Eelgrass [ds1503]

SDE Raster Dataset

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Tags
eelgrass, seagrass, zostera


Summary

To show eelgrass distribution in California.

Description

This is a 5m raster summary of the feature sources described in the supplemental information section of this metadata document. For footprints and descriptions of those source eelgrass surveys please refer to the original vector dataset ftp://ftp.wildlife.ca.gov/BDB/GIS/BIOS/Public_Datasets/1500_1599/ds1503.zip

Seagrass habitats are among the most productive and biologically diverse ecosystems on the planet. The most common type of seagrass in California is Zostera, or eelgrass, which grows under water in estuaries and in shallow coastal bays of the ecoregion. It is a flowering plant, not an alga, and occurs in dense beds. It helps prevent erosion and maintain stability near shore by anchoring sediment with its spreading rhizomes and slowing water flow. Eelgrass beds provide foraging, breeding, or nursery areas for invertebrates, fish, and birds. This file aggregates data from several sources across multiple years; see supplemental info. Features shown here should not be considered a representation of condition for any given year. Features represent the maximum extent of eelgrass found across multiple surveys over multiple years.

Credits

See supplemental info for regional differences in source data.

Use limitations

None.

Extent

West -124.324909 East -117.098008
North 40.898141 South 32.600408

Scale Range
Maximum (zoomed in) 1:500,000
Minimum (zoomed out) 1:150,000,000

ArcGIS Metadata

Topics and Keywords

Themes or categories of the resource environment, oceans


* Content type Downloadable Data


Place keywords California

Theme keywords eelgrass, seagrass, zostera

Citation

Title Eelgrass [ds1503]
Publication date 2016-05-2500:00:00


Presentation formats * digital table


Citation Contacts

Responsible party
Organization's name California Department of Fish and Wildlife
Contact's role originator


Responsible party
Individual's name Paulo Serpa
Organization's name California Department of Fish and Wildlife
Contact's position Research Analyst II
Contact's role point of contact


Contact information
Phone
Voice (831) 649-7143

Address
e-mail address Paulo.Serpa@wildlife.ca.gov



Resource Details

Dataset languages * English(UNITED STATES)
Dataset character set utf8 - 8 bit UCS Transfer Format


