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    Hydroacoustic data obtained around Elephant Island and South Orkney Islands during austral summer 2018

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    Numéro du document:
    WG-FSA-18/05
    Auteur(s):
    N.A. Alegría and P.M. Arana
    Soumis par:
    César Cárdenas (Chili)
    Approuvé par:
    César Cárdenas (Chili)
    Point(s) de l'ordre du jour
    Résumé

    This document presents the analysis of acoustic data obtained during the austral summer of 2018 as a complement to finfish research in Subareas 48.1 and 48.2 using bottom trawling nets. The acoustic information survey was carried out with a SIMRAD EK80 wide band scientific echosounder at a frequency of 38 kHz and a SIMRAD ES70 fishing echosounder equipped with a 120 kHz frequency transducer. The geographical distribution of krill concentrations and the presence of fish shoals are described in an area of 1,699 nautical miles over the continental shelf and slope (50-500 m) around Elephant Island (579 nm) and South Orkney Islands (1,120 nm). Concentrations of krill (Euphausia superba), the pelagic species with the greatest presence in the studied area, are described, mainly to the north of both islands. Likewise, mackerel icefish (Chamsocephalus gunnari) are identified, forming large concentrations in steep slope areas, mostly around Elephant Island. This species presents demersal characteristics during the day and pelagic characteristics at night. Additionally, some echoic records registered in the water column are presented, attributed to "Other species" of fish.