• Login
    View Item 
    •   Marine Institute Open Access Repository
    • Marine Institute Community of Research Publications
    • Survey & Cruise Reports
    • Acoustic Surveys
    • View Item
    •   Marine Institute Open Access Repository
    • Marine Institute Community of Research Publications
    • Survey & Cruise Reports
    • Acoustic Surveys
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Marine OARCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    Atlantic Herring in 6aS/7b, Industry Acoustic Survey Cruise Report, November-December 2022

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    NWHerring_2022_cruise_report.pdf
    Size:
    15.53Mb
    Format:
    PDF
    Download
    Author
    O’Malley, M.
    Mullins, Eugene
    Nolan, Cormac
    Keyword
    Acoustic survey
    Herring
    Clupea harengus
    Date
    2023
    Publisher
    Marine Institute
    
    Metadata
    Show full item record
    Abstract
    An acoustic survey of Atlantic herring Clupea harengus was conducted in ICES areas 6aS/7b in November/December 2022 and January 2023. The 2022 survey was conducted using five vessels; MFVs Crystal Dawn WD201, Ros Ard SO745, Girl Kate SO427, Johnny G S653 (d) and Conquest SO852. The 6aS/7b survey design in 2022 focused on 6 core areas with prior knowledge of herring distribution from previous surveys and the monitoring fishery were targeted for surveying. The change in survey design since 2020 was largely based on the results from ICES WKHASS (ICES 2020) and from lessons learned in the previous surveys in this area from 2016-2019. This design resulted in a much reduced survey area compared to previous years, but with better coverage of most of the important inshore bays where the monitoring fishery takes place. The survey design objective remained the same; to capture the distribution of winter spawning herring in the 6aS/7b area, but this design was not expected to achieve overall stock containment. The timing of surveys in the core areas was flexible from the outset by design. The greater flexibility allows for a targeted spatial and temporal approach which avoided the inevitable poor weather that can happen in this area during this time of the year and which led to reduced survey effort in some previous years. Using smaller vessels allowed surveys to be conducted in shallow inshore areas where herring are known to aggregate during this time of the year. This survey is the seventh consecutive annual acoustic survey for pre-spawning herring in this area at this time of the year. A pole-mounted system with a combi 38 kHz (split) 200 kHz (single) transducer was used successfully for the survey on small vessels (<18m) in 2022. Herring were again distributed inshore in shallow areas, and the improved survey design and use of small vessels for the survey resulted in a good measure of uncertainty (CV =0.25). The stock was not overall contained in 2022, particularly in the Donegal Bay area (Malin Beg, etc.) and more effort is required to target surveys earlier and later than December and January when herring tend to show up in these areas in difficult to predict patterns. Very strong herring marks were evident in Lough Foyle and Lough Swilly in the channel in marks that extended for many miles in some cases. This was in areas where smaller boats in the fishery were concentrating effort. Herring had left the Swilly and Foyle by mid-February. There was also a series of strong herring marks in Bruckless Bay, Fintra Bay and Inver Bay in discreet areas, particularly in December. The monitoring fishery was being conducted on smaller boats in the same areas and close to the same time as the survey and biological samples from some of these vessels were used. There was a fairly tight distribution of length classes in all hauls, with most hauls dominated by larger (> 22 cm) mature fish. The 2- and 3-wr age class of herring accounted for 72% of the overall numbers in 2022. The total stock biomass (TSB) estimate of 54,046 tonnes is considered to be a minimum estimate of herring in the 6aS/7b survey area at the time of the survey. The 2022 estimate is the highest estimate in the time series. The flexible survey design and focusing on discreet areas was generally successful and is providing a good template for future survey designs.
    URI
    http://hdl.handle.net/10793/1863
    Citation
    O'Malley, M., Mullins, E. and Nolan, C. (2023). Atlantic Herring in 6aS/7b, Industry Acoustic Survey Cruise Report, November-December 2022. FEAS Survey Series: Industry Acoustic Survey/01/2022. Marine Institute, Ireland
    Collections
    Acoustic Surveys

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us | MI Privacy Policy
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.