We provide a photographic reference set for Antarctic toothfish (Dissostichus mawsoni) from the Ross Sea region. The photographs were derived from the four otolith reference set blocks used by New Zealand with the “sister” otoliths provided to CCAMLR for use by other Members. Two photographs are provided for each otolith; one of the prepared otolith surface alone, and a second with symbols marking the location where each annulus was counted. The photographs link to an excel spreadsheet providing data on each otolith. We recommend that the CCAMLR Secretariat make this reference set available via the CCAMLR website for use by Members.

At its 2011 meeting, the Scientific Committee agreed that a time series of relative abundance from a well-designed survey would be a useful input into the Ross Sea stock assessment model. In this paper we provide results of the seventh annual survey in the time series. The objectives of this survey included monitoring sub-adult (≤ 110 cm TL) toothfish in the south of SSRUs 881.J and 881.L in the southern Ross Sea (Strata A–C) using standardised gear in a standardised manner; and monitoring trends in larger (large sub-adult and adult) toothfish in two areas (both situated in SSRU 881.M) of importance to mammalian toothfish predators: McMurdo Sound in 2018, and Terra Nova Bay surveyed in 2017. The estimated relative biomass index of toothfish for the core strata showed a decrease from 2017 to a value equal to the average index early in the time series, and length and age frequency data showed the progression of cohorts through the population that were observed in previous surveys. Notification of research for the agreed 2019 fixed-effort survey is included with a catch limit of 65 t.

We propose to test three hypotheses to describe the reproductive ecology of Antarctic toothfish (Dissostichus mawsoni):

1) Antarctic toothfish eggs are buoyant and accumulate under sea ice. If true, this would retain eggs near the spawning locations under the vast sea ice extent and once broken up in the spring, may provide access to a productive pagophilic ecosystem for feeding as well as a transport mechanism for subsequent advection patterns, all of which could be impacted by climate change. This would have implications on the understanding where recruiting fish originate and how those patterns may be influenced by changes in sea ice or circulation patterns that affect observed recruitment patterns.

2) Antarctic toothfish spawn throughout the Pacific Antarctic fracture zone. Evidence to date only exists from the west of the region (SSRU 88.1B), yet adult Antarctic toothfish are found much further east and north of the CCAMLR Convention area, which is bounded by latitude 60°S. Obtaining a better understanding of the location and movement of adult spawning toothfish has direct implications on the understanding of those parts of the adult stock that contribute to recruitment, and hence the productivity of the stock assumed in the stock assessment.

3) Biological characteristics of the northern spawning population change as younger, fatter, female fish move to the north for spawning during winter. Evidence to date found no change in these characteristics in June, suggesting sampling later in the spawning season is needed.

We propose to conduct a scientific survey during the austral winter in the northern Ross Sea region to test these hypotheses. The longline and plankton survey is designed to cover key gaps in the knowledge of the life cycle of Antarctic toothfish in the Ross Sea by collecting biological samples from a range of locations in the northern regions of Subarea 88.1 and 88.2 and begin in September 2019. The survey will be coordinated with a corresponding survey targeting Antarctic toothfish spawning dynamics in the southern area of the South Pacific Regional Fisheries Management Organisation (SPRFMO) area at a similar time.

This paper outlines the specific research objectives and plan to achieve them for the third year of an agreed 3-year longline survey, in the wider context of connecting the recently undertaken surveys in Subarea 48.2 with the established fishery in Subarea 48.4. The overall research objectives include determining population connectivity between these Subareas, improving understanding of Dissostichus sp population structures in this region, and improving available data on bathymetry and associated distributions of benthic bycatch species. This plan includes a three-year data collection and two-year data analysis plan leading towards the development of a stock hypothesis for the eastern regions of 48.2 and southern regions of 48.4.

Ukraine proposes to continue survey in the Subarea 48.2 in same boundary for the fifth year of research.

The research of Dissostichus in Subarea 88.3 carried out by Chile in 1998, New Zealand in 2005, Russia in 2011 and 2012 and the Republic of Korea in 2017 and 2018. It was noted that no tagged fishes were recaptured during the previous research activities. Studies are planned to be conducted from January to March, as ice conditions permit. It is planned that the number of longline sets will be 60 in four Reserch Blocks. It is planned to complete the study for Dissostichus spp. in Subarea 88.3 within 3 years.

Ukraine proposes to carry out a scientific survey of Dissostichus spp. by bottom longline in the eastern part of Subarea 48.1.

Russian Federation is going to continue investigation for toothfish in Ross Sea. The previous Russian program was undertaken in the Subarea 88.2 in 2010-2012. This paper presents the   research program in the frame of the research and monitoring associated with the Ross Sea region marine protected area.

Russian research program have objectives to investigate the life-cycle, distribution and movement, biological parameters and stock structure of Dissostichus species in the eastern part of the Ross Sea over shelf and continental slope within the Subarea 88.2 A.  The tagging toothfish and recapture tagged fishes to be in focus.  The study area is located in the Special Research Zone of the RSRMPA. Proposals include the priority elements of the research and monitoring plan for the Ross Sea region marine protected area. 

The research program shall be conducted in the Special Research Zone during 2018 - 2027 or the first reference period for existence of the RSRMPA. This program provides possibility for collaborative investigations in the Special Research Zone by Russian vessels and vessel from other CCAMLR country-members.

Russian program provides proposals to study the species composition, biology, life cycle, distribution and structure of craboids stock (Anomura, Decapoda)  and  assess their resource potential in the Bellingshausen Sea (Subarea 88.3) and Amundsen Sea (Subarea 88.2).