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    • EK80 Water Column Sonar Data Collected During DY2104

    Metadata Updated: November 10, 2022

    The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys in the Gulf of Alaska (GOA) 1 June to 10 July 2021 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted along the Gulf of Alaska shelf from the Islands of Four Mountains to Yakutat Trough. Survey operations were conducted aboard NOAA Ship Oscar Dyson, a 64 meter fisheries research vessel built in 2003 and equipped for stern trawling and included capabilities to collect acoustic, oceanographic, and biological scientific data. Acoustic data was collected for the survey using a Kongsberg Simrad EK80 split-beam echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). Mid-water trawls were conducted using an LFS 1421 mid-water trawl net equipped with a Kongsberg Simrad FS70 trawl sonar. The survey was divided into two segments with the first segment conducted from 1 June to 20 and the second segment conducted 24 June to 10 July with a mid-survey port call in Kodiak. The vessel departed Kodiak, Alaska on 1 June and conducted a calibration of the EK80 system prior to starting survey operations. The survey areas included the Gulf of Alaska shelf from the Islands of Four Mountains to southeast Kodiak Island, the Shumagin Islands, Barnabas Trough, Shelikof Strait, Chiniak Trough, and the Gulf of Alaska shelf from southeast Kodiak Island to Yakutat Trough. A post-survey calibration of the EK80 echosounder was completed prior to arrival in Kodiak, Alaska on July 10.

    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 January 20, 2022
    Metadata Created Date November 10, 2022
    Metadata Updated Date November 10, 2022
    Reference Date(s) June 1, 2021 (creation), January 20, 2022 (publication)
    Frequency Of Update notPlanned

    Metadata Source

    Harvested from NGDC MGG Sonar Water Column

    Other Data Resources

    Additional Metadata

    Resource Type Series
    Metadata Date January 20, 2022
    Metadata Created Date November 10, 2022
    Metadata Updated Date November 10, 2022
    Reference Date(s) June 1, 2021 (creation), January 20, 2022 (publication)
    Responsible Party NOAA National Centers for Environmental Information (Point of Contact)
    Contact Email
    Guid gov.noaa.ncei:DY2104_EK80
    Access Constraints Cite as: NOAA Alaska Fisheries Science Center. 2022. EK80 Water Column Sonar Data Collected During DY2104. NOAA National Centers for Environmental Information. https://doi.org/10.25921/r078-hp51 [access date], Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose., Resource may not be available for up to one year after initial collection.
    Bbox East Long -140.54708
    Bbox North Lat 60.24851
    Bbox South Lat 52.50397
    Bbox West Long -169.24277
    Coupled Resource
    Frequency Of Update notPlanned
    Harvest Object Id 8f408b88-5995-477b-ad82-c59d9bda28e4
    Harvest Source Id ab8b0290-e4db-4a00-89f2-4e427c2054b2
    Harvest Source Title NGDC MGG Sonar Water Column
    Licence These data are considered raw and have not been subjected to the NOAA's quality control or quality assurance procedures. They are released for limited public use as preliminary data to be used only with appropriate caution. 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., Not subject to copyright protection within the United States.
    Lineage Calibrated w/ calibration data
    Metadata Language eng; USA
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-169.24277, 52.50397], [-140.54708, 52.50397], [-140.54708, 60.24851], [-169.24277, 60.24851], [-169.24277, 52.50397]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System urn:ogc:def:crs:EPSG::4326
    Spatial Harvester True
    Temporal Extent Begin 2021-06-01T00:00:00
    Temporal Extent End 2021-07-10T11:59:59

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