WG-SAM-2025

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 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, and
(iv) Sampling design of research fishing and surveys.

Amendments to and adoption of the meeting agenda, assignment of meeting papers to agenda items.

In work plan table (SC-CAMLR-43, Annex 7), following items have been indicated as planned works for 2025 on:
a) Effective sampling size for length frequency distribution (Task 1)
b) Effective sample size for fish by-catch monitoring in the krill fishery (Task 14)
WG-SAM also invites work as previously noted as important by the Scientific Committee on contemporary data and analysis relating to:
a) The Spatial Overlap Analysis, and
b) Effective sample size calculations and data collection programs for estimating stock assessment parameters for krill from surveys.
c) Exploration of appropriate modelling approaches and diagnostics related to the incidental mortalities of seabirds and marine mammals associated with fishing.

In work plan table (SC-CAMLR-43, Annex 7), updates based on previous work are invited on:
a) Development of integrated stock assessment for krill (Task 2)

WG-SAM-2025 will review and discuss the relevant outcomes from the 2nd Age Determination Workshop.

A number of priority topics relating to biomass estimation for finfish remain outstanding. Tagging data and performance will be a priority topic at this WG-SAM-2025. Work plan tasks include:
a) Gear standardization effects on toothfish tagging program (Task 3)
b) Vessel configuration factors affecting tagging mortality (Task 8)
Additionally, SC-CAMLR-43 (para 3.24) requested WG-SAM to revisit tag metrics, not only focusing on tag overlap metrics, but also on the tag release and recapture performance to assess and potentially improve the quality of data for use in stock assessments.

WG-SAM invites work relating to designing robust surveys for biomass estimation of finfish species.

In work plan table (SC-CAMLR-43, Annex 7), following items have been indicated as planned works for 2025 about data collection from SISO and vessel operations;
a) Recording selection of non-random biological data (Task 5)
b) Develop protocol for toothfish conversion factors (Task 6)
Additionally, WG-SAM-2025 welcomes and progress made on tasks identified in other Working Groups on:
a) Development of a finfish specific C1 form.
b) Investigations into reconciling conversion factors in the finfish C1 form.

Following previous recommendations (WG-SAM-2024, para. 5.35) WG-SAM invites work relating to:
a) Examine the effect of age uncertainty on the stock assessment (Task 10)

The WG-SAM work plan table (SC-CAMLR-43, Annex 7) also indicates that Optimise tag-based study (spatial overlap) (Task 7) is a priority item for 2025.

WG-SAM welcomes work to further develop the stock assessments of fisheries, including the items in the general work plan outlined within SC-CAMLR-43, para 3.8, which include:
1. Investigations of sex-disaggregated assessment models.
2. Investigating alternative estimators of abundance based on tag-recapture data and comparing them with the Chapman estimator.
3. Continued ongoing work to account for spatial changes and other sources of bias in tag-recapture data, with incorporation into stock assessments.
4. Exploring alternative approaches to characterise variability and trends in future recruitment and apply these alternatives in stock projections.

The WG-SAM work plan table (SC-CAMLR-43, Annex 7), under ?Communication of progress, internal and external? has the item:
a) Diagnostic graphs on stock status (Task 15) as a priority item for WG-SAM-2025.
WG-SAM would welcome work on this which provides diagnostics related to both the stock assessments and independent of the stock assessment which can be used to support the recommendations of the Scientific Committee.

The WG-SAM work plan table (SC-CAMLR-43, Annex 7) lists Evaluation of the CCAMLR decision rules and potential alternative harvest control rules for assessed fisheries using Management strategy evaluation (MSE) (Task 12) as priority research topics under this agenda item.
The Scientific Committee requested WG-SAM-2025 to provide advice in 2025 on:
a) The range of uncertainties to which the management strategy should be robust, and
b) Suitable operating models for consideration in the MSE (SC-CAMLR-43, para 3.15).
As such, WG-SAM requests Members to submit papers to allow the meeting to fulfill this request from the Scientific Committee.

The WG-SAM work plan table (SC-CAMLR-43, Annex 7) indicates that Development and testing of data-limited fishery decision rules using MSE (Task 13) are high priority topics for data-limited finfish fisheries.
WG-SAM will also review updates and estimates of the current trend analysis.

The Working Group will prioritise review of new research proposals.

The Working Group should review ongoing research plans (Task 11) including their results according to the timetable below (Table 1).

The Working Group will review the work plan table (SC-CAMLR-43, Annex 7) based on the discussion during the WG-SAM-2025. SC-CAMLR-43 listed future works which have to be conducted and presented during future meetings of WG-SAM (SC-CAMLR-43, para 3.8).

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). Development of a toolbox for research plan design (SC-CAMLR-38, para 4.17) remains to be discussed in depth in WG-SAM.

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 summarized in this agenda item following general discussion in other agenda items.

The report of the meeting will be adopted.