WG-SAM-2024

Ce document traite de l'attribution de critères clairs et transparents au terme « meilleures preuves scientifiques disponibles » qui est utilisé dans l'article IX(f) de la Convention de la CCAMLR. Il est urgent et pertinent de clarifier les aspects scientifiques et juridiques de ce terme du fait de la présence de certains éléments importants dans l'ordre du jour de la CCAMLR, plus Read More
Soumis par:
Svetlana Kasatkina (Fédération de Russie)

Approuvé par:
Svetlana Kasatkina (Fédération de Russie)

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Following the recommendation by WG-SAM-2023 (paragraph 7.3(ii)), this paper presents a parameter perturbation analysis for the Agent-Based Model presented in WG-SAM-2023/17. This analysis provides a baseline response of the model which will be useful to assess the effects of changes to the model in the future.

Exploratory fishing for Antarctic toothfish (Dissostichus mawsoni) in East Antarctica (Divisions 58.4.1 and 58.4.2) began in 2003. While preliminary integrated stock assessments have been developed for these Divisions, robust estimates of stock biomass and precautionary catch limits according to CCAMLR decision rules remain to be determined. 

The stock structure of Antarctic toothfish (Dissostichus mawsoni) in Area 88 is being examined to understand stock boundaries for fishery management. It reveals ontogenetic progression in the Ross, Amundsen, and Bellingshausen Seas, with juveniles showing distinct distribution patterns. Korea Read More
Soumis par:
Sangdeok Chung (Corée, Rép. de)

Approuvé par:
Jaebong Lee

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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 Read More
Soumis par:
Takehiro Okuda (Japon)

Approuvé par:
Takehiro Okuda (Japon)

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The Ross Sea shelf survey has been conducted annually since 2012, with the most recent revised proposal presented in 2023 and spanning three years (2023–2025). This paper:

• serves as notification for the 2025 survey under CM 24-01 following the survey design proposed in WG-SAM-22/01 Rev. 1 and Read More
  Soumis par:
  Nathan Walker (Nouvelle-Zélande)
  
  Approuvé par:
  Nathan Walker (Nouvelle-Zélande)
  
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Mackerel icefish (Champsocephalus gunnari) is one of the most common and widespread species of Antarctic fish. That is a proposal to conduct a local acoustic-trawl survey of Champsocephalus gunnari in the statistical Subarea 48.2, Read More
Soumis par:
Kostiantyn Demianenko (Ukraine)

Approuvé par:
Kostiantyn Demianenko (Ukraine)

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An analysis of the Sea Ice Concentration (SIC), Sea Surface Temperature (SST) and winds in Research Blocks (RBs) 48.6_5 and 48.6_4 is presented. The SICs in RB5 and RB4 from Jan to Mar 2024 were the lowest in the 2017-2024 period.

A decreasing trend in SST spike sizes in Read More
Soumis par:
Roberto Sarralde Vizuete (Espagne)

Approuvé par:
Roberto Sarralde Vizuete (Espagne)

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We review the applicability of the CPUE by seabed area analogy method for the estimation of bycatch limits for macrourids for toothfish fisheries in the Convention Area with limited macrourid data. We examine the assumed relationship between longline CPUE and macrourid survey biomass in the Ross Sea, macrourid selectivity by gear type, and the effect of Read More
Soumis par:
Steve Parker (Secrétariat de la CCAMLR)

Approuvé par:
David Agnew (Secrétariat de la CCAMLR)

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Following the recommendation by WG-SAM-2023 (paragraph 7.3(iii)), this paper presents comparisons of outputs between the Agent-Based Model presented in WG-SAM-2023/17 and Casal2. Starting from a baseline simulation, additional complexity was incrementally added to the models. Results show that the ABM and Casal2 produce the same outcomes when using the same assumptions and the same population Read More
Soumis par:
Stéphane Thanassekos (Secrétariat de la CCAMLR)

Approuvé par:
Catherine Stubberfield (Secrétariat de la CCAMLR)

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This paper notes additions to both observer and vessel longline forms and manuals for introduction in the 2025 season, related to recommendations endorsed by the Scientific Committee in 2023. The inclusions cover additional skate injury fields as part of the Ross Sea Data Collection Plan, and more detailed tagging information and protocols developed during WS-TAG-2023.

Following feedback from WG-IMAF-2023 on the draft IMAF and warp strikes extrapolation method presented in WG-IMAF-2023/03 Rev. 1, this paper presents an updated method. The update includes definitions of observation effort for extrapolation purposes, a change to the way IMAF observation effort on board trawlers is calculated, and a proposed method to estimate uncertainty in extrapolated Read More
Soumis par:
Stéphane Thanassekos (Secrétariat de la CCAMLR)

Approuvé par:
Mariana Cordeiro (Secrétariat de la CCAMLR)

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Preliminary biomass estimates for research blocks in data-limited toothfish fisheries and the resulting preliminary catch limits for the 2025 season have been determined using the trend analysis decision rules. The resulting preliminary catch limits are for illustrative purposes only and do not constitute recommendations.