Spatial representation type * grid


Supplemental information
5/4/2016 Update of San Francisco Bay with data from Merkel & Associates (2014). This data should approximate previous data from ERMA, (see below) however, some topological differences were noted and previous features were replaced in favor of these records directly from Merkel and Associates. Features are aggregated with attributes dropped. See original source data for additional detail. Digital maps of the distribution of eelgrass throughout San Francisco Bay were created from interferometric side-scan survey data. Following completion of the surveys, sonar traces were downloaded and processed into rectified mosaic images in a GeoTiff format using Chesapeake Technologies, Inc. Sonar Wiz. Eelgrass was mapped by manually digitizing from registered sidescan mosaics and aerial photographs using ESRI ArcGIS software. Update of Estero Americano with data from Andrew Weltz, CDFW (2014). Bed areas in the Estero Americano were surveyed between June and September 2014 by CDFW staff using global positioning system (GPS) technology, observation, and field notes. Polygon features were digitized from the survey data with the aid of 2012 National Agriculture Imagery Program (NAIP) imagery. Update of Big River Estuary with data from Andrew Weltz, CDFW (2015). Bed areas in the Big River estuary were surveyed on 9/21/2015 by CDFW staff using global positioning system (GPS) technology, observations, and field notes. Polygon features were digitized from the survey data with the aid of 2012 NAIP imagery. Update of Albion River Estuary with data from Andrew Weltz, CDFW (2014, 2015). Bed areas in the Albion River estuary were initially surveyed on 10/3/2014 by CDFW staff using GPS, observations, and field notes, with a follow-up survey on 5/21/2015. Polygon features were digitized from the survey data with the aid of 2012 NAIP imagery. Update of Bodega Bay harbor and Drakes Estero with data from Ocean Imaging (2010). This vector dataset was developed for the Sea Grant MPA Baseline Program as part of the project High Resolution Nearshore Substrate Mapping and Persistence with Multispectral Aerial Imagery (#R/MPA17 09-015). The study region is the California North Central Coast (NCC). The imagery used for this habitat classification were collected by Ocean Imaging (OI) and Fugro EarthData. OI acquired this imagery on 03/26/2010 using the Digital Multispectral Camera (DMSC). Details on this system and the data processing are below in the Lineage section of this document. Fugro EarthData acquired the imagery used for this project between 09/22/2010 09/23/2010 and delivered fully georeferenced and orthorectified, 12-bit imagery with a spatial resolution of 0.30 meters to OI in 2011. Details on this system and the data processing are also below in the Lineage section of this document. Individual DMSC and ADS40 scenes were mosaicked into sections based on the USGS orthoquads for the California North Central Coast in order to generate the multispectral imagery required to produce the habitat classification thematic maps of the California North Central Coasts intertidal region and kelp beds from Pigeon Point up to Point Arena, including select bays and river mouths designated as MPAs. 9/9/2014 Update of San Francisco Bay and southern California regions (including Channel Islands) with sources available from NOAA's Environmental Response Management Application (ERMA - https://www.erma.unh.edu). See source features for specific survey data. 7/29/2013 Update area of Tomales Bay based on data recieved by Andrew Weltz, California Department of Fish and Wildlife. Source metadata: Abstract: Bed extents were digitized based on 2010 aerial imagery and 2013 ground-truthing surveys. Description: Zostera marina bed extents were digitized from 2010 CDFW aerial imagery. Photographs were taken on 6/29/2010 on the incoming tide following a -0.5 ft. low at 08:25. Photographs were georeferenced 5/6-5/8/2013. This shapefile was created 5/8/2013 - 7/26/2013. Credits: Shapefile digitized by Andrew Weltz of CDFW's Aquaculture and Bay Management Project from aerial photographs taken by Ron VanBenthuysen of CDFW and georeferenced by Andrew Weltz. 11/15/2009 Updated areas around Humboldt Bay with data provided by John Mello, CDFG. Those data derived from year 2000 IR imagery. Metadata abastract below: The areal distribution of Humboldt Bay (Humboldt County) California eelgrass was examined from aerial photographs taken in 18 September 2000 and on-ground observations. In ArcView 3.2 Geographic Information Systems (GIS) software the polygon drawing tool was used to delineate the extent of eelgrass coverage in the bay (Shull and Bulthuis 2002). Polygons were converted to shape files using ArcView 3.2 to calculate the areal distribution of eelgrass in hectares. The photomosaic was used to calculate eelgrass distribution. The lower intertidal limits of eelgrass beds were delineated using Humboldt Bay channels verified by visual observation during minus tides. Tidal elevation delineates the upper intertidal perimeter of the eelgrass beds adjacent to the shore. The upper intertidal perimeter of eelgrass beds was confirmed by walking to these areas at low tide or using a small boat at high tide and recording positions of bed perimeters with a handheld GPS. The GPS positions were compared with the delineation of the beds from the 2000 photo-mosaic. Only large continuous beds were measured. Pools and depressions in mid to high intertidal mudflats containing eelgrass were not included in the survey nor were eelgrass patches in sloughs around the bay. Seventeen eelgrass beds were defined, but only nine were used in the study (Fig. 1). Four eelgrass beds were in North Bay (beds 1, 4, 5, 6,), two in Central Bay (beds 9, 10) and three in South Bay (beds 12, 13, 15). Deep-water channels define the entire perimeter of bed 5 and the lower tidal elevation of beds 1, 4, 6, 9, 10,12, 13, and 15. Sample sites were located outside of shellfish culture operations. Large continuous eelgrass beds in North and South bays and narrow fringing beds in Central Bay cover 1890 ha. 6/27/05 Loaded additional areas for Elkhorn Slough eelgrass beds defined by Eric VanDyke. No additional attributes or metadata provided. Transmittal posted here: Sherry Palacios/Dick Zimmerman seagrass shapefile (UTM zone 10, WGS84) collected from a boat using differential GPS on April 4, 2000.
* Processing environment Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.4.0.5524


