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Sample records for antarctic bottom fauna

  1. The suppression of Antarctic bottom water formation by melting ice shelves in Prydz Bay.

    Science.gov (United States)

    Williams, G D; Herraiz-Borreguero, L; Roquet, F; Tamura, T; Ohshima, K I; Fukamachi, Y; Fraser, A D; Gao, L; Chen, H; McMahon, C R; Harcourt, R; Hindell, M

    2016-01-01

    A fourth production region for the globally important Antarctic bottom water has been attributed to dense shelf water formation in the Cape Darnley Polynya, adjoining Prydz Bay in East Antarctica. Here we show new observations from CTD-instrumented elephant seals in 2011-2013 that provide the first complete assessment of dense shelf water formation in Prydz Bay. After a complex evolution involving opposing contributions from three polynyas (positive) and two ice shelves (negative), dense shelf water (salinity 34.65-34.7) is exported through Prydz Channel. This provides a distinct, relatively fresh contribution to Cape Darnley bottom water. Elsewhere, dense water formation is hindered by the freshwater input from the Amery and West Ice Shelves into the Prydz Bay Gyre. This study highlights the susceptibility of Antarctic bottom water to increased freshwater input from the enhanced melting of ice shelves, and ultimately the potential collapse of Antarctic bottom water formation in a warming climate.

  2. The suppression of Antarctic bottom water formation by melting ice shelves in Prydz Bay

    Science.gov (United States)

    Williams, G. D.; Herraiz-Borreguero, L.; Roquet, F.; Tamura, T.; Ohshima, K. I.; Fukamachi, Y.; Fraser, A. D.; Gao, L.; Chen, H.; McMahon, C. R.; Harcourt, R.; Hindell, M.

    2016-08-01

    A fourth production region for the globally important Antarctic bottom water has been attributed to dense shelf water formation in the Cape Darnley Polynya, adjoining Prydz Bay in East Antarctica. Here we show new observations from CTD-instrumented elephant seals in 2011-2013 that provide the first complete assessment of dense shelf water formation in Prydz Bay. After a complex evolution involving opposing contributions from three polynyas (positive) and two ice shelves (negative), dense shelf water (salinity 34.65-34.7) is exported through Prydz Channel. This provides a distinct, relatively fresh contribution to Cape Darnley bottom water. Elsewhere, dense water formation is hindered by the freshwater input from the Amery and West Ice Shelves into the Prydz Bay Gyre. This study highlights the susceptibility of Antarctic bottom water to increased freshwater input from the enhanced melting of ice shelves, and ultimately the potential collapse of Antarctic bottom water formation in a warming climate.

  3. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using th

  4. Rapid bottom melting widespread near Antarctic ice sheet grounding lines

    Science.gov (United States)

    Rignot, E.; Jacobs, S.

    2002-01-01

    As continental ice from Antartica reaches the grounding line and begins to float, its underside melts into the ocean. Results obtained with satellite radar interferometry reveal that bottom melt rates experienced by large outlet glaciers near their grounding lines are far higher than generally assumed.

  5. The nematode fauna of a deep-sea site exposed to strong near-bottom currents

    Science.gov (United States)

    Thistle, David; Sherman, Kevin M.

    1985-09-01

    Nematodes are the most abundant metazoans in marine soft-bottom habitats, yet little is known of their role in deep-sea communities. We describe the nematode fauna from 4626 m depth in the North Atlantic (40°24.0'N, 63°07.4'W) at the family and genus level and compare our findings to previous reports on deep-sea nematodes. The results of covariance studies between nematodes and environmental parameters are also given. At the species level, there is no evidence of association between small-scale variation in nematode abundance and variation in abundance of bacteria or several classes of biogenous structures, but there is evidence of an association with pebbles. At the functional-group level, feeding groups show no correlation with environmental variables, nor do groups based on tail morphology. However, four of the tail-morphology groups are significantly disproportionately abundant in either the 0 to 1 or the 1 to 2 cm sediment layer. Individuals of one group may use their long, retractable tails to escape into the sediment to avoid resuspension by noncatastrophic erosive flows, which are common at this hydrodynamically active deep-sea locality.

  6. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    OpenAIRE

    E. G. Morozov; Tarakanov, R.Y.; Van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using three AquaDopp current meters. We found an alternating regime of flow, which changes direction several times during a year. The seasonal signal seems to dominate. The maximum daily ...

  7. Influence of Ross Sea Bottom Water changes on the warming and freshening of the Antarctic Bottom Water in the Australian-Antarctic Basin

    Directory of Open Access Journals (Sweden)

    K. Shimada

    2012-07-01

    Full Text Available Changes to the properties of Antarctic Bottom Water in the Australian-Antarctic Basin (AA-AABW between the 1990s and 2000s are documented using data from the WOCE Hydrographic Program (WHP and repeated hydrographic surveys. Strong cooling and freshening are observed on isopycnal layers denser than γn = 28.30 kg m−3. Changes in the average salinity and potential temperature below this isopycnal correspond to a basin-wide warming of 1300 ± 200 GW and freshening of 24 ± 3 Gt year−1. Recent changes to dense shelf water in the source regions in the Ross Sea and George V Land can explain the freshening of AA-AABW but not its extensive warming. An alternative mechanism for this warming is a decrease in the supply of AABW from the Ross Sea (RSBW. Hydrographic profiles between the western Ross Sea and George V Land (171–158° E were analyzed with a simple advective-diffusive model to assess the causes of the observed changes. The model suggests that the warming of RSBW observed between the 1970s and 2000s can be explained by a 21 ± 23% reduction in RSBW transport and the enhancement of the vertical diffusion of heat resulting from a 30 ± 7% weakening of the abyssal stratification. The documented freshening of Ross Sea dense shelf water leads to a reduction in both salinity and density stratification. Therefore the direct freshening of RSBW at its source also produces an indirect warming of the RSBW. A simple box model suggests that the changes in RSBW properties and volume transport (a decrease of 6.7% is assumed between the year 1995 and 2005 can explain 51 ± 6% of the warming and 84 ± 10% of the freshening observed in AA-AABW.

  8. Rapid variability of Antarctic Bottom Water transport into the Pacific Ocean inferred from GRACE

    Science.gov (United States)

    Mazloff, Matthew R.; Boening, Carmen

    2016-04-01

    Air-ice-ocean interactions in the Antarctic lead to formation of the densest waters on Earth. These waters convect and spread to fill the global abyssal oceans. The heat and carbon storage capacity of these water masses, combined with their abyssal residence times that often exceed centuries, makes this circulation pathway the most efficient sequestering mechanism on Earth. Yet monitoring this pathway has proven challenging due to the nature of the formation processes and the depth of the circulation. The Gravity Recovery and Climate Experiment (GRACE) gravity mission is providing a time series of ocean mass redistribution and offers a transformative view of the abyssal circulation. Here we use the GRACE measurements to infer, for the first time, a 2003-2014 time series of Antarctic Bottom Water export into the South Pacific. We find this export highly variable, with a standard deviation of 1.87 sverdrup (Sv) and a decorrelation timescale of less than 1 month. A significant trend is undetectable.

