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    Full Name
    Working Group on Statistics, Assessments and Modelling
    Meeting Start Date/Time:
    Meeting End Date/Time:
    Submissions Due
    Monday, 14 June 2021 - 00:00 Australia/Hobart (Working Group Paper)
    Meeting Report:
    e-sc-40-a5.pdf (378.25 KB)


      Document Number Title Agenda Item(s)
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      New research plan for Dissostichus spp. under CM 24-01, paragraph 3 in Subarea 88.3 by Korea and Ukraine from 2021/22 to 2023/24
      Delegations of the Republic of Korea and Ukraine
      More Info
      Notification for the Ross Sea shelf survey in 2022
      Delegation of New Zealand
      More Info
      Continuing research in the Dissostichus mawsoni exploratory fishery in East Antarctica (Divisions 58.4.1 and 58.4.2) from 2018/19 to 2021/22; Research plan under CM 21-02, paragraph 6(iii)
      Delegations of Australia, France, Japan, Republic of Korea and Spain
      WG-SAM-2021/04 Rev. 2
      More Info
      Proposal for continuing research on Antarctic toothfish (Dissostichus mawsoni) in Statistical Subarea 48.6 in 2021/22 from a multiyear plan (2021–2024): Research Plan under CM 21-02, paragraph 6(iii)
      Delegations of Japan, South Africa and Spain
      More Info
      Proposal to conduct a local survey of Champsocephalus gunnari in Statistical Subarea 48.2
      Delegation of Ukraine
      More Info
      Provisional Trend Analysis – Preliminary 2021 research blocks biomass estimates
      CCAMLR Secretariat
      More Info
      Antarctic krill proportional recruitment indices (2010–2020) in Subareas 48.1–48.3 from the observer data
      CCAMLR Secretariat
      More Info
      Preliminary exploration of H-based decision rules for managing toothfish fisheries
      R. Hillary, P. Ziegler and J. Day
      More Info
      Recruitment modelling for Euphausia superba stock assessments considering the recurrence of years with low recruitment
      C. Pavez, S. Wotherspoon, D. Maschette, K. Reid and K. Swadling
      More Info
      Multi-fleet stock assessment modelling with the Grym
      J. Liu, S. Wotherspoon and D. Maschette
      More Info
      Analysis of the factors influencing the fishing impact zone for the longline toothfish fishery
      O. Krasnoborodko, S. Kasatkina and A. Remeslo
      More Info
      Grym parameter values for Subareas 48.1, 48.2 and 48.3
      S. Thanassekos, K. Reid, S. Kawaguchi, S. Wotherspoon, D. Maschette, P. Ziegler, D. Welsford, G. Watters, D. Kinzey, C. Reiss, C. Darby, P. Trathan, S. Hill, T. Earl, S. Kasatkina and Y.-P. Ying
      More Info
      Updated stock assessment model for the Antarctic toothfish (Dissostichus mawsoni) population of the Ross Sea region for 2021
      A. Grüss, A. Dunn and S. Parker
      More Info
      Diagnostic plots for the 2021 assessment model for the Antarctic toothfish (Dissostichus mawsoni) population of the Ross Sea region
      A. Grüss, A. Dunn and S. Parker
      More Info
      Stock Annex for the 2021 assessment of the Antarctic toothfish (Dissostichus mawsoni) population of the Ross Sea region
      A. Grüss, A. Dunn and S. Parker
      More Info
      Options to include the Ukrainian quarantined data to the CCAMLR database
      I. Slypko and K. Demianenko
      More Info
      Report on the toothfish survey in the Subarea 48.1 by the Ukrainian vessel Calipso in 2021
      Delegation of Ukraine
      More Info
      Research Plan under CM 21-02, paragraph 6 (iii). Proposal for new multi-Member research on Dissostichus spp. in Divisions 58.4.1 and 58.4.2 from 2021/22 to 2023/24
      Delegation of the Russian Federation
      More Info
      Proportional recruitment and weight-length relationship for krill in Subarea 48.1 and 48.2 from RV Atlantida survey, 2020
      S. Kasatkina and S. Sergeev
      WG-SAM-2021/20 Rev. 1
      More Info
      Summary of proportional recruitment and multiyear biomass variability for krill in Subarea 48 from research surveys
      D. Kinzey
      More Info
      2021 updated analysis of the sea ice concentration (SIC) in research blocks 4 (RB4), and 5 (RB5) of Subarea 48.6 with sea surface temperature (SST) and winds
      T. Namba, R. Sarralde, T. Ichii, T. Okuda, S. Somhlaba and J. Pompert
      More Info
      Moving from biomass estimates towards precautionary catch limit: spatial scale revisited
      Y. Ying, X. Wang, X. Zhao, Y. Zhao, G. Fan and J. Zhu


