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    Full Name
    Groupe de travail sur les statistiques, les évaluations et la modélisation
    Leeuwarden, The Netherlands
    Date/heure de début de réunion:
    Date/heure de fin de réunion:
    Dates limites de soumission
    lundi 10 juin 2024 à 09:00 Australie/Hobart (Document de groupe de travail)

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      1     Introduction
      1.1     Opening of the meeting

      The terms of reference for WG-SAM are to provide advice to the Scientific Committee and its working groups on:
      (i) Quantitative assessment methods (including stock assessment methods and management strategy evaluation methods), statistical procedures, and modelling approaches for the conservation of Antarctic marine living resources
      (ii) The implementation of, and data requirements for, such methods, procedures and approaches
      (iii) Review of research plans and proposals
      (iv) Sampling design of research fishing and surveys.

      1.2     Adoption of the agenda

      The working group will consider amendments to and adoption of the meeting agenda.

      2     Development of methods to estimate biomass for krill

      SC-CAMLR-42 recommended a rollover of CM 51-07 for one year and noted the importance of providing definitive advice using contemporary data and analysis such as spatial overlap analysis (SC-CAMLR-42, paragraph 2.27). Acoustic surveys will include sampling of krill length distributions designed to characterise the biomass of krill in each management unit. WG-SAM has identified the effective sampling size for length frequency distribution (Task 1) under the priority research topic 'Data collection – SISO and vessels and CEMP'.

      3     Development of stock assessments to implement decision rules for krill

      The development of integrated stock assessments for krill (Task 2) has been identified as a potential approach to krill management. A Casal2 model for krill was encouraged to continue progressing through the consideration of six suggestions from WG-SAM-2023 (WG-SAM-2023, paragraph 4.3).

      4     Develop methods to estimate biomass for finfish
      4.1     Survey design

      Methods for calibration among vessels for tag release survival and tag detection have remained as a priority item for consideration by WG-SAM (SC-CAMLR-38, paragraph 13.4). Gear standardisation effects on toothfish tagging programs (Task 3) have been identified as a priority research topic for finfish biomass estimation in the workplan table (SC-CAMLR-42, Annex 7).

      4.2     Data collection – SISO and vessels

      In the work plan table (SC-CAMLR-42, Annex 7), the following items have been indicated as planned work for 2024 regarding data collection from SISO and vessel operations:
      a) Metrics of vessel tagging performance (Task 4)
      b) Recording selection of non-random biological data (Task 5)
      c) Development of protocols for toothfish conversion factors (Task 6)

      4.3     Improve biomass estimation methods

      The Scientific Committee identified work towards estimating and correcting for the effects of changing spatial distributions on fishing effort in assessments (see details SC-CAMLR-42, para 2.124). These issues are priority work items in the WG-SAM work plan as: Optimise tag-based study (spatial overlap) (Task 7) and, Vessel configuration factors affecting tagging mortality (Task 8).

      5     Develop stock assessments to implement decision rules for finfish
      5.1     Communication of progress, internal and external

      The Scientific Committee noted the commitment of Members undertaking integrated assessments for toothfish to collaboratively address the issues of effects of spatial bias in tagging data, and trends in recruitment in the short-term, and present results to WG-SAM-2024 with revised stock assessments to WG-FSA-2024 (SC-CAMLR-42, para 2.125).
      The WG-SAM work plan table (SC-CAMLR-42, Annex 7) also indicates diagnostic graphs on stock status (Task 20) as a priority item for WG-SAM-2024.

      5.2     WS-ADM2-2024

      The Scientific Committee asked WG-SAM to complete an evaluation of reader comparison of toothfish otolith ageing works (Tasks 9-13) with reference to the outcomes of WS-ADM2-2024. The Age Determination Workshop in 2023 (WS-ADM) requested that WG-SAM and WG-FSA develop target levels of precision (CV, IAPE) for age determination among readers or counts between a single reader and a reference set to monitor and maintain consistency in age interpretation (WG-FSA-2023/43, para 2.16.2, Task 10 of WG-SAM work plan table).

      6     Management strategy evaluations for target species
      6.1     Evaluation of the CCAMLR decision rules and potential alternative harvest control rules for assessed fisheries

      The Scientific Committee (SC-CAMLR-42, para 2.124) noted that WG-SAM needs to progress analyses of current and alternative decision rules, including building on the work of WG-FSA-2019/08, WG-SAM-2021/08, SC-CAMLR-38/15 and WG-FSA-2023/28 to investigate alternative rules and assumptions about future recruitment, and addressing recommendations 6.1 and 6.2 of the report of the independent review (SC-CAMLR-42/02 Rev. 2).

      6.2     Development and testing of data-limited fishery decision rules

      The WG-SAM work plan table (SC-CAMLR-42, Annex 7) indicates that development and agreement on an operating model (Task 15) and a management strategy evaluation (MSE) (Task 16) are high priority topics for data-limited finfish fisheries.

      7     Review of new research proposals

      The Working Group will prioritise review of new research proposals (Task 14).

      7.1     New proposals under CM 21-02
      7.2     New proposals under CM 24-01

      The Scientific Committee recommended that research on Dissostichus spp. under CM 24-01 in Subarea 48.2 should be revised and presented at WG-SAM-2024 (SC-CAMLR-42, para 2.156).

      8     Review of ongoing research plan results and proposals

      The Working Group should review ongoing research plan results and proposals (Task 14) according to the timetable specified in CCAMLR-38 paragraph 5.64

      8.1     Research results and proposals from Area 48
      8.2     Research results and proposals from Area 58
      8.3     Research results and proposals from Area 88
      9     Ecosystem monitoring

      The Scientific Committee requested that Members identify priority species for fish by-catch data collection in the krill fishery (SC-CAMLR-42, para 2.64). The WG-SAM work plan table (SC-CAMLR-42, Annex 7) also lists effective sample size for fish by-catch monitoring in the krill fishery (Task 19) as a priority item for WG-SAM-2024.

      The Scientific Committee recommended that future versions of warp strike and incidental mortality estimates in krill fisheries should include estimates of uncertainty in the extrapolations and encouraged members to submit papers to WG-SAM on undertaking approaches to inform the development of advice (SC-CAMLR-42, para 3.20). The Scientific Committee encouraged Members to submit analyses to WG-SAM on extrapolations from observations to inform mortality estimates (SC-CAMLR-42, para 3.38).

      10     Future work

      The Working Group will review the work plan table (SC-CAMLR-42, Annex 7) based on the discussion during WG-SAM-2024.

      11     Other business

      Participants are invited to identify issues for consideration under other business. Papers submitted under this agenda item need to link the content to a specific task of SAM, and identify the actions sought from the Working Group.
      In 2019, the Scientific Committee agreed on six priority items for the consideration of WG-SAM-2020 (SC-CAMLR-38, paragraph 13.4). The development of toolbox for research plan design (SC-CAMLR-38, para 4.17) remains to be discussed in WG-SAM.

      12     Advice to the Scientific Committee

      WG-SAM provides advice to each of the working groups and to the Scientific Committee on statistics, assessments and modelling. Specific advice will be summarised in this agenda item following general discussion within other agenda items.

      13     Adoption of report and close of meeting