  9. A dromaeosaur from the Maastrichtian of James Ross Island and the Late Cretaceous Antarctic dinosaur fauna

    Science.gov (United States)

    Case, Judd A.; Martin, James E.; Reguero, Marcelo

    2007-01-01

    The recovery of material of a small theropod from the Early Maastrichtian, Cape Lamb Member of the Snow Hill Island Formation is an unusual occurrence from primarily marine sediments. The pedal morphology of the specimen that includes a Metatarsal II with a lateral expansion caudal to Metatarsal III, a third metatarsal that is proximally narrow and distally wide, a Metatarsal III with a distal end that is incipiently ginglymoidal and a second pedal digit with sickle-like ungual are all diagnostic of a theropod that belongs to the family of predatory dinosaurs, the Dromaeosauridae. Yet this Antarctic dromaeosaur retains plesiomorphic features in its ankle and foot morphology. As new dromaeosaur species are being recovered from the mid-Cretaceous of South America and the retention of primitive characters in the Antarctic dromaeosaur, a new biogeographic hypothesis on dromaeosaur distribution has been generated. Gondwanan dromaeosaurs are not North America immigrants into South America and Antarctica; rather they are the relicts of a cosmopolitan dromaeosaur distribution, which has been separated by the vicariant break up of Pangea and created an endemic clade of dromaeosaurs in Gondwana.

  10. Quasi-parabolic reflecting bottom surfaces of the Drygalski Antarctic floating ice tongue

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    E. Zuccheretti

    2001-06-01

    Full Text Available Very high frequency deep radio sounding systems for ice thickness measurements are practically the only useful apparatuses for large scale radar flight surveys in polar regions. The morphology of the bottom surface of an Antarctic floating ice tongue, in the Ross Sea area, East Antarctica, was studied using the arrival times of signal echoes of the radio sounding system. The amplitude variations of radar signals from the reflecting surface were analyzed to determine the gain or the loss of the reflectors. Such surfaces show quasi-parabolic geometrical shapes at the ice/water interface with both concave and convex faces towards the sounding system. Electromagnetic analysis performed on radar echoes indicates that amplitude variations detected by the antenna are focusing or defocusing effects only due to the reflector's shape. A factor in the radar equation that represents the surface shape when coherent reflectors are involved is introduced. This factor allows us to determine more precisely the morphology and electromagnetic characteristics of the interface between the media investigated by means of radio echo sounding.

  11. Distribution and fate of aliphatic and aromatic hydrocarbons in Antarctic fauna and environment

    Science.gov (United States)

    Platt, H. M.; Mackie, P. R.

    1980-03-01

    With the depletion of oil resources in more accessible areas, those of remote regions are being considered or indeed are now being exploited. In many of these regions, especially the polar ones, little is known of the effects such exploitation will have on the environment. But it is known that the ecosystems are often subject to great stress by natural climatic conditions and additional burdens imposed by man may have catastrophic environmental effects. South Georgia, a sub-Antarctic island, has a history of industrial activity mainly concerned with whaling operations that peaked around 1925-1935 but has since declined to virtually nothing. Studies of the ecology of the area provided a unique opportunity to assess the long-term effects that such activities had on the ecosystem. Off the whaling stations a considerable amount of waste material, including fuel oil, was released into the bays and inevitably some of this material was deposited in the sediments. Chemical evidence in the form of both paraffinic and aromatic hydrocarbons still persists in the sediments. The implications of this persistence in relation to the possible influence of the low temperature conditions are discussed. The superficial sediments, marine biota and terrestrial plants, which since 1965 have returned virtually to a pristine state, contain hydrocarbons essentially similar to unpolluted areas around the coast of Britain. Relatively high levels of carcinogenic/mutagenic polynuclear aromatic hydrocarbons in surface sediments suggests a world-wide background of abiogenic hydrocarbons probably disseminated by airborne transport. This appears to indicate that contamination reaches even remote parts of the world in relatively undiminished quantities.

  12. Warming, Contraction, and Freshening of Antarctic Bottom Water since the 1990s, with a Potential Ice-Sheet Melt Feedback.

    Science.gov (United States)

    Johnson, Gregory; Purkey, Sarah; Rintoul, Stephen; Swift, James

    2013-04-01

    We analyze changes in Antarctic Bottom Waters (AABW) around the deep Southern Ocean using repeat section data collected between 1981 and 2012. The international World Ocean Circulation Experiment (WOCE) Hydrographic Program collected a global high-quality baseline of full-depth, accurate oceanographic transects in the 1980s and 1990s. Since the 2000s, some of these transects are being reoccupied, again through international collaboration, as part of GO-SHIP (The Global Ocean Ship-Based Hydrographic Investigations Program). The average dates of the first and last data used to estimate these trends are circa 1991 and 2008. Temperature analyses reveal a nearly global-scale signature of warming in the abyssal ocean ventilated from the Antarctic. In the deep basins around Antarctica, AABW warmed at a rate of 0.02 to 0.05 °C per decade below 4000 m. In addition, the waters between 1000 and 4000 m within and south of the Antarctic Circumpolar Current warmed at a rate of about 0.03 °C per decade. With this warming, cold, deep isotherms are sinking in the Southern Ocean. The 0 °C potential isotherm sinking rate is around 100 m per decade, implying a 8.2 (±2.6) Sv contraction rate of AABW, about 7% per decade. In addition to this contraction, AABW freshening is observed within the Indian and Pacific sectors of the Southern Ocean. The freshening signal is stronger closer to AABW sources. Its spatial pattern implies recent changes in AABW formation, perhaps partly owing to freshening of the shelf waters, which has been linked to increases in glacial ice sheet melt. The observed rate of water-mass freshening for AABW colder than 0°C in the Indian and Pacific Sectors of the Southern Ocean is about half of the estimated increase in mass lost by glacial ice sheets there in recent years. A positive feedback loop might link the AABW contraction and ice sheet melt-influenced freshening as follows: Increased ocean heat flux drives enhanced basal melt of floating ice shelves

  13. Living (Rose Bengal stained benthic foraminiferal faunas along a strong bottom-water oxygen gradient on the Indian margin (Arabian Sea

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    C. Caulle

    2015-02-01

    Full Text Available Rose Bengal stained foraminiferal assemblages were analysed along a five-station bathymetric transect across the core and the lower part of the oxygen minimum zone (OMZ on the Indian margin of the Arabian Sea. Sediment cores were collected using the manned submersible Shinkai 6500 during RV Yokosuka cruise YK08-11 in the post-monsoon season (October 2008 at water depths ranging from 535 to 2000 m, along a gradient from almost anoxic to well-oxygenated (0.3 to 108 μM bottom waters. Stained foraminiferal densities were very high in the OMZ core (535 m and decreased with depth. The faunas were dominated (40–80% by non-calcareous taxa at all stations. These were mainly species of Reophax and Lagenammina but also included delicate monothalamous taxa (organic-walled "allogromiids", agglutinated saccamminids, psammosphaerids and tubular forms. These new data from the Indian margin are compared to previous studies from the Murray Ridge, the Pakistan margin and the Oman margin. The fact that similar species were found at sites with comparable bottom-water oxygen concentrations but with very different surface water productivity suggests that, within the strongly developed Arabian Sea OMZ, bottom-water oxygen concentration, and not the organic flux to the sea floor, is the main factor controlling the species composition of the foraminiferal communities. Several foraminiferal species (e.g. Praeglobobulimina sp. 1, Ammodiscus sp. 1, Bolivina aff. dilatata were confined to the core of the OMZ and are presently known only from the Arabian Sea. Because of their association with extremely low-oxygen concentration, these species may prove to be good indicators of past OMZ variability in the Arabian Sea.

