Kelp Canopy: California, 1989

Description:

This polygon shapefile depicts kelp beds along the California coast, which are a critical habitat for many important sport and commercial species of invertebrates and fishes. The 1989 California Coastal Kelp Resources Survey is a statewide mapping of kelp, acquired under contract by the California Department of Fish and Wildlife from ECOSCAN Resources. Aerial photos, taken in July through October 1989, were projected onto 1:24000 United States Geological Survey (USGS) topographic maps and kelp canopy features were delineated. Kelp distribution on this map represents the largest possible extent of kelp canopy and subsurface kelp based on these data, which represent the best readily available information. The maps include the topographic base, shorelines, watercourses, rocky intertidal zones, offshore rocks/islands, sand beaches, selected geographic place names and the California Department of Fish and Wildlife (CDFW) administrativeteal kelp bed numbers. Details on kelp bed designations and harvest regulations are set forth in Title 14 California Code of Regulations, Section 165.5. Detailed methodology of kelp mapping is available from ECOSCAN Resources. CDFW scanned the original 24'x36' black and white paper maps into packbit-compressed tif images and georeferenced them to the above USGS base using a custom ARC/INFO application developed by ESRI. File reindexed to match CDFW administrative kelp bed boundaries modified by changes to California Code of Regulations, Title 14, Section 165, effective April 1, 2014. This coverage can be used for kelp harvest assessment, kelp bed lease management, and related biological applications. Kelp bed area statistics were compiled from this and previous surveys. California Department of Fish and Wildlife Marine Resources Region. (1999). Kelp Canopy: California, 1989. California Department of Fish and Wildlife. Marine Resources Region. Available at: http://purl.stanford.edu/ym276qx0632. This dataset was revised on 10/2/09. The dataset was intersected with an updated kelp bed administrative layer. The update accounted for a slight shift in the kelp bed admininstrative boundaries and resulted in a slight change in individual kelp bed area. This dataset was revised on 08-11-09. Image artifacts were removed in kelp bed 304 between Bourns Landing and Robinson Point in Mendocino County. The is a derived dataset from the original 1989 kelp bed shapefiles. Original adimistrative kelp beds were merged using ArcView 3.2. Absent representation of kelp with the attribute gridcode 0 was deleted. This created a smaller file size and eliminated the need to distinguish kelp from non kelp areas. DISCLAIMER The user is cautioned against making direct comparisons between the various kelp surveys for the following reasons: 1) Timing of the survey is important, particularly with respect to growing season conditions in the ocean, and storms and harvest levels preceding the dates of survey photography. Seasonal variability may account for differences in surveys, which may not reflect a change in the bed's extent, productivity, or harvest level. 2) Statistical significance in change of area should be evaluated. To do this, a variance parameter is needed, which is obtained by repeated measurements. Most of the coastline, however, has been surveyed only on five occasions (1967, 1989, 1999, 2002, 2003). 3) Survey methods have not been/may not be consistent. Some method of calibration between the methods needs to be performed in order to insure a change of area is not due to survey instrumentation, and not misinterpreted as a biological change. 4) An area where apparently no kelp data are present may truly represent an area devoid of kelp, or may represent an area where kelp was not detected due to poor photo quality, missing photo coverage, or other issues with data collection and processing. Photo coverage is extensive for the state, but the user is advised to consult the photo index for each year to determine whether photographs were acquired for an area of interest. 8/9/2004 Original file name: Coastwide_Kelp_1989.shp This file contained a 100m westward shift. Correction: Original shapefiles (by kelp bed 1 - 309) were remerged using ArcMap 8.3 to create one shapefile for kelp coastwide. All features (GRID CODE = 1) were dissolved showing presence of surface kelp. This coastwide file was intersected with kelpadmbed.shp to create one feature per CDFG administrative bed. New file name 'Kelp1989.shp'. There was minor cropping of some edges during the intersection with kelpadmbed.shp These are public data. The Department of Fish and Wildlife must be credited with the collection, analysis and distribution of these data. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

Resource Link:

https://purl.stanford.edu/ym276qx0632

Identifier:

https://purl.stanford.edu/ym276qx0632

Language:

English

Creator:

California. Department of Fish and Game. Marine Resources Region

Publisher:

California. Department of Fish and Game. Marine Resources Region

Provider:

Stanford

Resource Class:

Datasets

Subject:

Coasts, Marine habitats, Kelps, Algae, Remote sensing, Aerial surveys, Biology and Ecology, and Oceans

Temporal Coverage:

1989

Date Issued:

1999

Spatial Coverage:

California and Pacific Ocean

Access Rights:

Public

Format:

Shapefile