A collaborative research program has been undertaken by Japan and South Africa since 2013 to enhance data collection and analysis in the subarea 48.6 under CM 21-02. Spain joined the proposal starting from 2018/19 fishing season in order to contribute to the data acquisition and to speed up the integrated assessments of the Antarctic toothfish (Dissostichus mawsoni) stock in this subarea (WG-FSA-18/34).

The continuation of the three-member research proposal for 2021/22 season is presented to ensure continuity of previous research activities. Data and investigations about the population structure and various demographic parameters of D. mawsoni using trotline (JPN and ZAF) and Spanish longline (ESP) gears, established tagging techniques, pop-up tags and genetic analysis will provide the basis for the development of spatial population models and assessments in support of management advice. An Integrated Stock Assessment (ISA) which takes into account the tag time series from southern research areas of Subarea 48.6 D. mawsoni is going to be continually developed until the end of the 2023/24 season.

The updated CCAMLR Research Plan – Research Proponent Self-Assessment can be found in Appendix 1.

To aid the development of a simple first step management approach for the Antarctic krill in Subarea 48.1, the suitable spatial scale for biomass estimate, the choice of recruitment index for the GrYM model and some considerations for the risk assessment are discussed.  

Parasitological study was conducted onboard the Ukrainian trawler “MORE SODRUZHESTVA”, which fished Antarctic krill during the cruise from the end of December 2020 till the end of March 2021. All fish specimens collected and examined were infected with helminths of five taxonomic groups (Nematoda, Cestoda, Trematoda, Acanthocephala or Monogeneans). Two groups of helminths dominated in the helminth communities – nematodes (consists from 28 to 61% of the total parasite number) and cestodes (from 15 to 22%); trematodes and acanthocephalans accounted for 3 to 8% of the total number of helminths found in different species of fish.

Cetacean observations were conducted onboard the Ukrainian trawler “MORE SODRUZHESTVA”, which fished Antarctic krill and was used as a platform of opportunistic research during the cruise from December 2020 till March 2021. During the Australian summer the fishing grounds were in the CCAMLR Statistical Area 48.2 (South Orkney Islands). Visual observations of marine mammals were conducted.

The SCAR Antarctic Biodiversity Portal (biodiversity.aq) is an international effort that seeks to increase our knowledge and understanding of Antarctic and Southern Ocean biodiversity. It does so by supporting the publication of Antarctic and Southern Ocean biodiversity data, integrating data flows and the development of tools for the retrieval and integration of biodiversity data.

Here we provide an update of current activities relevant for CCAMLR.

This report summarizes the workshop sponsored by the Integrating Climate and Ecosystem Dynamics in the Southern Ocean program (ICED). The workshop, held from 17-20 May 2021, was focussed on improving our modeling of Antarctic krill and strengthening connections between the krill modeling community, the SCAR Krill Action Group (SKAG) and the scientists involved in CCAMLR (particularly WG-EMM). Workshop attendees represented a broad cross-section of the international krill modeling community, in addition to researchers focussed on other species, comprising ~80 registered participants across all career stages. The workshop included a background session and three themed sessions focussing on key aspects of krill modeling. The workshop also aimed to provide Early Career Researchers (ECRs) with opportunities to network and highlight their work, as part of ICED’s wider goal of including ECRs in ICED activities to foster career development and shape the future of ICED research. This paper presents the initial findings for research priorities, data requirements, facilitation methods for integrating modeling approaches, and ideas on fostering research networks and involvement within the Antarctic krill modeling community and beyond.

Distribution pattern of living resources is spatial scale-dependence, therefore an inappropriate scale may produce misleading results. As a key species in the Antarctic ecosystem, distribution of Antarctic krill (Euphausia superba) demonstrates significant spatial-temporal heterogeneity. The distribution pattern of this species is spatiotemporal complex and cannot be predicted effectively. In order to understand the spatial-temporal distribution pattern of krill resource in the Antarctic Peninsula, an important ecological and commercial-interested regions, the Moran's I value of krill density distribution was calculated at 12 spatial scales (5'×5' - 60'×60') by 5' grid of latitude and longitude. The results showed that the spatial pattern of krill is differed in spatial scales. The distribution of krill density showed a discrete trend at the 25'×25' scale, but the distribution of krill density showed a clustering trend at the other 11 spatial scales. According to the correlogram between the Moran's I value and spatial scale, the characteristic spatial scales of krill density distribution were determined as about 25'×25', which was determined by the Moran's I value inter-crossing the x-axis for the first time, and 15'×15', which was determined by the smallest scale with no significant difference between the Moran's I value and zero in the correlogram, respectively. This study showed that the method with no significant difference between the Moran's I value and zero value was more consistent with the characteristics of krill resource. It was, therefore, recommended that 15'×15' could be the optimum spatial scale for analyzing the distribution of krill density in this region.

Based on the results of RV Atlantida cruise in January - March 2020 in Subareas 48.1 and 48.2  data on the structure, quantitative indicators and spatial distribution of phytoplankton and zooplankton (species composition, abundance, biomass), primary production phytoplankton, chlorophyll concentration were obtained. Sampling stations were located above depths of 82 - 4300 m. Chlorophyll was studied at 180 stations, zooplankton and phytoplankton at 66 stations, and primary production at 66 stations. Phytoplankton during the summer period was represented by 120 identified species, mainly diatoms.  In the entire  study area, 4 phytoplankton communities were identified, which has different biotope conditions, spatial distribution and complex of the main structure-forming species. Zooplankton was represented by 53 species, mainly copepods. High correlations of surface concentration of chlorophyll a with the abundance and biomass of phytoplankton, primary production and chlorophyll content on average and integral for the photosynthesis zone have been obtained, which makes it possible to use remote satellite observations for assessments of abundance and productivity of phytoplankton as the basis of food chains, including krill, in the Atlantic sector of the Southern Ocean. Phytoplankton and zooplankton data are essential components for further analysis with the spatial distribution of environmental conditions and krill abundance to identify the relationships that determine ecosystem dynamics in the Antarctic sector of the Southern Ocean.

Results of observations of seabirds and mammals obtained during the acoustic survey in the Subarea 48.1 and 48.2 in January-March 2020 onboard the RV “ATLANTIDA” are presented  Seabirds were represented by 27 species. Marine mammals were represented by thirteen species of marine mammals.  Ten species belonged to cetaceans, three species belonged to the group of pinnipeds (carnivora).  Distribution of abundance of seabird and mammal in relation to krill density  is shown.