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 collected between 2016 and 2017 from a related NST study in the GNDNERR (Middle Bay and North Rigolets) can be found at https://doi.org/10.5066/P9BFR2US
. Please read the full metadata for details on data collection, dataset variables, and data quality.
Net sedimentation tiles (also called sediment plates, tiles, or traps) are an inexpensive tool to assess sediment deposition in coastal zones. Each of the four study sites consisted of five NST plots at 5, 10, 15, 20, and 25 m from the shoreline. Multiple NSTs per distance were used to assess the spatial variation within the marsh and across the shoreline to the marsh interior. To begin this study, textured NST were used to assess the temporal variability in the sediment depositional flux by varying the deployment duration (two consecutive 3-month versus one 6-month deployment period). The initial design (textured NST) used the textured bottom of a 4.25-inch (in) square glazed tile commonly found at local hardware stores glued to a PVC stem and pushed flush into the marsh surface. Six textured NST were deployed in each plot in July 2018 (30 per site or 120 total). In October 2018, three of the six NST (60 total NST) were collected, and three new textured NST were then placed in the same locations. In February 2019, all 120 NST (60 three-month NST and 60 six-month NST) were collected. After the textured NST were collected, three NST of both designs (textured and untextured) were deployed within the same NST plot (120 total NST deployed) to determine if there was a statistical difference in sediment retention. Subsequent NST (untextured) were constructed using a 4.25-in. square fully unglazed and untextured tile, which can be ordered at specialty tile or art supply stores, glued to a PVC stem and inserted until the top of the NST was flush with the marsh surface. From February to August 2019, all 120 NST were collected and redeployed, every three months. From August 2019 to January 2020, only three untextured NST were deployed in each plot (60 total NST deployed) and were collected and redeployed every three months. This data release includes spreadsheets summarizing particle size analysis results for select NST and surface samples collected from Grand Bay.
Data was collected through quarterly field visits. Each field visit was assigned a field activity number (FAN) and sub-FAN by the U.S Geological Survey (USGS). This publication contains data for field activities from: 1) 2018-332-FA (18CCT01, July 2018), 2) 2018-358-FA (18CCT10, July 2018-October 2018), 3) 2019-303-FA (19CCT01, October 2018-February 2019; 19CCT02, February 2019-May 2019, 19CCT03, May 2019-August 2019; 19CCT04, August 2019-November 2019), 4) 2020-301-FA (20CCT01, November 2019-January 2020). NSTs were deployed on the start date and collected on the end date. The unedited output grain size files with statistics for each sample run along with averaged statistics for each sample generated by the USGS Average and Check Standard Deviation macro are available upon request. The averaged results for the subset of statistical parameters that apply to these data are summarized and published in this data release.
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: unconsolidated deposits
Theme_Keyword: coastal processes
Theme_Keyword: net sedimentation tile
Theme_Keyword: sediment plate
Theme_Keyword: physical parameters
Theme_Keyword: U.S. Geological Survey
U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
Theme_Keyword: grain size
Theme_Keyword: particle size analysis
Place_Keyword: Grand Bay National Estuarine Research Reserve
Place_Keyword_Thesaurus: Common Geographic Areas
Place_Keyword: Gulf of Mexico
Place_Keyword: United States
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests that it be acknowledged as the originator of this dataset in any future products or research derived from these data. This metadata record should be reviewed in its entirety.
Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. Users should be aware that comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies in data collection methods. These data are not legal documents and are not to be used as such.
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