CCAMLR

Data from electronic archival tags are often used to characterise movement and migration patterns in fishes. Understanding these movement patterns is one of the key information needs for the assessment and management of Antarctic toothfish. We deployed 4 pop-off satellite archival tags on large toothfish on the Ross Sea slope in January 2013 and report on the first recovery of an Antarctic toothfish tagged with an archival tag. The fish was recaptured in the fishery the following season (December 24, 2013), providing 335 days of data archived at 10 min intervals. Summaries of raw data show strong and contrasting patterns throughout the time series in several variables recorded and several periods with distinct behavioural profiles, suggesting significant activity throughout the winter period. With the lack of any daylight signal resulting from constant light or darkness, along with living below the photic zone and under ice, positioning using light-based geolocation is not possible. Current efforts focus on developing a Bayesian modelling approach to fit the most likely movements of the tagged fish during its time at liberty, based on the environmental variables recorded by the tag compared with spatial environmental data on depth, temperature and magnetic field strength.

This paper investigates factors affecting the bycatch of skates (Rajiformes) and grenadiers (Macrouridae) taken by the longline fishery in statistical subarea 48.3. Bycatch was greater for vessels using autoline system than for those using the “Spanish” system, due to differences in proximity to the sea bed and type of bait used. The areas of greatest catch rates differed by area and depth range. During the period 1996–1999 skate bycatch was higher in February-March, while that of grenadiers was lower in July-August; since the limitation to a winter longline fishery there in no longer any significant seasonal variation.

Most things related to Dissostichus spp. in the eastern side of Antarctic has not been known well as namely the area is data poor areas. In the Division 58.4.1 there are two stocks; one extends from the SSRU 58.4.1C to the SSRU 58.4.2A, and the other one to the SSRU 58.4.1H. The population sizes were vulnerable with a big range of about 100-1,500 t per SSRU in 58.4.2. During the 2004-2014 fishing seasons in Division 58.4.2, 1,618 Dissostichus spp. were tagged and released, but any tagged fish have not been recaptured. Therefore, there were not enough data to estimate stock biomass for considering the precautionary catch limit. The catch limits agreed during the meetings in 2013 increased to get more recapture. The food-web of Dissostichus spp. has started to be studied in the southern Ross Sea and 58.4.1C. Some studies on biology of the fish have been evaluated, but those are not enough to assess the stocks and consider proper management measures. Based on CCAMLR’s fishery report, the eastern area is still data-poor area showing low recapture rate. Consequently, providing catch and effort data from the area, analysing biological samples, and collecting recapture data focusing on SSRUs in Division 58.4.2 is very important.

Therefore, Korea notifies the participation in exploratory fishery for Dissostichus spp. in the SSRUs in Division 58.4.2 from 2014/2015 season to 2018/2019 using Korean commercial bottom longline vessel, KINGSTAR belonged to Sunwoo Company in accordance with paragraph of CM 24-01 and paragraph 6 (iii) of CM 21-02 to collect the catch and effort, CTD, tagged and released, recaptured data including archival tag, biological data for estimating biomass for Dissostichus spp. using CASAL and evaluating migration and distribution pattern by developmental maturity and size stages.

Most things related to Dissostichus spp. in the eastern side of Antarctic has not been known well as namely the area is data poor areas. In the Division 58.4.1 there are two stocks; one extends from the SSRU 58.4.1C to the SSRU 58.4.2A, and the other one to the SSRU 58.4.1H. The population sizes were vulnerable with a big range of about 1,000-2,000 t per SSRU in 58.4.1. During the 2004-2014 fishing seasons in Division 58.4.1, 4,998 Dissostichus spp. were tagged and released, but only 14 fishes among them have been recaptured which were not enough data to estimate stock biomass for considering the precautionary catch limit. Therefore, the catch limits that the meeting got in 2013 meetings increased to get more recapture. The food-web of Dissostichus spp. has started to be studied in the southern Ross Sea and 58.4.1C. Some studies on biology of the fish have been evaluated, but those are not enough to assess the stocks and consider proper management measures. Based on CCAMLR’s fishery report, the eastern area is still data-poor area showing low recapture rate. Consequently, providing catch and effort data from the area, analysing biological samples, and collecting recapture data focusing on SSRUs in Division 58.4.1 is very important.

The Korean scientists collected and analysed the catch, effort, and biological data such as length, weight, gonadal development, and muscle by NO. 3 INSUNG in Division 58.4.1 during 2012/2013 season. However, the results were still not good enough according to lack of data because of the bad sea-ice condition for the survey. Therefore, we will extend the research area and sample size of catch and fishing efforts, and biological data to get more accuracy and effective results to manage the eastern side area of Antarctic.

Therefore, Korea notifies the participation in exploratory fishery for Dissostichus spp. in the SSRUs in Division 58.4.1 from 2014/2015 season to 2018/2019 using Korean commercial bottom longline vessel, KINGSTAR belonged to Sunwoo Company in accordance with paragraph of CM 24-01 and paragraph 6 (iii) of CM 21-02 to collect the catch and effort, CTD, tagged and released, recaptured data including archival tag, biological data for estimating biomass for Dissostichus spp. using CASAL and evaluating migration and distribution pattern by developmental maturity and size stages.

