CCAMLR

At present less than 1% of South Africa’s Exclusive Economic Zone (EEZ) is protected within Marine Protected Areas. This project aimed to support the identification of a spatial management network in order to represent offshore biodiversity, protect vulnerable ecosystems, contribute to fisheries sustainability and reduce bycatch. This was achieved by collating data, engaging with relevant industries, scientists, government departments and conducting systematic planning using Marxan. The project identified nine priority areas for spatial management including no-take MPAs, benthic protection zones and fishery and bycatch management areas. In addition, the project has engaged with offshore stakeholders from the outset, has overcome significant challenges in engaging petroleum, diamond mining and fisheries sectors and has built some support for offshore MPAs. Considerable challenges remain in the implementation of spatial management but the project has garnered effective scientific support across multiple institutions and is building industry understanding and support through a flexible approach.

Two studies are tabled for the Subantarctic pelagic area of CCAMLR areas 58.5.1 and 58.6, which covers the Crozet Basin and the north of the Kerguelen Plateau: one based on marine pelagic species (plankton and fish), and the second on top predators.
In this report, we followed three types of methodology: (1) a taxonomic approach based on communities only, (2) a physiognomic approach used for the bioregionalisation of the Southern Ocean based on abiotic and chlorophyll-a characteristics of the habitat only, and (3) a mixed approach, we called “ecoregionalisation”, which includes taxonomic, ecological and physiognomic data.  The mixed approach is a relatively new method and is demonstrated on mesopelagic fish here. It will be also applied to pelagic fish and zooplankton as work progresses.
The Kerguelen Plateau influences the position of the major frontal zones and acts as a barrier to the Antarctic Circumpolar Current which passes along its northern escarpment and through troughs to the south. North of the Kerguelen shelf, the subantarctic zone does not really exist. Instead, there is a narrow latitudinal band, the Transition Frontal Zone (TFZ), caused by the juxtaposition of the Subtropical (STF) and the Subantarctic Front (SAF). The Polar Frontal Zone (PFZ), between the Antarctic Polar Front and the SAF, is closer to the TFZ in the Kerguelen shelf area than it is in the Crozet area. The Agulhas Return Current zone, north of the CCAMLR area, is composed of warm subtropical waters. Our studies indicate that the change in communities and regions is very sharp at the PFZ and the TFZ. The main biogeographical barriers in this area are the SAF and the Agulhas Front. Over the island shelves and seamounts, essential habitats for fish larvae were related to currents and retention zones.
In this report, we showed the existing information that we can use to achieve the pelagic ecoregionalisation of this area. There are numbers of difficulties as samples are from different historical surveys and mainly concentrated in the Kerguelen area.
Four variables were used for the epipelagic physical regionalisation: mean dynamic topography, sea surface height variability, depth, and near-surface chlorophyll-a. Eleven environmental types were apparent. The results show a general latitudinal banding structure broadly consistent with the frontal structure of the region, with the Agulhas Return Current clearly apparent. Shallow topography around the region’s island groups and bathymetric features (Conrad Rise, Walters Shoal) give rise to smaller-scale structure generally associated with higher productivity.
Some examples on ecoregionalisation based on mesopelagic fish are presented. The first one concerns the modelling of the myctophid community at the scale of the Indian sector of the Southern Ocean using Generalised Dissimilarity Modelling. 12 groups delineated ecoregions which were associated with frontal zones and the topography. A boosted regression tree model was used to predict potential habitat of target myctophids. The series of fronts and their associated eddies developed south of the Subtropical Front influences these species habitat. One of the target species was E. antarctica. The models indicated that the probability of presence was expected to be low in the north, consistent with the limit of the main distribution of the species. The quasi-absence of E. antarctica from island shelves is explained by its pelagic nature and diel behaviour. A modelling based on abundances showed that the preferential habitat towards the east differs in intensity from one year to the next.
Application of these methods on plankton and pelagic fish will be carried out in 2012. A report showing the application of these methods on the pelagic realm of the study area will be presented in 2012 at the EMM working group.
 