  14. Evidence for the Late Cenozoic Antarctic Ice Sheet evolution and bottom current dynamics in the central-western Ross Sea outer margin, Antarctica

    Science.gov (United States)

    Kim, Sookwan; De Santis, Laura; Kuk Hong, Jong; Cottlerle, Diego; Petronio, Lorenzo; Colizza, Ester; Bergamasco, Andrea; Kim, Young-Gyun; Kang, Seung-Goo; Kim, Hyoungjun; Kim, Suhwan; Wardell, Nigel; Geletti, Riccardo; McKay, Robert; Jin, Young Keun; Kang, Sung-Ho

    2016-04-01

    Sedimentary records in polar continental margins provide clues for understanding paleo-depositional environments, related to ice sheet evolution and bottom-water current dynamics, during times of past climate and global sea level changes. Previous seismostratigraphic studies of the Ross Sea embayment, Antarctica, illustrated its general stratigraphic framework and the distribution of glacial sedimentary features over the continental shelf, since the onset of Antarctic ice-sheets at the Eocene-Oligocene boundary (~34.0 Ma). In contrast, there are a fewer studies for the outer continental margin, where continuous sedimentary deposits generally preserve the record of past climate cycles with minimum hiatus, comparing to the inner- and mid-continental shelf, where grounding ice streams eroded most of the sediments. Here we present a seismostratigraphic analysis of 2-D multichannel seismic reflection profiles, from the Central Basin located in the central-western Ross Sea outer margin. A glacial prograding wedge developed at the mouth of the Joides Basin since early-middle Miocene times (RSU4: ~14.0 Ma). And the Central Basin was filled with stacked debris-flow deposits and turbidites. The sediment depocenter shifted from the Central Basin toward the slope in the Pliocene (after RSU2: ~3.3 Ma). Pliocene foreset beds are steep and pinch out at the base of the continental slope. Bottom current controlled sediment drifts well developed since the middle Miocene, along the western slope of the central Basin and on the basement highs These areas are far from the mouth of the Joides trough, where most of the glacial sediment is deposited, and they are also more elevated than the basinal areas, where gravity flow maximum thickness accumulated. Along the western slope of the central Basin and over the basement highs, the signature in the sediments of the action of bottom current reworking and shaping the sea floor can be then clearly recognized. We present the sediment drifts

  15. Evolution and ecology of antarctic sponges

    OpenAIRE

    Vargas Ramirez, Sergio

    2012-01-01

    Sponges are abundant and species-rich in Antarctic waters, and play important roles in the benthic ecosystems of the continent. The taxonomy of Antarctic sponges is, to some extent, well established, yet the phylogenetic relationships of this fauna remain unknown. Here, the first contributions to the knowledge of the evolution of Antarctic sponges are presented. A molecular phylogeny for the common Antarctic shelf glass sponge genus Rossella is provided. Based on nuclear and mitochondrial mar...

  16. Fauna Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of fauna (animals), and environmental change derived from animal fossils. Parameter keywords describe what was measured in this data set. Additional summary...

  17. Fauna Europaea

    DEFF Research Database (Denmark)

    Pape, Thomas; Beuk, Paul; Pont, Adrian Charles;

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding th...

  18. Antarctic clouds

    OpenAIRE

    Lachlan-Cope, Tom

    2010-01-01

    Sensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best ...

  19. Antarctic crabs: invasion or endurance?

    Science.gov (United States)

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis".

  20. Deep-sea whale fall fauna from the Atlantic resembles that of the Pacific Ocean

    Science.gov (United States)

    Sumida, Paulo Y. G.; Alfaro-Lucas, Joan M.; Shimabukuro, Mauricio; Kitazato, Hiroshi; Perez, Jose A. A.; Soares-Gomes, Abilio; Toyofuku, Takashi; Lima, Andre O. S.; Ara, Koichi; Fujiwara, Yoshihiro

    2016-01-01

    Whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. Although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the NE Pacific Ocean. The present work describes the community composition of the deepest natural whale carcass described to date found at 4204 m depth on Southwest Atlantic Ocean with manned submersible Shinkai 6500. This is the first record of a natural whale fall in the deep Atlantic Ocean. The skeleton belonged to an Antarctic Minke whale composed of only nine caudal vertebrae, whose degradation state suggests it was on the bottom for 5–10 years. The fauna consisted mainly of galatheid crabs, a new species of the snail Rubyspira and polychaete worms, including a new Osedax species. Most of the 41 species found in the carcass are new to science, with several genera shared with NE Pacific whale falls and vent and seep ecosystems. This similarity suggests the whale-fall fauna is widespread and has dispersed in a stepping stone fashion, deeply influencing its evolutionary history. PMID:26907101

  1. Deep-sea whale fall fauna from the Atlantic resembles that of the Pacific Ocean

    Science.gov (United States)

    Sumida, Paulo Y. G.; Alfaro-Lucas, Joan M.; Shimabukuro, Mauricio; Kitazato, Hiroshi; Perez, Jose A. A.; Soares-Gomes, Abilio; Toyofuku, Takashi; Lima, Andre O. S.; Ara, Koichi; Fujiwara, Yoshihiro

    2016-02-01

    Whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. Although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the NE Pacific Ocean. The present work describes the community composition of the deepest natural whale carcass described to date found at 4204 m depth on Southwest Atlantic Ocean with manned submersible Shinkai 6500. This is the first record of a natural whale fall in the deep Atlantic Ocean. The skeleton belonged to an Antarctic Minke whale composed of only nine caudal vertebrae, whose degradation state suggests it was on the bottom for 5–10 years. The fauna consisted mainly of galatheid crabs, a new species of the snail Rubyspira and polychaete worms, including a new Osedax species. Most of the 41 species found in the carcass are new to science, with several genera shared with NE Pacific whale falls and vent and seep ecosystems. This similarity suggests the whale-fall fauna is widespread and has dispersed in a stepping stone fashion, deeply influencing its evolutionary history.

  2. Antarctic Entomology.

    Science.gov (United States)

    Chown, Steven L; Convey, Peter

    2016-01-01

    The Antarctic region comprises the continent, the Maritime Antarctic, the sub-Antarctic islands, and the southern cold temperate islands. Continental Antarctica is devoid of insects, but elsewhere diversity varies from 2 to more than 200 species, of which flies and beetles constitute the majority. Much is known about the drivers of this diversity at local and regional scales; current climate and glacial history play important roles. Investigations of responses to low temperatures, dry conditions, and varying salinity have spanned the ecological to the genomic, revealing new insights into how insects respond to stressful conditions. Biological invasions are common across much of the region and are expected to increase as climates become warmer. The drivers of invasion are reasonably well understood, although less is known about the impacts of invasion. Antarctic entomology has advanced considerably over the past 50 years, but key areas, such as interspecific interactions, remain underexplored.

  3. Fauna of an acid stream

    Energy Technology Data Exchange (ETDEWEB)

    Jewell, M.E.

    1922-01-01

    The hydrogen-ion concentration of the water of the big muddy river was found to vary between pH 5.8 and pH 6.8 to 7.2, the higher acidity occurring during the winter. The bottom fauna was characterized by the abundance of clams and shrimp, and by the absence of branchiate snails and ephemerid nymphs. Fish fry and fingerlings were found in large numbers during the summer in weakly acid water, pH 6.8. Observations on our acid streams, continued over a considerable period of time, would tell us much concerning the adaptability of various species to different hydrogen-ion concentrations and are greatly needed in the interpretation of experimental data.

