CCAMLR

Present work contains considerations and proposals of possible joint research of Russian and German scientists in the eastern part of the Weddell Sea. Data on potentially valuable for commercial fishing species in the eastern part of the Weddell Sea collected by German investigators in 1979-1989 are also included, as well as results of Russian longline survey of Antarctic toothfish in 2013-2014 in the eastern part of the Weddell Sea.

The review of Russian expeditions carried out during 1970-2000 in the south-eastern part of the Atlantic Antarctic Area was discussed. Distribution of krill with reference to the structure and dynamics of the water masses, species dominated in Phytoplankton and Ichthyofauna were analyzed.

It was shown that the area of the continental slope and shelf of Antarctica (between 20ºW and 30ºE) can be perspective area for commercial fishery operations. To our opinion the above said area should be become the areas of exploratory fishery in the Area 48.

This progress report represents a follow up of WG-EMM-13/22 (WG-EMM, Jul 2013, Bremerhaven) and SC-CAMLR-XXXII/BG/07 (SC-CAMLR-XXXII, Oct 2013, Hobart). The authors intend to update the Working Group on Ecosystem Monitoring and Management on the actual state of our project, particularly on the proceeds of the data acquisition process and the preliminary scientific analysis. In addition, we present the report of the International Expert Workshop on the Weddell Sea MPA project (7-9 April 2014, Bremerhaven) as supplementary paper. The main objectives of this document are (i) to provide an updated summary of the data identification and acquisition process, (ii) to set out the preliminary scientific analysis which was worked out so far, (iii) to present on the report of the International Expert Workshop on the Weddell Sea MPA project (7-9 April 2014, Bremerhaven), and (iv) to give an update on the further process.

The embryonic development of Antarctic krill (Euphausia superba) is sensitive to elevated seawater CO₂ levels and successful hatching is impaired at CO₂ levels greater than 1000 μatm. Exposure to elevated CO₂ during the first 3 days of embryonic development significantly retards subsequent development even if the embryos are transferred to seawater with current levels of CO₂. Krill embryos appear more vulnerable to ocean acidification than other pelagic crustaceans such as copepods. pCO₂ in the Southern Ocean are predicted by models to rise to above 1500 μatm in some parts of krill’s depth range by the year 2100 unless emissions are mitigated.  Risk maps, combining modelled hatch rates and the 3-dimensional circumpolar projection of future pCO₂, predict that by 2100 the Weddell Sea and the waters to the east (the Haakon VII Sea) are the highest risk areas for krill embryos.  The entire Southern Ocean south of the Polar Front is predicted to be unsuitable for hatching by the year 2300, which would lead to collapse of the krill population. This is the first report that explores the circumpolar impacts of ocean acidification on krill.

This report describes the work and preliminary results from the fourth annual survey conducted around the South Orkney Islands, using a commercial krill fishing vessel as research platform. The overall purpose is to describe taxonomy of the macrozooplankton community, demography and density of Antarctic krill as well as the occurrence and distribution of krill predators.

Antarctic krill (Euphausia superba) aggregate in various ways depending on a range of factors, from biological (e.g. antipredatory behavior, social interactions and food availability) to physical forcing (e.g. advection and retention). Some areas, often associated with topographical features such as shelf edges and canyons, are considered as hotspots of high importance for regional pelagic ecosystems and also for the krill fishing industry. Despite the importance of such krill hotspots, their dynamics over time with respect to spatial distribution and demographical composition of krill including spawning state is not well described or understood. In the present study, a krill fishing vessel during regular operation was used as a platform for frequent collection of biological data to investigate krill demographic composition and the continuous acquisition of acoustic data for studying their distribution within a 75 km strip on the shelf edge northwest of the South Orkney Islands. The study was carried out towards the end of the reproductive season, during 29 January to 1 March 2009, and during the study, the occurrence of all the sub adult male stages (MIIA1, MIIA2 and MIIA3) decreased. Concurrently, the occurrence of both male adult stages (MIIIA and MIIIB) increased, but at a lower rate. Overall, there was also a gradual decrease from more than 0.8 to less than 0.3 in the proportion of males relative to females. The decrease in subadult males indicates segregation according to demographical composition, and the change in male to female ratio that there might be a flux of krill to/from the hotspot location. There was generally a clear diel vertical migration pattern with deeper and vertically more compact swarms during daytime than night-time. However, there was days with very small differences in distribution between day and night and in general also a huge day-to-day variability in daytime depth distribution. The fishing pattern reflected the fluctuating vertical distribution. It is essential for management purposes to understand the mechanisms behind the distribution and demography patterns described here, and also to obtain quantitative data on krill flux and retention potential, especially if the fishing activity expands in future.

