Jonathan Pitchford Michael Brochard Joseph F. Terrano Kathryn E.L. Smith 20230605 1.0 tabular digital data Kathryn E.L. Smith Joseph F. Terrano Jonathan Pitchford Michael Brochard Joseph M. Vargas Isabelle D. Atchia Cheyenne S. Everhart Christopher G. Smith 20200713 2.0 Multimedia presentation U.S. Geological Survey data release doi:10.5066/P9ONI8PS St. Petersburg, FL U.S. Geological Survey https://doi.org/10.5066/P9ONI8PS 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, Mississippi (GNDNERR). 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 four 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, turbidity, and wave data) are also provided in this data release. Data were collected during 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. Vegetation species and abundance data can provide important information on the health of a marsh. Vegetation surveys were conducted within each NST plot (1 square meter) during the 19CCT02 and 20CCT01 trips. Within each plot the average vegetation canopy height was measured, a percent cover for each species was estimated, and a sub-sampled stem count of each species from 1/16th of a meter of the plot was collected. Data was collected through two 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) 2019-303-FA (19CCT02, May 2019), and 2) 2020-301-FA (20CCT01, January 2020). 20190507 20200128 ground condition Complete As needed -88.449757 -88.396209 30.429843 30.335728 USGS Metadata Identifier USGS:a1888bbc-b5f1-413a-a1f9-8a560a92f6fa ISO 19115 Topic Category environment oceans geoscientificinformation USGS Thesaurus unconsolidated deposits geology geomorphology coastal processes wetland ecosystems plot sampling land use and land cover vegetation None sediment net sedimentation tile NST sediment plate physical parameters U.S. Geological Survey USGS U.S. Geological Survey St. Petersburg Coastal and Marine Science Center SPCMSC deposition marsh None Grand Bay National Estuarine Research Reserve NERR Common Geographic Areas Gulf of Mexico United States Mississippi None sediment surface No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Common CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. U.S. Geological Survey - St Petersburg Coastal and Marine Science Center Kathryn E.L Smith Research Ecologist Mailing

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St. Petersburg FL 33701 727-502-8073 727-502-8182 kelsmith@usgs.gov 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. Environment as of Metadata Creation: Microsoft Windows 10 Enterprise Version 17763.1098 (Build 1809); Microsoft Excel for Microsoft 365 MSO (Version 2202 Build 16.0.14931.20648) Kathryn E.L. Smith Joseph F. Terrano Nicole S. Khan Chelsea A. Stalk 20200226 St. Petersburg, Florida U.S. Geological Survey https://doi.org/10.5066/P9BFR2US Joseph F. Terrano Alisha M. Ellis Kathryn E.L. Smith Jonathan Pitchford Michael Archer Joseph M. Vargas Jonathan P. Griffiths Samuel M. Randall Matthew Virden Cheyenne S. Everhart Eric Sparks 20250527 St. Petersburg, Florida U.S. Geological Survey hhttps://doi.org/10.5066/P13VT3ET Kathryn E.L. Smith Jonathan L. Pitchford Eric L. Sparks Michael J. Archer Matthew F. Virden Joseph F. Terrano Christopher G. Smith 20250612 Estuaries and Coasts Volume 48, Article 128 Online Springer Nature https://doi.org/10.1007/s12237-025-01564-7 Kenneth Moore 20091201 Gloucester Point, Virginia Chesapeake Bay National Estuarine Research Reserve System in Virginia https://coast.noaa.gov/data/docs/nerrs/Research_TechSeries_TechReportSWMPBio-MonitoringProtocol.pdf The physical parameters reported in the table were analyzed at the USGS St. Petersburg Coastal and Marine Science sedimentology lab. This sediment dataset has not been independently verified for accuracy. The data included in Grand_Bay_Vegetation_Data.csv are related to: FAN, alternate FAN, site, plot distance, plot canopy height, vegetation species, percent cover, and stem counts. Additional attribute information and definitions are provided below. This is a complete, vegetation survey data file for data collected within the Grand Bay National Estuarine Research Reserve, Mississippi. Four previously established study sites (Sites 5, 6, 7, and 8) containing net sedimentation tiles (NST) within the Grand Bay National Estuarine Research Reserve, Mississippi were used to collect vegetation data. NST plots (a 1 square meter plot) were located at 5, 10, 15, 20 and 25 m inland and perpendicular to the shoreline. Vegetation surveys were conducted by Grand Bay National Estuarine Research Reserve staff in 19CCT02 (May 2019) and 20CCT01 (February 2020) using NERR system wide monitoring protocols (Moore, 2009). First, a 1 square meter quadrat was placed on the corner PVC markers of the plot to ensure the quadrat covered the study area. To collect percent cover, the observer looked at the whole plot, then visualized that all of one species were gathered together and pushed to once side of the quadrat (if it appears that three-quarters of the quadrat is covered, then the percent cover for that species is 75%). This was repeated for each of the vegetation species, making sure that the overall sum of percent cover with species was not greater than 100%. To collect canopy height, a pole marked at 25-centimeter (cm) intervals was used to estimate the average height of the vegetation within the plot. To collect stem densities, the quadrat was marked at 1/16th of a meter in the upper right corner. Within the smaller quadrat area, the number of stems for each species were counted. Field sheet data was then transferred to comma separated value (CSV) file for publication. 2020 Grand_Bay_Vegetation.csv U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center Joseph F. Terrano Physical Scientist Mailing and physical

