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    Analysis of the longline fishery data in the Ross Sea (SSRUs 881B, C and G)

    Request Meeting Document
    Document Number:
    WG-FSA-16/14
    Author(s):
    S. Kasatkina
    Submitted By:
    Dr Svetlana Kasatkina (Russian Federation)
    Approved By:
    Mr Dmitry Kremenyuk (Russian Federation)
    Abstract

    The analysis of the toothfish fishery data in the northern part of the Ross Sea (SSRU 88.1 B, C and G) was performed using haul-by-haul data from the CCAMLR database for the period 1997-2015.  The variability of catch per haul (kg) and CPUE (kg/1000 hooks) depending on the hauling duration (min) and hauling speed   (min/1000 hooks) were analyzed.

    Our analysis shows that there is a possible presence of  number of high CPUE and catches , which are outside the  upper limit of confidence interval of 99,7% CI. These CPUE and catch values are statistically unreliable and questionable high with respect to the fishery data in the year under consideration.  It was shown that total questionable catch within SSRU as well as questionable catches obtained by State flagged vessels may be significant.   It is necessary to clarify of how   questionable catches and CPUE were obtained and how such questionable catches should be treated.   

    It was also shown that the current approach to analyze longline fishery data in the presence of questionable CPUE values does not allow revealing adequate information for decision-making.