More than 30 expeditions have surveyed the Kerguelen Plateau over the last 80 years. However, few of them have collected benthic organisms. Between 1961 and 1970, numerous surveys were initiated by Arnaud, Délepine, Hureau and Rannou. Sampling was done mainly close to the coast, and in limited areas. However, they collected numerous specimens and led to a first estimate of the local biological diversity. The richest cruises for the quantity of benthos collected are MD03 and MD04 (1974 and 1975 respectively) on the research vessel “Marion Dufresne”. The purpose of these cruises was to obtain quantitative and qualitative data on benthos and demersal fishes. The majority of the specimens have already been studied, although a number of them are still to be sorted and studied.

In 1987 and 1988, the French-Soviet SKALP surveys allowed identifying fish species over the continental shelf including fish larvae. Coastal studies were carried out during the 1990’s on fish larvae, juveniles and adults (Koubbi et al., 2001). More recently, the POKER I survey (2006), for demersal fish, POKER II (2010) for benthos and demersal fish, collected a large number of specimens on the Kerguelen island shelf, with 409 operations at depths ranging from 100 to 1000 m. The aim of SKALP and POKER was to investigate the abundance, biomass and distribution of fish, including fish species on the Kerguelen Islands shelf, surrounding banks and upper deep-sea stratum. POKER II allowed to estimate the biodiversity and the distribution of benthos. Additional data over the shelf are provided by commercial fishing boats.

The ichthyofauna of the Kerguelen Plateau is now well-known with 23 species occurring from the coastal area to the slope of the shelf (and surrounding banks), 32 deep-sea species and 57 species from the pelagic layers (epi-, meso- and bathypelagic) (Duhamel et al., 2005). Fish larvae distribution showed that there is an island mass effect allowing retention of notothenioid larvae over the shelf (Koubbi et al., 1991 and 2009). Segregation of early life stages was found to follow the scheme of Harden-Jones for some of the demersal species (Koubbi et al., 2000).

Currently, 960 species have been recorded for benthos (Améziane et al., 2011) including 111 species of sponges, 58 species of bryozoans, 58 species of polychaetes, 51 species of pycnogonids, 219 species of crustaceans, 196 species of molluscs, 105 species of echinoderms, 93 species of ascidians and 11 species of cnidarians. All these data are available in the literature and geo-referenced.

The French MPA project in Kerguelen will study Essential Fish Habitat, VME and patterns of diversity over the shelf including its slope and the seamounts. Essential Fish Habitat will be determined with delimiting spawning grounds, areas of distribution of larvae and nursery grounds for the most dominant species. Potential assemblages’ distributions will be determined in relation with environmental factors. For benthos, a precise inventory of species will be the first outcome. In order to define VME in the Heard-Kerguelen area, the ascidans, sponges and stalked crinoids, all recognised key taxa, will be analyzed in detail. The benthic communities will be described and used in habitat description and modelling.
 

The large-scale trawl exploitation targeting virgin stocks of marbled notothenia (Notothenia rossii) off the Kerguelen Islands occurred after the discovery by the Soviet Union scouting fishing fleet of the fishing grounds in the early 1970’s. The fishery shifted to icefish (Champsocephalus gunnari) and grey notothen (Lepidonotothen squamifrons) when overexploitation on the shelf and surrounding banks resulted in the sharp decline in the catches of marbled notothenia. The creation of the French EEZ in 1978 closed the free fishery but did not stop the reduction of the biomass of exploited stocks. The SKALP first surveys (1987 and 1988), despite bias in the protocols, revealed the poor state of biomass in these shelf stocks. Only the icefish fishery maintained a series of strong cohorts with harvestable biomass, which eventually declined and lead to its closure in the 1990’s. However, the more recent biomass survey (POKER, 2006) showed no recovery in these stocks. Possible changes between species (predators-prey relationships, ecological niche) and in the marine environment may have contributed to the decline of stocks. Only one species, the Patagonian toothfish (Dissostichus eleginoides), of which deep-sea stocks have been naturally protected at the beginning of 1990. It maintained a high amount of biomass despite a strong IUU fishing episode from 1997-2004. The management of the stock needs to consider the migration pat¬terns of the species over the Plateau and outside. The analysis of fish distribution during the historic fishing period (1970-2010) shows permanent aggregations by species in specific and different areas of the shelf. This knowledge contributes in conserving vulnerable stocks, while providing opportunity to consider marine protected areas.

