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. (2011). Polar Science, 5(2), 298–312.
Abstract: The Dumont dUrville Sea (East Antarctic region) has been less investigated for DNA barcoding and molecular taxonomy than other parts of the Southern Ocean, such as the Ross Sea and the Antarctic Peninsula. The Collaborative East Antarctic MARine Census (CEAMARC) took place in this area during the austral summer of 20072008. The Australian vessel RSV Aurora Australis collected very diverse samples of demersal and benthic organisms. The specimens were sorted centrally, and then distributed to taxonomic experts for molecular and morphological taxonomy and identification, especially barcoding. The COI sequences generated from CEAMARC material provide a sizeable proportion of the Census of Antarctic Marine Life barcodes although the studies are still ongoing, and represent the only source of sequences for a number of species. Barcoding appears to be a valuable method for identification within most groups, despite low divergences and haplotype sharing in a few species, and it is also useful as a preliminary taxonomic exploration method. Several new species are being described. CEAMARC samples have already provided new material for phylogeographic and phylogenetic studies in cephalopods, pycnogonids, teleost fish, crinoids and sea urchins, helping these studies to provide a better insight in the patterns of evolution in the Southern Ocean.
Keywords: Barcode, Cytochrome oxidase 1, CEAMARC, Taxonomy, Systematics,
Programme: 1044
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. (2011). Evolutionary pathways among shallow and deep-sea echinoids of the genus Sterechinus in the Southern Ocean
. Deep Sea Research Part II: Topical Studies in Oceanography, 58(12), 205–211.
Abstract: Antarctica is structured by a narrow and deep continental shelf that sustains a remarkable number of benthic species. The origin of these species and their affinities with the deep-sea fauna that borders the continent shelf are not clear. To date, two main hypotheses have been considered to account for the evolutionary connection between the faunas: (1) either shallow taxa moved down to deep waters (submergence) or (2) deep-sea taxa colonized the continental shelf (emergence). The regular sea urchin genus Sterechinus is a good model to explore the evolutionary relationships among these faunas because its five nominal species include Antarctic and Subantarctic distributions and different bathymetric ranges. Phylogenetic relationships and divergence times among Sterechinus species were established using the COI mitochondrial gene by assuming a molecular clock hypothesis. The results showed the existence of two genetically distinct main groups. The first corresponds exclusively to the shallow-water Antarctic species S. neumayeri, while the second includes all the other nominal species, either deep or shallow, Antarctic or Subantarctic. Within the latter group, S. dentifer specimens all formed a monophyletic cluster, slightly divergent from all other specimens, which were mixed in a second cluster that included S. agassizi from the continental shelf of Argentina, S. diadema from the Kerguelen Plateau and S. antarcticus from the deep Antarctic shelf. These results suggest that the deeper-water species S. dentifer and S. antarcticus are more closely related to Subantarctic species than to the shallow Antarctic species S. neumayeri. Thus, for this genus, neither the submergence nor emergence scenario explains the relationships between Antarctic and deep-sea benthos. At least in the Weddell quadrant, the observed genetic pattern suggests an initial separation between Antarctic and Subantarctic shallow species, and a much later colonization of deep water from the Subantarctic region, probably promoted by the geomorphology of the Scotia Arc.
Keywords: Sea urchins, Coastal zone, Deep water, Phylogeny, Biogeography, Evolutionary patterns, COI,
Programme: 1044
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. (2011). Phylogeography and demographic inference in Nacella (Patinigera) concinna (Strebel, 1908) in the western Antarctic Peninsula
. Deep Sea Research Part II: Topical Studies in Oceanography, 58(12), 220–229.
Abstract: Endemic to Antarctic ecosystems, the limpet Nacella (Patinigera) concinna (Strebel, 1908) is an abundant and dominant marine benthic invertebrate of the intertidal and shallow subtidal zone. In order to examine the phylogeographic pattern and historical demography of the species along the western Antarctic Peninsula, we amplified 663 bp of the mitochondrial DNA cytochrome oxidase subunit I of 161 N. concinna specimens from five localities, as well as two specimens from South Georgia and Sub-Antarctic Marion Island. As two different morphotypes, one characterized by an elevated shell in the intertidal and the other by a flat one in the subtidal, have been recurrently reported for this species, we also compared intertidal and subtidal samples from two localities of King George Island (Admiralty and Fildes Bay) through geometric morphometric and genetic analyses. As a result, elliptic Fourier analyses on shell shape morphology detected highly significant differences between intertidal and subtidal morphotypes. In contrast, mtDNA analyses between these morphotypes did not detect statistical differences between them and support the hypothesis that subtidal and intertidal N. concinna forms correspond to be the same population unit.
Keywords: Southern Ocean, Antarctica, Nacella concinna, COI, Genetic structure, Median-joining network, Elliptic Fourier analysis, Bottleneck effect, Founder effect,
Programme: 1044
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. (2011). Temporal and spatial variability of the stable isotopic composition of atmospheric molecular hydrogen: observations at six EUROHYDROS stations
. Atmos. Chem. Phys., 11(14), 6985–6999.
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Bruhwiler L M P, Michalak A M, Tans P P. (2011). Biogeosciences, 8(5), 1309–1331.
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. (2011). Bachelor's thesis, , .
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. (2012). Performance of modern tide gauges: towards mm-level accuracyJF
. Sci. Mar., .
Abstract: Considerable efforts are being made worldwide to upgrade tide gauge networks using new technologies. Because of the unique location of the Kerguelen Islands, the measurement of sea level there has received particular attention, with up to four systems equipped with modern sensors functioning simultaneously (two pressure tide gauges, a radar tide gauge, and a GPS-equipped buoy). We analysed and compared the sea level data obtained with these systems from 2003 to 2010, together with a time series of tide pole observations. This is the first time that a multi-comparison study with tide gauges has been undertaken over such a long time span and that the stability of modern radar tide gauges has been examined. The multi-comparison enabled us to evaluate the performance of the tide gauges in several frequency ranges, identify errors and estimate their magnitude. The drift of the pressure sensors (up to 8.0 mm/yr) was found to be one of the most relevant sources of systematic error. Other sources of difference such as clock drift, scale error and different locations of the instruments were also detected. After correcting the time series of sea level for these errors we estimated an upper bound for the radar instrumental error in field condition at ~0.3 cm.
Keywords: radar; pressure gauges; sea level changes; sea level measurement; tide gauges; Kerguelen Islands; GPS buoy,
Programme: 688
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Lecointre G. (2011). Testing the occurrence of marine benthic species flocks of the Antarctic shelf: a research summary of the French research program ANTFLOCKS. World Conference on Marine Biology, Aberdeen, UK, 26-30 septembre. Bachelor's thesis, , .
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Authier M. (2011). Bachelor's thesis, , .
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Thiebot J.B. (2011). Bachelor's thesis, , .
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