The scientific research fishing was conducted by the vessels “Greenstar” (KOR) and “Marigolds” (UKR) in CCAMLR Subarea 88.3 following the survey design (WG-FSA-2022/26). The total catch of Dissostichus mawsoni was 73020.7 kg comprising 3747 individuals. The CPUE for D. mawsoni varied among the research blocks; CPUE demonstrated high variability in research blocks 88.3_1, 88.3_3 and 88.3_4 with Read More
Soumis par:
Illia Slypko (Ukraine)

Approuvé par:
Kostiantyn Demianenko (Ukraine)

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This is a draft report prepared for WG-SAM. A final report will be prepared for WG-FSA.

Management strategies provide a more predictable approach than the traditional use of stock assessments to provide scientifically-based fisheries management advice. The effectiveness of management strategies relies on an agreed set of agreed management objectives for the fishery and the stock, and then using Management Strategy Evaluation (MSE, also known Read More
Soumis par:
Philippe Ziegler (Australia)

Approuvé par:
Philippe Ziegler (Australia)

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CCAMLR has a well-established framework to determine precautionary toothfish catch limits based on the CCAMLR Decision Rules. In recent years, CCAMLR has discussed the Decision Rules for toothfish and how they could be improved in determining catch limits for the assessed toothfish fisheries. Specifically, discussions have centred on how the Decision Rules Read More
Soumis par:
Philippe Ziegler (Australia)

Approuvé par:
Philippe Ziegler (Australia)

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In this paper, we use simulations based on operating models using the most recent (2023) toothfish stock assessments in the Ross Sea region, Subarea 48.3, Division 58.5.1 and Division 58.5.2 to evaluate a range of harvest control rules (HCRs) which were based on harvest rates Read More
Soumis par:
Philippe Ziegler (Australia)

Approuvé par:
Philippe Ziegler (Australia)

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New Zealand intends to conduct a trial employing pots to catch toothfish (Dissostichus spp.) in the Ross Sea (88.1) in the 2025 season. The objective of this trial is to assess the feasibility of pot fishing in this region. Specifically, the trial aims to investigate the effectiveness of pot Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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Following advice by WG-SAM 2023 regarding the tag-overlap calculation method, the Secretariat published the public R package `CCAMLRTOOLS`, which contains an easy-to-use function to calculate the overlap statistic from the standard CCAMLR data extract. Additional functions can be added to this package upon request by Members.

The time series of relative abundance and age structure from the Ross Sea shelf survey provides information about year class strength, variability, and autocorrelation, and hence is an important input into the Ross Sea region toothfish stock assessment. This was the thirteenth survey in the time series and for the first time, the 2024 survey was not Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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The exploration of changes in spatial and temporal change in fishing and tagging effort provides important context for the interpretation and evaluation of M-R estimates derived from the Chapman estimator. In particular, the evaluation encourages a wider discussion of the compatibility of the data sets that have been collected in assessment areas in Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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The current CCAMLR toothfish Decision Rules to determine catch limits for assessed toothfish fisheries are based on a stock projection forward for 35 years from the most recent year included in the assessment. As a result, the outcomes rely heavily on recruitment assumptions as the stock and catch at the end of the projection period will be dominated by Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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This document is a selected summary of some of the analyses, tests and results which were undertaken to explore patterns of fishing and tagging effort over time as presented in the primary document (Masere et al. 2024). The inclusion of this material is intended to not only provide support for the findings presented in the main paper yet also as a Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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Changes in the underlying productivity for a stock can result in changes in the carrying capacity, and hence effect biomass-based reference points. The CCAMLR toothfish Decision Rules use reference points based on B₀ and assume that the underlying productivity of a stock does not change Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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The integration of available sources of information is a challenge for any attempt to know dynamics populations for Antarctic Krill *Euphausia superba* in an integrated stock assessment model.Being able to identify sources of information, systematize and integrate it in a model and estimate krill population variables in a context of change and fisheries management is vital for Read More
Soumis par:
Mauricio Mardones (Chili)

Approuvé par:
Francisco Santa Cruz (Chili)

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The Western Antarctic Peninsula ecosystem plays a critical role in the cycle life of Antarctic krill (Euphausia superba). Recent environmental changes and increasing exploitation in this area have led to alterations in the structure of the krill population, calling for a review of the management approach. In this study, we derive growth Read More
Soumis par:
Mauricio Mardones (Chili)

Approuvé par:
Francisco Santa Cruz (Chili)

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