  4. Differential extinction and the contrasting structure of polar marine faunas.

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    Andrew Z Krug

    Full Text Available BACKGROUND: The low taxonomic diversity of polar marine faunas today reflects both the failure of clades to colonize or diversify in high latitudes and regional extinctions of once-present clades. However, simple models of polar evolution are made difficult by the strikingly different faunal compositions and community structures of the two poles. METHODOLOGY/PRINCIPAL FINDINGS: A comparison of early Cenozoic Arctic and Antarctic bivalve faunas with modern ones, within the framework of a molecular phylogeny, shows that while Arctic losses were randomly distributed across the tree, Antarctic losses were significantly concentrated in more derived families, resulting in communities dominated by basal lineages. Potential mechanisms for the phylogenetic structure to Antarctic extinctions include continental isolation, changes in primary productivity leading to turnover of both predators and prey, and the effect of glaciation on shelf habitats. CONCLUSIONS/SIGNIFICANCE: These results show that phylogenetic consequences of past extinctions can vary substantially among regions and thus shape regional faunal structures, even when due to similar drivers, here global cooling, and provide the first phylogenetic support for the "retrograde" hypothesis of Antarctic faunal evolution.

  5. On the Linkage between Antarctic Surface Water Stratification and Global Deep-Water Temperature

    OpenAIRE

    Keeling, R.F.; Visbeck, Martin

    2011-01-01

    The suggestion is advanced that the remarkably low static stability of Antarctic surface waters may arise from a feedback loop involving global deep-water temperatures. If deep-water temperatures are too warm, this promotes Antarctic convection, thereby strengthening the inflow of Antarctic Bottom Water into the ocean interior and cooling the deep ocean. If deep waters are too cold, this promotes Antarctic stratification allowing the deep ocean to warm because of the input of North Atlantic D...

  6. Fauna Europaea: Diptera - Brachycera

    NARCIS (Netherlands)

    T. Pape; P. Beuk; A.C. Pont; A.I. Shatalkin; A.L. Ozerov; A.J. Woźnica; B. Merz; C. Bystrowski; C. Raper; C. Bergström; C. Kehlmaier; D.K. Clements; D. Greathead; E.P. Kameneva; E. Nartshuk; F.T. Petersen; G. Weber; G. Bächli; F. Geller-Grimm; G. van de Weyer; H.-P. Tschorsnig; H. de Jong; J.W. van Zuijlen; J. Vaňhara; J. Roháček; J. Ziegler; J. Majer; K. Hůrka; K. Holston; K. Rognes; L. Greve-Jensen; M. Munari; M. de Meyer; M. Pollet; M.C.D. Speight; M.J. Ebejer; M. Martinez; M. Carles-Tolrá; M. Földvári; M. Chvála; M. Barták; N.L. Evenhuis; P.J. Chandler; P. Cerretti; R. Meier; R. Rozkosny; S. Prescher; S.D. Gaimari; T. Zatwarnicki; T. Zeegers; T. Dikow; V.A. Korneyev; V.A. Richter; V. Michelsen; V.N. Tanasijtshuk; W.N. Mathis; Z. Hubenov; Y. de Jong

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the C

  7. Fauna Europaea: Gastrotricha

    Science.gov (United States)

    d`Hondt, Jean-Loup; Kisielewski, Jacek; Todaro, M. Antonio; Tongiorgi, Paolo; Guidi, Loretta; Grilli, Paolo

    2015-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Gastrotricha are a meiobenthic phylum composed of 813 species known so far (2 orders, 17 families) of free-living microinvertebrates commonly present and actively moving on and into sediments of aquatic ecosystems, 339 of which live in fresh and brackish waters. The Fauna Europaea database includes 214 species of Chaetonotida (4 families) plus a single species of Macrodasyida incertae sedis. This paper deals with the 224 European freshwater species known so far, 9 of which, all of Chaetonotida, have been described subsequently and will be included in the next database version. Basic information on their biology and ecology are summarized, and a list of selected, main references is given. As a general conclusion the gastrotrich fauna from Europe is the best known compared with that of other continents, but shows some important gaps of knowledge in Eastern and Southern regions. PMID:26379467

  8. Early cenozoic differentiation of polar marine faunas.

    Directory of Open Access Journals (Sweden)

    J Alistair Crame

    Full Text Available The widespread assumption that the origin of polar marine faunas is linked to the onset of major global cooling in the Late Eocene-Early Oligocene is being increasingly challenged. The Antarctic fossil record in particular is suggesting that some modern Southern Ocean taxa may have Early Eocene or even Paleocene origins, i.e. well within the Early Cenozoic greenhouse world. A global analysis of one of the largest marine clades at the present day, the Neogastropoda, indicates that not only is there a decrease in the number of species from the tropics to the poles but also a decrease in the evenness of their distribution. A small number of neogastropod families with predominantly generalist trophic strategies at both poles points to the key role of seasonality in structuring the highest latitude marine assemblages. A distinct latitudinal gradient in seasonality is temperature-invariant and would have operated through periods of global warmth such as the Early Cenozoic. To test this concept a second global analysis was undertaken of earliest Cenozoic (Paleocene neogastropods and this does indeed show a certain degree of faunal differentiation at both poles. The Buccinidae, s.l. is especially well developed at this time, and this is a major generalist taxon at the present day. There is an element of asymmetry associated with this development of Paleocene polar faunas in that those in the south are more strongly differentiated than their northern counterparts; this can in turn be linked to the already substantial isolation of the southern high latitudes. The key role of seasonality in the formation of polar marine faunas has implications for contemporary ecosystem structure and stability.

  9. Fauna Europaea: Gastrotricha

    Directory of Open Access Journals (Sweden)

    Maria Balsamo

    2015-08-01

    Gastrotricha are a meiobenthic phylum composed of 813 species known so far (2 orders, 17 families of free-living microinvertebrates commonly present and actively moving on and into sediments of aquatic ecosystems, 339 of which live in fresh and brackish waters. The Fauna Europaea database includes 214 species of Chaetonotida (4 families plus a single species of Macrodasyida incertae sedis. This paper deals with the 224 European freshwater species known so far, 9 of which, all of Chaetonotida, have been described subsequently and will be included in the next database version. Basic information on their biology and ecology are summarized, and a list of selected, main references is given. As a general conclusion the gastrotrich fauna from Europe is the best known compared with that of other continents, but shows some important gaps of knowledge in Eastern and Southern regions.

  10. Fauna europaea: Diptera - brachycera.

    Science.gov (United States)

    Pape, Thomas; Beuk, Paul; Pont, Adrian Charles; Shatalkin, Anatole I; Ozerov, Andrey L; Woźnica, Andrzej J; Merz, Bernhard; Bystrowski, Cezary; Raper, Chris; Bergström, Christer; Kehlmaier, Christian; Clements, David K; Greathead, David; Kameneva, Elena Petrovna; Nartshuk, Emilia; Petersen, Frederik T; Weber, Gisela; Bächli, Gerhard; Geller-Grimm, Fritz; Van de Weyer, Guy; Tschorsnig, Hans-Peter; de Jong, Herman; van Zuijlen, Jan-Willem; Vaňhara, Jaromír; Roháček, Jindřich; Ziegler, Joachim; Majer, József; Hůrka, Karel; Holston, Kevin; Rognes, Knut; Greve-Jensen, Lita; Munari, Lorenzo; de Meyer, Marc; Pollet, Marc; Speight, Martin C D; Ebejer, Martin John; Martinez, Michel; Carles-Tolrá, Miguel; Földvári, Mihály; Chvála, Milan; Barták, Miroslav; Evenhuis, Neal L; Chandler, Peter J; Cerretti, Pierfilippo; Meier, Rudolf; Rozkosny, Rudolf; Prescher, Sabine; Gaimari, Stephen D; Zatwarnicki, Tadeusz; Zeegers, Theo; Dikow, Torsten; Korneyev, Valery A; Richter, Vera Andreevna; Michelsen, Verner; Tanasijtshuk, Vitali N; Mathis, Wayne N; Hubenov, Zdravko; de Jong, Yde

