CCAMLR

Stock assessment of the Antarctic toothfish in the Subarea 88.2 H using Peterson method is presented in this paper. Calculated stock value of the Antarctic toothfish in the Subarea 88.2 H is 9307 t with 95% confidence interval ranging from 7502 t to 11967 t. In 2014-2015 values of potential catch with incomplete taking of 3%, 5% and 10% were determined as 280 t, 465 t and 931 t, respectively.  

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 at most part of the Weddell Sea during most 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, currents system and follows from results of the fist and the second stage of this program, highlight the Weddell Sea as one of the most promising area for exploratory fishery of Dissostichus sp. However, fishery in Subarea 48.5 is closed on the basis data on stock assessment absence. The main objective of the present program is collecting data for reliable stock assessment and following estimation of precautionary limits in accordance with CCAMLR decision rules. The program contains schedule and research program of the third stage of the Russian Federation multi-year research program in the Weddell Sea that are prospected for 5 years. Detailed plan of fishing operations, collecting and analysis of data will be provided for the Scientific Committee and Commission consideration.

Russian Federation intends to continue research in Subarea 88.2 that began in 2010-2012. The main objectives are studying of toothfish migration from SSRU 88.1 K to Subarea 88.2 A.

Results of longline survey on Antarctic toothfish in the Weddell Sea (Stage II) are presented in the paper. Options I and II of the survey were carried out from February 10 to February 22, 2014. A total of 34 longlines were set: the Option I – 10+20 and the Option II – 4 at the depths ranging from 605 to 2031 m. A total number of hooks – 116 100, area – 13565 km². Catch value of the Antarctic toothfish was 228 t, by-catch – appr. 2 t. CPUE per 1 km main line was 1635 kg at average. As a result of the Research program Stage II the entire measured biomass of the Antarctic toothfish in the Weddell Sea was determined (565 000 t). It was calculated using areal method recommended by CCAMLR (SC-CCAMLR-XXX, 2011; п. 2.40 (ii)). The research Program Stage II in the Weddell Sea accepted by the CCAMLR Commission (CAMLR-XXXII, par. 5.59-6.60) has been successfully completed.

We present a new, high resolution (300 m) bathymetric grid of the South Orkney Islands and surrounding continental shelf, northeast of the Antarctic Peninsula. The new grid, derived from a compilation of marine echo-sounding data improves previous regional bathymetric representations and helps to visualise the morphology of the shelf in unrivalled detail. The compilation forms important baseline information for a range of scientific applications and end users including oceanographers, glacial modellers, biologists and geologists. In particular, due to our limited understanding of glacial history in this region, the bathymetry provides the first detailed insights into past glacial regimes. The continental shelf is dominated by seven glacially eroded troughs, marking the pathways of glacial outlets that once drained a former ice cap centred on the South Orkney Islands. During previous glacial periods, grounded ice extended to the shelf edge north of the islands. A large, ~250 km long sediment depocentre, interpreted as a maximum former ice limit of one or more Cenozoic glaciations, suggests that ice was only grounded to the ~300-350 m contour in the south. Hypsometric analyses support this interpretation, indicating that a significant proportion of the shelf has been unaffected by glacial erosion. Using these observations, we propose a preliminary ice cap reconstruction for maximum glaciation of the South Orkney plateau, suggesting an ice coverage of about ~19,000 km². The timing of maximum ice extent, number of past advances and pattern of subsequent deglaciation(s) remain uncertain and will require further targeted marine geological and geophysical investigations to resolve.

A geomorphic zonation derived from the new compilation of bathymetric datasets allows for the analysis of ecosystem properties in the region, forming a key element for habitat mapping which will contribute to decisions about the designation of potential future marine reserves.

In late 2012 SCAR, BirdLife and BAS developed a successful proposal (to the UK Darwin Plus Fund) to build an integrated database that would facilitate the analysis of penguin tracking data. The database will have a web-based user interface that will allow data holders to submit data and attach a range of access levels; access may be granted only to the data holder, to a wider group, or to a general public domain. A penguin database (built along analogous lines and interoperable with the BirdLife Global Procellariiform Tracking Database) will allow spatial analyses to be undertaken that will help inform a variety of CCAMLR analyses, including work on the development of a variety of feedback management approaches for the krill fishery, and work on the spatial planning processes needed for identifying candidate CCAMLR MPAs.

This note is a brief report on progress since WG-EMM-13.