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Alaska Harbor Seal Aerial Survey Units

Metadata Updated: May 1, 2024

Aerial surveys of coastal Alaska are the primary method for estimating abundance of harbor seals. A particular challenge associated with aerial surveys of harbor seals is maintaining consistent spatial representation of haulout locations. In some cases, seals aggregate into a single large grouping at a particular area. In other cases, seals aggregate into several smaller groups spread over a particular area. To establish geo-spatial consistency, the Alaska Fisheries Science Center developed coastal survey units (spatial polygons) throughout the distriubtion of harbor seals in Alaska. Each survey unit was designed to be approximately 10-15 kilometers in coastal length, to faciliate efficient aerial surveys, and to aggregate known harbor seal haulout locations. Each survey unit was assigned a unique alphanumeric identifier and the spatial data are provided in the geographic (epsg:4326) coordinate reference system. The survey units form the spatial foundation for estimation of harbor seal abundance and trend.

Access & Use Information

License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Date April 17, 2024
Metadata Created Date May 1, 2024
Metadata Updated Date May 1, 2024
Reference Date(s) (publication)
Frequency Of Update asNeeded

Metadata Source

Harvested from NMFS AFSC

Additional Metadata

Resource Type Dataset
Metadata Date April 17, 2024
Metadata Created Date May 1, 2024
Metadata Updated Date May 1, 2024
Reference Date(s) (publication)
Responsible Party (Point of Contact, Custodian)
Contact Email
Guid gov.noaa.nmfs.inport:17349
Access Constraints Cite As: Alaska Fisheries Science Center, [Date of Access]: Alaska Harbor Seal Aerial Survey Units [Data Date Range], https://www.fisheries.noaa.gov/inport/item/17349., Access Constraints: The data set is in the process of being archived with the NOAA National Centers for Environmental Information. Once the archival process is complete and verified, the data set will be publicly available., Use Constraints: User must read and fully comprehend the metadata prior to use. Applications or inferences derived from the data should be carefully considered for accuracy. While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. Acknowledge NOAA/NMFS/AFSC or the specified citation as the source from which these data were obtained in any publications and/or other representations of these data. Communication and collaboration with dataset authors is strongly encouraged., Distribution Liability: While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Bbox East Long -130
Bbox North Lat 61.5
Bbox South Lat 51
Bbox West Long 172
Coupled Resource
Frequency Of Update asNeeded
Harvest Object Id 29801809-ed78-455c-b081-53e1b7399d63
Harvest Source Id 26a29bb9-50b0-47fd-920b-edc74aa6ec76
Harvest Source Title NMFS AFSC
Licence NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
Lineage The aerial survey units (polygons) were derived from a multi-stage effort that combined historical knowledge of harbor seal haul-outs, typical aerial survey routes and techniques, and detailed coastline maps. Each unit was designed to be approximately 10-15 km in coastline length and 1-2 km in width. The units were designed such that an aircraft surveying obliquely would be within a unit boundary under typical survey conditions. Additionally, the survey unit boundaries were optimized to limit the number of known haul-out locations near the boundary.
Metadata Language eng
Metadata Type geospatial
Old Spatial {"type": "Polygon", "coordinates": [[[172.0, 51.0], [-130.0, 51.0], [-130.0, 61.5], [172.0, 61.5], [172.0, 51.0]]]}
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True

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