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the Caucasus region). The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing taxonomic specialists throughout Europe and is a unique (standard) reference suitable for many user communities in science, government, industry, nature conservation and education. The Diptera-Brachycera is one of the 58 Fauna Europaea major taxonomic groups, and data have been compiled by a network of 55 specialists. Within the two-winged insects (Diptera), the Brachycera constitute a monophyletic group, which is generally given rank of suborder. The Brachycera may be classified into the probably paraphyletic 'lower brachyceran grade' and the monophyletic Eremoneura. The latter contains the Empidoidea, the Apystomyioidea with a single Nearctic species, and the Cyclorrhapha, which in turn is divided into the paraphyletic 'aschizan grade' and the monophyletic Schizophora. The latter is traditionally divided into the paraphyletic 'acalyptrate grade' and the monophyletic Calyptratae. Our knowledge of the European fauna of Diptera-Brachycera varies tremendously among families, from the reasonably well known hoverflies (Syrphidae) to the extremely poorly known scuttle flies (Phoridae). There has been a steady growth in our knowledge of European Diptera for the last two centuries, with no apparent slow down, but there is a shift towards a larger fraction of the new species being found among the families of the nematoceran grade (lower Diptera), which due to a larger number of small

  11. Environmental effects of the US Antarctic Program`s use of balloons in Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    McCold, L.N.; Eddlemon, G.K.; Blasing, T.J.

    1995-06-01

    The USAP uses balloons in Antarctica to conduct scientific research, to facilitate safe air transport, and to provide data for global weather predictions. However, there is the possibility that balloons or their payloads may adversely affect Antarctic fauna or flora. The purpose of this study is to provide background information upon which the USAP may draw when complying with its responsibilities under the National Environmental Policy Act of 1969, the Antarctic Treaty, and the Madrid Protocol.

  12. Fauna Europaea: Mollusca - Bivalvia.

    Science.gov (United States)

    Araujo, Rafael; de Jong, Yde

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. For the Mollusca-Bivalvia, data from 5 families (Margaritiferidae, Unionidae, Sphaeriidae, Cyrenidae, Dreissenidae) containing 55 species are included in this paper. European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbiculafluminea) and the Dreissenoidea the famous invasive zebra mussel (Dreissenapolymorpha). Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

  13. A note on Antarctic benthic mollusks collected with a beam-trawl from Breid Bay by the 25th Japanese Antarctic Research Expedition

    OpenAIRE

    Takashi, Okutani

    1986-01-01

    The molluscan specimens sorted out from benthos samples trawled from depths of 310 and 215m in Breid Bay were studied. A single species of Polyplacophora, 7 gastropods, one scaphopod, 6 bivalves and 2 octopod cephalopods were identified. The general compositions of the present collection represents typical shelf fauna in the Antarctic.

  14. The impacts of local human activities on the Antarctic environment

    Science.gov (United States)

    Tin, T.; Fleming, Z. L.; Hughes, K. A.; Ainley, D. G.; Convey, P.; Moreno, C. A.; Pfeiffer, S.; Scott, J.; Snape, I.

    2009-04-01

    An overview of a recently published review of the scientific literature from the past decade on the impacts of human activities on the Antarctic environment is presented. An assessment of the cumulative effects of scientists and accompanying base construction, tourists and fishery activities in Antarctica is timely given a decade since the Protocol on Environmental Protection to the Antarctic Treaty came into force in 1998 and the increasing attention given to and human presence in Antarctica during this 2007-2009 IPY. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived, with contemporary sewage management practices at many coastal stations insufficient to prevent local contamination. Human activities, particularly construction and transport, have affected Antarctic flora and fauna and a small number of non-indigenous plant and animal species has become established on some of the Antarctic Peninsula and sub Antarctic islands. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity on bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its instruments, in particular the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the Environmental Protocol, provide a framework within which management of human activities take place. In order to ensure comprehensive protection of the Antarctic environment, including its intrinsic, wilderness and scientific values in the face of the continuing expansion of human activities in Antarctica, a more effective implementation of a wide range of measures is essential. These include effective environmental impact assessments, long-term monitoring, mitigation measures for non-indigenous species, ecosystem-based management of living resources, and increased regulation of National Antarctic

  15. Is the species flock concept operational? The Antarctic Shelf case

    OpenAIRE

    Guillaume Lecointre; Nadia Améziane; Marie-Catherine Boisselier; Céline Bonillo; Frédéric Busson; Romain Causse; Anne Chenuil; Arnaud Couloux; Jean-Pierre Coutanceau; Corinne Cruaud; Cédric d'Udekem d'Acoz; Chantal De Ridder; Gael Denys; Agnès Dettaï; Guy Duhamel

    2013-01-01

    There has been a significant body of literature on species flock definition but not so much about practical means to appraise them. We here apply the five criteria of Eastman and McCune for detecting species flocks in four taxonomic components of the benthic fauna of the Antarctic shelf: teleost fishes, crinoids (feather stars), echinoids (sea urchins) and crustacean arthropods. Practical limitations led us to prioritize the three historical criteria (endemicity, monophyly, species richness) ...

  16. Antarctic Dry Valley Sediments as Analogs for Microbial Systems in a Cold Mars-Like Environment

    Science.gov (United States)

    Bishop, J. L.; Englert, P.

    2016-05-01

    Investigations of surface and lake bottom sediments in the Antarctic Dry Valleys have revealed microbial life nearly everywhere and some evidence for clays, carbonates, sulfates and other minerals associated with microbes in the sediments.

  17. The promise and perils of Antarctic fishes: The remarkable life forms of the Southern Ocean have much to teach science about survival, but human activity is threatening their existence

    OpenAIRE

    O'Brien, Kristin M; Crockett, Elizabeth L.

    2012-01-01

    The waters around the Antarctic are a treasure trove of fauna specially adapted to extreme cold temperatures. However, as with many other marine ecosystems, its life forms are threatened by human actions.

  18. Antarctic research today

    International Nuclear Information System (INIS)

    With the appetite for living and dead natural resources, the political and economical interest concerning the Antarctic increases throughout the world. There are three interrelated main subjects accounting for the international interest: The shelf tectonic puzzle of the original continent of Gondwana, where the Antarctic is situated in the centre, between Australia, South Africa and South America, and the hopes concerning the existence of mineral resources under the ice of the Antarctic are based thereon. The Antarctic forms the biggest unified living space of the world. (orig.)

  19. Bottom production

    International Nuclear Information System (INIS)

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations

  20. Bottom production

    Energy Technology Data Exchange (ETDEWEB)

    Baines, J.; Baranov, S.P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M.; Caner, A.; Coadou, Y.; Corti, G.; Damet, J.; Dell-Orso, R.; De Mello Neto, J.R.T.; Domenech, J.L.; Drollinger, V.; Eerola, P.; Ellis, N.; Epp, B.; Frixione, S.; Gadomski, S.; Gavrilenko, I.; Gennai, S.; George, S.; Ghete, V.M.; Guy, L.; Hasegawa, Y.; Iengo, P.; Jacholkowska, A.; Jones, R.; Kharchilava, A.; Kneringer, E.; Koppenburg, P.; Korsmo, H.; Kramer, M.; Labanca, N.; Lehto, M.; Maltoni, F.; Mangano, M.L.; Mele, S.; Nairz, A.M.; Nakada, T.; Nikitin, N.; Nisati, A.; Norrbin, E.; Palla, F.; Rizatdinova, F.; Robins, S.; Rousseau, D.; Sanchis-Lozano, M.A.; Shapiro, M.; Sherwood, P.; Smirnova, L.; Smizanska, M.; Starodumov, A.; Stepanov, N.; Vogt, R.

