Robert Welk Kate V. Ackerman Zafer Defne Neil K. Ganju 20200331 3.0 Vector Digital dataset (Polygon) data release 10.5066/P91H426U Woods Hole Coastal and Marine Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Hazards and Resources Program https://doi.org/10.5066/P91H426U https://www.sciencebase.gov/catalog/item/5ddda8fae4b04a30051ac270 Robert Welk Kate V. Ackerman Zafer Defne Neil Ganju 2020 3.0 data release 10.5066/P91H426U Reston, VA U.S. Geological Survey Suggested citation: Welk, R., Ackerman, K.V., Defne, Z., and Ganju, N.K., 2020, Coastal wetlands of eastern Long Island, New York (ver. 3.0, May 2026): U.S. Geological Survey data release, https://doi.org/10.5066/P91H426U. https://doi.org/10.5066/P91H426U https://www.sciencebase.gov/catalog/item/5dd56511e4b0695797628ca6 *In this revision (version 3), the marsh plains were subdivided into smaller marsh units, and metrics were updated to reflect this change. Details can be found in the process steps below. This dataset (shoreline change rate) was not revised; it is included here only to provide shoreline change rates at the marsh plain scale rather than at the marsh unit scale.* This data release contains coastal wetland synthesis products for the geographic region of eastern Long Island, New York, including the north and south forks, Gardiners Island, and Fishers Island. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, and mean tidal range, are calculated for smaller units delineated from a Digital Elevation Model, providing the spatial variability of physical factors that influence wetland health. Through scientific efforts initiated with the Hurricane Sandy Science Plan, the U.S. Geological Survey has been expanding national assessment of coastal change hazards and forecast products to coastal wetlands with the intent of providing Federal, State, and local managers with tools to estimate the vulnerability and ecosystem service potential of these wetlands. For this purpose, the response and resilience of coastal wetlands to physical factors need to be assessed in terms of the ensuing change to their vulnerability and ecosystem services. This dataset displays shoreline change rates for eastern Long Island. Shoreline change rates are based on analysis of digital vector shorelines acquired from historical topographic sheets provided by National Oceanic and Atmospheric Administration (NOAA). Analysis was performed using the Digital Shoreline Analysis System (DSAS), an extension for ArcMap, created by the U.S. Geological Survey. Linear Regression Rates (LRR) and End Point Rates (EPR) of shoreline change were averaged along the shoreline of each salt marsh plain to generate this dataset. LRR rates were used in areas where three or more historical shorelines were available, while EPR was used in areas where only two were available. Positive and negative values indicate accretion and erosion respectively. *In this revision (version 3), the marsh plains were subdivided into smaller marsh units, and metrics were updated to reflect this change. Details can be found in the process steps below. This dataset (shoreline change rate) was not revised; it is included here only to provide shoreline change rates at the marsh plain scale rather than at the marsh unit scale.* Analysis of shoreline change rates is part of a comprehensive assessment to identify the factors and their weights in determining the vulnerability and resiliency of salt marshes. This polygon dataset facilitates quantifying these rate changes in the eastern Long Island salt marsh complex by summarizing the rate change results over the previously determined conceptual salt marsh unit polygons. 2020 Publication date of original release. Complete None -72.748198 71.885316 41.291362 40.766433 USGS Metadata Identifier USGS:5ddda8fae4b04a30051ac270 USGS Thesaurus geospatial datasets wetland ecosystems wetland functions coastal ecosystems coastal processes tides (oceanic) None shoreline coastline accretion sediment salt marsh vegetation marsh health estuary resilience vulnerability polygon shapefile ISO 19115 Topic Category oceans inlandWaters environment GNIS Atlantic Ocean State of New York Suffolk County, New York Great Peconic Bay Little Peconic Bay Moriches Bay Shinnecock Bay Long Island Sound No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Commons 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. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset. These data are not to be used for navigation. U.S. Geological Survey Robert Welk Hydrologic Technician mailing and physical address

