CCAMLR

We analysed the available data from vessel and scientific observer logbooks from the exploratory fishery for Antarctic toothfish (Dissostichus mawsoni) and Patagonian toothfish (D. eleginoides) in CCAMLR subarea 48.6 (South East Atlantic). This report summarises the catch, effort, timing, depth, location, size structure and maturity of Dissostichus spp.  Information on the composition of  bycatch species caught in the fishery over the period 2003-4 to 2011-12 are also presented. For the Antarctic toothfish, accumulated catch across years yielded 1,353 tons with the majority of the catch coming from SSRUs 48.6G and 48.6E. For the Patagonian toothfish the accumulated catch was 349 tons and almost all was reported exclusively in the SSRUs 48.6A and 48.6G. Most of the catches were reported by vessels from Japan (58%) and Rep. of Korea (31%) and to a lesser extent, from South Africa (7%) and Norway (4%).

Unstandardized raw catch and effort data suggested that the median catch per unit of effort in Antarctic toothfish has generally increased over the course of the fishery whilst it has decreased over time for Patagonian toothfish. In both species average length of catches is larger in females. Antarctic toothfish is caught at deeper waters and have a larger mean length than Patagonian toothfish. There is not evidence of truncation in the overall length frequency distribution of both species, although some evidence of reduction in the mean fish length has been observed in the last three fishing seasons. In both sexes, high frequencies of maturity stages 2 and 3 were observed in Antarctic toothfish whereas for Patagonian toothfish immature (stage 1) fish were  most frequently observed. The bycatch for both toothfish species is composed of few species. In term of biomass, the most important bycatch species are grenadiers and blue antimora. A total of 3,828 individuals of toothfish have been tagged in this area but only 19 have been recaptured. We concluded that from the data examined from the fishery to date there is not evidence for substantial changes in the population structure of both species in this subarea.

Errors in the growth model used in stock assessments of Antarctic krill, specifically higher rates of growth than occur in reality, could inadvertantly lead to over-exploitation of the krill population and cause impacts on krill predators.  We review the three classes of models available for modelling krill growth – the von Bertalanffy class, the moult-cycle class based on measures of the duration of the intermoult period and the instantaneous growth rate at moult, and the energetics class, based on the energetics of growth.  We present a new model which is a combined energetics moult-cycle model that can flexibly take account of regional and interannual variation, including time trends, of temperature and food supply.  The parameterisation for the energetic-moult-cycle model provides results consistent with the general expectations for krill growth models as well as having the flexibility to be generally applied under spatially and temporally varying conditions.  In the context of assessments of precautionary yield for krill in CCAMLR, we recommend that this new model be incorporated into those assessments.  The current uncertainty in many of the parameter values could be included in the Monte Carlo population projections that are used to determine yield, particularly in relation to the future trends in food supply of krill.

We present a synopsis of the US AMLR satellite telemetry data, including both ARGOS and GPS positions estimates, to inform spatial planning efforts in the Antarctic Peninsula and Scotia Sea region. Identifying the patterns of habitat utilization by marine organisms is critical for proper spatial planning. Moreover, the timing and extent of habitat use by multiple species must be considered to correctly identify the location and overlap of critical habitat for multiple species.

The US AMLR program has collected satellite telemetry data from summer foraging trips and overwinter migratory routes of penguins and pinnipeds tagged at Cape Shirreff, Livingston Island and at Admiralty Bay, King George Island since 1997/98 for penguins and 2000/01 for pinnipeds. Species tracked include Adélie, chinstrap, and gentoo penguins, and Antarctic fur, Weddell, and leopard seals. The data from 14 years of tracking are presented to highlight patterns of local habitat use and long-range migration of these six species.

Krill consumption by natural predators represents a critical link between surveys and models of standing krill biomass and the design of a sustainable krill fishery for the Scotia Sea. Antarctic krill (Euphausia superba) is a significant component of diet for penguins breeding in this region and, consequently, uncertainties regarding penguin population abundances contribute to uncertainties in krill predation estimates. We use a comprehensive database of Antarctic penguin abundances to identify 14 breeding colonies that contribute most significantly to uncertainty regarding the total number of pygoscelid penguins breeding in this region. We find that a high quality survey of Zavodovski Island alone would decrease uncertainty in total population by 24.8%, whereas high quality surveys of all 14 “high-influence” locations would decrease uncertainty by almost 72%. Updated population estimates at these sites should be considered top priority for future field work in the region. Our results are based on a robust quantitative method for assessing data priorities in estimating krill consumption that is easily extended to other groups of krill predators.

