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    A descriptive analysis of the toothfish (Dissostichus spp.) tagging programme in the Ross Sea up to 2005/06

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    Номер документа:
    A. Dunn and S.M. Hanchet (New Zealand)
    Пункт(ы) повестки дня

    A descriptive analysis of the toothfish tagging programme carried out in Subareas 88.1 and 88.2 since 2001 is presented. The paper updates tag-release and tag-recapture data for fish that were both released and recaptured from New Zealand vessels. It also presents release and recapture data for non- New Zealand vessels for the first time. However, tag data were only available for all of these vessels for 2005 and for about half of these vessels for 2004.

    A reported total of 8888 Antarctic toothfish have been released and 176 recaptured, and 635 Patagonian toothfish released and 23 recaptured. Tagging rates by area over the past three years have been in the same proportion as the catch by area. However, recapture rates have tended to be higher in the northern and eastern SSRUs 88.1C and 88.2E. About 20% of the recaptures could not be matched to a release observation, mainly because of missing release data. It is recommended that all outstanding release and recapture data be provided to the Secretariat as soon as possible so that the analysis can be updated in time for the 2006 WG-FSA meeting.

    Several large-scale movements have now been reported from the tagging data. Five fish tagged at McMurdo Sound have moved over 800 km, whilst a further four fish tagged in the fishery have moved over 300 km. However, the majority (>80%) Antarctic toothfish have moved less than 50 km. In 2006, New Zealand vessels greatly increased the size of toothfish being tagged so that for the first time the size distribution of the tagged fish was almost identical to the size composition of the catch.