A proposal for conducting a reserach cruise for Dissostichus spp. in Subarea 48.2 is presented by Chile.

The proposal seeks to estimate presence and abundance of Dissostichus species in a data-poor area. The reserach proposed, if approved, will be conducted for three seasons.

Climate change will affect populations and fisheries in the Southern Ocean as area typically covered by seasonal sea-ice become ice free in some winters (Stammerjohn et al. 2008). For Antarctic krill (Euphausia superba), a key forage species (Laws 1977; Smetacek and Nicol 2005) and a target of a commercial fishery (Nicol et al. 2010; Watters et al. 2013), recent declines in seasonal sea-ice extent and duration has negatively impacted their populations (Loeb et al. 1997; Loeb et al. 2009; Saba et al. 2014; Atkinson et al. 2004) and is likely to increase krill-predator-fishery interactions during autumn and winter (Nicol 2006; Flores et al. 2012a; Nicol et al. 2011). Research cruises conducted around the Antarctic Peninsula in winters with contrasting ice conditions provide the first acoustic estimates of krill biomass, habitat use, and association with top predators to examine these likely interactions. Krill were virtually absent in offshore waters of the Drake Passage during all three winters, compared to summer. In Bransfield Strait, median krill abundance was an order of magnitude higher (8 krill m ^-2) compared to summer (0.25 krill  m ^-2 ) regardless of ice concentration. Krill biomass was an order of magnitude higher (~5 500 000 tons in 2014) than summer average biomass (520 000 tons) in Bransfield Strait.  This concentration of krill represents 79% of the mean summer biomass (19 yrs; 6.9 million tons) in the larger (124 000 km² ) study area. Ice obligate, krill dependent predators (e.g. crabeater seal (Labodon carcinophagus)) were concentrated in Bransfield Strait regardless of sea-ice extent. Winter biomass estimates show krill are overwintering in coastal basin environments independent of ice, or primary production and in areas that are becoming more frequently ice free (Stammerjohn et al. 2008; Hill et al. 2013; Flores et al. 2012) increasing their availability to autumn and winter krill fisheries. In the near term, climate change induced variability will increase the risks of negative fishery-krill-predator interactions during low ice years when ice obligate predators are habitat limited and open waters are available to fishing vessels. Changes to conservation measures may be necessary to limit this interaction and ensure that risks to krill-dependent predators are minimized in accordance with Article II of the Convention for the Conservation of Antarctic Marine Living Resources. 

We provide a document describing ideas regarding the development of a feedback management strategy. No specific quantitative attributes have been modeled or investigated but ideas are used to advance arguments regarding within-season feedback management.

Regarding the low levels of stocks of Dissostichus spp. and the high levels of IUU fishing, CCAMLR decided to close the fishery in 2002 in division 58.4.4. Since 2008 only one vessel, Shinsei maru No. 3, had conducted research fishing in accordance with a research plan submitted under CM 24-01. In 2014, WG-FSA agreed research fishing conducted in the research blocks C and D by two vessels using longlines: Shinsei Maru No. 3 (Japan) and the Saint André (France). For the season 2014/15, the catch limit for Dissostichus spp. is 25 tons for SSRU C and 35 tons for SSRU D. France notified its intention to achieve a robust stock assessment that would provide advice on a catch limit according to CCAMLR decision rules. This paper aims to present a research plan for 2015/2016 that takes into account the remarks made during the WG-FSA 2014. In SSRU 58.4.4D, tag recaptures are insufficient (the first tag recaptures were obtained in 2014), and consequently stock abundance (around 800 tonnes) has been estimated using the ‘CPUE seabed area analogy’ method. The biomass in division SSRU C was estimated during WG-FSA 2014 using a CASAL model constructed for D. eleginoides. The vulnerable biomass was estimated around 700 tonnes. CASAL model is updated with 2014 data but in the absence of an assessment using the CCAMLR decision rules, the catch limit should remain unchanged for 2015/16 to maximize the expectation of tag-recapture: SSRU C at 25 tons and SSRU D at 35 tons.

Antarctic ecosystems are dynamic and characterized by physically forced variability caused e.g. by fronts, eddies and ice. This creates a challenging dynamics for scientific sampling and monitoring. Realistic understanding of what can and cannot be achieved with the available sampling techniques and strategies is essential. This paper focuses on approaches for observing processes at the time-space scales at which they occur, which is essential for some of the management challenges of CCAMLR, for example the FBM.  

