About the Atlas
Initial Digitizing
Processing for Digital Atlas
Table 1. Marine mammals
Table 2. Fishes
Table 3. Invertebrates
Table 4. Life stage
Table 5. Relative abundance
For More Information
Contributors
References

ABOUT THE ATLAS

The West Coast of North America Data Atlas was the fourth in a set of hardcopy atlases, published by NOAA's strategic assessment program during the late 1980’s, covering the major coastal areas of the nation. This series is part of a national program characterizing potential conflicts among users of the U.S. Exclusive Economic Zone (EEZ) and adjacent coastal areas. The goal of the strategic assessment program is to communicate this information to decision makers and public and private institutions involved in resource-use issues.

Two preliminary volumes covering the study area region from the Bering Sea south to the Gulf of California were published. The Marine Mammal volume presents information on the spatial and temporal distributions of 33 species. The Invertebrate and Fish volume contains 66 species. A map, description, vertical profile, and scale drawing are provided for each species. The map shows important areas by life stage, abundance, time period, and commercial and recreational use. The description is a written summary of scientific knowledge on topics such as life history attributes and catch statistics. For the digital atlas, all 99 species were included in the digitized geographic files.

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INITIAL DIGITIZING

Each physical plate (side of a sheet of paper) in the original atlas contains the map for one or more species. In digitizing these plates, the species depicted on each plate were treated separately by assigning a species code to each. In general, these codes follow the order in the atlas index for each section, but this rule is not inviolate. The life history for each species was divided into submaps, each representing presence/absence of a (1) life stage, (2) abundance level, and (3) season (the applicable time of year). Separate data sets were maintained for the northern and southern parts of the maps, because they were separate pieces of paper. Care was taken to do proper edge matching between the pages, but there was no formal check to ensure match. Areas were digitized as priority polygons so they could be clipped by a land mask. Thus, the details of the species polygons over land are arbitrary. The exceptions to this principle are the salmonoid species files (Pink, Chum, Coho, Sockeye, and Chinook Salmon and Steelhead) and the Striped Bass because the adult and spawning life stages for these species have polygons over land showing their occurrences in rivers and streams, which were not digitized, and thus, are not included in this digital atlas.

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PROCESSING FOR DIGITAL ATLAS

Source digital arcs and topology were first converted into MapInfo layer files and edited. The species files were joined to their northern and southern halves, if applicable, and clipped to retain only the water portions of the polygons using a 1:2,000,000 land coverage, named 'Land' [wcna_land.shp]. Some additional life stages were added according to the map notes. After edits and additions were complete, the species files were exported to ArcView SHP files. Each file represents one unique species and is named using a species code (as listed in the tables below). For example, the file name for species 35, Pacific Herring, is 35.shp. Once the files were converted, another quality check was performed on the life history code [LHC] for valid entries. Generally, the species codes were assigned according to the order in which they exist in the original atlas. Thus there is an internal grouping of similar species. Because the adult and spawning life stages of salmonoid species and Striped Bass occur in rivers and streams, these seven species files were clipped to the land boundary, which eliminated these life stages from the digital file.

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The following tables identify the species included in the digital atlas, along with their species code:

Table 1. Marine mammals

Table 2. Fishes

Table 3. Invertebrates

The life history/abundance code [LHC] has three digits and is generated as the combination of the Life stage code and the Abundance code. The [LHC] is also broken out into separate fields as [Life_stage] and [Abundance] respectively. These fields are used in subsetting the data. For example, a [LHC] value of 101 signifies an adult area in high abundance. The corresponding [Life stage] code is 10 and the [Abundance] code is 1. The following tables define the values for each of the code components (not all life stages are present in the WCNA atlas):

Table 4. Life stage

Table 5. Relative abundance

During the GIS operations, all three lookup tables (species_desc.dbf, stage_desc.dbf, and abund_desc.dbf) are linked to the data through the code field [Code] to provide textual names for menu selection.

Seasonality is encoded as a 13-character string [Season], with one character for each month and a 13th character to indicate presence during all months of the year. Any character in the string other than "-" or "blank" indicates the theme is active for that month. The preferred values for each month in sequence are [JFMA5678SONDY]. An internal check, if the 13th character is active (a "Y"), then the preceding 12 characters should also be active.

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FOR MORE INFORMATION

For questions regarding the digitization of the data or the application development, please contact the Special Projects office. For questions relating to the West Coast Atlas content, the atlas itself in hardcopy should be consulted, especially the text material on each plate, which expands on the map presentations.

CONTRIBUTORS

Contributors for the digital product include Peter Grose, Holly Baun, Heidi Johnson, Marilyn King, Tracy Gill, and Lisa Butler.

REFERENCES

Strategic Assessment Branch and Northwest and Alaska Fisheries Center, 1990: West Coast of North America Strategic Assessment: Data Atlas. Invertebrate and Fish volume. Pre-publication edition. Rockville, MD: National Oceanic and Atmospheric Administration. 112 pp.

Strategic Assessment Branch and Northwest and Alaska Fisheries Center, 1988: West Coast of North America Strategic Assessment: Data Atlas. Marine Mammals volume. Pre-publication edition. Rockville, MD: National Oceanic and Atmospheric Administration. 58 pp.

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