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    Otolith chemistry reflects local stock connectivity of Antarctic toothfish (Dissostichus mawsoni) between research blocks in Subarea 48.6: an updated report

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    Document Number:
    G.P. Zhu, L. Wei, T. Okuda, R. Sarralde and S. Somhlaba
    Submitted By:
    Professor Guoping Zhu (China)
    Approved By:
    Dr Xianyong Zhao (China)

    The local stock structure of Antarctic toothfish (Dissostichus mawsoni) in some Research Blocks (RBs) of Subarea 48.6 has been investigated in Wei et al. (2018), but this study has not included the RB 48.6_5 into the analysis and the stock connectivity between RBs has also not examined. Therefore, this study is aimed to update the information about stock connectivity of D. mawsoni across RBs using otolith core and edge chemistry data. Only one stock can be identified using otolith chemistry data. Fish moves across RBs frequently, although more fish moves southwardly to shelf/slope areas. It’s need to be concerned about the immigration from Division 58.4.2 and emigration to subareas 48.3 and 48.4, and fishery in subarea 48.6 is suggested to be managed as one stock. A modelling study on the dispersal of eggs and juveniles for this species is suggested.