This paper represents the annual report of a multi-member longline survey on Antarctic toothfish (Dissostichus mawsoni) at Statistical Subarea 48.6 for 2016/17 fishing season by Japan and South Africa. The data set, C2 and Oｂserver data, was provided by the CCAMLR Secretariat on the 20th of April, 2018. In this paper, the data set during last fishing season (2016/17) was used for reporting the quantity of data, samples collected, and results of quick analysis as a progress toward research milestones.

This paper represents the annual report of a multi-member longline survey on Patagonian toothfish (Dissostichus eleginoides) at Division 58.4.4b in 2016/17 fishing season by France and Japan. The data set, C2 and Observer data, was provided by the CCAMLR Secretariat on the 20th April 2018 (30 May, 2018 for September to November French cruise). In this paper, the data set during last fishing season (2016/17) was used for reporting the quantity of data, samples collected, and results of quick analysis as a progress toward research millstones.

The document presents the experience of the age determination of toothfish of the genus Dissostichus by recording structures (otoliths). Sampling processing is carried out on the basis of annual data collected in the CCAMLR Convention Area. The equipment used, the procedure for processing and reading age are described. The achieved volumes and results are given. And also the problems that arose and the ways to solve them.

The fourth 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 fourth year survey design was slightly amended in comparison with the one of the second year and approved by WGs SAM, FSA and SC CCAMLR.  Obtained data will be used for the future biomass estimation of the target species and making decision for the future fishing on that fishing ground.

In the fishing season of 2018, three Ukrainian fishing vessels collected oceanographic data (salinity and temperature). The method of data collection is described. A preliminary analysis of the data was carried out.

During open discussions at the Third International Symposium on Krill (St Andrews, Scotland, June 2017) attended by representatives of the Association of Responsible Krill harvesting companies (ARK), the Marine Stewardship Council (MSC) and CCAMLR, it became apparent that no bycatch of Ice krill (Euphausia crystallorophias) had been reported from fishing vessels targeting Antarctic krill (E. superba). Furthermore there seemed to be little confidence amongst participants that under present observer practice any such bycatch would be detected – this despite the fact that fishers are obligated as a condition of their fishing permits to report all bycatch. Since the present-day Antarctic krill fishery operates in geographic areas that overlap with the known range of Ice krill, that Ice krill and Antarctic krill can occupy similar depths in the water column, and that both species are morphologically similar, the possibilities of bycatch and the failure to detect it cannot be dismissed. Here we analyse publicly-available aggregated decadal-scale krill catch data to evaluate the likelihood that Ice krill will have been included in the reported Antarctic krill catch. We conclude that the likelihood is effectively 100%. The MSC asserts that “bycatch and discards remain[ed] significant to ensuring sustainability. They are considered a waste of resources and contradictory to the overall concept of responsible fisheries” (https://improvements.msc.org/ database/discards; our emphasis). Stemming from this, the MSC now (as of April 2015) requires “fisheries to regularly review alternative mitigation measures to minimise mortalities of unwanted catch”. The krill fishery prosecuted by Aker Biomarine (a member of the Association of Responsible Krill harvesting companies; our emphasis) achieved MSC re-certification in August 2015 (https://www.msc.org/newsroom/news/ msc-labelled-aker-biomarine-krill-products-are-from-a-sustainable-and-well-managed-fishery), but it is not apparent if the probability of bycatch of Ice krill was considered for this re-certification. In the absence of any data, or clear statement, on Ice krill bycatch, it is difficult to reconcile the MSC’s statement (ibid.) that the Aker Biomarine “fishery remains excellent in its performance against MSC standards”. As part of the ongoing MSC assessment of the Deris S.A. – Pesca Chile Antarctic krill fishery (https://fisheries. msc.org/en/fisheries/deris-s.a.-pesca-chile-antarctic-krill-fishery/) and the scheduled re-assessment of Norway’s Aker Biomarine Antarctic krill fishery (https://fisheries.msc. org/en/fisheries/aker-biomarine-antarctic-krill/@@view; due before June 2020) we suggest that due consideration be given to the possibility of under-recording of bycatch of Ice krill in the Antarctic krill fishery, and to associated measures to address this situation.

