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    An updated descriptive analysis of the toothfish (Dissostichus spp.) tagging program in Subareas 88.1 and 88.2 for 2006/07

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    A. Dunn, S.M. Hanchet and S.L. Ballara (New Zealand)
    Agenda Item(s)

    Descriptive analyses of the toothfish tagging programme carried out in Subareas 88.1 and 88.2 since 2001 are updated. The paper provides a preliminary update of the tag-release and tag-recapture data that were presented at the October 2006 meeting of WG-FSA by including data from New Zealand vessels and preliminary data for other vessels that fished in 2007.
    Release and recapture data that previously were unavailable for about half of the non-New Zealand vessels for 2004 are now available and described in this paper for the first time. Overall, a reported total of 12 177 Antarctic toothfish have been released and 333 recaptured, and 859 Patagonian toothfish released and 29 recaptured since 2001.
    The number of tags recaptured in the Ross Sea in 2007 by New Zealand vessels was the highest annual recapture to date and double the number caught in 2006, although the nature of these recaptures suggests that assumptions of homogeneous mixing may need to be investigated. For the first time, long distance movements of Antarctic toothfish were observed from fish tagged by fishing vessels. A total of four fish moved significant distances from the slope fisheries in SSRUs 88.1H, 88.1I, and 88.1K to Terra Nova Bay in SSRU 88.1J. There was also some evidence that more fish are recaptured after a longer time at liberty on the slope than in the North.
    However, we note that data from the 2007 season for the non-New Zealand vessels were incomplete at the time of this analyses and will need to be updated in future analyses.