WG-FSA-13

Data related to IUU (and probable IUU) activity submitted to the Secretariat were used to provide an overview of the potential spatial and temporal distribution of recent IUU activity in the CAMLR Convention Area. Combining all information available to the Secretariat indicates that IUU is concentrated in the Indian Ocean Sector; however, the spatial and temporal pattern of IUU activity based Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In response to a request from WG-SAM, the secretariat inspected the available data on toothfish within-season recaptures (i.e. fish that have been tagged and recaptured in the same fishing season). Despite short times at liberty, the frequency distribution of distances between tag and recapture locations for these fish was similar to that of all recaptured fish. The relative frequency of Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In 2011/2012, a French vessel conducted its first exploratory fishery for Dissostichus spp. in division 58.4.3a. A new campaign is scheduled for 2013. France has also notified its intention to participate in this exploratory fishery over the next three years in order to achieve a robust stock assessment that would provide advice on catch limits according to CCAMLR decision rules. This Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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A preliminary assessment is undertaken to increase the knowledge of the Patagonian toothfish (Dissostichus eleginoides) stock in Crozet area. 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 Killer whales impact. Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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France presented at the CCAMLR XXVIIth meeting, an action plan aiming to reduce incidental avian mortality by half in the French EEZ included in the statistic division and subarea 58.5.1 and 58.6, for the period 2008/2009 to 2011/2012.  



France demonstrated at the CCAMLR XXXth meeting, to have successfully fulfilled its commitments and to have obtained encouraging Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We present our data on DNA-analysis of recent (2011-2013) samplings of Antarctic toothfish from CCAMLR Subareas – 48.5 (2013), 48.6 SSRU G (2011), 58.4.1 SSRU G and E (2011), 58.4.2 SSRU E (2011),  88.1 SSRU C (2011), 88.2 SSRU A(2011, 2012), and 88.3 SSRU C (2012). No significant genetic differences between geographic locations or between samples collected in consequent years were Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Scientific observers on board vessels fishing in Kerguelen and Crozet EEZ have contributed to a whale photo-identification program for several years. This paper describes the gear used, camera settings, data checking at sea and the information needed to identify individuals and interactions, based on this experience. These guidelines have been assembled to help members wishing to start a photo Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Closed mostly within the Weddell Sea Subarea 48.5 is one of the closed data-poor CCAMLR subareas, where stock assessment should be carried out. In spite of hard ice conditions during most of the time of the year, this large water area is very similar with the Ross Sea. This similarity, which could be found in geographical location, bathymetric profile and current system, highlight the Weddell Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Chile has submitted a notification for research fishing in Subareas 48.1 and 48.2 in 2014, 2015 and 2016 in accordance with Conservation Measure 24-01 (paragraph 3). The research will provide information on finfish distribution, abundance and size composition, with the objective of determining the current status of fish stocks in the study area. Research fishing will be limited to 100 tonnes Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Research program in data-poor Subarea 48.5 (Weddell Sea) have been carried out for the first time. New commercial and biological data on the target (Dissostichus mawsoni Norman, 1937) and by-catch species have been collected. Toothfish tagging program have been executed. Distribution of Antarctic toothfish and by-catch species by depth ranges has been investigated. Data on CPUE and Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In 2011 and 2012 in Subarea 88.3 research fishing for toothfish has been conducted by Russia. In 2011 fishing was carried out by Russian longliner “Sparta” out and in 2012 it was longliner “Chio Maru 3”. Totally, during the work period 44 longlines were set at a depth from 625 to 2336 m. Collected in research fishing data contributes to the achievement of the main objectives of research for Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The Scientific Committee (SC -XXXI, par. 9.30)  focused on distribution pattern of toothfish in SSRU 88.2 A and adjacent SSRUs 88.1 K and L, and discussed a need to carry out background investigations considering insufficient information on this area, and how catch limits used in the Ross Sea can be applied for this SSRU.

Investigations conducted by Russian scientists in SSRU 88.2A Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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According to the stock assessment survey, as well as using CPUE data collected by Russian and South Korean vessels in three Antarctic sectors in 2003-2010, it has been shown that fishery of the Antarctic toothfish is commercially viable not only for countries which are close to the fishing areas. The assessment study was conducted by several researchers using various models designed for the Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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A revision of the research plan and preliminary results of the Spanish exploratory longline fishery for Dissostichus spp in Divisions 58.4.1 and 58.4.2, submitted to the XXXII-WG-SAM, taking into account the advice made by the Working Group, is presented.



