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30 December 1965, Volume 26 Issue 4-English Previous Issue    Next Issue
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Summer distribution of marine mammals encountered along transects between South Africa and Antarctica during 2007 – 2012 in relation to oceanographic features Claude R. Joiris, Grant R.W. Humphries & Alain De Broyer 2015, 26 (4-English):  265-273.  DOI: 10.13679/j.advps.2015.4.00265 Abstract ( 591 )   PDF (2556KB) ( 656 )   The at-sea summertime distribution of marine mammals between South Africa and Antarctica was determined along eight transects surveyed between December 2007 and January 2012. During 1930 30-minute transect counts, 1390 marine mammal individuals were attributed to 19 species: eight toothed whales (Odontoceti), six pinnipeds, and five baleen whales (Mysticeti). An additional two toothed-whale species were encountered ‘out of effort’. The four most numerous species accounted for 85% of the total number of individuals encountered: crabeater seal (Lobodon carcinophagus), humpback whale (Megaptera novaeangliae), Antarctic Minke whale (Balaenoptera bonaerensis) and fin whale (B. physalus). The distribution of these species was related to oceanographic features, such as water masses and fronts, pack ice and ice edge: These differences were statistically highly significant. Biodiversity was compared with other polar marine ecosystems. Related Articles | Metrics

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The various substrates of Usnea aurantiaco-atra and its algal sources in the Fildes Peninsula, Antarctica CAO Shunan, ZHENG Hongyuan, LIU Chuanpeng, TIAN Huimin, ZHOU Qiming & ZHANG Fang 2015, 26 (4-English):  274-281.  DOI: 10.13679/j.advps.2015.4.00274 Abstract ( 557 )   PDF (5661KB) ( 590 )   The lichen species Usnea aurantiaco-atra (Jacq.) Bory is the most dominant vegetation on the Fildes Peninsula, Antarctica. Most individuals grow on rocks, and some are found with mosses. During the 27th and 28th Chinese National Antarctic Research expeditions of the Great Wall Station, U. aurantiaco-atra was observed growing on the lichen thallus of Umbilicaria antarctica Frey & I.M. Lamb, or on wood, which indicated that Usnea aurantiaco-atra could grow on various substrates. The diversities of the symbionts in U. aurantiaco-atra collected in the Fildes Peninsula were investigated using ITS rDNA sequences. The results showed that the sequences from mycobionts of U. aurantiaco-atra growing on various substrates did not exhibit significant differences. All photobionts in this lichen species were the green algae Trebouxia jamesii (Hildreth & Ahmadjian) Gärtner. The identical sequences from the photobionts of both Umbilicaria antarctica and Usnea aurantiaco-atra indicated there was an algae pool in this area and different mycobionts could obtain their algal partners from this pool. The variety of substrates for U. aurantiaco-atra suggested its photobiont could be obtained from a mature lichen thallus by vegetative propagation; from other lichen thalli (e.g. Umbilicaria antarctica); or from the surroundings. This study will promote understanding of the distribution of photobionts and the process of lichenization. Related Articles | Metrics

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Major hotspots detected along the Scotia Ridge in autumn for southern right whales Eubalaena australis, Antarctic fur seals Arctocephalus gazella and Antarctic prions Pachyptila desolata Claude R. Joiris, Grant R. W. Humphries, Diederik D’Hert, René-Marie Lafontaine, Henri Robert & Roseline C. Beudels-Jamar 2015, 26 (4-English):  282-291.  DOI: 10.13679/j.advps.2015.4.00282 Abstract ( 576 )   PDF (7538KB) ( 695 )   We investigated the role of hydrological features, such as water masses, fronts, eddies, and sea ice, in affecting the distribution of upper trophic level species in the Scotia Sea region during autumn. On board RV Polarstern, we performed 365 30-min strip transects recording seabirds and marine mammals along the North Scotia Ridge and the South Sandwich Trench in March—April 2013. Among the 7 identified cetacean species recorded, the humpback whale Megaptera novaeangliae was the most abundant baleen whale (40 individuals), and noteworthy were sightings of six southern right whales Eubalaena australis. Pinnipeds (3 species, 1650 individuals) were dominated by Antarctic fur seal Arctocephalus gazella (99%), and seabirds (36 species, 18900 individuals) by Antarctic prion Pachyptila desolata (~50%). The distribution of these top predators was highly patchy with the majority of observations concentrated in a few counts. This heterogeneity is likely a result of prey availability, and we discuss how hydrological features may have caused the patchiness. Related Articles | Metrics

