Macrobenthos by-catch are used to identfy Vulnerable Marine Ecosystems (VME). These VME indicators have been recorded as part of the C2 and also as part of observers data since CM 22.07 has been published in 2013. Here we report on VME bycatch in research blocks 58.4.1, 58.4.2, 54.4.3a and 58.4.4b. We looked at spatial variation of VME units at different scales, and analysed taxa spatial distribution. We also compared gear types in terms of number of VME units collected. We suggest that taxonomic diversity index and specimens count may also be considered as proxy to limiting fishing impacts on benthic ecosystems.

France and Japan revised a research plan to continue investigating the populations of Patagonian toothfish (D. eleginoides) in the Division 58.4.3a during the next fishing seasons from 2017/18 onwards, using standardized longline gear and established observation and tagging programs.

In this Division, research fishing has been conducted by France and Japan since 2012 in the research block by three vessels using longline: “Shinsei Maru No. 3” (Japan), “Saint André” (France) and “Mascareignes III” (France). The first Franco-Japanese exploratory longline fishery research plan for Dissostichus spp. in Division 58.4.3a (WG-FSA-16/55) was presented to WG-FSA-16, which included research objectives, methods and milestones in accordance with Conservation Measure 41-06 and associated measures.

In October 2017, the Scientific Committee agreed that the research plan was appropriate to achieve its objectives (SC-CAMLR-XXXVI, para. 3.121). France and Japan commonly notifies their intention to continue their exploratory fisheries in Division 58.4.3a over the coming years in order to contribute to the tagging program and to achieve a robust stock assessment. We present here a proposal for the continuation of the research plan as set out in WG-FSA-17/55, and taking into account the Scientific Committee’s recommendations.

Summary of revised points from WG-SAM-18/08 is as follows:

• Updates the timeline table of milestones
• Track changes of milestones
• Summary of previous recommendations by WGs and SC (Annex 1).

This paper presents the annual report of a multi-Member longline survey on Patagonian toothfish (Dissostichus eleginoides) in Division 58.4.3a in the 2017/18 fishing season by France and Japan. One fishing cruise by French vessel (“Mascareignes III”) took place in May 2018 and caught 2.5 tonnes of D. eleginoides in 58.4.3a. The data set, C2 and Observer data, were provided by the CCAMLR Secretariat on the 21th August 2018. In this paper, the data set during current fishing season (2017/18) was used for reporting the quantity of data, samples collected, and results of analysis as a progress toward research millstones. The research operations in 58.4.3a have not yet been completed in the 2017/18 fishing season which means that some data may not be reflected in tables and figures at the time of submission of this document.

Following Operation Sparrow 2, WG-FSA-17 noted the unprecedented availability of catch data from four IUU vessels including reported removals, video footage, and catch in gillnets recovered by an NGO vessel. As requested in WG-FSA-17 paragraph 2.16, this document provides an analysis of the spatio-temporal distributions of catch and effort by the Chang Bai, Nihewan and Jiangfeng in Division 58.4.1 during the 2013/14 season, as well as the Thunder in Division 58.4.3b during the 2014/15 season. During the 2013/14 season the Chang Bai, Nihewan and Jiangfeng operated across SSRUs 58.4.1C, 58.4.1D and 58.4.1E and caught a total of 792 tonnes of toothfish. Daily catch rates were similar between IUU and authorised vessels. Based on data from 2013/14, total removals by IUU vessels fishing with gillnets were higher than authorised vessels fishing with longlines, and the presence of an authorised vessel in the region of IUU activity did not appear to deter the IUU fleet. Hence there have been substantial and unaccounted for IUU removals, which may have impacted on research activities in Division 58.4.1.

Exploratory fishing for toothfish (Dissostichus mawsoni) in East Antarctica (Divisions 58.4.1 and 58.4.2) began in 2003. Robust stock assessments and catch limits according to CCAMLR decision rules remain to be determined for these Divisions. WG-FSA-16/29 outlined the first multi-member toothfish exploratory fishery research plan up to 2017/18 for East Antarctica, which the Scientific Committee agreed was appropriate to achieve the research objectives (SC-CAMLR-XXXV, para. 3.244). Subsequent research progress including evaluation of standard approaches to identify precautionary catch limits (WG-FSA-17 para. 4.28-4.38) and bycatch mitigation (Maschette et al. 2017), suggests a low risk profile for this fishery. Furthermore, examination of bycatch data and underwater video footage have not led to the identification of vulnerable marine ecosystem (VME) indicator species (Maschette et al. 2017). Here, we present a succeeding research proposal with updated research objectives for 2018/19 to 2021/22, in accordance with Annex 24-01/A, Format 2. This succeeding plan has been designed as a 4-year plan, based on the low risk profile of this fishery and to allow more time for review by Working Groups of major reporting and review years in non-stock-assessment years. Based on the outcomes of the approach to review the locations of research blocks presented in WG-SAM-18/17, research blocks will be retained in their current locations.

