DisMOSH, Cost, MOSH_Shoreline: Distance to foraging areas for piping plovers including foraging shoreline, cost mask, and least-cost path distance: Fisherman Island, VA, 2014

Fish14_MOSH_Shoreline.shp
This vector file delineates foraging shorelines with moist substrates for piping plovers and their chicks. These are areas where piping plovers and their chicks could forage for terrestrial arthropods, invertebrates, marine worms, and other foods. Foraging shorelines are defined as low-energy and could include the shorelines of sound- or bay-side beaches, interior ponds, and ephemeral pools. Ocean shorelines are not considered low-energy foraging shorelines.
Full methods are provided in the associated Open-File Report (Zeigler and others, 2019). All processing was performed in ArcGIS version 10.4.1.
We converted the shoreline polygon file (fish14_shoreline.shp in larger work) to polyline format using the 'Polygon to Line' tool in ArcGIS. We overlaid the output shoreline polylines on the orthoimage and - in an Edit session - manually removed sections of the lines that did not correspond to inlets, ponds, ephemeral water bodies, or back-barrier sandy beaches. This included removing the ocean-facing shoreline. These features were identified based on visual inspection of the orthoimage.
Also during this Edit session, we hand-digitized the boundaries of low-energy shorelines that were not included as part of the shoreline polygon(s). These included the boundaries of ephemeral pools, inland ponds, and the interior edges of marsh channels. The determination of landscape type was based on visual inspection of the orthoimage.

Fish14_Cost.tif
This spatial coverage was created to establish boundaries to the movements of piping plover chicks (which are unable to fly pre-fledging). Development, moderate to dense vegetation, and persistent water are considered barriers to movement of plover chicks. We assumed that adults and chicks might be able to walk across temporarily exposed portions of the beach at low tide.
Full methods and additional figures are provided in the associated Open-File Report (Zeigler and others, 2019). Input classification layers (Fish14_GeoSet.tif, Fish14_SubType.tif, Fish14_VegType.tif, and Fish14_VegDen.tif) are published in the larger work. All processing was performed in ArcGIS version 10.4.1.
We used the ‘Combine’ tool in ArcToolbox to merge the input categorical landcover layers—geomorphic setting, substrate type, vegetation type, and vegetation density—into a single raster with a values attribute table.
We added an additional column ‘Cost’ to the attribute table of this combined layer. We manually assigned a cost value of 10 to every row that contained:
- ‘Development’ (substrate type, vegetation type, and vegetation density); - ‘Moderate’, ‘Dense’, or ‘Moderate or Dense’ (vegetation density); or - ‘Water’ (for substrate type; unless geomorphic setting was also 'Beach').
All remaining combinations in the attribute table were assigned a cost value of 0, indicating that there is no cost or resistance to movement through these raster cells. The cost value of 10 indicates a high cost of—or resistance to—movement. The values of 10 and 0 are arbitrary and do not impact data quality. In cases where the substrate type, vegetation type, or vegetation density were unknown (and the remaining known habitat variables did not contain a movement barrier), we allowed for movement so as not to preclude what could be a movement corridor.
We converted the Cost column into a new raster layer using the ‘Lookup’ tool in ArcToolbox. In the resulting layer, cell values were equivalent to those in the ‘Cost’ column in the attribute table of the combined raster layer.
We reclassified this layer such that every cell with a value of 10 was assigned NoData (-9999) and every cell with a value of 0 was assigned 1 (Reclassify tool). The output extent of the reclassification was set to that of the study area in geoprocessing settings. Thus the final Movement Cost layer indicates barriers to movement with a NoData value (-9999) and possibility of movement with value of 1.

Fish14_DisMOSH.tif
We calculated the least-cost path distance from the center of every 5x5 m raster cell to the nearest low-energy foraging area with moist substrates using the ‘Path Distance’ tool in ArcGIS (version 10.4.1). The foraging shoreline vector layer (Fish14_MOSH_Shoreline.shp) was considered the ‘Source data’ and the movement cost layer (Fish14_Cost.tif) was considered the ‘Input cost layer’. This tool calculates the least accumulative cost distance for each cell to the nearest source (foraging shoreline) while accounting for surface distance and horizontal cost factors (movement cost). The output extent was set to a custom boundary that spans the entire coverage of the Fisherman Island site relevant to the broader research program (see Zeigler and others, 2019 for more details). The extent of this custom boundary does not affect the data quality of the distance to foraging layer.
We then reclassified this path distance layer using 'Reclassify'. Cells previously coded as NoData within the study area boundaries were converted to a fill value of 99,999, which denoted ‘No Access’ while cells outside the study area retained the NoData designation (-9999). We assumed that cells marked as movement barriers in the movement cost layer had no access to foraging areas. Those cells received a fill value.
Please review the individual attribute descriptions as well as Zeigler and others (2019) for detailed information and example figures.

Added keywords section with USGS persistent identifier as theme keyword.