In 2015, An Icefish specific trawl survey was undertaken at Kerguelen Islands (Division 58.5.1) to collect information about the size distribution and the biomass status of mackerel icefish, Champsocephalus gunnari. Data from this random stratified trawl survey was used for a short term assessment of C. gunnari on Kerguelen EEZ. The standard CCAMLR methods were used to provide potential yields, a catch limit of 8278 t is recommended for 2016 and 6701 t for 2017.

An updated assessment of the Patagonian toothfish (Dissostichus eleginoides) stocks in Kerguelen area is presented. This study is based on a CASAL (C++ Algorithmic Stock Assessment Laboratory) model. Different statistical and biological datasets are used: catches, tag releases/recaptures data, commercial catch-at-length, data from the “PoKer” surveys, and the last age readings.

This paper is an update on exploratory fishing for toothfish by the New Zealand vessel San Aspiring pursuant to CMM 4.14, approved by the SPRFMO Commission in January 2016. This update is provided for the consideration of the SPRFMO Scientific Committee meeting in October 2016 such that it can advise the SPRFMO Commission meeting in early 2017 on progress with the exploratory fishery.

The WG-SAM in 2016 “agreed the importance of identifying a set of diagnostics and clear criteria to assess the likelihood that a vessel is operating as would be expected in normal research activities”, further noting that a characterisation of fishing activities was also required in order to achieve such a goal (WG-SAM 2016, paragraph 4.19).

In this paper, we further develop the analysis of Large et al. (2016), using fishing activities in the northern Ross Sea region as an example. We investigate the time taken to haul a line as a metric, and estimate vessel effects associated with fishing events such as research surveys. Results showed that individual vessels exhibited significantly different times to haul lines once standardised for other factors, but that the activities carried out as part of the SSRU 88.2A–B North survey were within the expected range for the vessels involved. Additional fishing activity metrics, combinations of those metrics, or area effects could be investigated by developing this methodology further.

This report provides a characterisation of the toothfish fishery and associated tagging programme in the Amundsen Sea Region (SSRUs 88.2C–H) up to and including the 2015/16 fishing year. A research plan was implemented in the region beginning in 2014/15 to concentrate fishing in the South (SSRUs 88.2C-G) into four smaller research blocks in order to increase the likelihood of recaptures of previously tagged toothfish. In 2015/16, a total of 9 inter-season tagged fish were recaptured in these research blocks, confirming the utility of this approach to recapture tagged fish, and providing key information on the size of the population. Furthermore, 11 tagged fish were recaptured in the north (SSRU 88.2H). The data provided in this paper form the basis for the data inputs into the stock assessment for the Amundsen Sea region.

This paper presents further progress towards a two-area stock assessment model for Antarctic toothfish (Dissostichus mawsoni) in the Amundsen Sea region, defined here as SSRUs 88.2C–H. The region is split into two main areas: the North (SSRU 88.2H) comprising large mature fish, and the South (SSRUs 88.2C–G) comprising a mix of large mature fish and small immature fish.

Two-area stock assessment models were first developed for the region in 2014 and refined in 2015. Results showed the need to collect mark-recapture data in the South to help inform the estimation of biomass in the South. We present an update on these two-area stock models, which include two years of new data collected under a research plan. The assessment models were fit to the proportions-at-age in the catch and the mark-recapture data from the two areas. The results suggest that the research plan is successful in starting to inform the model, and in particular the size of the fish population in the South. We recommend that the current research plan be extended for a further 2-year period so that additional mark-recapture data can be collected particularly from the South, and that the models be developed further in the interim period. We also recommend that all Members, where possible, contribute to the development of annual age-length keys, using agreed otolith reading protocols and aging validation.

A multi-year research plan as outlined in CM 41-04 (2012, 2013, 2014) was initiated in Statistical Subarea 48.6 by Japan and South Africa during the 2012/13 fishing season. Two vessels participated in the research project in each of the three fishing seasons and the progress achieved during the first 3.5 years is reported.

The emphasis of the progress report is on block 486_2, since more tag returns have been recovered from this block and a preliminary stock assessment has been attempted using data mainly from block 486_2.  

We present preliminary results on age and growth of Dissostichus mawsoni for the second season (2013/14) of the Spanish research fishing in the 58.4.1 Division obtained for growth rings on otolith readings. It is included the age-length key and growth parameters estimates by sex. Growth parameters obtained using length-age pair values are: L_∞: 175.7, k: 0.1078 and t₀: 1.528 for females; L_∞: 150.3, k: 0.1491 and t₀: 1.809 for males; and L_∞: 169.8, k: 0.1087 and t₀: 1.168 all combined. These results are very similar to those reported previously for the first season (2012/13) although they differ slightly with the values used in the Ross sea assessment for males.

The second year survey and observations of Dissostichus spp. in statistical subarea 48.2 on board the Ukrainian vessel SIMEIZ were conducted in accordance with the recommendations of the Scientific Committee and Commission. The second year survey design was amended in comparison with the one of the first year and approved by WGs SAM, FSA and SC CCAMLR.  Obtained data used for the preliminary biomass estimation of the target species and making decision for the future fishing on that fishing ground. During the survey the fragments of IUU nets were taken on board.