Recent, rapid climate change is now well documented in the Antarctic, particularly in the Antarctic Peninsula region. One of the most evident signs of climate change has been ice shelf collapse; overall, 87% of the Peninsula’s glaciers have retreated in recent decades. Ice shelf collapse will lead to the loss of existing marine habitats and the creation of new habitats. In general, fauna under ice shelves exist in oligotrophic conditions, and because ice shelf collapse may lead to greater nutrient input, there may be consequent loss of some species or communities. Colonisation of new habitats after ice shelf collapse may simply include species from areas that are immediately adjacent to the collapsed ice shelf; however, other complex processes may also take place as warmer waters may create opportunities for species to return that were last present during the last interglacial, a warmer period than at present. In addition, altered ecosystem dynamics may allow new species to invade as ocean warming potentially removes physiological barriers that have previously led to the isolation of the Antarctic fauna. Habitats revealed by collapsed ice shelves offer unique scientific opportunities. Given the complexity of the possible interactions and the need to study these in the absence of any other human induced perturbation, we recommend that commercial fishing activities should not be permitted in these habitats. We suggest that in Subareas 48.1, 48.5 and 88.3, areas under existing ice shelves should be preserved for scientific study as Marine Protected Areas (MPAs). We recommend that the boundaries of these areas should henceforth remain fixed, even if the ice shelves recede or collapse in the future. Designation of areas under ice shelves as MPAs for scientific study would fulfil one of the recommendations made by the Antarctic Treaty Meeting of Experts in 2010.

Annually (from 1973 to 1991) 1-4 fishing vessels carried out research and scouting operations in the Indian sector of the Southern Ocean (statistical divisions 58.4.1 and 58.4.2) for the purposes of the searching of fishable aggregations of Antarctic krill (Euphausia superba). Commercial fishing for the Antarctic krill in the Indian sector of the Southern Ocean was carried out from 1977 to 1984. The main peculiarity of fishable aggregations in the Cooperation Sea as a rule out of shelf water (over the depths more than 1000 m).

This document analyses and relates long term information on population trends of inshore demersal fish and Antarctic shags of the South Shetland Islands. The analysis is complemented with comparable information on diet, foraging patterns and breeding output of shags from the Danco Coast, western Antarctic Peninsula, an area that has remained out of the influence of the commercial fishery. Instead of climate change processes, indicated as responsible for the diminution of other bird populations, the most reliable cause of the declining trend observed in shag colonies at the South Shetland Islands is the concomitant decrease in the abundance of two of their main preys, the nototheniids Notothenia rossii and Gobionotothen gibberifrons, owed to the intensive industrial fishing in the area in the late 1970s.

The CCAMLR MPA Workshop on Marine Protected Areas, held in Brest (France) in August 2011, recommended that the Scientific Committee considers supporting three technical workshops including one specific to Planning Domain 5. Planning Domain 5 includes Marion and Prince Edward Islands, the Del Cano Rise and the Crozet Archipelago in the north. It also includes the Ob and Lena seamounts. The workshop focusing on Planning Domain 5 was held in St Pierre, La Réunion, France from 15th May to 18th May, 2012 at the headquarters of TAAF (French Southern and Antarctic Territories). It followed a meeting on the northern part of Planning Domain 5, which was held in South Africa in 2008, organized and funded by WWF South Africa and known as Del Cano 1. The intention of the CCAMLR workshop was to study the ecological values and the use of the marine environment and to identify possible threats that might occur in this area. It extended the Del Cano 1 study spatially and also ecologically to include the benthic and pelagic realms. Identification of objectives for Conservation Planning and future research were discussed in relation to national and international projects.

Depending on the availability of data, the approach was based on mapping species distributions (either observed data or predictions for species or community presence/abundance based on environmental factors). Various national and international datasets were used including data from CCAMLR. However, South African and French data relevant to the Planning Domain 5 and surrounding domains were a major focus in the workshop because these CCAMLR member nations are the major scientific actors in this region. Species distributions were visualized by the mean of a Geographic Information System. Available Norwegian data from the Bouvetøya region were also discussed, but this region is less studied compared to the Planning Domain 5.

The workshop provided benthic and pelagic abiotic classifications of the Planning Domain using geographic and oceanographic features. Distributions of plankton, mesopelagic fish and top predators were consistent with the abiotic regionalization showing latitudinal patterns of communities for the pelagic species. The importance of frontal zones such as the Antarctic Polar Front and especially the Subantarctic Front were highlighted. North of the CCAMLR area, the Agulhas Return Current has a strong influence on this region. The latitudinal zonation of bioregions according to frontal zones may be influenced by climate change. This will have consequences for marine bird and mammal populations as it will change the habitat of their main pelagic prey species (e.g. euphausiids, squids, mesopelagic fish, etc.).

The working group concluded that ecoregionalisation has to be conducted at the scale of plateaus which includes Prince Edward Islands, Del Cano Rise and Crozet Islands i.e. a more detailed level than what has been done to date. High productive pelagic areas must be considered in relation to the bathymetry, iron enrichment, fronts and island mass effects, which contrast with high nutrient low chlorophyll areas farther south. Ichtyofauna and benthos were described as being characteristic of the subantarctic zone with some species being endemic. However, cryptic benthic species have not yet been studied.