    2000-03-15

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations.

  1. Biodiversity change after climate-induced ice-shelf collapse in the Antarctic

    NARCIS (Netherlands)

    Gutt, J.; Barratt, I.; Domack, E.; Scheidat, M.

    2011-01-01

    The marine ecosystem on the eastern shelf of the Antarctic Peninsula was surveyed 5 and 12 years after the climate-induced collapse of the Larsen A and B ice shelves. An impoverished benthic fauna was discovered, that included deep-sea species presumed to be remnants from ice-covered conditions. The

  2. Benthic fauna of mangrove environment

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    The distribution, abundance and importance of benthic fauna in a mangrove environment has been discussed. This ecosystem is enriched with terrestrial, aquatic, marshy and mudflat species mangrove environment. Qualitative and quantitative...

  3. Golf courses and wetland fauna

    OpenAIRE

    Colding, Johan; Lundberg, Jakob; Lundberg, Stefan; Andersson, Erik

    2009-01-01

    Golf courses are often considered to be chemical-intensive ecosystems with negative impacts on fauna. Here we provide evidence that golf courses can contribute to the support and conservation of wetland fauna, i.e., amphibians and macroinvertebrates. Comparisons of amphibian occurrence, diversity of macroinvetebrates, and occurrence of species of conservation concern were made between permanent freshwater ponds surveyed on golf courses around Sweden's capital city, Stockholm, and off-course p...

  4. Antarctic Ozone Hole, 2000

    Science.gov (United States)

    2002-01-01

    Each spring the ozone layer over Antarctica nearly disappears, forming a 'hole' over the entire continent. The hole is created by the interaction of some man-made chemicals-freon, for example-with Antarctica's unique weather patterns and extremely cold temperatures. Ozone in the stratosphere absorbs ultraviolet radiation from the sun, thereby protecting living things. Since the ozone hole was discovered many of the chemicals that destroy ozone have been banned, but they will remain in the atmosphere for decades. In 2000, the ozone hole grew quicker than usual and exceptionally large. By the first week in September the hole was the largest ever-11.4 million square miles. The top image shows the average total column ozone values over Antarctica for September 2000. (Total column ozone is the amount of ozone from the ground to the top of the atmosphere. A relatively typical measurement of 300 Dobson Units is equivalent to a layer of ozone 0.12 inches thick on the Earth's surface. Levels below 220 Dobson Units are considered to be significant ozone depletion.) The record-breaking hole is likely the result of lower than average ozone levels during the Antarctic fall and winter, and exceptionally cold temperatures. In October, however (bottom image), the hole shrank dramatically, much more quickly than usual. By the end of October, the hole was only one-third of it's previous size. In a typical year, the ozone hole does not collapse until the end of November. NASA scientists were surprised by this early shrinking and speculate it is related to the region's weather. Global ozone levels are measured by the Total Ozone Mapping Spectrometer (TOMS). For more information about ozone, read the Earth Observatory's ozone fact sheet, view global ozone data and see these ozone images. Images by Greg Shirah, NASA GSFC Scientific Visualization Studio.

  5. Antarctic news clips, 1991

    Science.gov (United States)

    1991-08-01

    Published stories are presented that sample a year's news coverage of Antarctica. The intent is to provide the U.S. Antarctic Program participants with a digest of current issues as presented by a variety of writers and popular publications. The subject areas covered include the following: earth science; ice studies; stratospheric ozone; astrophysics; life science; operations; education; antarctic treaty issues; and tourism

  6. Fauna Europaea: Helminths (Animal Parasitic)

    NARCIS (Netherlands)

    D.I. Gibson; R.A. Bray; D. Hunt; B.B. Georgiev; T. Scholz; P.D. Harris; T.A. Bakke; T. Pojmanska; K. Niewiadomska; A. Kostadinova; V. Tkach; O. Bain; M.C. Durette-Desset; L. Gibbons; F. Moravec; A. Petter; Z.M. Dimitrova; K. Buchmann; E.T. Valtonen; Y. de Jong

    2014-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fa

  7. Sugars in Antarctic aerosol

    Science.gov (United States)

    Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2015-10-01

    The processes and transformations occurring in the Antarctic aerosol during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic aerosol collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic aerosol. The total mean concentration of sugars in the aerosol collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the aerosol collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the aerosol collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the aerosol collected during the oceanographic cruise.

  8. The alien terrestrial invertebrate fauna of the High Arctic archipelago of Svalbard: potential implications for the native flora and fauna

    Directory of Open Access Journals (Sweden)

    Stephen J. Coulson

    2015-09-01

    Full Text Available Experience from the Antarctic indicates that the establishment of alien species may have significant negative effects on native flora and fauna in polar regions and is considered to be amongst the greatest threats to biodiversity. But, there have been few similar studies from the Arctic. Although the terrestrial invertebrate inventory of the Svalbard Archipelago is amongst the most complete for any region of the Arctic, no consideration has yet been made of alien terrestrial invertebrate species, their invasiveness tendencies, threat to the native biology or their route of entry. Such baseline information is critical for appropriate management strategies. Fifteen alien invertebrate species have established in the Svalbard environment, many of which have been introduced via imported soils. Biosecurity legislation now prohibits such activities. None of the recorded established aliens yet show invasive tendencies but some may have locally negative effects. Ten species are considered to be vagrants and a further seven are classified as observations. Vagrants and the observations are not believed to be able to establish in the current tundra environment. The high connectivity of Svalbard has facilitated natural dispersal processes and may explain why few alien species are recorded compared to isolated islands in the maritime Antarctic. The vagrant species observed are conspicuous Lepidoptera, implying that less evident vagrant species are also arriving regularly. Projected climate change may enable vagrant species to establish, with results that are difficult to foresee.

  9. 南极半岛东北海域表层沉积有机质来源及其沉积环境%The source of organic matter and its sedimentary environment of the bottom surface sediment in northeast waters to Antarctic Peninsula based on the biomarker features

    Institute of Scientific and Technical Information of China (English)

    韩喜彬; 赵军; 初凤友; 潘建明; 唐灵刚; 许冬; 边叶萍; 葛倩

    2015-01-01

    采用气相色谱-质谱技术对南极半岛东北海域海底表层沉积物的总有机碳、有机质碳同位素(δ13 Corg)和生物标志化合物等进行了测试分析。研究区表层沉积物总有机碳 TOC 平均值高于现代深海沉积物中的平均含量。δ13 Corg 的变化说明该海域有机碳来源呈海洋水生生物来源和陆源混合的特征。正构烷烃的峰型分布、主峰碳、饱和烃轻重比ΣC-21/ΣC+22和(C21+C22)/(C28+C29)、甾烷组合和藿烷组合证实研究区西部表层沉积物有机质来源以陆源高等植物为主,其陆源可能来自于附近的南极半岛和南舍得兰群岛;研究区东部表层沉积物有机质来源偏以海源为主,且以低等浮游生物、藻类及细菌生物等海源输入为主。碳优势指数(Carbon preference index,CPI)、奇偶优势指数(Odd-even Predominance,OEP)和甾烷 C29ααα20S/(20S+20R)比值显示研究区 D1-7站位和 D5-9沉积物有机质演化程度较高,D5-2和 D2-4站位的有机质演化程度低,其他站位介于中间状态。饱和烃中姥鲛烷、植烷及其比值(Pr/Ph)等组合显示研究区西部以氧化-弱还原的沉积环境为主,其可能是受高温低盐别林斯高晋海水流和附近火山喷发的影响所致;研究区东部以还原—强还原沉积环境为主,可能是受低温高盐的威德尔底层水(WSBW)和威德尔海深层水(WS-DW)影响所致。%The organic geochemical characteristics and molecular biomarker are tests analyzed by gas chromatogra-phy-mass spectrometry which are soluble extracted from the bottom surface sediments in the northeast waters to Antarctic Peninsula.Results show that the average contents of TOC (total organic carbon)of the surface sediment in the study is higher than the average contents of organic matter in modern deep-sea sediments.δ13 Corg (Organic carbon isotope)values change means that the source