The overall purpose of this study was to estimate the mortality rate of Antarctic krill (Euphausia superba) that escape from the most common mesh size used in the current commercial fishery. The experiment was carried out on the krill fishing grounds off South Orkney Islands (60°35’S, 45°30’W), during January-February 2014. The method applied consisted of a covered trawl codend system for retaining escapees, thereafter kept on the surface in tanks to monitor rates of mortality. Hauling depth and duration as well as handling effects on land including exposure to temperature differences likely influenced on the mortality rates found. A decrease in body length was also found significantly correlated with increased mortality rate. The escape mortality rate from experiment parallels and considered to be closest to a realistic catching process in a 16 mm mesh size, was found to be 1-6%. Krill may be more tolerant to mechanical damage than other taxon due to their durable exoskeletons.

During 18 Ukrainian Antarctic expeditions, from March 31 2013 to April 7 2014, in region Ukrainian Antarctic station "Academic Vernadsky" study of avifauna was conducted. Magellanic Penguin Spheniscus magellanicus was newly recorded for that area. Currently, this finding is the southernmost part of this species.

Acoustic and net sampling of Antarctic Krill and other euphausiids was conducted at 88 stations around the South Shetland Islands during a 30 day cruise between 10 August and 9 September 2013. Abundance and demographic patterns revealed that Antarctic krill were concentrated in the southern Bransfield Strait, and that these krill were approximately 33mm in length, about 10mm larger than found during the 2012 winter survey (Reiss and Jones 2013; WG-EMM 13/40) but similar in size to krill found in the German survey during summer in 2013 (Siegel 2013; WG-EMM 13/24). Large krill (>50mm), although present around Elephant Island, were not abundant in any area, and were also not abundant in the water column between 170 and 650m depth in the Antarctic Circumpolar Current. Sea ice extent and concentration was expansive (north of 60 S around Elephant Island) and the sea ice concentration was mostly more than 50%. Observations of birds and mammals showed that many species were found in southwestern Bransfield Strait, associated with the high concentrations of krill, an area targeted by the krill fishery in recent years. Species of note included Crabeater seals, Antarctic fur seal (sub-Adults), Leopard seal, and Adelie penguins. The high abundance of predators and prey in the Bransfield Strait, where the krill fishery is prosecuted into autumn, suggests that overlap between krill dependent predators and the fishery extends throughout the post reproductive period of many higher predators. Such overlap could impact the overwinter survival of predators if the fishery extracts prey from hotspots during autumn.

In June 2014, the ICED programme, the British Antarctic Survey and WWF co-hosted a two day workshop entitled “Understanding the objectives for krill fishing and conservation in the Scotia Sea and Antarctic Peninsula region” which involved participants from the science, conservation and fishing industry sectors. This report summarises the key initial conclusions and recommendations from the workshop. There is broad cross-sector commitment to maintaining a healthy ecosystem and support for management of the krill fishery that minimises the risk of the fishery negatively impacting ecosystem health. This accord could be strengthened by articulating a clear research and development strategy to support progress in the management of the krill fishery; broadening participation in WG-EMM to include other sectors and areas of expertise; and improving the availability of key information to all sectors.