2045 Route 112

Coram NY 11743 631-736-0783 x141 rwelk@usgs.gov https://www.sciencebase.gov/catalog/file/get/5ddda8fae4b04a30051ac270?name=ShCR_ELI_browse.png&allowOpen=true Graphic that shows the shoreline change rate overlaying Esri Map. PNG Environment as of Metadata Creation: Microsoft 10 Version 6.2 (Build 9200); Esri ArcGIS 10.7.1 (Build 11595) Service Pack N/A (Build N/A); and ArcGIS Pro 2.8.8. Water-land boundaries and marsh unit boundaries inherit their accuracy from the source data, the conceptual salt marsh units. Shoreline change rate is calculated by averaging the values from the source layer (shoreline change transects are drawn every ~50 meters along a baseline) for each marsh unit. Shoreline change rates in the source data are influenced by availability and accuracy Mean Linear Regression Rate (LRR) and mean End Point Rate (EPR) of shoreline change is calculated by averaging the LRR and EPR transects that cross the shoreline of a marsh unit, respectively. If a marsh unit has a shoreline, but no transect is available to assign a shoreline change rate, the mean LRR and/or mean EPR is set to zero. The results are specific to the marsh polygons as defined within the boundaries of the eastern Long Island salt marsh complex. A detailed on-the-ground analysis of a single site may result in a different interpretation of the wetland and marsh unit boundaries. All of the marsh units are assigned a value. If MEAN_LRR is 0 for a marsh unit, 0 in the TRANS_PER_L field indicates the marsh unit has no shoreline and -1 indicates there are no transects available. Likewise, if MEAN_EPR is 0 for a marsh unit, 0 in the TRANS_PER_E field indicates the marsh has no shoreline and -1 indicates there are no transects available. Horizontal accuracy for the polygon boundaries is inherited from the source layer, the conceptual marsh units and considered to be +/- 6 meters. Robert Welk 2019 1.0 Vector Digital dataset (Polyline) data release DOI:10.5066/P9JVMLFT Reston, Virginia U.S. Geological Survey https://doi.org/10.5066/P9JVMLFT Online 2019 publication date LRR_transects Used the LRR and EPR transects to calculate the shoreline change rates at each marsh unit. Download date was 2019/08/01. U.S. Fish and Wildlife Service 2017 Vector Digital dataset (Polygon) Madison, WI U.S. Fish and Wildlife Service https://www.fws.gov/program/national-wetlands-inventory/download-state-wetlands-data Digital 2017 publication date NWI Downloaded wetlands data for the state of New York in shapefile format from the NWI download page. Projection was NAD 1983 Albers. Download date was 2019/08/01. This process step and all subsequent process steps were performed in ArcMap (ver. 10.7.1) using tools from ArcToolbox, unless otherwise stated. For complex operations, names of specific tools used are given in CAPITAL letters (any critical parameters used are given in parentheses, separated by a semicolon, immediately after the tool name). The input and output file names are provided in [square brackets] when necessary. Units for length and area calculations are meters (m) and square meters (m2) unless otherwise stated. Shoreline change rates for the eastern Long Island salt marsh complex are based on "Rate of shoreline change statistics for New York State coastal wetlands" by R. Welk. 2019 U.S. Geological Survey Robert Welk Hydrologic Technician mailing and physical address

