CCAMLR

We present a novel index of Antarctic krill biomass in CCAMLR subareas 48.1 to 48.4, based on data from scientific nets and covering the years between 2000 and 2011. The annual biomass variation was significant (CV=73%) but no systematic change in krill biomass was evident during the period. The index also suggests that realised exploitation rates were below 0.5% (i.e. catch was <0.5% of biomass) and that the potential exploitation rates implied by the operational catch limit (the trigger level) were below 2% during this period. These exploitation rates are much lower than the precautionary yield estimate for the krill fishery (which is 9.3%). Biomass indices from local scale acoustic surveys also suggest that exploitation rates are low and that there is no evidence of a systematic change in the krill stock. This evidence suggests that the trigger level is a highly precautionary operational catch limit which is currently appropriate for achieving the conservation criteria for the krill stock. It also suggests that the catch levels seen in the first decade of the 21st century are unlikely to have adversely impacted the krill stock. Nonetheless the Commission also needs to manage the risk of adverse impacts on dependent and related populations which might occur if fishing is concentrated in sensitive areas. Advances are needed to improve management of krill fisheries to manage these risks and to ensure that management is robust to the potential impacts of climate change. We suggest that frequent assessment of the krill stock, at scales relevant to the Commission’s conservation objectives, is a prerequisite for such advances. The most effective means to achieve this is likely to be through increased use of fishing vessels to collect data, while maintaining current time series.

Article II of the Convention requires the Commission to maintain harvested populations above levels that ensure stable recruitment. WG-EMM is currently developing candidate feedback management (FBM) approaches for the krill stock in subareas 48.1 to 48.4. These approaches include some which adjust fishing (catch, effort, location or timing) based on information about stock size. Thus CCAMLR needs reliable indicators of krill stock size at appropriate spatial scales. It is likely that future FBM approaches will require regular information on krill stock size at relatively fine spatial scales (subarea or less). However, periodic large-scale surveys (comparable to the CCAMLR 2000 synoptic survey) might also play a role in the future management of the krill fishery. Such surveys provide an indication of krill biomass at the larger scale which is robust to uncertainties about krill flux. Current constraints on research funding suggest that coordinated mobilization of multiple research vessels, as in 2000, is now unlikely. However, future large-scale surveys may be possible with the engagement of the fishing industry. We recommend that any such large scale surveys should be coordinated through CCAMLR’s scientific working groups. We identify the key components of a large-scale survey and the key technical and resource issues that must be addressed. We suggest that CCAMLR’s working groups should establish a process for addressing these issues if these groups consider that large-scale surveys are likely to be important in the future management of the krill fishery. The design of the CCAMLR 2000 survey might be a useful basis for designing future surveys, subject to a review which should be the first task in preparing for a future survey.  

The current state of the krill fishery in the Area 48 during 2008 - 2014 was analyzed in terms of catches, CPUE, catch per haul, fishing efforts (hours fished) and fishing vessel locations for traditional and continuous fishing methods. The CCAMLR fishery statistics was used. Summarized results of this analysis for Subareas 48.1, 48.2 and 48.3 with details on small-scale management units (SSMU) are presented in this paper.

The aim of this work was to assess the possibilities of automatically generating a dataset of dive behaviour of air-breathing predators, based on acoustic data from a monitoring survey and from commercial krill fishing operations. Our results documents that some form of automatic detection of diving predators in the data is feasible. A relatively low detection probability of our algorithms compared to the manual detections, suggest that there is significant room for improvement. Given the caveats of an imperfect methodology, the results document the possibilities to automatically extract, with a reasonable level of precision, data on the dive behaviour of air-breathing predators from the echo-sounder data.

The authors discussed the necessity to investigate krill flux for estimating the local harvest rates-indicators that could be used to reveal the potential risk of the fishery development. Estimates of krill flux factors in Subarea 48.3 based on the Soviet/Russian scientific observations from 1962 to 2002 are shown as an example.

