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    Interannual variability of standardised index of krill abundance in Area 48 according to CCAMLR fishery statistics database

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    Document Number:
    WG-EMM-10/17
    Author(s):
    P.S. Gasyukov and S.M. Kasatkina (Russia)
    Abstract

    Standardization of fishing effort on the basis of the generalized linear models with mixed effect (GLMM) allows to the authors to analyze the specific character of the spatial distribution of fishery at the scale of Area 48, Subareas 48.1-48.3, SSMUs and years using CAMLR statistical database. The interannual variability of the standardized CPUE related to the fishery performance was analyzed. It was revealed that dynamics of the most important fishery index - standardized abundance index CPUE in Subareas 48.1-48.3 and SSMUs did not correspond to the dynamics of krill density and biomass distribution, obtained from CCAMLR 2000 Survey and available data of the national acoustic surveys. The performance of the fishery and attractiveness of any SSMU for fleet operation will determined by the fishable part of krill biomass rather than the total krill biomass in the area. The high variability and different trends of CPUE distribution by Subareas and SSMUs, differences between spatial-temporal distributions of CPUE and krill biomass from acoustic surveys , huge confidential intervals of annual CPUE estimates evidence that inter-annual variability of standardized abundance index of krill obtained from CAMLR statistical database cannot be used for quantitative understanding of the process of the actual krill distribution in Area 48. The long-term fishery management in Area 48 will be required new international acoustic surveys and full-scale usage of available data from the national acoustic surveys.