The French and South African islands support substantial colonies of seabirds and seals, which for several species have global importance. For example, the Crozet and Prince Edward Islands together host the entire population of Crozet shag, about 70% of the world population of wandering albatross, 54% of king penguin, 33% of Indian yellow-nosed albatross, 33% of subantarctic fur seal, 27% of sooty albatross and 21% of the world’s southern rockhopper penguin. The high productivity in the vicinity of the islands, together with the large aggregations of seabirds and seals found at the islands, attract various other animals, e.g. several cetaceans, to their vicinity. The populations of several seabirds that breed at the islands have decreased. There is accumulating evidence that decreases of albatrosses and petrels have been substantially influenced by by-catch mortality in fisheries, whereas decreases in some penguins are probably attributable to decreased availability of prey that may have been caused by environmental change. Although the islands themselves enjoy a protected status and fishing is at present excluded within 12 nautical miles of the islands, providing some protection to inshore-foraging species, many of the seabirds and seals range well beyond the immediate precincts of the islands. Some circumnavigate Antarctica and others move to the north well beyond the CCAMLR convention area. Hence, many seabirds and seals are affected by human activities, and almost certainly environmental change, in other CCAMLR domains as well as in regions of the high seas that are administered by other Regional Fisheries Management Organisations. In particular the CCAMLR Planning domains that neighbour Domain 5 are of importance, as is the southern region of the Indian Ocean Tuna Commission (IOTC, FAO Area 51). Human activities in these other areas adversely influence the conservation status of animals from Planning Domain 5, as is the case with by-catch mortality, it will be necessary for CCAMLR to work in close association with other Regional Fisheries Management Organisations (e.g. IOTC), treaties (e.g. Agreement on the Conservation of Albatrosses and Petrels, ACAP) and conservation organisations (e.g. BirdLife International) to achieve a favourable conservation status for species that are at present Threatened or Near Threatened. The problem is sometimes compounded by albatrosses and petrels segregating their at-sea distributions by sex or age or both, so that components of populations may suffer particularly high mortality leading, e.g., to sex imbalances or inadequate recruitment into breeding populations. Preliminary models suggest that both topographical (e.g. plateau and rises) and oceanographic (e.g. locations of fronts) features play important roles in defining good foraging grounds for some wide-ranging predators. Whereas topographical features are permanent, the locations of oceanographic features may be changing, thereby presenting a greater challenge for spatial conservation planning. For some albatrosses (notably Thalassarche spp.) and penguins (notably Eudyptes spp.) there is accumulating evidence that populations and species may segregate their feeding grounds, which also will need to be accounted for in any form of spatial conservation planning.

The Working group noted set of preliminary strategic points essential to Systematic Conservation Planning, which include accounting for ecological relationships with surrounding areas (Bouvet to the West, Kerguelen to the East and East Antarctica to the South). The working group concluded that subtropical areas north of the Planning Domain 5 should be included in the planning, because of the spatial range covered by top predators, and also because the limit of the CCAMLR area cuts across the EEZs of both the Prince Edward and the Crozet Islands, as well as the  Del Cano Rise. Strategic points include:

• First of all, biodiversity features needed to be mapped. The workshop concentrated on this objective most of the time.
• Second, biodiversity targets need to be determined. France will see how to adapt the ones that were used by Lombard et al. (2007) for the EEZ of the Prince Edward Islands, to the Crozet Islands. For the high seas, the working group recommended that the definition of targets should be discussed by EMM and the MPA circumpolar workshop.
• Third, the Working Group started to evaluate pressures and areas of research that need to be defined (spawning and nursery areas, bycatch, interactions with killer whales, etc.).

The involvement of stakeholders was discussed, including fishing industries, NGOs, other relevant treaties and CCAMLR members for the high sea areas. This general theme has to be more specifically discussed during the circumpolar workshop and at the SC. The workshop also considered MPAs existing under national jurisdiction in the Planning Domain, procedures to extend them, and the need for strengthened cooperation between CCAMLR and other relevant legal instruments, organizations and initiatives. To achieve these goals, research and monitoring were discussed under three headings: (1) census of biodiversity, (2) ecoregionalisation classification and (3) monitoring. 

Such research would make up for a current lack of data, e.g. with regard to the benthos (deep and shallow), the mesopelagic zone and plankton. With regard to monitoring ecological processes, especially at the northern limits of the CCAMLR area, CCAMLR may wish to broaden the lists of species and environmental parameters that are monitored, to consider parameters of species that may best reflect change associated with global warming and, if necessary, develop protocols for any new parameters to be monitored. This would naturally include the use of the Continuous Plankton Recorder and tracking for birds, seals and mammals.