assess short- and long-term deposition that can be deployed in highly dynamic environments without the compaction associated with traditional coring methods. The NST were deployed for three month sampling periods, measuring sediment deposition from July 2018 to January 2020, with one set of NST being deployed for six months. Sediment deposited on the NST were processed to determine physical characteristics, such as deposition thickness, volume, wet weight/dry weight, grain size, and organic content (loss-on-ignition [LOI]). For select sampling periods, ancillary data (water level, elevation, and wave data) are also provided in this data release. Data were collected during USGS Field Activities Numbers (FAN) 2018-332-FA (18CCT01), 2018-358-FA (18CCT10), 2019-303-FA (19CCT01, 19CCT02, 19CCT03, and 19CCT04, respectively), and 2020-301-FA (20CCT01). Additional survey and data details are available from the U.S. Geological Survey Coastal and Marine Geoscience Data System (CMGDS) at,
https://cmgds.marine.usgs.gov/. Data from a related NST study in the GNDNERR (Middle Bay and North Rigolets) can be found in Smith and others (2020). Data collected after the living shoreline (subtidal sill) installation can be found in Terrano and others (2025). For additional information on data processing and analysis, refer to the accompanying journal publication Smith and others (2025). Please read the full metadata for details on data collection, dataset variables, and data quality.
USGS scientists collected sediment samples and shore profiles from Grand Bay, Mississippi, during a total of six surveys. Each field visit was assigned a FAN and sub-FAN by (USGS staff. This publication contains data for field activities from: 2019-303-FA (19CCT01, October 2018-February 2019; 19CCT02, February 2019-May 2019, 19CCT03, May 2019-August 2019; 19CCT04, August 2019-November 2019), and 2020-301-FA (20CCT01, November 2019-January 2020). Water level data from 19CCT02 (Sites 5 and 8) were determined to have affected by sensor drift (a gradual degradation of the sensor and its components that resulted in reading offsets when compared to the factory-calibrated state). To correct the drift, the data were split into two date ranges and corrected accordingly. The 19CCT04 Site 7 elevations were corrected by 0.14 m to account for field measurement error (data were not collected prior to moving well). In addition to the comma-separated values (CSV) text file format, water level data are also provided as Hypertext Markup Language (HTML) graphs.
