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    • EK80 Water Column Sonar Data Collected During DY2102

    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 Shelikof Strait area of the Gulf of Alaska (GOA) in the late winter of 2021 to estimate distribution and abundance of walleye pollock (Gadus chalcogrammus). These surveys were conducted aboard NOAA Ship Oscar Dyson (built in 2003, 64 meters, 2500 tons, 3100 hp), a research stern trawler equipped with acoustic and oceanographic instrumentation. The primary water column acoustic instrument for the survey was a Simrad EK80 split-beam scientific echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). The vessel departed Kodiak, Alaska on 2 March and conducted the Shelikof Strait survey 3-10 March, and the Marmot Bay survey 13-15 March. A calibration of the EK80 echosounder was conducted prior to starting the surveys on 2 March in Kalsin Bay, Kodiak Island, Alaska and a follow-up post-cruise calibration was conducted in Kalsin Bay, Kodiak Island, Alaska on 15 March. Trawl operations were conducted using an LFS1421 mid-water trawl net.

    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.

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    Dates

    Metadata Date September 15, 2021
    Metadata Created Date November 10, 2022
    Metadata Updated Date November 10, 2022
    Reference Date(s) March 2, 2021 (creation), May 2, 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 September 15, 2021
    Metadata Created Date November 10, 2022
    Metadata Updated Date November 10, 2022
    Reference Date(s) March 2, 2021 (creation), May 2, 2022 (publication)
    Responsible Party NOAA National Centers for Environmental Information (Point of Contact)
    Contact Email
    Guid gov.noaa.ncei:DY2102_EK80
    Access Constraints Cite as: NOAA Alaska Fisheries Science Center. 2021. EK80 Water Column Sonar Data Collected During DY2102. NOAA National Centers for Environmental Information. https://doi.org/10.25921/ahkf-jp49 [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 -151.718935612148
    Bbox North Lat 58.6439015246328
    Bbox South Lat 55.4696586276267
    Bbox West Long -157.081643335452
    Coupled Resource
    Frequency Of Update notPlanned
    Harvest Object Id 2970a644-4720-4878-a195-ea403ad63ec9
    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": [[[-157.081643335452, 55.4696586276267], [-151.718935612148, 55.4696586276267], [-151.718935612148, 58.6439015246328], [-157.081643335452, 58.6439015246328], [-157.081643335452, 55.4696586276267]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System urn:ogc:def:crs:EPSG::4326
    Spatial Harvester True
    Temporal Extent Begin 2021-03-02T00:00:00
    Temporal Extent End 2021-03-16T11:59:59

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