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    Analysis of the diet of Champsocephalus gunnari in Subarea 48.3, Dr E. Holmberg survey, February 1995

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    Numéro du document:
    WG-FSA-95/36
    Auteur(s):
    Marschoff, E., Barrera-Oro, E., Casaux, R.
    Point(s) de l'ordre du jour
    Résumé

    About 1300 stomach contents of the icefish Champsocepha1us gunnari caught in the Subarea 48.3 in February 1995, were analyzed using the frequency of occurrence (%) method. Krill (Euphausia superba) (58%) and the amphipod hyperiid Themisto gaudichaudii (55%) occurred similarly at South Georgia and constituted the main food. At Shag Rocks, T. gaudichaudii was the main prey item (52%), followed in importance by the mysid Thysanoessa sp. (35%) and krill (24%). The picture around SG was found to be similar to that observed in the E. Holmberg survey in February/March 1994: common levels of krill availability indicated by frequency of occurrence, but, on the other hand, high proportions of empty stomachs (also at Shag Rocks), close to the values reported for years of krill scarcity. While no krill aggregations were found in the South Georgia shelf during the Holmberg Cruise in Feb-March/1994, an acoustic survey carried out in the same area in March 1995 detected such aggregations. It is suggested that krill availability for C. gunnari around South Georgia in the 1995 summer season, was somewhat below the historical years of high abundance, but above than in 1994.