  10. A Late Pleistocene transgression in Thailand: A marine molluscan fauna from Ban Praksa (Samut Prakan Province)

    Science.gov (United States)

    Negri, Mauro Pietro

    2012-01-01

    A Late Pleistocene molluscan fauna sampled at Ban Praksa, near the Chao Phraya River mouth (Lower Central Plain of Bangkok, Thailand) is herein analyzed and paleoecologically characterized, revealing a shallow infralittoral, coarse/hard-bottomed environment. The comparison of the Ban Praksa association with several coeval ones recovered from Phra Pradaeng Formation seems to be evidence of a 10,000 year hiatus between two separate groups of marine faunas, possibly belonging to different interstadial transgressive peaks that occurred during the long-term sea-level regression following the Last Interglacial.

  11. potencialmente repelentes à fauna consumidora

    Directory of Open Access Journals (Sweden)

    Guilherme O. S. Ferraz de Arruda

    2007-01-01

    Full Text Available The seed of Araucaria angustifolia, “pinhão”, is becoming a alternative way of income for many families living at south and southeast of Brazil. The intensive attack on Paraná pine seeds by the wild fauna, that occur at newly-planted areas by direct sowing and at nursery of seedlings, is one of several adverses and distimulating factors to specie spreading. The objective of this work was to verify probable phytotoxics effects of some naturals and synthetics substances potentially repellentes to wild fauna, in Araucaria angustifolia seeds “in vitro”. The experiment was realized at Phytopatology and Plant Physiology Laboratory of Center of Agroveterinary Sciences, University of Santa Catarina State – Brazil, from june to december, 2004. The Paraná pine seeds, after preparation and treatment with vegetal and not vegetal substances, were sown in plastic trays with vermiculite substratum and put on cabin of growth with controlled temperature, relative humidity of air, humidity of substratum and photoperiods. It was adopted the randomized complete design with 15 treatments, with 10 seeds each treatment and with 4 repetitions. The tested substances separately or in mixtures were: extract of fruit of red pepper, root of parsley, stem and leaf of wormwood herb, lemon scented gum essential oil, linseed oil, castor bean oil, rosin, copper oxychloride, copper sulphate, sulphur and látex ink. The root emission, stem emission, length of main root and length of stem were evaluated 76 days after sowing and statisticaly analyzed. The analysis make possible to conclude that the tested extract do not have phytotoxic effect on seeds and that the substances tested “in vitro” can be used in field experiments, in repellence traits for Parana pine seeds consuming fauna. Keywords: effects fitotóxicos; pine seeds of Araucaria angustifolia; predação of seeds.

  12. Large-scale distribution analysis of Antarctic echinoids using ecological niche modelling

    OpenAIRE

    Pierrat, B.; Saucede, T.; Laffont, R.; De Ridder, C.; Festeau, A.; David, B.

    2012-01-01

    Understanding the factors that determine the distribution of taxa at various spatial scales is a crucial challenge in the context of global climate change. This holds particularly true for polar marine biota that are composed of both highly adapted and vulnerable faunas. We analysed the distribution of 2 Antarctic echinoid species, Sterechinus antarcticus and S. neumayeri, at the scale of the entire Southern Ocean using 2 niche modelling procedures. The performance of distribution models was ...

  13. Geoethical Approach to Antarctic Subglacial Lakes Exploration

    Science.gov (United States)

    Talalay, Pavel; Markov, Alexey; Sysoev, Mikhail

    2014-05-01

    Antarctic subglacial aquatic environment have become of great interest to the science community because they may provide unique information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Nowadays it is generally recognized that a vast network of lakes, rivers, and streams exists thousands of meters beneath Antarctic Ice Sheets. Up to date only four boreholes accessed subglacial aquatic system but three of them were filled with high-toxic drilling fluid, and the subglacial water was contaminated. Two recent exploration programs proposed by UK and USA science communities anticipated direct access down to the lakes Ellsworth and Whillans, respectively, in the 2012/2013 Antarctic season. A team of British scientists and engineers engaged in the first attempt to drill into Lake Ellsworth but failed. US research team has successfully drilled through 800 m of Antarctic ice to reach a subglacial lake Whillans and retrieve water and sediment samples. Both activities used hot-water drilling technology to access lakes. Hot water is considered by the world science community as the most clean drilling fluid medium from the present point of view but it cannot solve environmental problems in total because hot-water even when heated to 90 °C, filtered to 0.2 μm, and UV treated at the surface could pick up microorganisms from near-surface snow and circulate them in great volume through the borehole. Another negative impact of hot-water circulation medium is thermal pollution of subglacial water. The new approach to Antarctic subglacial lakes exploration is presented by sampling technology with recoverable autonomous sonde which is equipped by two hot-points with heating elements located on the bottom and top sides of the sonde. All down-hole sonde components will be sterilized by combination of chemical wash, HPV and UV sterilization prior using. At the beginning of the summer season sonde is installed on the surface of the

  14. Fauna Europaea: Helminths (Animal Parasitic

    Directory of Open Access Journals (Sweden)

    David Gibson

    2014-09-01

    Full Text Available Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region, and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard reference suitable for many users in science, government, industry, nature conservation and education. Helminths parasitic in animals represent a large assemblage of worms, representing three phyla, with more than 200 families and almost 4,000 species of parasites from all major vertebrate and many invertebrate groups. A general introduction is given for each of the major groups of parasitic worms, i.e. the Acanthocephala, Monogenea, Trematoda (Aspidogastrea and Digenea, Cestoda and Nematoda. Basic information for each group includes its size, host-range, distribution, morphological features, life-cycle, classification, identification and recent key-works. Tabulations include a complete list of families dealt with, the number of species in each and the name of the specialist responsible for data acquisition, a list of additional specialists who helped with particular groups, and a list of higher taxa dealt with down to the family level. A compilation of useful references is appended.

  15. Regional genetic diversity patterns in Antarctic hairgrass (Deschampsia antartica Desv.)

    NARCIS (Netherlands)

    van de Wouw, M.J.; Van Dijk, P.J.; Huiskes, A.H.L.

    2008-01-01

    Aim To determine patterns in diversity of a major Antarctic plant species, including relationships of Antarctic populations with those outside the Antarctic zone. Location Antarctic Peninsula, Maritime Antarctica, sub-Antarctic islands, Falkland Islands and South America. Methods Amplified fragment

  16. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly...... Science) Antarctic Ice Sheet (DAIS) model (Shaffer 2014) is forced by reconstructed time series of Antarctic temperature, global sea level and ocean subsurface temperature over the last two glacial cycles. In this talk a modelling work of the Antarctic ice sheet over most of the Cenozoic era using...... the DAIS model will be presented. G. Shaffer (2014) Formulation, calibration and validation of the DAIS model (version 1), a simple Antarctic ice sheet model sensitive to variations of sea level and ocean subsurface temperature, Geosci. Model Dev., 7, 1803‐1818...

