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    • Aerial Survey Counts of Harbor Seals in Coastal Alaska (2003-2011)

    Metadata Updated: May 1, 2024

    This dataset supports efforts to estimate the abundance and trends in population size of Alaska harbor seals. Annual surveys of harbor seal populations are fundamental to estimation of seal abundance, distribution, and trends, which in turn are essential for stock assessment, conservation, and management. The most feasible approach to determining harbor seal distribution and abundance is to use aircraft to count seals when they haul out of the water and are visible. Harbor seals in Alaska occupy a geographically extensive range from approximately long. 172ºE to 130ºW (over 3,500 km east to west) and from lat. 51ºN to 61.5ºN (over 1,000 km north to south). Estimation of the abundance of harbor seals statewide requires broad-scale aerial surveys and these surveys have been conducted by NOAA Fisheries, the Alaska Department of Fish and Game, and other collaborators since the early 1980s. This dataset reflects counts of harbor seals from surveys conducted between 2003 and 2011.

    This dataset differs from earlier datasets in a few key areas: 1) records generally correspond to a count of the number of harbor seals within a single, geo-referenced digital photo, 2) photographs were not taken when no seals were present so additional analysis of survey effort and flight tracks was required to determine 0 counts.

    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

    Other Data Resources

    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:26741
    Access Constraints Cite As: Alaska Fisheries Science Center, [Date of Access]: Aerial Survey Counts of Harbor Seals in Coastal Alaska (2003-2011) [Data Date Range], https://www.fisheries.noaa.gov/inport/item/26741., 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 9bdbdc8b-25df-4df9-8939-9125c4f32e8a
    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 Data collection and processing protocols were updated and improved on a nearly annual basis during the 2003-2011 period. For example, aerial survey observers transitioned from using paper maps and rudimentary GPS units to using advanced GPS units and moving map software on laptop computers for in-flight navigation and data recording purposes. 35 mm film cameras were replaced by digital SLR cameras with new, higher-resolution models being added every few years. And the seal counting process transitioned from projecting slides on a white board to using computers with photo-processing software and high-resolution monitors to mark and count individual seals. In most cases, records within this dataset represent seal counts within a single, geo-referenced photograph taken by a trained observer during dedicated aerial surveys for harbor seals.
    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 underDevelopment
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2003
    Temporal Extent End 2011

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