Credits
See supplemental info for regional differences in source data.
ArcGIS item properties
* Name Eelgrass [ds1503]
* Location Server=; :; Database=; User=; Version=
* Access protocol ArcSDE Connection

Extents

Extent
Geographic extent
Bounding rectangle
Extent type Extent used for searching
* West longitude -124.324909
* East longitude -117.098008
* North latitude 40.898141
* South latitude 32.600408
* Extent contains the resource Yes

Extent in the item's coordinate system
* West longitude -13839785.600287
* East longitude -13035290.600287
* South latitude 3842384.080073
* North latitude 4997329.080073
* Extent contains the resource Yes

Resource Maintenance

Resource maintenance
Update frequency as needed


Resource Constraints

Constraints
Limitations of use

None.


Spatial Reference

ArcGIS coordinate system
* Type Projected
* Geographic coordinate reference GCS_WGS_1984
* Projection WGS_1984_Web_Mercator_Auxiliary_Sphere
* Coordinate reference details
Projected coordinate system
Well-known identifier 102100
X origin -20037700
Y origin -30241100
XY scale 148923141.92838538
Z origin -100000
Z scale 10000
M origin -100000
M scale 10000
XY tolerance 0.001
Z tolerance 0.00020000000000000001
M tolerance 0.00020000000000000001
High precision true
Latest well-known identifier 3857
Well-known text PROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator_Auxiliary_Sphere"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0],AUTHORITY["EPSG",3857]]

Reference system identifier
* Value 3857
* Codespace EPSG
* Version 8.8(9.3.1.2)


Geoprocessing history

Distribution

Distribution format
* Name SDE Raster Dataset


Transfer options
Online source
Location http://bios.wildlife.ca.gov
Function performed information

Online source
Location ftp://ftp.wildlife.ca.gov/BDB/GIS/BIOS/Public_Datasets/1500_1599/ds1503.zip
Function performed download

Fields

Details for object SDE_VAT_360
* Type Table
* Row count 21


Field OBJECTID
* Alias OBJECTID
* Data type OID
* Width 4
* Precision 10
* Scale 0
* Field description
Internal feature number.
* Description source
Esri
* Description of values
Sequential unique whole numbers that are automatically generated.




Field VALUE
* Alias VALUE
* Data type Integer
* Width 4
* Precision 10
* Scale 0
Field description
Year of source data. Features in this layer SHOULD NOT be considered a representation of condition for any given year


Field COUNT_
* Alias COUNT_
* Data type Integer
* Width 4
* Precision 10
* Scale 0






Metadata Details

* Metadata language English(UNITED STATES)
Metadata character set utf8 - 8 bit UCS Transfer Format


Scope of the data described by the metadata * dataset
Scope name * dataset


* Last update 2016-06-02


ArcGIS metadata properties
Metadata format ArcGIS1.0
Metadata style North American Profile of ISO19115 2003
Standard or profile used to edit metadata NAP


Created in ArcGIS for the item 2016-05-1915:01:49
Last modified in ArcGIS for the item 2016-06-0209:44:58


Automatic updates
Have been performed Yes
Last update 2016-06-0209:44:58


Metadata Contacts

Metadata contact
Individual's name Paulo Serpa
Organization's name California Department of Fish and Wildlife
Contact's position Research Analyst II
Contact's role point of contact


Contact information
Phone
Voice (831) 649-7143

Address
e-mail address Paulo.Serpa@wildlife.ca.gov



Metadata Maintenance

Maintenance
Update frequency as needed


Thumbnail and Enclosures