Coho Salmon (Central California Coast ESU)

The lines in this dataset were extracted from a 2018 version of the high resolution National Hydrography Dataset (NHDFlowline feature class). The lines were split at specific locations to represent the upstream ends of critical habitat; other vertices were not altered.

Data creation process 2019.

COCCC_CH.shp

Central California Coast (CCC) coho data were developed as part of an effort to interpret and depict several salmonid critical habitat designations completed in the 1990s that relied on text-based descriptions but lacked GIS data. Critical habitat areas were identified based on the following:

- The regulatory definition of ESA critical habitat for this ESU found at 50 CFR 226.210 (a) and the supporting final rule (64 FR 24061, May 5, 1999);

- U.S. Geological Survey (USGS) high resolution National Hydrography Dataset (NHD) - downloaded February 2018;

- Intrinsic Potential (IP) GIS data from a juvenile coho rearing model developed by the Southwest Fisheries Science Center (SWFSC);

- National Elevation Data and Digital Topographic Maps;

- California Fish Passage Assessment Database [ds69, published 2019-03-05] and Coho Distribution [ds326, published 2016-06-22] from the California Department of Fish and Wildlife (CDFW);

- The professional judgment of biologists from the NMFS California Coastal Office, Protected Resources Division, and SWFSC; and

- Maps and documentation in these references:

Spence, B.C., Harris, S.L., Jones, W.E., Goslin, M.N., Agrawal, A., and E. Mora. 2005. Historical occurrence of coho salmon in streams of the Central California Coast coho salmon Evolutionarily Significant Unit. Technical Memorandum NOAA-TM-NMFS-SWFSC-383. Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Dept of Commerce.

Agrawal, A., Schick, R.S., Bjorkstedt, E.P., Szerlong, R.G., Goslin, M.N., Spence, B.C., Williams, T.H., and K.M. Burnett. 2005. Predicting the potential for historical coho, Chinook and steelhead habitat in Northern California. Technical Memorandum NOAA-TM-NMFS-SWFSC-379. Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Dept of Commerce.

NMFS. 2012. Final Recovery Plan for Central California Coast coho salmon Evolutionarily Significant Unit. National Marine Fisheries Service, Southwest Region, Santa Rosa, California.

Spatial analysis steps to produce data.

1) Clipped the NHD to the text description from the critical habitat designation

2) Partitioned the NHD into 100 meter segments

3) Calculated the gradient of each 100 meter segment using a 10 meter USGS digital elevation model (DEM)

4) Used the NHD's flow direction and a geometric network to analyze gradient, removed segments upstream of 7% gradients (reference: Agrawal et. al. 2005 - Figure 1 gradient suitability curve for coho)

5) Retained segments downstream of 7% gradients that were too small (<= 20 meters) to rely on the gradient value (i.e., 1 to 2 pixels in the DEM) or were artificial paths (NHD FCode 55800) to maintain network connectivity

6) Retained segments that overlapped with CDFW coho distribution data (field observations) and SWFSC intrinsic potential coho data (model) with the 21.5 deg C temperature mask applied (Agrawal et. al. 2005)

7) Removed segments upstream from total natural barriers, total anthropogenic barriers, and partial barriers that were specifically identified as blocking upstream adult coho migration

8) Removed segments identified by NMFS biologists as not being accessible to or suitable habitat for coho.

The following tribal lands were excluded from the Central California Coast coho critical habitat designation, but were not clipped out of the spatial data: Cloverdale Rancheria, Coyote Valley Rancheria, Dry Creek Rancheria, Guidiville Rancheria, Hopland Rancheria, Lytton Rancheria, Manchester/Point Arena Rancheria, Pinoleville Rancheria, and Stewarts Point Rancheria.

**IMPORTANT NOTE**

Critical habitat was designated to include "all river reaches accessible in 1999" to CCC coho salmon from Punta Gorda in northern California south to the San Lorenzo River in central California, including Arroyo Corte Madera Del Presidio and Corte Madera Creek, tributaries to San Francisco Bay. These spatial data are NMFS' best estimate of "all

The source data in COCCC_CH.shp (GCS_North_American_1983) were post processed to COCCC_ch_FINAL_20210524 (GCS_North_American_1983).

The 100 meter segments (39,816 feature count) leftover from the gradient analysis were cumbersome and deemed unnecessary for publication.

COCCC_CH.shp fields: FID, Shape, Permanent_, FDate, Resolution, GNIS_ID, GNIS_Name, LengthKM, ReachCode, FlowDir, WBArea_Per, FType, FCode, MainPath, InNetwork, Visibility, Enabled, POINT_X, POINT_Y, POINT_X_1, POINT_Y_1, RASTERVALU, RASTERVA_1, Diff, Percent, meters, Shape_Leng, DPS

Geometry editing steps included:

1) ccc_coho_post_processing_remove100msegs.gdb -> converted "COCCC_CH.shp" to a feature class "COCCC_CH" in the gdb

2) Selected, by location, all features in the original 2018 NHD that shared a line segment with "COCCC_CH"

3) Exported selected NHD features to "COCCC_CH_NHDselectexport"

4) Used "COCCC_CH" to clip NHD features in "COCCC_CH_NHDselectexport" and created "COCCC_CH_NHDselectexport_clip"

5) Reviewed output against source and found a single feature that did not migrate, added the feature in with merge tool to create final layer "COCCC_ch_FINAL_20210524" (feature count 7,301).

Version COCCC_ch_FINAL_20210524 (GCS_North_American_1983) was converted into the standardized feature class SalmonCoho_CentralCaliforniaCoastESU_19990505 (GCS_WGS_84 wkid 4326) using the National Critical Habitat Geodatabase processing protocol.

During standardization, geometry was not edited. Attributes were edited. Metadata was edited and populated using the final rule/CFR and the source COCCC_CH.shp (GCS_North_American_1983).

Migrated fields: "GNIS_Name" into "UNIT", "FCode" into "NOTES" (populated descriptions with FCode values)

Dropped fields: OBJECTID, Permanent_Identifier, FDate, Resolution, GNIS_ID, LengthKM, ReachCode, FlowDir, WBArea_Permanent_Identifier, FType, MainPath, InNetwork, VisibilityFilter, Shape_Length