Revised new research plan for Antarctic toothfish (Dissostichus mawsoni) exploratory fishery in Statistical Subarea 48.6 from 2024/25-2027/28): Research Plan under CM21-02, paragraph 6(iii)

A collaborative research program for exploratory fishery has been undertaken by Japan and South Africa since 2013 to enhance data collection and analysis in the subarea 48.6 under CM 21-02. Spain joined the research program for exploratory fishery starting from 2018/19 fishing season in order to contribute to the data acquisition and to speed up the integrated assessments of the Antarctic toothfish (Dissostichus mawsoni) stock in this subarea (WG-FSA-18/34). Data collected by the three participants form bases of the results of the plan that have been presented annually to CCAMLR Working Groups.

This document provides a new research plan for 2024/25 through to 2027/28, in accordance with Annex 24-01/A, Format 2, to continue research in the exploratory fishery in Subarea 48.6. The spatial design of this plan is unchanged from the previous research plan arranging four research blocks. South Africa will contribute to the plan only with laboratory work, and the Republic of Korea will join to the research program for exploratory fishery to increase research capacity contribute to the achievement of objectives. This plan has been designed as a 4-year plan, based on the low risk profile of this fishery and to allow more time for reviewing of the stock assessments by Working Groups in the so-called ‘non-assessment’ years for established toothfish fisheries. The updated ‘CCAMLR Research Plan - Research Proponent Self-Assessment’ can be found in Appendix 1, and the description of vessel tagging procedures following the survey questionnaire (see Comm Circ-21-54 and SC-Circ-21-68) in Appendix 2.

To address comments from WG-SAM-2024 (WG-SAM-2024 paragraph 7.4), the following points have been revised in this research plan for 2024/25 through to 2027/28.

• The sample size of by-catch species collected have been increased up to 30 fish per species per set, not only for Macrourus spp. but also for other major by-catch species (Table 3).
• The particle tracking modeling works are included under “Objective 2” (Table 1 and “(c) Method for data analysis to achieve the objective in 1(a)”).
• In section “3. Survey design, data collection and analysis”, sentences explaining the following two points are added; 1) why it is difficult to implement depth stratified design and 2) why it is easy to implement comparing/calibrating/standardizing multiple gear effect after the fishing operation.