The Spanish vessel Tronio started the research plan in the 2012/13 season using the Spanish bottom longline Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In the fishing season 2012/2013 Russian vessel “Yantar-35” worked in the Weddell Sea for the first time since fishery of Dissostichus mawsoni began. It has allowed extending a sampling area on biology of this species. In particular, size-age and growth samples of the Antarctic toothfish were collected in this sea.

During the Antarctic krill fishing in the area off the North-Western slope of the South Orkney Islands shelf were caught 5000 kg of Champsocephalus gunnari.

 

This paper proposes extending the fishing season in the Patagonian toothfish longline fishery in CCAMLR statistical division 58.5.2 on a trial basis during the 2013/14 and 2014/15 fishing seasons by a further two weeks. This would increase the fishing season to include the period from 1 to 14 November as part of the post-season extension with day/night setting allowed.

This paper proposes extending the trial of daytime setting of longlines between 15 and 30 April in the Patagonian toothfish longline fishery in CCAMLR Statistical Division 58.5.2 to encompass the 2013/14 and 2014/15 fishing seasons.  Extending the trial for a further two years will enable sufficient daytime fishing effort to occur in the trial period to ensure there is a proper basis for Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The annual random stratified trawl survey (RSTS) at Heard Island and McDonald Islands (HIMI) was completed during April of 2013. The catches of D. eleginoides for 2013 were half that of 2012 and lower than the long-term (2006-2012) average. Conversely, mackerel icefish catches were seven times the long term average. Catches of Channichthys rhinoceratus were higher and those Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The fisheries targeting Patagonian toothfish (Dissostichus eleginoides) and mackerel icefish (Champsocephalus gunnari) in the Australian Fishing Zone surrounding Heard Island and McDonald take three species of skates, Bathyraja eatonii, B. irrasa and B. murrayi, as their most common bycatches. A tagging program has operated in these fisheries since Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The annual Random Stratified Trawl Survey was undertaken in Division 58.5.2 in the vicinity of Heard Island during April 2013. This paper provides a preliminary assessment of mackerel icefish population structure, abundance and yield for the area of Division 58.5.2 to the west of 79° 20’ E using standard CCAMLR methods. A large cohort of fish, estimated to be 3+, dominates the population in Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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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 the start of August 2013. Compared to the last assessment in 2011, this assessment updated the growth model and compared the effects of a range of alternative fishery structures and model assumptions for year class Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Analytical data on determination of reproductive potential of Antarctic toothfish D. mawsoni in the Pacific (SSRUs 88.1, 88.2, 88.3), Indian Ocean (SSRUs 58.4.1 и 58.4.2) and Atlantic (SSRU 48.6) Antarctic areas are presented. Morphological indices of females and males, indices of gonads, fecundity, and condition by Fulton are described. Spawning time and regions for Antarctic Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Data on demersal fish species composition and abundance was collected from 1277 research hauls conducted in depths < 350m during 19 research random stratified trawl surveys carried out on the Shag Rocks and South Georgia Shelf region between 1986 and 2013. Consistent hotspots of fish biomass were seen across survey years. Species counts were highly variable across the shelf region and Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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A bootstrap procedure was applied to estimate the demersal biomass of mackerel icefish (Champsocephalus gunnari) in CCAMLR subarea 48.3 using data from the UK trawl survey conducted in January 2013. The CCAMLR harvest control rule was then applied to determine catch limits for the 2013/14 and 2014/15 fishing season. Application of the CCAMLR rule, which ensures 75% biomass escapement Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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This review summarises current knowledge of the elasmobranch fish occurring in the Antarctic and sub-Antarctic waters of the CCAMLR area. About 14–15 species of elasmobranch have been recorded, with skates (Rajiformes) the most speciose order. Two genera of skates are known (Amblyraja and Bathyraja), although the current taxonomic knowledge of some species or species-groups is incomplete. Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Mark-recapture data is a central element in the assessment of population size and growth and the stock assessment for Patagonian Toothfish (Dissostichus eleginoides) in CCAMLR subarea 48.3 relies on accurate tagging samples for its assessment. The bias in tagging survival and tag detection is assumed to be minimal in the model, but this assumption has not previously been tested; a Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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A preliminary assessment of toothfish (Dissostichus eleginoides.) in Subarea 48.3 is presented.

