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    The annual random stratified trawl survey to estimate the abundance of Dissostichus eleginoides and Champsocephalus gunnari in the Heard Island region (Division 58.5.2) for 2012

    Solicitar acceso a documento de reunión
    Número de documento:
    G.B. Nowara and T. Lamb (Australia)
    Presentado por:
    Sarah Mackey (Secretaría de la CCRVMA)

    The annual random stratified trawl survey at HIMI was completed in March to May of 2012. A codend liner, usually in place for the entire survey, was used only in the icefish strata, Gunnari Ridge, Plateau Southeast and Plateau West, and in a repeat of the hauls in Ground B. Catches in this RSTS were generally high in comparison with previous years, with the total fish catch being twice as high as the long term average (2006-2011). The catches of Dissostichus eleginoides for 2012 were twice those of 2011 and about one and a half times higher than the long-term average. Champsocephalus gunnari catches were twice the long term average. Catches of all the major fish species were higher in 2012 than the long-term average, except for those of Channichthys rhinoceratus which was 10% lower. The catch of Lepidonotothen squamifrons was four times higher than the average. A slightly higher than average weight of skates was also taken in 2012.

    The catch of invertebrates in the 2012 survey, 4 t, was about half that of the long term average. The most abundant taxa in the catches were poriferan sponges, medusa (jellyfish), anemones and corals. Catches of individual taxa were generally much lower than in previous years, except for coral, with a reported catch of 0.6 t, being significantly greater than the long term average (50 kg). A possible explanation for the generally lower catches is that the smaller mesh codend liner was not in place for most of the survey.

    Lengths and biological measurements were taken for many thousands of fish, 1095 pairs of otoliths collected and 524 toothfish were tagged.