CCAMLR-XXXIV (para. 5.68) endorsed new pre-season (1–14 April) and post-season (15–30 November) trial season extensions, in addition to an existing pre-season (15–30 April) and trial post-season (1–14 November) extension in the Patagonian toothfish longline fishery in Statistical Division 58.5.2 (WG-FSA-15/48).

Australia undertook to report annually on the results of all the trials. This paper presents information on fishing effort and seabird interactions with fishing gear collected during the periods 1–14 November 2017, 15–30 November 2017, 1–14 April 2018 and 15–30 April 2018. This report complements the fishing effort and interaction data reported in 2015 (WG-FSA-15/48), 2016 (WG-FSA-16/28 Rev. 1), and 2017 (WG-FSA-17/20).

The annual random stratified trawl survey was undertaken in Division 58.5.2 in the vicinity of Heard Island and McDonald Islands during April 2018. This paper provides an updated growth model and a preliminary assessment for mackerel icefish (Champsocephalus gunnari) population structure, abundance and yield in Division 58.5.2 to the west of 79^o 20’ E using standard CCAMLR methods (CMIX and Generalized Yield Model).

The 2018 survey showed a large 2+ cohort in the population. Catches of 443 t in the 2018/19 season and 320 t in the 2019/20 season respectively satisfied the CCAMLR decision rules.

The annual random stratified trawl survey (RSTS) of 2018 around Heard Island and McDonald Island (HIMI) in Division 58.5.2 took place from the end of March to the end of April, with the completion of 163 stations plus eight extra fine mesh hauls. The survey was conducted on the FV Atlas Cove. Sampling protocols such as the design and the duration of the hauls were similar to recent surveys, but with a new set of randomly selected station points.

The catch of Dissostichus eleginoides (Patagonian toothfish) was twice that of 2017 while the catch of Champsocephalus gunnari (mackerel icefish) was two thirds of the 2017 survey catches. The catches of the other managed bycatch species, Channichthys rhinoceratus (unicorn icefish), Lepidonotothen squamifrons (grey rockcod) and Macrourus spp. (macrourids combined) were also two to three times greater than those of last year. Catches of skates were similar to those of 2017. Invertebrate catch (including jellyfish) in the 2018 survey was 1.5 times the low value of 2017.

The calculated biomass for 2018 of the target species D. eleginoides and C. gunnari in the survey area were close to the highest estimates for the past 10 years. For the managed by-catch species C. rhinoceratus and Macrourus spp. the biomass estimate was similarly high. Conversely, the estimate for L. squamifrons has been low for the past 4 years. The 2018 biomass estimates for each of the three Bathyraja spp. (skates) were the highest in the last 10 years.

Length measurements and sex were taken for nearly 22 000 fish and for more than half of those biological measurements were also recorded. Otoliths were collected from 656 D. eleginoides and 609 individuals were tagged and released.

During the 2017/18 season the Spanish F/V Tronio fished in Statistical Subarea 88.1 and Division 58.4.1 where the latter area required a tag rate of five fish per ton greenweight caught and also where the overall size of the fish exceeds 115cm. The tagging station on the FV Tronio is on the upper deck above the hauling station providing easy access to retrieve smaller fish directly from the hauling station and to operate the cradle over the side for landing larger fish. To optimise the use of the cradle a series of modifications were trialed to optimize the handling of the cradle, achieve rapid retrieval to minimize hauling downtime, minimize handling and time out of the water of the fish and use the cradle to release the fish. The modification achieved most of these objectives, with room for some further suggested alteration to further improve the system.

In the present study a comparative morphometric analysis of sagittal otoliths was performed in three Channichthyids (Pseudochaenichthys georgianus, Chaenocephalus aceratus and Chaenocephalus gunnari) collected during a research survey carried out between January 23 and February 13, 2016, along the continental shelf and slope around Elephant Island (Subarea 48.1) and the South Orkney Islands (Subarea 48.2). Morphometric analysis was addressed using Basic size descriptors (BSD; area & perimeter), shape indices (SI; circularity, squareness and roundness) and elliptical Fourier Descriptors (EFD) on 2D binarized images of left and right otoliths for fish ranging from 20 to 67 cm TL. To test for significant differences between the left and right sagittae in BSDs, a univariate and multivariate ANOVA and MANOVA were used, with BDSs as dependent variables and otolith type as fixed factor. ANOVA and MANOVA showed all standardized BSDs did not varied significantly between right and left sagittae (P>0.05). All EFDs derived from the 20 harmonics analyzed were homoscedastic and normal, and showed very low level of correlation among them. Hence, all coefficients were used in MANOVA and LFDA. MANOVA showed significant differences in the contour between both otolith pairs for each species (p<0.001). Similarly, EFS coefficients showed a high discriminatory power to distinguish the left and right otoliths, with a total percentage of correct classification of 76, 96, and 89% for P. georgeanus, C. gunnari and C. aceratus. A link between the extreme environmental conditions of Antarctic waters and the occurrence of the unusual high asymmetry in the otolith contour is proposed for Channichthyids and its implications are discussed.