Preliminary analysis of long term dataset on individual tracking of 19 species of seabirds and seals breeding in the French Southern Territories (Crozet, Kerguelen and Amsterdam Islands) to identify area of importance for conservation in the Southern Ocean.
The preliminary results on locations data show that top predators are largely distributed on the southern part of the Indian Ocean from the tropics to the Antarctica. They overlap with numerous Exclusive Economic Zones (belonging to France, Australia, South Africa, Namibia and New Zealand) and high sea waters covered by six RFMOs (CCAMLR, Indian Ocean Tuna Commission-IOTC, Commission for the Conservation of Southern Bluefin Tuna-CCSBT, Southern Indian Ocean Fisheries Agreement-SIOFA, International Commission for the Conservation of Atlantic Tunas-ICCAT, South East Atlantic Fisheries Organization-SEAFO) suggesting the importance of collaboration for the conservation of top predators.
 

The Kerguelen Plateau possesses a very diverse benthic fauna. Over the years, the number of species recorded from the Kerguelen has substantially increased. From 172 species reported by Arnaud (1974), the total number of species has increased dramatically to 735 (Jouventin et al., 1996) and then to 960 in the present study. This area is particularly vulnerable to human activities and global climate change. Coastal benthic ecosystems are likely to be heavily impacted. However, these environments have been neglected and understudied during the last 30 years. The Kerguelen Plateau, situated at the northern limit of the Polar Front is probably one of the best study areas to (1) monitor the impact of climate forcing on coastal benthic assemblages; (2) assess the benthic community changes in relation to environmental forcing; and (3) assess the biodiversity of these benthic communities.

Biodiversity studies produce a large amount of data. Few are well-documented, compiled, readily available and easily accessible. The development of a specific database for the Kerguelen Plateau is an important step to provide data and analyses for supporting research and fisheries management.
    SIMPA is a database which covers all data from MNHN scientific expeditions, collections and fisheries from the French Sub-Antarctic Territories. The use of reference tables and standardized computer language procedure open the data to exchange links with other databases like the Global Biodiversity Information System Facility (GBIF) and FishBase.
    The data already integrated into SIMPA provide information on research expeditions from 1874 to present and on fisheries from 1979 to present. The next step is to encode data on the benthic marine invertebrates of the Kerguelen Plateau. This will improve the features of SIMPA, making it a desirable tool for fisheries management and ecosystem modeling in the region.
 