Antarctic Krill (Euphausia superba) is a ‘keystone species’ in the Southern Ocean providing the main source of food for many taxa high in the food chain such as baleen whales, penguins and seals. Despite its ecological and economic importance, research into krill and other crustacean diseases remains a deficit area with little to nothing known about infection dynamics. Over the past century the waters of Antarctic krill northern distribution limit have experienced significant warming. In a changing environment, disease agents that require specific temperatures for growth may be able to survive and infect across an altered geographic range. In this paper we present the initial findings from a histological survey of krill from the Southern Ocean. In the present study and for the first time, krill were sampled for a gregarine parasite along a south-north gradient over several water masses, moving from the ice edge to the open ocean onto the shelf in 48.3. The presented paper offers for the first time a systematic histological analysis of normal, healthy organs of krill, creating a histological atlas which can provide a baseline for future pathogen research, as well as an atlas of infected tissue. This paper further shows circumstantial evidence for a viral infection in around 1% of sampled krill. The known gregarine krill parasite Cephaloidophora pacifica has previously not been shown to occur as far north as in the presented report. Studies on the diseases of wild crustaceans are severely lacking, despite their importance as components of the global food chain, and krill are no exception to this with very few studies carried out on their pathogen fauna. Only when this information is gathered can we accurately model future changes and therefore predict impact on the other species that rely on crustaceans as key components of marine food chains.

The Australian Antarctic research and resupply vessel, RV Aurora Australis, was directed to undertake an opportunistic marine science survey for 17 days during 21 February to 10 March 2015 using ship time that became available due to unexpectedly favourable ice conditions for Mawson station resupply. 

The purpose of this opportunistic Marine Science work was to assess:

1. The spatial variability, particularly along the shelf break, of the prey field for penguins, flying seabirds and marine mammals in East Antarctica.
2. The small scale variability of prey in key foraging locations near to land-based colonies of penguins and flying seabirds in East Antarctica.
3. Feasibility and potential of utilising annual station resupply voyages as a cost effective means to undertake monitoring and research to better understand the ecosystem in the region. 

The survey completed 5 acoustic box surveys including a total of 53 RMT target and routine trawls, 6 demersal trawls, 131 phytoplankton samples from underway sampling, and 214 hourly observations of predators.  These activities were successfully supervised remotely.

The Committee on Environmental Protection and SC-CAMLR have endorsed the proposal to hold a second Joint CEP/SC-CAMLR Workshop in 2016. The agreed general scope of the workshop is to identify the effects of climate change that are considered most likely to impact the conservation of the Antarctic, and to identify existing and potential sources of research and monitoring data relevant to the CEP and SC-CAMLR. At its meeting in 2015, the CEP discussed the workshop Terms of Reference, Steering Committee and workshop participation, and its possible location and timing. In order to make further progress on planning for the 2016 joint workshop, we encourage WG-EMM to:

1. Consider items to be included in a draft Agenda, based on the proposed Terms of Reference
2. Make further nominations for the Steering Committee, if required
3. Consider potential invited experts who could provide relevant input to the workshop
4. Discuss options for location and timing of the workshop, and remote participation
5. Provide recommendations on the above points to the Steering Committee, and SC-CAMLR-XXXIV as appropriate.

In this paper, we describe developments towards a set of standard diagnostic principles and tools used to characterise assessment models. CCAMLR has yet to develop a set of recommended statistical diagnostics tools to support their evaluations. While there are a number of standard visual and statistical diagnostics available for integrated assessments, their sufficiency to evaluate if a model is well specified and fits the data adequately needs to be considered. This paper provides a platform for discussions about describing the characteristics and diagnostic information needs that are common to integrated stock assessments used by CCAMLR. We further identify evaluations that could be undertaken when performing an assessment, as well as discuss statistical tools that will enable a more systematic evaluation of stock assessment models in the future.