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Assessment and application of electromagnetic induction method to measure Arctic sea ice thickness GUO Jingxue, WANG Huajun & SUN Bo 2015, 26 (4-English):  292-298.  DOI: 10.13679/j.advps.2015.4.00292 Abstract ( 740 )   PDF (827KB) ( 763 )   The electromagnetic induction method is widely used to measure sea ice thickness. Based on the electrical properties of sea ice and seawater, the method measures the apparent conductivity, which represents the conductivity of the half-space, and calculates the thickness of the sea ice. During the fourth Chinese National Arctic Research Expedition in summer 2010, an integrated electromagnetic induction system was set up on the icebreaker R/V XUE LONG to measure sea ice thickness along the ship’s tracks to the north of the Chukchi Sea. The conductivities of sea ice, seawater, and brine were measured and a simple forward model was used to explain the effect of changes in those conductivities on the apparent conductivity over a horizontal layered structure. The results of this analysis indicated that when using the electromagnetic induction method to measure sea ice thickness, the conductivity of sea ice could be neglected and the conductivity of seawater could be treated as a constant. The ice distribution results derived from the electromagnetic induction method showed that the typical sea ice thickness was 160 cm and 90 cm during the outbound and the return legs of the voyage, respectively. Related Articles | Metrics

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Methodological approach to the isolation of functionally active proteins from the tissues of marine hydrobionts: an example of Adamussium colbecki Nataliia Raksha, Dmytro Gladun, Oleksii Savchuk & Lydmila Ostapchenko 2015, 26 (4-English):  299-304.  DOI: 10.13679/j.advps.2015.4.00299 Abstract ( 517 )   PDF (928KB) ( 548 )   Enzymes from cold-adapted organisms have significant application potential. Because of their unique properties they have been found to be useful in various industries. Despite indisputable practical interest, cold active enzymes also represent a valuable model for fundamental research into protein folding and catalysis. Many investigators have focused their attention on marine hydrobionts, which are growing in importance as a promising source of enzymes. The nature of the source not only determines the availability and the cost of biomolecules of interest but also determines the choice of method for their extraction. A simple and convenient methodological approach of two-stage extraction of proteins has been tested on the Antarctic marine hydrobiont—Adamussium colbecki. This method extracts enough effective protein directly from primary raw materials, as well as when using leftover crude precipitates. The electrophoretic pattern of proteins showed the presence of molecules in a wide range of molecular weights in the samples of A. colbecki after the first and the second stage of extraction. The general proteolytic activity in the first and the second extracts were examined using a zymogram technique. Our experiments revealed that the second extract of A. colbecki contained thermo stable protease exhibiting a molecular weight of 95 kDa in a gelatin zymogram. Further biochemical assays, using different substrates, were conducted to partially identify the types of hydrolases present in the first and the second extracts. Our results revealed the presence of enzymes with collagenolytic and some amylolytic activities preserved in the second extracts. But no esterase or amidase trypsin-like activities were found in the second extract, in contrast to the first extract where this type of activity was significant. Related Articles | Metrics

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A new method of measuring optical turbulence of atmospheric surface layer at Antarctic Taishan Station with ultrasonic anemometer WU Xiaoqing, TIAN Qiguo, JIANG Peng, CHAI Bo, QING Chun, CAI Jun, JIN Xinmiao & ZHOU Hongyan 2015, 26 (4-English):  305-310.  DOI: 10.13679/j.advps.2015.4.00305 Abstract ( 605 )   PDF (1052KB) ( 637 )   To find the optimal location for large-aperture telescopes is a goal of astronomy. Chinese Antarctic astronomy has begun to flourish in recent years, and it is an urgent need in basic astronomical work to measure and analyze the optical turbulence spatiotemporal distribution in the Antarctic region. We analyzed turbulence data measured by a mobile atmospheric parameter measurement system from 30 December 2013 to 10 February 2014 at Antarctic Taishan Station. Because there is a discrepancy between the refractive index structure constant Cn2 measured by an ultrasonic anemometer with a single-point temperature structure function method and by micro-thermometer, a new method to measure Cn2 with a temperature spectrum method is proposed herein. Through comparing long-term continuous Cn2 data derived from ultrasonic anemometer with those via the new method and micro-thermometer, trend, magnitude and measured weak turbulence of ~2×10-16m-2/3 are generally satisfactory. The reason for the discrepancy inCn2 measurement between the ultrasonic anemometer with the old method and micro-thermometer is investigated. Related Articles | Metrics