A proposal for a representative system of MPAs (RSMPA) for eastern Antarctica (CCAMLR Divisions 58.4.1 and 58.4.2) has been developed to satisfy overall the principles of comprehensiveness, adequacy and representativeness (CAR).  The Dumont d’Urville Sea area, including the Mertz Polynya, is one of the areas identified in the proposal (140-150°E from the coast to 60°S). This area has been studied by a number of countries in the CEAMARC surveys (Collaborative East Antarctic Marine Census) as part of the Census of Antarctic Marine Life. This report details some of the outcomes of a workshop hosted by France in Brest in late May 2011.  It collates and synthesises available data from the CEAMARC and other studies to provide a detailed ecological picture of this area and to further evaluate this area relative to the CAR principles and relative to its use as a reference area for understanding ecosystem change in the region.
The offshore zone is separated latitudinally by the presence of three fronts separating species assemblages and by the presence of an eddy (62°- 64°S, 138-140°E). Two of the fronts, the Southern Boundary (SB) and the Antarctic Slope Front (ASF) were identified to have a major influence on the biogeography of the pelagic species. The SB is the northern limit of Euphausia superba and the ASF clearly separates most of the neritic species from the oceanic. Vertical segregation of assemblages of pelagic cnidarians and ctenophores, fish and plankton were observed. However, this segregation does not apply on the continental slope as deep pelagic fauna can be upwelled with the Modified Circumpolar Deep Water. These characteristics combined with complex canyon systems indicate the continental slope is a transitional area between the neritic and oceanic zone. It is also important to note that it is on the slope area that two Vulnerable Marine Ecosystems have been identified by CCAMLR. Two large basins are found on the shelf in this area, differing in their physical characteristics and one, the George V Basin, is where the Adélie Land Bottom Water (ALBW) is formed and flows offshore.
Revised physical pelagic and benthic regionalisations of the East Antarctic sector showed 5 predominant cluster types over the shelf and two offshore in the pelagic realm and 9 distinct cluster types over the shelf in the benthic realm. Ecoregions were then defined according to both benthic and pelagic characteristics. They are based primarily on the benthic regionalisation with some of the benthic regions being divided further to take account of the differentiation in the pelagic environment.
The shelf pelagic regionalisation is explained by sea-ice and water masses. Spatial differences in pelagic species assemblages are observed but it varies from year to year. The variability in spatial structure of these assemblages is because of the dominance of Pleuragramma antarcticum and Euphausia crystallorophias. These two species are prey of top predators and control the planktonic production. The Adélie Basin is an important area for seals and penguins of the Pétrels Archipelago when they forage at a short distance from their colonies.
The benthic ecoregions over the shelf clearly separate coastal zones from the deep basins, their upper edge and the banks. Close association between demersal fish and benthic communities was identified. Grounded icebergs and long-term sedimentation patterns play a major role in structuring the bottom seascape. Suspension feeders are abundant on rocky and sandy substrates, while detritus and deposit feeders dominate the muddy basin sediments. The coastal zone is also the place of specific assemblages at least for fish for which some species are mainly coastal.
The workshop held in Brest at the end of May 2011 agreed that the Mertz area will be more likely to satisfy the CAR principles and its use as a reference area by changing the western boundary from 140°E to 136°E and the eastern boundary from 150°E to 148°E.
 

This short note describes a circumpolar, pelagic regionalisation of the Southern Ocean south of 40°S, based on sea surface temperature, depth, and sea ice information. The results show a series of latitudinal bands in open ocean areas, consistent with the oceanic fronts. Around islands and continents, the spatial scale of the patterns is finer, and is driven by variations in depth and sea ice. The results are broadly consistent with the earlier circumpolar results of Grant et al. (2006) and regional results from the Ross Sea (Sharp et al. 2010).This short note describes a circumpolar, pelagic regionalisation of the Southern Ocean south of 40°S, based on sea surface temperature, depth, and sea ice information. The results show a series of latitudinal bands in open ocean areas, consistent with the oceanic fronts. Around islands and continents, the spatial scale of the patterns is finer, and is driven by variations in depth and sea ice. The results are broadly consistent with the earlier circumpolar results of Grant et al. (2006) and regional results from the Ross Sea (Sharp et al. 2010).

The World Summit on Sustainable Development implementation plan requires, by 2012, a representative system of marine protected areas (RSMPA) for the purposes of long-term conservation of marine biodiversity.  A great challenge for meeting this goal, particularly in data-poor regions, is to avoid inadvertant failure while giving science the time and resources to provide better knowledge.  A staged process is needed for identifying areas in data-poor regions that would enable the objectives to be achieved in the long term.  We elaborate a procedure that would satisfy the first stage of identifying a RSMPA, including areas suitable as climate change refugia and as reference areas for monitoring change without direct interference of human activities. The procedure is based on the principles of systematic conservation planning. The first step involves the identification of ecologically-separated provinces along with the physical heterogeneity of habitats within those provinces.  Ecological theory is then used to identify the scale and placement of MPAs, aiming to be the minimum spatial requirements that would satisfy the principles for a representative system: comprehensiveness, adequacy and representativeness (CAR).  We apply the procedure to eastern Antarctica, a region with spatially-restricted sampling of most biota. We use widely available satellite and model data to identify a number of large areas that are likely to encompass important areas for inclusion in a RSMPA.  Three large areas are identified for their pelagic and benthic values as well as their suitability as climate change refugia and reference areas.  Four other areas are identified specifically for their benthic values.  These areas would need to be managed to maintain these values but we would expect them to be refined over time as more knowledge becomes available on the specific location and spatial extent of those values.