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    • EK80 Water Column Sonar Data Collected During DY2207

    Metadata Updated: April 1, 2025

    The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC), conducted an acoustic-trawl (AT) stock assessment survey on the Easter Bering Sea shelf from Bristol Bay to U.S.-Russia Convention Line in the late spring and summer of 2022 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). This survey was 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 Kongsberg EK80 split-beam scientific echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). Trawl operations were conducted using an LFS1421 mid-water trawl net.

    The survey was conducted in three legs starting and ending in Dutch Harbor, Alaska with intermediate port calls in Dutch Harbor. Survey leg 1 was conducted 3-15 June, leg 2 was 22 June to 8 July, and leg 3 was 20 July to 5 August; the dates listed are for actual survey operations and do not include the additional transit time between port and area of operations. The delay between legs 2 and 3 was due to vessel staffing issues. Calibrations of the EK80 echosounder system were conducted prior to starting the survey (31 May), at the end of leg 2 (9 July), and at the end of the survey (5 August) in Captains Bay, Unalaska Island (Dutch Harbor), Alaska.

    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 March 26, 2025
    Metadata Created Date April 1, 2025
    Metadata Updated Date April 1, 2025
    Reference Date(s) May 31, 2022 (creation), March 26, 2025 (publication)
    Frequency Of Update notPlanned

    Metadata Source

    Harvested from NGDC MGG Sonar Water Column

    Other Data Resources

    Additional Metadata

    Resource Type Series
    Metadata Date March 26, 2025
    Metadata Created Date April 1, 2025
    Metadata Updated Date April 1, 2025
    Reference Date(s) May 31, 2022 (creation), March 26, 2025 (publication)
    Responsible Party (Point of Contact); NOAA National Centers for Environmental Information (Point of Contact)
    Contact Email
    Guid gov.noaa.ncei:DY2207_EK80
    Access Constraints Cite as: NOAA Alaska Fisheries Science Center. 2025. EK80 Water Column Sonar Data Collected During DY2207. NOAA National Centers for Environmental Information. https://doi.org/10.25921/j9aq-t085 [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 -161.32663
    Bbox North Lat 63.14678
    Bbox South Lat 53.84409
    Bbox West Long -178.90504
    Coupled Resource
    Frequency Of Update notPlanned
    Harvest Object Id 58e6d610-911e-463c-8c00-25476861010a
    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": [[[-178.90504, 53.84409], [-161.32663, 53.84409], [-161.32663, 63.14678], [-178.90504, 63.14678], [-178.90504, 53.84409]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System urn:ogc:def:crs:EPSG::4326
    Spatial Harvester True
    Temporal Extent Begin 2022-05-31T00:00:00
    Temporal Extent End 2022-08-06T11:59:59

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