1. The assessment results from this year’s analyses are very similar to those of 2011. SSB in the terminal assessment year continues to be estimated at around 54% of virgin biomass, consistent with the CCAMLR harvest control rule.
2. The 3-fleet assessment model Read More
   Submitted By:
   Sarah Mackey (CCAMLR Secretariat)
   
   Request Meeting Document

To date, the stocks of toothfish in Subarea 48.4 have been divided, for assessment purposes, into northern and southern components. The northern component is assessed as a single species of D. eleginoides whilst the southern component is assessed as a combination of D.eleginoides and D. mawsoni. Both species are caught throughout Subarea 48.4 although D. Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In 2009 CCAMLR agreed to incrementally and conditionally bring forward the start date of the Patagonian toothfish fishery in sub-Area 48.3. This allowed vessels that had been 100% compliant with CM 25-01 in the previous season to start 5-days early in 2010 (April 26th) and a further 5 days early in 2011 (April 20th). In 2011, following the success of the initial trial, CCAMLR agreed to further Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Tagging studies of skates and rays worldwide provide valuable information to help better understand a wide range of metrics including movements and migrations, stock units, growth rates, longevity, discard survival and abundance. Most Antarctic skate species are little known and, coupled with taxonomic and identification problems, this makes the tagging studies undertaken in the CCAMLR area a Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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A survey was conducted to collect data of stock status and various biological information of toothfish in SSRUs C and D of Division 58.4.4a & b (Ob Lena Banks) from April 25 to May 22, 2013. A total of 64 research hauls using normal trotline system were made in SSRUs C and D. Total catch of Dissostichus eleginoides (excluding those tagged and released) was 31.1 tonnes in the Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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I revised the CASAL catch-at-length models for stock status assessments of Dissostichus eleginoides in SSRUs C in Division 58.4.4 a & b (WG-SAM-13/21) following several advices during the last WG-SAM meeting as follows: 1)I included 2012 tag data (which was not used for model runs in WG-SAM-13/21), and a combined value of over-dispersions were used for all tag-release years (2008 Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We revised stock status assessments of D. eleginoides in SSRUs C and D using comparative CPUE, modified Lincoln-Petersen and CASAL models following advices during the last WG-SAM meeting. Detailed results using CASAL models in SSRU C are described in a separated document.

The catch and tagging data in SSRU D were not enough to be applied to modified Lincoln-Petersen and CASAL Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Catch and effort data recorded by all vessels were analyzed using the latest CCAMLR C2 and observer data.

The stock size estimates for research blocks were revised following advice in the last WG-SAM meeting. We tentatively recalculated a sample size of Dissostichus spp in each block in such a way that the numbers of tag recoveries in the 2016 season shows an approximately 0.3 Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

Request Meeting Document

Catch and effort data recorded by all vessels were analyzed using latest CCAMLR C2 and observer data.

The stock size estimates for research blocks were revised following advice in the last WG-SAM meeting. We tentatively recalculated a sample size of Dissostichus spp in each block in such a way that the numbers of tag recoveries in the 2016 season shows an approximately 0.3 of Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Catch and effort data recorded by all vessels were analyzed using latest CCAMLR C2 and observer data.

The stock size estimates for the research block (5842E) was revised following advice in the last WG-SAM meeting. We tentatively recalculated a sample size of Dissostichus spp in each block in such a way that the numbers of tag recoveries in the 2016 season shows an Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Catch and effort data recorded by all vessels were analyzed using the latest CCAMLR C2 and observer data.

The stock size estimate for a research block (5843a) was revised following advice in the last WG-SAM meeting. We tentatively recalculated a sample size of Dissostichus spp in each block in such a way that the numbers of tag recoveries in the 2016 season shows an Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We reanalyzed data collected by the longline fishery in Subarea 88.1 to compare the bycatches of VME taxa made by vessels using Autolines and Spanish longlines. The fractions of sets with positive bycatch, as well as the weights of bycatch when bycatches were observed, were higher for Autolines than for Spanish longlines. Using a generalized linear approach with a Tweedie distribution to model Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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To identify the important prey items for pre-recruit Antarctic toothfish in the SSRUs 88.1.K of the southern Ross Sea and 58.4.1.C of the eastern Antarctic Sea, their fatty acid (FA) composition and stable carbon and nitrogen isotope ratios were determined and compared to those of bycatch species and stomach samples. Sampling efforts were made during a longline survey of pre-recruit toothfish Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Stocks of Dissostichus mawsoni in Division 58.4.1 were vulnerable with a big range of about 1,000-2,000 t per SSRU in Division 58.4.1. However, there is not enough data and information to assess the robust stocks and deliberate proper measurements for sustainable utilize, especially relate to diet and feeding strategy which may lead to think about ecosystem based stock assessments and Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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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 and 100-1,500 t per SSRU in 58.4.2. During the 2003-2007 fishing seasons, 3,434 Dissostichus spp. were tagged and released, but only 5 fishes among them Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In the Division 58.4.1 there are two stocks of Dissostichus mawsoni, which is vulnerable with a big range of about 1,000-2,000 t per SSRU in 58.4.1. However, there is not enough data to utilize stocks properly, especially relate to reproductive mechanism. Therefore, the Korean scientists analyze the reproductive ecology of Dissostichus mawsoni in SSRU 58.4.1C based Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Proposed Research plan for the survey of Ukrainian longliner in 48.2 subarea