Sustainable management of fisheries resources requires quantitative knowledge and understanding of species distribution, abundance, and productivity-determining processes. Conventional sampling by physical capture is inconsistent with the spatial and temporal scales on which many of these processes occur. In contrast, acoustic observations can be obtained on spatial scales from centimetres to ocean basins, and temporal scales from seconds to seasons. The concept of marine ecosystem acoustics (MEA) is founded on the basic capability of acoustics to detect, classify, and quantify organisms and biological and physical heterogeneities in the water column. Acoustics observations integrate operational technologies, platforms, and models and can generate information by taxon at the relevant scales. The gaps between single-species assessment and ecosystem-based management, as well as between fisheries oceanography and ecology, are thereby bridged. The MEA concept combines state-of the-art acoustic technology with advanced operational capabilities and tailored modelling integrated into a flexible tool for ecosystem research and monitoring. Case studies are presented to illustrate application of the MEA concept in quantification of biophysical coupling, patchiness of organisms, predator–prey interactions, and fish stock recruitment processes. Widespread implementation of MEA will have a large impact on marine monitoring and assessment practices and it is to be hoped that they also promote and facilitate interaction among disciplines within the marine sciences.

The Secretariat has embarked on a major overhaul of CCAMLR data holdings and associated IT and data infrastructure. This work, which begun in 2013, includes developing an Enterprise Data Model, redeveloping the CCAMLR database, improving data quality assurance, and modernising the data work flow.

The user community can expect to notice significant improvements in data quality and database documentation as the new system is rolled out from late 2015. Consequential changes will be required in requested data extracts to reflect the new data model and nomenclature.

This paper provides an update on progress.

Subareas 58.6 and 58.7 are closed to fishing outside of the Exclusive Economic Zones (EEZs) around the Crozet (France) and Prince Edward (South Africa) Archipelagos. The current boundary between Subareas 58.6 and 58.7 bisects the South African EEZ around the Prince Edward Islands. Thus fishery statistics reported for Subarea 58.7 reflects only part of the fishery in the South African EEZ, whereas statistics for Subarea 58.6 reflects data for the fisheries in the French EEZ at the Crozet Archipelago and part of the South African EEZ combined. As a result statistics reported by Subarea are of no use for management of the fisheries in these two Subareas. We propose that the boundary between Subareas 58.6 and 58.7 be repositioned on the 44°E meridian so that it falls in the high seas between the French and South African EEZs, and corresponds to the existing boundary between SSRUs 58.6A and 58.6B.

A multi-year research plan as outlined in CM 41-04 (2012, 2013 & 2014) was initiated Statistical Subarea 48.6 by Japan and South Africa during the 2012/13 fishing season. Two vessels participated in the research project in each of the three fishing seasons and the progress achieved during the first 2.5 years is reported.

Between December 2012 and April 2015 a total of 291 Dissostichus eleganoides and 3273 D. mawsoni were tagged and released, and a total of 10 and 49 tagged D. eleganoides and D. mawsoni, respectively were recaptured. It is encouraging that 10 tagged D. mawsoni have been recaptured in the southern half of Subarea 48.6 already in the current season, more than total number for all previous seasons.

To date for the first three years of the research project biological data have been collected from 25 052 toothfish and length data from a total of 15 157 individuals from 18 different species.

Two-area population models for Antarctic toothfish in the Amundsen Sea Region were developed further as current single area models did not fully explain the patterns in the observed data on tag recaptures and age composition. Although the hypothesised stock structure spans SSRUs 88.2C–H, these models were limited to data collected in SSRU 88.2H as there were few data available to inform estimation of biomass in SSRUs 88.2C–G. Additional data resulting from a two-year research plan implemented in 2014/15 are expected to better inform the assessment of the entire stock including SSRUs 88.2C–G in the future.

Results showed that a two-area model with sex- and age-specific migrations from SSRUs 88.2C-G to SSRU 88.2H and back provided the best fits to the age and tag data collected in SSRU 88.2H. Furthermore, a resident population in 88.2H was not required to explain the patterns observed in the data, nor was annually-varying or density-dependent migration. Finally, using subsets of the data, or excluding small tagged fish, did not improve the fits to the data.

We recommend this model be further developed once additional age and tag data have been collected in SSRUs 88.2C–H as part of the two-year research plan. 

Appendix: CASAL files

Management Strategy Evaluation (MSE) has been acknowledged as the best practice to take account of uncertainties in the assessment of stocks and as a method to ensure robust management approaches. The Scientific Committee of CCAMLR has recommended MSE be used to determine the extent to which the management objectives for toothfish fisheries are being met. While the choice of management targets used by CCAMLR has been based on MSE simulations, formal MSE studies have yet to be fully implemented.

To date there have been a number of analyses and simulation studies reported for the assessment of toothfish that have evaluated the sensitivity of models and the resulting estimates of sustainable yields with respect to management objectives.

In this paper we develop approaches using operating and estimation models and show how they can be used to assist in identifying aspects of model and parameter misspecification that could then be evaluated using more computationally complex MSE approaches. We apply this to the assessment of Antarctic toothfish in the Ross Sea region with some example parameters and parameter values.

Our results can assist in prioritising further MSE analyses that fully account for the feedback mechanisms that the CCAMLRs decision rules provide. However, we note that different assessment models may be sensitive to different parameters and parameter values, and may require different approaches to MSE. We also note the importance of developing and maintaining data collections that can contribute to more accurate parameter specifications for any parameters identified as priorities through the MSE process.