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      1     Introduction

      WG-SAM has been established with a directed emphasis on developing, refining and evaluating quantitative approaches for all Antarctic marine living resources managed by CCAMLR. WG-SAM serves as a flexible technical group to address quantitative issues relevant to WG-FSA, WG-EMM and ad hoc WG-IMAF (SC-CAMLR-XXV, paragraphs 13.4 to 13.8). WG-SAM is to provide advice necessary for the work of these working groups and the Scientific Committee.

      Focus topics are prioritised by the Scientific Committee, and submitted meeting papers, along with presentations and analyses conducted during the meeting, will form the basis for discussion and advice.

      The terms of reference for WG-SAM are to provide advice to the Scientific Committee and its working groups on:

      (i)    quantitative assessment methods, statistical procedures and modelling approaches for the conservation of Antarctic marine living resources

      (ii)     the implementation and data requirements of such methods, procedures and approaches.

      In 2017, the Scientific Committee developed a 5-year work plan (SC-CAMLR-XXXVI/BG/40) and identified topics for WG-SAM in 2020 as: development of integrated assessments at population scale in order to develop management advice consistent with Article II for fisheries with more limited data.

      In 2019, the Scientific Committee agreed on six priority items for the consideration of WG-SAM-2020 (SC-CAMLR-38, paragraph 13.4). Because the WG-SAM e-group could not discuss these priorities sufficiently in 2020 due to COVID-19, the Scientific Committee considered that these priorities remained relevant for the forthcoming intersessional period as indicated in SC-CAMLR-39, paragraph 3.1 and SC CIRC 20/130. Two of these items, open-source GYM for krill assessment model and re-estimation method of catch inconsistencies between C2 and CDS, have been addressed in WG-SAM-2020 e-group discussions (SC-CAMLR-39/BG/15). Therefore, the following four items remain as Scientific Committee priorities to be discussed in WG-SAM:

      (a) management strategy evaluations: refinement of harvest control rule, including F-based rules

      (b) methods for calibration between vessels for tagging survival and tag detection

      (c) development of coding for toolbox for research plan review

      (d) toothfish conversion factors.

      In addition, in 2020, the Scientific Committee noted the high priority for the revised krill fishery management procedure and the work required for the revision of Conservation Measure (CM) 51-07, updated integrated assessments and data-limited approaches for toothfish (SC-CAMLR-39, paragraph 3.1).

      2     Opening of the meeting
      2.1     Adoption of the agenda and organisation of the meeting

      Amendments to, and adoption of, the meeting agenda, assignment of meeting papers to agenda items. The Secretariat will be responsible for rapporteuring and report production. Day 4 will be dedicated to report review by participants offline and Day 5 will be dedicated to report adoption (online meeting).

      3     Development and progress of stock assessments
      3.1     Stock assessments for krill

      One of the main priorities for the Scientific Committee this year is to provide the Commission with advice on the krill fishery management taking into consideration the scheduled review of CM 51-07. The joint discussion during WG-SAM-2020, and WG-EMM-2020 e-groups validated the use of Grym (generalised R yield model) for krill stock assessment.

      In 2021, WG-SAM has been tasked to agree on parameterisation for the application of Grym at the scale of Subareas 48.1, 48.2, 48.3 and 48.4. The model parametrisation will focus on Subarea 48.1, which will be used as a template for other subareas in Area 48 as it has all of the component information to provide advice using a data-limited approach.

      Discussions regarding parameter values undertaken in an e-group will be summarised and presented to the meeting. Further discussions regarding the configuration of the Grym(e.g. recruitment model) will be held to determine whether the current configuration (‘base case’) may be used to provide advice.

      3.2     Stock assessment for established toothfish fisheries

      If papers are submitted on important new developments impacting the provision of management advice for the toothfish fishery, the Working Group will review these papers.

      3.3     Stock assessment for data-limited toothfish fisheries
      3.3.1     Trend analysis for data-limited toothfish fishery

      In 2020, the Scientific Committee faced difficulty for determining a catch limit in divisions where directed fishing did not occur in the past two years. The trend analysis was run (SC-CAMLR-39, Table 5) and the Commission agreed to use the lower value of catch limits whether it was the value calculated using the trend analysis or the value adopted by the Commission for 2019/20 (CCAMLR-39, paragraph 5.38). It also noted that this practice should not become a precedent.

