WG-SAM-15

The Scientific Committee established the Working Group on Statistics, Assessments and Modelling (WG-SAM) during CCAMLR-XXV (SC-CAMLR-XXV, paragraph 13.12), 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.

Meeting papers submitted to WG-SAM, 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; and

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

Welcome to participants and overview of facilities, Secretariat’s offices, computer support, Internet access and extracurricular activities.

Amendments to and adoption of the meeting agenda, assignment of meeting papers to agenda items, appointment of rapporteurs and procedures for the preparation of the report and establishment of ad hoc subgroups if necessary.

The agenda has been structured to target the highest priority areas of work for WG-SAM in 2015.

Methods for assessing stock status and yield have been agreed and are in use for Dissostichus spp., Champsocephalus gunnari and Euphausia superba for the main areas in which these species are fished. Proposals to modify these methods, or to consider alternative methods, will be reviewed under this item.

A review of progress towards updated integrated assessments of toothfish for the following subareas and divisions:

1. Develop methods to estimate survey catchability (q) within the stock assessment model in Division 58.5.2 for Dissostichus eleginoides (SC-CAMLR-XXXIII, paragraph 3.129).
2. Investigate how the ageing error matrix may influence stock assessment estimates in Division 58.5.2 and decision rule projections (SC-CAMLR-XXXIII, Annex 7, paragraph 4.21)
3. Review progress on the development of a two-area model for Dissostichus mawsoni in Subarea 88.2 SSRUs C–H (SC-CAMLR-XXXIII, Annex 7, paragraph 5.18).
4. Review progress on the development of Dissostichus spp. stock assessment in Division 58.4.3a (Elan Bank), including how the data collection plan for this fishery may be modified once an assessment is available (SC-CAMLR-XXXIII, paragraphs 3.191 and 3.194)
5. Review progress on the development of Dissostichus spp. stock assessments in Division 58.4.4b (Ob and Lena Banks) (SC-CAMLR-XXXIII, Annex 7, paragraphs 5.86 and 5.87).

1.  Develop a standard set of diagnostic tools for use in CCAMLR’s integrated assessments (SC-CAMLR-XXXIII, Annex 5, paragraphs 2.40 and 2.41)
2. Develop an estimation method for the lower 1-sided 95% confidence interval for krill biomass estimates (SC-CAMLR-XXXIII, paragraph 3.28)
3. Develop methods to validate fishery and observer data (SC-CAMLR-XXXIII, paragraph 3.69)
4. Evaluate the effect of uncertainty in the steepness parameter of the stock-recruit relationship on CCAMLR’s projection of yields (SC-CAMLR-XXXIII, Annex 7, paragraph 10.3).

Additional work topics, as discussed and prioritised by WG-SAM-14 will be considered based on paper submissions and time available. These include data weighting and screening, processes for local biomass estimation, management strategy evaluations (MSEs) of CCAMLRs harvest decision rules, comparison of MCMC and covariance resampling methods, methods to account for the bias  introduced from low tag overlap, and methods to determine the influence of spatial patterns of tag releases and fishing effort on estimates of stock dynamics (SC-CAMLR-XXXIII, Annex 5, paragraphs 2.40 and 2.42).

A requirement to submit research plans in notifications for exploratory fisheries in areas other than Subareas 88.1 and 88.2 was adopted by the Commission at its 2011 meeting (CCAMLR-XXX). WG-SAM will review the performance of research carried out under these plans and the proposals for research to be carried out for 2015/16 to determine whether they continue to meet the requirements for CCAMLR-sponsored research as laid out in SC-CAMLR-XXX, Annex 5, paragraphs 2.25 and 2.26 using the format provided in Table 6 of WG-SAM-2012 where appropriate. Evaluation of potential constraints of sea ice on research performance will be an important aspect to address. Note that seasonal patterns in sea-ice concentration in each research block have been summarised for 2000–2013 (SC-CAMLR-XXXIII, Figure 1). In addition, details of the data collection plan and the fishery operations plan relative to the evaluation of potential impacts on dependent and related species will be included relative to CM 21-02, paragraphs 3(ii–iv) and 6(iid).

Scientific research carried out in 2014/15 will be reviewed and proposals for further research in these areas evaluated. WG-SAM will review any new research proposals to determine whether they continue to meet the requirements for CCAMLR-sponsored research using the format provided in Table 6 of WG-SAM-2012 where appropriate or according to the objectives and methods set out in the proposal. Evaluation of potential constraints of sea ice on research performance will be an important aspect to address. Note that seasonal patterns in sea-ice concentration in each research block have been summarised for 2000–2013 (SC-CAMLR-XXXIII, Figure 1).

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

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 apparent during the meeting for the development and refinement of quantitative methods.

As is usual practice in meetings of the Scientific Committee and its working groups, rapporteurs will draft sections of the report according to general guidelines for its production. The Secretariat is responsible for formatting, editing and circulation of the report. Any proposed changes to the report prior to report adoption need to be arranged through the rapporteurs, who will then provide the appropriate changes to the Secretariat. Adoption of the report will be conducted interactively using a video projector and support from the Secretariat.

Discussion will conclude by midday Thursday, allowing Thursday afternoon and Friday morning for report preparation and reading. Report adoption will be on Friday afternoon.