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    • EK80 Water Column Sonar Data Collected During DY2308

    Metadata Updated: March 1, 2024

    The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC), conducted an acoustic-trawl (AT) stock assessment survey in areas of the Gulf of Alaska (GOA) in the summer of 2023 to estimate 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). The survey was conducted in three segments (10-22 June, 30 June to 21 July, and 7-20 August) starting and ending in Kodiak, Alaska with two port calls also in Kodiak. The vessel departed Kodiak, Alaska on 11 June and conducted a standard sphere calibration on the Kongsberg EK80 echosounder system on 11 June in Uyak Bay, Kodiak Island, Alaska. The survey areas included the Gulf of Alaska Shelf (between 14 June and 17 August), the Shumagin Islands (18-20 June), Shelikof Strait (1-8 July), Barnabas Trough (15-18 July), and Chiniak Trough (19-21 July). A second calibration of the EK80 echosounder system was conducted on 12 August in North Arm, Nuka Sound, Kenai Peninsula, Alaska. Mid-water trawl operations were conducted using an LFS1421 mid-water trawl net. Water column CTD casts were conducted at select positions on most days throughout the cruise using a Sea-Bird Scientific SBE 911Plus water column profiling system. During the second segment of the cruise, experimental operations were conducted using an iXblue DriX unmanned surface vessel (USV) remotely operated from the vessel and/or shore stations. The USV was equipped with a Kongsberg EK80 echosounder system. Survey operations were concluded on 18 August and the vessel returned to port (Kodiak) on 20 August.

    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 19, 2024
    Metadata Created Date March 1, 2024
    Metadata Updated Date March 1, 2024
    Reference Date(s) June 11, 2023 (creation), January 19, 2024 (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 19, 2024
    Metadata Created Date March 1, 2024
    Metadata Updated Date March 1, 2024
    Reference Date(s) June 11, 2023 (creation), January 19, 2024 (publication)
    Responsible Party NOAA National Centers for Environmental Information (Point of Contact)
    Contact Email
    Guid gov.noaa.ncei:DY2308_EK80
    Access Constraints Cite as: NOAA Alaska Fisheries Science Center. 2024. EK80 Water Column Sonar Data Collected During DY2308. NOAA National Centers for Environmental Information. https://doi.org/10.25921/rhsc-v339 [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 -139.73631
    Bbox North Lat 60.26279
    Bbox South Lat 52.50876
    Bbox West Long -169.24273
    Coupled Resource
    Frequency Of Update notPlanned
    Harvest Object Id 1341a804-12e8-41d2-af5b-22c986699e8f
    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 Uncalibrated w/ calibration data
    Metadata Language eng; USA
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-169.24273, 52.50876], [-139.73631, 52.50876], [-139.73631, 60.26279], [-169.24273, 60.26279], [-169.24273, 52.50876]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System urn:ogc:def:crs:EPSG::4326
    Spatial Harvester True
    Temporal Extent Begin 2023-06-11T00:00:00
    Temporal Extent End 2023-08-20T11:59:59

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