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St. Petersburg FL 33701 U.S. (727) 502-8047 jterrano@usgs.gov Grand_Bay_Vegetation.csv Vegetation data collected from NST plots located in the marsh at Grand Bay National Estuarine Research Reserve, Mississippi, from May 2019 and February 2020. USGS FAN USGS field activity number (FAN) assigned to each sample collection trip. USGS Field activity numbers were assigned by the USGS to track field collection of samples. The FAN consists of YYYY-XXX-FA, with YYYY being the 4-digit year and XXX being the trip number, and FA representing that it is a field activity. Alt_FAN Alternate (abbreviated) FAN assigned each collection trip. USGS FANs were assigned by the USGS and are YYCCTXX, where YY is the 2-digit year, CCT stands for coastal change and transport, and XX is the trip number. Site Site number USGS 5 8 Plot distance (meters) Distance inland to the NST plot from the shoreline. USGS 5 25 meters (m) Plot canopy* height (meters) *Canopy height is an average of all vegetation species for the plot. Only one value is presented per plot. USGS 0.1 1.25 meters (m) Vegetation species Codes used to identify the type of NST that was deployed. USGS Scientific name (genus and species) of the vegetation. Percent cover (%) Percent of the plot that was covered by each species. Combined percent of all species cannot exceed 100 percent. The difference between 100 percent and the sum of all species within the plot represents unvegetated area. USGS <5 70 percent (%) Stem^ count ^Stem count sub samples were collected from a marked area on the quadrat (at 1/16 of a meter) from the top right corner of each plot. Stem counts with "--" denote no stems of that species were counted in the sub sampled plot, however that vegetation type is present in the overall plot. USGS 1 28 U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center USGS SPCMSC Data Management mailing and physical

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Saint Petersburg FL 33701 United States 727-502-8000 gs-g-spcmsc_data_inquiries@usgs.gov Grand_Bay_Vegetation.csv Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Any use of trade, firm, or product name is for descriptive purposes only and does not imply endorsement by the U.S. Government. Comma-delimited text 1 .csv Unzip 0.021 https://coastal.er.usgs.gov/data-release/doi-P9ONI8PS/Grand_Bay_Vegetation_Data.zip None, if obtained online None The spreadsheet included in this .zip file were created for use with Microsoft Excel 365. The file may also be viewed with the Microsoft Excel viewer or by downloading a Microsoft Compatibility Pack to view with older versions of Microsoft Excel. 20250618 U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center USGS SPCMSC Data Management mailing and physical

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Saint Petersburg FL 33701 United States 727-502-8000 gs-g-spcmsc_data_inquiries@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998