Fig 1.
Schematic of data sources used in EBEEM analysis and outlined in Table 1.
A) Elevation (topography and bathymetry) from lidar DEM and modified CUSP shoreline data. B) 50% exceedance elevation boundary derived from DEM surface. C) National Wetlands Inventory (NWI) and C-CAP Regional Land Cover data within estuary extent layer. D) West Coast USA Estuarine Biotic Habitat layer derived from NWI and C-CAP. E) Indirect Assessment of West Coast USA Tidal Wetland Loss layer.
Table 1.
Data sources for estimation of elevation-based estuary extent model (EBEEM) and wetland loss, and how data were used in GIS modeling.
See S1 File for URLs to elevation data sources.
Fig 2.
Observations of elevational data (relative to NAVD88) from 14 estuary systems across California, Oregon, and Washington.
Estuaries (south to north in order from left to right) evaluated include Tijuana (TJ), Morro Bay (Mo), Elkhorn Slough (El), Tomales Bay (To), Coquille (Co), South Slough (So), Tillamook (Ti), Young’s Bay (Yo), Willapa Bay (Wi), Nisqually (Ni), Snohomish (Sn), South Fork Skagit (SkS), North Fork Skagit (SkN), and Nooksack (No). In contrast to MHHW (green line) and MHW (black line), 50% exceedance elevation (orange line) consistently surpasses average lidar-based elevations of all four tidal wetland types (other symbols) which were verified as tidally inundated in the field (S2 File).
Fig 3.
Extent of VDatum coverage for the Pacific Coast and its estuaries.
A) Coverage of VDatum across Washington, Oregon, and California. B) illustration of estuarine areas (in orange) that required spatial interpolation because they lie landward of the range of VDatum data coverage.
Table 2.
CMECS classifications used in unit definition, and sources of information used to make classifications.
Abbreviations: MEOW = Marine Ecoregions of the World, PMEP = Pacific Marine and Estuarine Fish Habitat Partnership, NWI = National Wetlands Inventory, C-CAP = Coastal Change Analysis Program.
Table 3.
Summary of tidal wetland loss classification for National Wetlands Inventory (NWI) wetland types.
Blank cells represent attribute combinations not present in the database. "Lost" indicates wetlands that were probably once vegetated tidal wetlands, but are no longer in that category. "Retained" indicates areas that were probably historically vegetated tidal wetlands and still remain in that category. "NA" indicates wetlands omitted from the analysis, because the analysis is limited to emergent (EM), scrub-shrub (SS) and forested (FO) tidal wetland vegetation classes.
Fig 4.
% exceedance levels on the Pacific Coast.
50 Interpolated 50% exceedance water levels (top panel) corresponding to coastal segments of the Pacific Coast (bottom panel), including the seaward edges of mapped estuaries. Also noted are NOAA’s 22 long-term tide gauges used to predict 50% exceedance contours (blue squares) and average values from 14 ground-truthed estuaries (green diamonds) shown in Fig 2. Note that 50% exceedance values within estuaries are adjusted using VDatum and therefore vary from the seaward edge values (orange line).
Fig 5.
Comparison of historical estuarine footprint in the Sacramento-San Joaquin delta.
The comparison illustrates agreement and disagreement between the historical footprint from EBEEM mapping (PMEP) compared to historical ecology mapping by the San Francisco Estuary Institute [17]: the entire extent of the delta (A), a magnified region in the north delta (B), a region in the south delta (C), and an urban area in the central delta with a large amount of disagreement between mapping efforts (D).
Fig 6.
Location and physiographic type of 444 estuaries in four ecoregions of the Pacific Coast.
Individual estuaries are denoted by circles of different colors corresponding to physiographic type. For larger estuaries, the entire polygon is shaded with the same colors.
Table 4.
Summary of estuaries identified in four ecoregions of the Central Pacific Coast of the United States.
Total area is current plus historical estuary extent as defined by EBEEM mapping, and most common estuary types are abbreviations of CMECS terms: major river delta, riverine estuary, and embayment/bay.
Fig 7.
Summary of estuaries in the Salish Sea/WA coast ecoregion of the Pacific Coast (Washington, Oregon and California).
Map in upper left panel (A) shows the number and extents of estuaries by physiographic type. Upper right panel (B) shows the extent percent representation of each estuary type as calculated by the number of each type (Quantity) and by areal coverage (Size), while the middle right panel (C) illustrates the cumulative distribution function of the number of estuaries as a function of their size in hectares (ha). The map in the lower panel (D) illustrates an example estuary from each the ecoregion including spatial extent of historical footprint based on 50% exceedance contour (“EBEEM”) and area of current tidal wetlands based on National Wetland Inventory classes (“NWI”), data used to calculate habitat loss. Note: Unvegetated and aquatic bed areas shown in blue are within the EBEEM Historical extent, but were excluded from the wetlands loss analysis.
Fig 8.
Summary of estuaries in the Oregon and Northern California ecoregion of the Pacific Coast.
See Fig 7 for details.
Fig 9.
Summary of estuaries in the Central California ecoregion of the Pacific Coast.
See Fig 7 for details.
Fig 10.
Summary of estuaries in the Southern California Bight ecoregion of the Pacific Coast.
See Fig 7 for details.
Fig 11.
Wetland loss in 55 estuary systems across the Pacific Coast.
The map at left denotes all estuaries used in the analysis, and the bar graph at right illustrates both % estuarine wetland loss (blue bars, top axis) and amount of loss in hectares (gray bars, bottom axis), based on indirect assessment (comparison of NWI data with EBEEM).
Table 5.
Area and percent loss of tidal wetlands in emergent, scrub-shrub and forested classes for 55 estuaries on the Pacific Coast, by estuary type and marine ecoregion.
Table 6.
Comparison between this project’s region-wide tidal wetland loss assessment (Region) and local assessment (Local) for the Lower Columbia River estuary [41], San Francisco Bay [42], and Oregon estuaries (http://www.coastalatlas.net/cmecs).