      The trend analysis procedure must be reviewed to clarify this issue.

      4     Management strategy evaluations: consideration of alternative toothfish harvest control rules, including F-based rules for stocks with integrated assessments

      WG-FSA-2019 discussed the robustness of the CCAMLR decision rule to potential climate change induced variation in toothfish productivity and highlighted that this sensitivity should be considered by the Scientific Committee and its working groups (WG-FSA-2019, paragraph 3.14). The Scientific Committee endorsed the recommendation of WG-FSA to task WG-SAM with investigating potential refinements of the CCAMLR decision rules to increase their robustness in specific circumstances, such as using target and limit exploitation rates, through management strategy evaluations (SC-CAMLR-38, paragraph 3.67).

      5     Cross-cutting issues in toothfish fisheries affecting data or stock assessment model quality

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      5.1     Uncertainties in tagging programs (tag matching, vessel calibration method, etc.)

      The Scientific Committee noted the results of the tagging study (WG-FSA-2019, paragraphs 4.21 to 4.25) which highlighted the variable nature of tagging operations across the fishing fleet. Given the importance of tagging data in toothfish stock assessments, it remains a priority to keep developing metrics for tagging program performances to enable vessels comparison, provide advice in tagging practices for vessels with poorer performance and account for this variation in stock assessment models.

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      5.2     Conversion factors

      In 2019, the Scientific Committee recommended the Secretariat conduct a survey similar to that of the tagging survey on how conversion factors are calculated and applied for each vessel, and provide the results of this survey to WG-SAM (SC-CAMLR-38, paragraph 4.2). Analysis demonstrating the importance of conversion factor estimation on stock assessment models would be welcomed.

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      6     Development of a toolbox for designing research plans

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      6.1     Demo of the CCAMLR R GIS package

      The Scientific Committee noted the discussion at WG-FSA (WG-FSA-2019, paragraph 4.34), regarding the use of a standard map projection as specified within the CCAMLR GIS, or providing the projection used in the map. Additionally, the Scientific Committee recommended that maps within papers provide references for data layers used (e.g. bathymetry). This would allow the reproducibility and analysis of maps/research design within working groups, should that be required (SC-CAMLR-38, paragraph 4.23).

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      6.2     Tools to design sampling strategy for research surveys (under CM 24-01)

      The Scientific Committee discussed that there are many tools used by various Members whilst developing research plans, and the development of a ‘tool box’ which contains analytical tools for use by all Members in the development of research plans (SC-CAMLR-38, paragraph 4.17). These tools may include:

      (i) mapping tools or tutorials

      (ii) scripts for statistical power analysis with detailed tutorials adapted to the question asked and the type of data available

      (iii) scripts for the random selection of stations

      (iv) indications on the definition and delimitation of sampling strata

      (v) diagnostic methods for sea-ice conditions

      (vi) scripts for comparative analysis of vessel tagging performance (but see agenda item 5.1).

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      7     Data service advisory group

      The Working Group will consider progress reported by the DSAG (SC-CAMLR-XXXVII, paragraph 3.42). In addition, the Working Group will provide feedback developing data services needs.

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      9     Review of ongoing research results and proposals

      Ongoing proposal describes a research plan that was accepted with a specified time period and has not reached the end of that period. Subsequent proposals for research that follow on from other research in an area are not ‘ongoing’ proposals for the purposes of the review process but new proposals. See also Annex table ‘review process and timetable according to CCAMLR-38, paragraph 5.64’ for details.

      9.3     Research results and proposals from Area 88
      10     Future work

      The Working Group will prioritise future work in accordance with progress made in 2021 and update the work plan to keep providing advice to the Scientific Committee.

      11     Other business

      Participants are invited to identify issues for consideration under other business.

      Note: This agenda item will be discussed only if time permits and papers submitted under these agendas are considered as urgent issues.

      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 that has been requested will be summarised in this agenda item following general discussion in other agenda items. Advice will also be given to the Scientific Committee on the priorities discussed during the meeting for the development and refinement of quantitative methods.

      13     Adoption of report and close of meeting

      According to the ‘Ad-hoc guidelines for the virtual meetings’, the Secretariat will be responsible for rapporteuring and report production. Draft report will be made available on Day 4 of the meeting for offline review and report adoption will take place online during Day 5.