The spatial distribution of the Antarctic krill fishery in Subareas 48.1 to 48.3 has changed over time. The majority of catches in Subarea 48.1 are now taken south of the South Shetland Islands, following regional decreases in seasonal sea-ice cover. As the cumulative spatial footprint of the fishery has expanded along the West Antarctic Peninsula, the cumulative numbers of krill-eating penguin colonies that are close to the fisheries footprint have also increased. As yet, it is not clear whether this has lead to competition for resources between the fishery and these penguins. Such competition would occur where there is significant functional overlap (that is, the fishery and the penguins target the same type types of krill swarms in the same places). In contrast to Subarea 48.1, the fishery footprint in Subarea 48.2 has stayed relatively constant over time. This contrast offers the potential for an experiment to establish whether functional overlap occurs and how it affects penguin colonies. Such an experiment would necessarily require endorsement by the Scientific Committee and the Commission. If CCAMLR decides not to engage in the necessary experiments to establish the degree to which functional overlap occurs, other measures, consistent with the precautionary approach, should be considered.
Abstract:
During 2013, WG-EMM agreed to form two inter-sessional task groups to progress work that might facilitate the development of new management procedures for the krill fishery in Area 48. In 2014, the state of ecological knowledge for Subarea 48.2 was reviewed, and it was suggested that the development of any new management approaches would be highly improbable based on the current level of ecological information. In 2014 we therefore suggested that there was an urgent need to improve the ecological knowledge base, but that this would take time, especially in the context of climate change. Here, we suggest that if the krill fishery in Subarea 48.2 is to expand beyond its current level, a new experimental approach should be developed that will help provide the information needed. This paper therefore outlines an experimental framework that has the potential to provide the types of information required. We suggest that the experimental framework should be a CCAMLR community project involving as many Members as possible. This will be necessary if the experimental framework is to have a high probability of success. The proposed framework includes the use of CEMP sites, remote cameras at important land-based predator breeding colonies, at-sea observations of predators, oceanographic moorings with acoustic sensors, acoustic data collection during fishing operations and repeated fine-scale acoustic surveys. We propose that the experiment should be evaluated after 5 years in order to explore initial results and to determine if the experimental framework should be continued.
Abstract:
During WG-EMM-14, it was noted that characterisation of overlap between land-breeding predators and the krill fishery was desirable throughout the Scotia Sea; it was recognised that such work could be advanced by either tracking animals originating from additional breeding colonies, or by using existing tracking data and developing habitat models that predict foraging habitats as functions of environmental variables. Consequently, in May 2015, an expert meeting was convened to consider the utility of using tracking data to build habitat use and preference models for krill-eating penguins. The meeting considered that such models would be of critical value in the development of feedback management approaches for the krill fishery as well as in marine spatial planning and the identification of candidate marine protected areas. The meeting brought together both penguin ecologists and experts in the analysis of tracking data. Six CCAMLR Members were represented at the meeting as well as scientists from BirdLife International and SCAR. The meeting agreed an outline programme of work that is designed to advance the development of habitat use models over the coming year with a view to check on progress at the forthcoming 10th International Penguin Conference in Cape Town during September 2016. In considering the need to better understand how penguins utilize their habitat and make use of available resources during critical periods when they overlap with the krill fishery, the workshop highlighted a number of issues of relevance to CCAMLR.
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.