Most things related to Dissostichus spp. in the eastern side of Antarctic has not been known well as namely the area is data poor areas. In the Division 58.4.1 there are two stocks; one extends from the SSRU 58.4.1C to the SSRU 58.4.2A, and the other one to the SSRU 58.4.1H. The population sizes would be vulnerable like the neighbour divisions if there is the same population. During the 2004-2014 fishing seasons in Subarea 48.6, 3,589 Dissostichus spp. were tagged and released, but only 4 fishes among them have been recaptured which were not enough data to estimate stock biomass for considering the precautionary catch limit. Therefore, the catch limits that the meeting got in 2013 meetings increased to get more recapture. The food-web of Dissostichus spp. has started to be studied in the southern Ross Sea and 58.4.1. Some studies on biology of the fish have been evaluated, but those are not enough to assess the stocks and consider proper management measures. Based on CCAMLR’s fishery report, the eastern area is still data-poor area showing low recapture rate. Consequently, providing catch and effort data from the area, analysing biological samples, and collecting recapture data focusing on SSRUs in Subarea 48.6 is very important.

Therefore, Korea notifies the participation in exploratory fishery for Dissostichus spp. in the SSRUs in Subarea 48.6 from 2014/2015 season to 2018/2019 using Korean commercial bottom longline vessel, KINGSTAR belonged to Sunwoo Company in accordance with paragraph of CM 24-01 and paragraph 6 (iii) of CM 21-02 to collect the catch and effort, CTD, tagged and released, recaptured data including archival tag, biological data for estimating biomass for Dissostichus spp. using CASAL and evaluating migration and distribution pattern by developmental maturity and size stages.
 

An updated and revised assessment of the Patagonian toothfish (Dissostichus eleginoides) stocks in Kerguelen and Crozet areas 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 and data from the recent POKER survey (2013). Preliminary results show stable estimates of biomass and SSB never fall below 60% of the initial biomass considering the actual level of catches (5100t in Kerguelen and 700t in Crozet).
 

We addressed the revisions requested by the WG-SAM-14 regarding the results of the second year of Spanish research experience and ongoing research plan presented in WG-SAM- 14/12 and WG-SAM-14/09. 

A summary of the results of the Spanish research that took place in the 58.4.1 division during the last two fishing seasons is presented.   

A prospective estimation of the local biomass (B_LOC) of three SSRUs visited using the local depletion method, together with the extrapolation to the total Biomass in the entire SSRUs, as well as an estimation of the Biomass in SSRU 58.4.1H using the mark-recapture Petersen model is made.

Current CCAMLR maturity stages for skates (Rajiformes) use a three-stage key. As such, important elements of the reproductive cycle may go unrecorded, including females in the process of egg-laying. Additionally, the current description of females at stage 2 (maturing) in the CCAMLR observer manual could lead to some confusion between fish at stage 2 and stage 3 (mature). Suggestions for updating the descriptions of the maturity stages for skates are provided, as is a rationale for considering a four-stage key that allows for the collection of data for fish that are at active stages of the reproductive cycle.

This paper presents an updated assessment for Patagonian toothfish (Dissostichus eleginoides) at the Heard and the McDonald Islands (Division 58.5.2) with data until mid August 2014. This paper presents a bridging analysis and proposes a new base case assessment model which is based on the best available estimates of model parameters, the use of abundance estimates from a random stratified trawl survey (RSTS), an estimated survey catchability coefficient q, and auxiliary commercial composition data to aid with the estimation of year class strength and selectivity functions of sub-fisheries.

Compared to the 2013 assessment, this assessment takes into account the recommendations of WG-FSA-2013, SC-CAMLR-2013 and WG-SAM-2014, and incorporates (a) new fishery observations up to 2014 including new ageing data from the 2012, 2013 and 2014 random stratified trawl surveys (RSTS) and commercial ageing data from 2013, (b) a Beverton-Holt stock-recruitment relationship, (c) a simplified model structure, (d) an updated ageing error matrix, (e) an updated growth model, and (f) a prior for the survey catchability q which has been estimated from the ratio of survey fish abundance using the swept area method and the proportion of tag-recaptures in survey catch on the main trawl ground. All model runs were conducted with the CASAL version that was agreed on by WG-SAM-14. These changes substantially improved the internal consistency and stability of the assessment model.

The new base case assessment model indicates that the virgin spawning stock biomass (SSB₀) is higher than that estimated in 2013, with an MCMC estimate of 136 714 tonnes (95% CI: 96 982-186 401 tonnes). Estimated SSB status in 2014 was 0.72 (95% CI: 0.63-0.81), and survey q was estimated at 0.32 (95% CI: 0.23-0.47). Using this model, a catch limit of 6110 tonnes satisfies the CCAMLR decision rules. The projected stock remains above the target level for the entire projection period.