A multi-year plan for research by Japan and South Africa aimed at yielding a tag-based assessment of the Dissostichus resource in statistical Subarea 48.6 was adopted in 2012 and formulated in CM 41-04. This paper presents a revised work plan for the South African contribution to the second year of this research in 2013/14 and is to be read in conjunction with WG-SAM-13/11.

This report summarises the timing, depth, and location of fishing together with the biological aspects and catch of Antarctic toothfish for the period 1997–98 to 2012–13. In 2012–13, all the Ross Sea slope SSRUs were clear of ice and catches were evenly distributed across the three SSRUs. As in recent years, the remaining catches came mainly from SSRUs 88.1C, 88.1J, and 88.2H. Unstandardised Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We provide an update of the descriptive analyses of the toothfish tagging programme in Subareas 88.1 and 88.2, including summaries of data for the 2013 season. Overall, a total of 37 047 Antarctic toothfish have been reported as released and 1903 recaptured, and 1155 Patagonian toothfish released and 95 recaptured since 2001. In recent years, most vessels have achieved or exceeded the required Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Vessel-specific indices of tag detection rates and tagging mortality rates were developed in 2012 and further developed in 2013, using a methodology which controls for the spatial and temporal variability of fishing operations by pairing each individual tag release or recapture event with all other fishing events which occurred in the same time and place (i.e. within a specific distance and in Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We provide an update of the Bayesian sex and age structured population stock assessment model for Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea region (Subareas 88.1 and SSRUs 88.2A–B), using revised catch, catch-at-age, and tag-recapture data for the 2012–2013 seasons.  Several models were examined including an update of the 2011 base case (R1), a model Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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This paper presents the Bayesian sex and age structured population stock assessment of Antarctic toothfish (Dissostichus mawsoni) in Subarea 88.2 covering SSRUs 88.2C, D, E, F, G, and H (SSRUs 88.2C–H). We examined several models including the 2013 implementation of the 2011 base case (R1), using the revised data selection method (R2), using a logistic selectivity for the northern Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We present a spatially explicit age-structured population dynamics operating model for Antarctic toothfish in the Ross Sea region, for a medium scale spatial resolution (189 spatial cells) covering the Ross Sea region. In this model run we spatially restrict the stock to cells where at least 5% of the depth is deemed suitable as habitat for toothfish (120 cells – semi-restricted model), and Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We review tagging protocol changes made in 2012/13 and provide further recommendations to improve the quality of collected tagging programme data, and conduct research to improve effective tag releases and recoveries. We also provide a tagging training module to inform vessel observers and crew on tagging procedures.

We have identified key uncertainties in the stock assessment of Antarctic toothfish in Subareas 88.1 ad 88.2 which could be addressed using specific research surveys and other dedicated voyages. Given the continued uncertainty arising from the relative paucity of abundance data, age and length composition data and gonad data for toothfish in some geographic areas and seasons, and from lack of Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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We detail the procedure followed to check the Ross Sea CCAMLR fisheries data prior to using them in a stock assessment of Antarctic toothfish (Dissostichus mawsoni). The R codes used in this procedure have been made available to the Secretariat.

An accurate history of catch is an important input into the assessment of toothfish stocks, and uncertainty or bias in the amount of catch from an area must be taken into account in the assessment of a stock.