2045 NY 112

Coram NY 11735 631-736-0783 x141 rwelk@usgs.gov Calculate shoreline length for each marsh unit. a) From NWI, SELECT BY ATTRIBUTES(WETLAND_TY = 'Estuarine and Marine Deepwater') to obtain coastal water polygon features. EXPORT to obtain [NWI_deepwater.shp]. b) DISSOLVE (Input Features = [NWI_deepwater.shp]) to obtain Output Feature Class = [NWI_deepwater_dissolve.shp]. c) BUFFER (Input features=[NWI_deepwater_dissolve.shp]; Linear unit= -5 meters; Dissolve type=All) to obtain [NWI_deepwater_buffern5m.shp]. d) Create a bounding box polygon [bounding_box.shp]. e) ERASE(Input Features=[bounding_box.shp]; Erase Features=[NWI_deepwater_buffern5m.shp]; Output Feature Class=[land_polygon.shp]). f) ELIMINATE POLYGON PART(Input Features=[land_polygon.shp]; Output Feature Class=[land_polygon_elim.shp]; Condition='Percent'; Percentage=99; Eliminate contained parts only). g) Revert back to open water polygon by ERASE(Input Features=[bounding_box.shp]; Erase Features=[land_polygon_elim.shp]; Output Feature Class=[open_water_polygon.shp]) and BUFFER(Linear unit= 5 meters) to obtain [open_water_buff5m.shp]. h) DISSOLVE(Input Features = [CMU_ELI.shp]; Dissolve Field=FID_CMU) to obtain [CMU_dissolve.shp] and convert to line feature by POLYGON TO LINE to get [CMU_line.shp] i) Obtain marsh unit shorelines by INTERSECT(Input Features = [CMU_line.shp] and [open_water_buff5m.shp]; XY Tolerance=1.0 meters; Output Type=LINE) to obtain [mu_shorelines.shp] CMU_ELI.shp NWI 2019 mu_shorelines.shp Calculate the transect coverage and mean LRR shoreline change in each marsh unit. Transect coverage is the average shoreline length represented by the transects in a marsh unit. a) EXPORT dissolved marsh unit layer [CMU_dissolve.shp] to obtain [mu_ShRC.shp] b) SPATIAL JOIN(Target features=[mu_ShRC.shp]; Join features=[LRR_transects.shp]; Output features=[mu_LRR_trans_join.shp];Join_one_to_many; Match option=INTERSECT) to assign LRR values to the intersecting marsh units. Repeat step for EPR transects to obtain [mu_EPR_trans_join.shp]. b) Calculate the mean LRR for each marsh unit with SUMMARY STATISTICS(Input table=[mu_LRR_trans_Join.shp]; Output_table=[s_LRR]; Statistics Fields=LRR; Statistics type=MEAN; Case field='TARGET_FID'). Repeat step for EPR transects to obtain [s_EPR]. c) Join statistics fields to the marsh unit layer using JOIN FIELD(Input Table=mu_ShRC.shp; Input Join Field=FID_CMU; Join Table=s_LRR; Output Join Field=FID_CMU; Join Fields=MEAN_LRR, FREQUENCY). Repeat step for EPR. d) ADD the TRANS_PER_L field and calculate it as the total shoreline length divided by FREQUENCY. Assign a value of -1 if the number of transects is equal to zero. Repeat step for EPR transects by adding the TRANS_PER_E field and making the same calculation. e) Edit the attribute table to choose fields to keep and to format the field names. Export the dataset as final output [mu_LRR_EBFNWRp.shp] CMU_dissolve.shp LRR_transects.shp EPR_transects.shp 2019 mu_shoreline_ELI.shp Added keywords section with USGS persistent identifier as theme keyword. 20200806 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Version 2 updates. Updates were performed in ArcGIS Pro 2.8.8. Duplicate marsh units were manually identified and compared to make sure the most appropriate duplicate marsh unit was deleted. Seventy-six duplicate marsh units were identified (out of 2828) in Mecox Bay, Sagaponack Pond and Georgica Pond and have been removed. After the duplicate marsh units were deleted, the elevation, hydroflattened percentage and elevation flag values were recalculated. Authorship was updated to include Kate Ackerman. 20240116 Kate Ackerman U.S. Geological Survey Geologist mailing address

384 Woods Hole Road

Woods Hole MA 02543 US 508-548-8700 x2331 508-457-2310 kackerman@usgs.gov Version 3 Updates. All updates were completed in ArcGIS Pro 3.4.3, using the version 2 of the dataset as the starting dataset. In the original dataset, each marsh plain was not subdivided into smaller parcels ("marsh units") because two processing steps were not completed. For Version 3, these processing steps were completed, resulting in each marsh plain being properly subdivided into these smaller marsh units. Using the new marsh units, UVVR and elevation values were recalculated. Tide range values were carried over from the original (larger) marsh plain polygons and applied to the new, smaller marsh units. However, exposure potential (SCoRR) values and shoreline change values could not be recalculated at the marsh unit scale. They remain unchanged and still represent the larger marsh plain polygons. In the SCoRR and shoreline change datasets, the field FID_CMU has been renamed to MP to indicate that those polygons correspond to marsh plains, not the newly created marsh units. In the title of the data release for exposure potential and shoreline change, the words "marsh units" were changed to "marsh plains." Throughout the exposure potential and shoreline change metadata, the term 'marsh unit' is still used, but readers should understand that it actually refers to the marsh plain. Previous versions of the data can be obtained by contacting whsc_data_contact@usgs.gov. 20260501 Kate Ackerman U.S. Geological Survey Geologist mailing address

384 Woods Hole Road

Woods Hole MA 02543 US 508-548-8700 x2331 508-457-2310 kackerman@usgs.gov Change the name of the FID_CMU field to "MP", for "marsh plain" since these polygons refer to marsh plains rather than marsh units. Also changed the name of the shapefile from "mu_shoreline_ELI" to "mp_shoreline_ELI." 2026 Kate Ackerman U.S. Geological Survey Geologist mailing address