A finfish survey was completed using bottom trawl fishing gear according to a random stratified sampling design between 50 and 500 m on shelf areas of Subarea 48.1 (Elephant Island) and Subarea 48.2 (South Orkney Island). The sampling stations were set in approximately the same geographical coordinates as those on previous R/V 'Polarstern' surveys around Elephant Island (Kock & Jones, 2012) and on shelf areas of the South Orkney Islands according to a subsample of stations sampled by the R/V 'Yuzhmorgeologiya' (Jones & Kock, 2009).

The cruise took place 6-27 January, 2018, primarily using a Hardbottom Snapper trawl (NET Systems, Inc.), previously used by the US AMLR Program, Southwest Fisheries Science Center, National Marine Fisheries Service. A total of 36 hauls were carried out with this bottom trawl, 15 around Elephant Island and 21 around the South Orkney Islands. Additionally, eight hauls were conducted using either a Casanova bottom trawl (3 hauls) or a Gloria 704 midwater trawl (5 hauls).

For stations sampled using the Hardbottom Snapper trawl, 36 fish species were caught with a total volume of 19,112.28 kg. The main species extracted with this gear corresponded to Notothenia rossii and Champsocephalus gunnari, with landings weighing 16,204.38 (84.79%) and 875.69 kg (4.58%), respectively. Other species of fish registered noticeably lower amounts (10.63%), such as Gobionotothen georgianus (329.97 kg), Chaenocephalus aceratus (321.91 kg), and Pseudochaenichthys georgianus (299.39 kg).

As a result of nearing the maximum research catch specified in Subarea 48.1 (95% of authorized research catch), we were unable to complete the planned number of bottom trawl stations (n=37), with 35% of proposed stations completed (n=13). In Subarea 48.2, we were unable to complete the planned number of stations (n=28) because of limited ship time, where 75% of proposed stations were completed (n=21). This resulted in a very low sample size with which to estimate standing stock biomass, and thus results presented here should be taken as indicative. Indicative estimates of standing stock biomass suggest that N. rossii is the most abundant demersal finfish species in the Elephant Island area followed by C. gunnari. On the South Orkney Island shelf, the most abundant species was G. gibberifrons followed by P. georgianus.

The acoustic survey was carried out around both groups of islands and its processing will contribute to knowledge regarding bathymetry and distribution of the concentrations of fish and krill in the studied area (track of 579 nm around Elephant Island and 1,120 nm around South Orkney Islands). During the acoustic survey, five hauls were carried out with a mid-water trawling net in order to identify the shoal marks registered in the echo sounders. One of the mid-water hauls identified a shoal of icefish (33.6 t), while the other four obtained other species of icefish, such as P. georgianus, and krill.

In addition, 1,176 tissue samples representing 21 species of nototenoids, four species of the family Rajidae, and another 12 species that make up six families of teleost fishes were collected for genetic studies. A further 1,182 specimens were evaluated for parasite infestation (Euhirudinea), with 140 specimens of Trulliobdella capitis,Truliobdella bacilliformis, and Nototheniobdella sawyeri collected.

Leopard seals are an important Antarctic apex predator that can affect marine ecosystems through local predation. Here we report on the successful use of micro geolocation logging sensor tags to track the movements, and activity, of four leopard seals for trips of between 142-446 days including one individual in two separate years.  Whilst the sample size is small the results represent an advance in our limited knowledge of leopard seals. We show the longest periods of tracking of leopard seals’ migratory behaviour between the pack ice, close to the Antarctic continent, and the sub-Antarctic island of South Georgia. It appears that these tracked animals migrate in a directed manner towards Bird Island and, during their residency, use this as a central place for foraging trips as well as exploiting the local penguin and seal populations. Movements to the South Orkney Islands were also recorded, similar to those observed in other predators in the region including the krill fishery. Analysis of habitat associations, taking into account location errors, indicated the tracked seals had an affinity for shallow shelf water and regions of sea ice. Wet and dry sensors revealed that seals hauled out for between 22 and 31% of the time with maximum of 74 hours and a median of between 9 and 11 hours. The longest period a seal remained in the water was between 13 and 25 days. Fitting GAMMs showed that haul out rates changed throughout the year with the highest values occurring during the summer which has implications for visual surveys. Peak haul out occurred around midday for the months between October and April but was more evenly spread across the day between May and September. The seals’ movements between, and behaviour within, areas important to breeding populations of birds and other seals, coupled with the dynamics of the region’s fisheries, shows an understanding of leopard seal ecology is vital in the management of the Southern Ocean resources.