In 2013, Korea held a workshop on the anomalous CPUE data reported from some Korean vessels in data-poor exploratory fisheries (Delegation of Korea 2013). That paper Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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In this contribution we report the presence of 6 vulnerable marine ecosystems (VME) around the South Georgias archipelago (CCAMLR Subarea 48.3). These areas, which  are proposed for inclusion in the CCAMLR VME registry, were detected during a research cruise performed by the National Institute of Fishery Research and Development (INIDEP) and the Argentine Antarctic Institute (IAA) during Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The reproductive biology of C.gunnari, C. aceratus and P.georgianus was studied on samples taken around South Georgias and Shag Rocks. The macroscopic analysis indicated the presence of totally mature females of three species (with hydrated oocytes). C. gunnari, C. aceratus and P. georgianus  This not only confirms the Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Diet components and trophic interactions in five demersal fish caught around of South Georgia’s waters was determined. Data were obtained from samples of Champsocephalus gunnari, Chaenocephalus aceratus, Pseudochaenichthys georgianus, Notothenia rossii and Dissostichus eleginoides, on a cruise carried out during the month of May 2013, on board of RV Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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This report presents a summary of the work conducted onboard and a preliminary description of the results obtained during the research survey. The cruise started on april 26th and returned to Mar del Plata the 21st may 2013.

The work was conducted in the CCAMLR statistical area 48.3 and its main objective was to obtain information on the status of the stocks of Chamsocephalus Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Information on biological aspects of the finfish catches obtained in the survey of BIP Dr.  E L  Holmberg, conducted around Shag Rocks and the South Georgias Islands in April-May 2013, is presented. A total of 25 tows were taken, catches comprised sixteen finfish species, being Champsocephalus gunnari, Chaenocephalus aceratus, Notothenia rossii, Pseudochaenichthys georgianus, Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The present report re-analyses data regarding CPUE for both species of toothfish in northern area of 48.6 (SSRU 48.6A, 48.6G). This report is a re-analysis of the CPUE time series proposed in previous work (SAM 13/29) which includes all those comments and suggestions made in the last SAM meeting. Here, the  length of the line was used as effort unit and also high CPUE values reported by a Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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The stock of Antarctic toothfish in the CCAMLR subarea 48.4 was estimated using as the Petersen method as  640 tonnes. Application of the harvest rate used for D. eleginoides in Subarea 48.3 (γ = 0.038) gives yields of 24 t for the Antarctic toothfish in the region vs. previous estimation of 30 tonnes.

The local densities of Champsocephalus gunnari  observed in the 2013 survey are compared with those observed in 1994-1997. A significant increase in densities across 24 sites previously sampled was found. The comparison of the length distribution functions suggests that the stock depletion in the early 1990’s was due to recruitment collapse, probably a consequence of overfishing Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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Pleuragramma antarcticum is the only Antarctic notothenioid characterized by a complete pelagic life cycle and plays a major trophic role in the coastal Antarctic marine ecosystem. A previous genetic study investigated the population structure of this species, but used mitochondrial DNA sequencing and was unable to discriminate between hypotheses of panmixia, with occasional Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

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This paper summarises the data collected by Scientific Observers operating in the Convention Area on board longline and  finfish trawl vessels during the 2013  (based on data received by the Secretariat up to 30 Sept 2013). .

Information on observer coverage, incidental mortality (including the implementation of mitigation related CMs), tagging and  conversion factors Read More
Submitted By:
Ms Doro Forck (CCAMLR Secretariat)

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Among all validation methods of age determination in fish, release of known age and marked specimens gives the most reliable information. We carried out a tagrecapture experiment on Notothenia rossii at Potter Cove, to validate, for first time for this species using this method, the principle of annual deposition of an annulus in scales and otoliths. Of 132 juvenile specimens (TL = 22 Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

Publication:
(Polar Biol., 2013, doi 10.1007/s00300-013-1392-7)

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This article reviews the adequacy of data and models currently being used to estimate the present and future population sizes of the Antarctic toothfish (Dissostichus mawsoni Norman) in the Ross Sea regional ecosystem. It argues that the current tagging program is unlikely to provide an accurate picture of total population size, and that estimates of both the pre-exploitation spawning Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

Publication:
(Ant. Sci, accepted)

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Using a modeling framework for toothfish (Dissostichus spp.) population dynamics, fishing, and data collection, this study investigated how the bias and precision of biomass estimates from an integrated tag-based assessment are influenced by various aspects of a multiyear tagging program, particularly the effects of the size of tagged fish compared with the size of fish in the catch ( Read More
Submitted By:
Sarah Mackey (CCAMLR Secretariat)

Publication:
(Can. J. Fish. Aquat. Sci., 70 (2013): 1031–1045)

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