384 Woods Hole Road

Woods Hole MA 02543 US 508-548-8700 x2331 508-457-2310 kackerman@usgs.gov Removed the web services distribution formats in preparation for ScienceBase moving platforms and those services no longer being available. 20260501 Kate Ackerman U.S. Geological Survey Geologist mailing address

384 Woods Hole Road

Woods Hole MA 02543 US 508-548-8700 x2331 508-457-2310 kackerman@usgs.gov Vector G-polygon 2752 WGS 1984 Web Mercator Auxiliary Sphere (ESRI Full Name: WGS_1984_Web_Mercator_Auxiliary_Sphere) 0.0 0.0 0.0 0.0 coordinate pair 0.6096 0.6096 Meter D_WGS_1984 WGS_1984 6378137.0 298.257223563 mp_shoreline_ELI Table containing attribute information associated with the dataset. USGS FID Internal feature number. Esri Sequential unique whole numbers that are automatically generated. Shape Feature geometry. Esri Coordinates defining the features. MP Unique whole number that represents the identification number for each polygon, or "marsh plain". In revision 3.0, this field was changed from "FID_CMU" to "MP." USGS 2 3455 MEAN_LRR Shoreline change rate based on a linear regression. A zero value may indicate: a) the rate of change is actually zero, b) the marsh unit does not have a shoreline (SHORE_LEN=0), or c) no transect is available for calculation (TRANS_PER_L=-1). USGS -0.96 2.32 meters/year MEAN_EPR Mean shoreline change rate based on an end-point method. A zero value may indicate: a) the rate of change is actually zero, b) the marsh unit does not have a shoreline (SHORE_LEN=0), or c) no transect is available for calculation (TRANS_PER_I=-1). USGS -0.97 1.36 meters/year SHORE_LEN Shoreline length USGS 0 5319.578975 meters TRANS_PER_L Average shoreline length represented per LRR transect. Calculated by dividing SHORE_LEN by number of LRR transects. A value of -1 indicates no LRR transect is available, and a value of 0 means the marsh unit has no shoreline. USGS 0.034619 793.854658 meters TRANS_PER_E Average shoreline length represented per EPR transect. Calculated by dividing SHORE_LEN by number of EPR transects. A value of -1 indicates no LRR transect is available, and a value of 0 means the marsh unit has no shoreline. USGS 0.053653 313.531974 meters FLG Marsh unit flag indicating anomalous marsh units based on elevation, surface area, and absence of vegetation. FLG values indicate: (-1) no vegetated area; (-10) marsh unit elevation higher than the 99.8 percentile; (-100) marsh unit elevation less than 0.2 percentile; (-200) greater than 25% of marsh unit has hydroflattened area and has -9999 as its elevation value; (-1000) marsh unit surface area less than 900 m2; and (0) no flag. Combination of negative values indicate combination of flags. For example, -1001 indicates no vegetated area and area less than 900 m2. USGS -11201 0 None In this dataset, shoreline change rates are averaged over each marsh plain polygon in eastern Long Island. Negative and positive values indicate erosion and accretion, respectively. Decimal values in the attribute table are a result of double precision calculations while significant digits are considered in defining the attribute measurement resolutions. Therefore, the smallest unit increment for shoreline change rate values can be assumed to be a practical value such as 0.01 meters/year. U.S. Geological Survey U.S. Geological Survey - ScienceBase mailing and physical address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov mp_shoreline_ELI.shp (and files associated with a shapefile), browse graphic, and CSDGM metadata in XML format. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. shapefile ArcGIS Pro 2.8.8 This dataset contains a polygon shapefile and its components and metadata in xml format 20 https://www.sciencebase.gov/catalog/file/get/5ddda8fae4b04a30051ac270 https://www.sciencebase.gov/catalog/item/5ddda8fae4b04a30051ac270 https://doi.org/10.5066/P91H426U The first link in network resources is to download data directly. The second link points to a landing page with metadata and data. The third link is to the main page of the data release. None. No fees are applicable for obtaining the dataset. 20260519 U.S. Geological Survey, Northeast Region Robert J Welk Hydrologic Technician mailing address

2045 Route 112

Coram NY 11727 US 631-736-0783 x141 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with USGS. FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998