  17. The impact of tourists on Antarctic tardigrades: an ordination-based model

    Directory of Open Access Journals (Sweden)

    Sandra J. McInnes

    2013-05-01

    Full Text Available Tardigrades are important members of the Antarctic biota yet little is known about their role in the soil fauna or whether they are affected by anthropogenic factors. The German Federal Environment Agency commissioned research to assess the impact of human activities on soil meiofauna at 14 localities along the Antarctic peninsula during the 2009/2010 and 2010/2011 austral summers. We used ordination techniques to re-assess the block-sampling design used to compare areas of high and low human impact, to identify which of the sampled variables were biologically relevant and/or demonstrated an anthropogenic significance. We found the most significant differences between locations, reflecting local habitat and vegetation factor, rather than within-location anthropogenic impact. We noted no evidence of exotic imports but report on new maritime Antarctic sample sites and habitats.

  18. Antarctic Tourism and Maritime Heritage

    OpenAIRE

    Basberg, Bjørn L.

    2010-01-01

    Maritime activities in the Antarctic region date back to the eighteenth century. They evolved from exploration and discoveries to commercial enterprises, especially sealing, whaling and fishing. Antarctic tourism is a much more recent phenomenon, developing mainly from the 1950s and 1960s. Today over 40,000 tourists visit the Antarctic annually, most of them on cruise ships. This essay reviews the historical development of this tourism. The focus is on how maritime heritage has been treated a...

  19. Antarctic science preserve polluted

    Science.gov (United States)

    Simarski, Lynn Teo

    Geophysicists are alarmed at the electromagnetic pollution of a research site in the Antarctic specifically set aside to study the ionosphere and magnetosphere. A private New Zealand communications company called Telecom recently constructed a satellite ground station within the boundaries of this Site of Special Scientific Interest (SSSI), protected since the mid-1970s. The placement of a commercial facility within this site sets an ominous precedent not only for the sanctity of other SSSIs, but also for Specially Protected Areas—preserves not even open to scientific research, such as certain penguin rookeries.The roughly rectangular, one-by-one-half mile site, located at Arrival Heights not far from McMurdo Station, is one of a number of areas protected under the Antarctic treaty for designated scientific activities. Many sites are set aside for geological or biological research, but this is the only one specifically for physical science.

  20. New Records of Aphid Fauna in Turkey

    OpenAIRE

    Kaygin, Azize Toper; Gorur, Gazi; Cota, Figen

    2010-01-01

    Three aphid species were identified as new records for Turkey aphid fauna from Bartin province. These species are Ceruraphis viburnicola (Gillette) (Hemiptera: Aphididae), Dysaphis apiifolia (Theobald) (Hemiptera: Aphididae) and Macrosiphum mordvilkoi Miyazaki (Hemiptera: Aphididae). These records increase the recorded aphid-fauna of Turkey to 433 species.

  1. Time variable bottom water outflow in the Northwestern Weddell Sea

    Science.gov (United States)

    Kanzow, Torsten; Rohardt, Gerd

    2015-04-01

    The Antarctic Bottom Water (AABW) has shown widespread warming in recent decades, with implications for sea level rise and global heat uptake. Anomalously warm AABW has recently been reported to have reached the Brazil basin in the South Atlantic, while the warming further south partly seems to have come to a halt. The Weddell Sea represents the primary source of Antarctic Bottom Water (AABW) formation in the Southern Ocean. More than 60% of the AABW are supplied by Weddell Sea Deep Water, of which Weddell Sea Bottom Water (WSBW) is the main source. WSBW descends down the continental slope along the western margin of the Weddell Sea as a northward flowing plume, thereby entraining warmer ambient waters. The plume has been observed using moored current meters and temperature sensors between 1989 and 1998 and between 2005 and 2012 near the tip of the Antarctic Peninsula, complemented by repeated cross-slope CTD sections along the mooring array. In this study we extend the WSBW volume transport and temperature time series of Fahrbach et al. (2001) originally covering the 1989-1998 interval by the more recent period. We will report on both seasonal to inter-annual variability and possible longer-term trends in both volume transport and temperature of WSBW. The results will be discussed in the context of changes in the source areas of WSBW, such as the breakup of parts of the Larsen Ice Shelf on the eastern Arctic Peninsula, possibly fueling the formation dense water on the shelf.

  2. Antarctic Pliocene Biotic and Environmental Change in a Global Context Changes

    Science.gov (United States)

    Quilty, P. G.; Whitehead, J.

    2005-12-01

    The Pliocene was globally an interval of dramatic climate change and often compared with the environment evolving through human-induced global change. Antarctic history needs to be integrated into global patterns. The Prydz Bay-Prince Charles Mountains region of East Antarctica is a major source of data on Late Paleozoic-Recent changes in Antarctic biota and environment. This paper reviews what is known of 13 marine transgressions in the Late Neogene of the region and attempts to compare the Antarctic pattern with global patterns, such as those identified through global sequence stratigraphic analysis. Although temporal resolution in Antarctic sections is not always as good as for sections elsewhere, enough data exist to indicate that many events can be construed as part of global changes. It is expected that further correlation will be effected. During much of the Pliocene, there was less continental ice, reduced sea-ice cover, probably higher sea-level, penetration of marine conditions deep into the hinterland, and independent evidence to indicate that this was due to warmth. The Antarctic Polar Frontal Zone probably was much farther south than currently. There have been major changes in the marine fauna, and distribution of surviving species since the mid-Pliocene. Antarctic fish faunas underwent major changes during this interval with evolution of a major new Subfamily and diversification in at least two subfamilies. No palynological evidence of terrestrial vegetation has been recovered from the Prydz Bay - Prince Charles Mountain region. Analysis of origin and extinction data for two global planktonic foraminiferal biostratigraphic zonations shows that the interval Late Miocene-Pliocene was an interval of enhanced extinction and evolution, consistent with an interval of more rapid and high amplitude fluctuating environments.

  3. Antarctic, Sub-Antarctic and cold temperate echinoid database

    Directory of Open Access Journals (Sweden)

    Benjamin Pierrat

    2012-06-01

    Full Text Available This database includes spatial data of Antarctic, Sub-Antarctic and cold temperate echinoid distribution (Echinodermata: Echinoidea collected during many oceanographic campaigns led in the Southern Hemisphere from 1872 to 2010. The dataset lists occurrence data of echinoid distribution south of 35°S latitude, together with information on taxonomy (from species to genus level, sampling sources (cruise ID, sampling dates, ship names and sampling sites (geographic coordinates and depth. Echinoid occurrence data were compiled from the Antarctic Echinoid Database (David et al., 2005a, which integrates records from oceanographic cruises led in the Southern Ocean until 2003. This database has been upgraded to take into account data from oceanographic cruises led after 2003. The dataset now reaches a total of 6160 occurrence data that have been checked for systematics reliability and consistency. It constitutes today the most complete database on Antarctic and Sub-Antarctic echinoids.

  4. Ocean processes at the Antarctic continental slope.

    Science.gov (United States)

    Heywood, Karen J; Schmidtko, Sunke; Heuzé, Céline; Kaiser, Jan; Jickells, Timothy D; Queste, Bastien Y; Stevens, David P; Wadley, Martin; Thompson, Andrew F; Fielding, Sophie; Guihen, Damien; Creed, Elizabeth; Ridley, Jeff K; Smith, Walker

    2014-07-13

    The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An iron-cycling model embedded in an eddy-permitting ocean model reveals the importance of sedimentary iron in fertilizing parts of the Southern Ocean. Ocean gliders play a key role in improving our ability to observe and understand these small-scale processes at the continental shelf break. The Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project deployed three Seagliders for up to two months in early 2012 to sample the water to the east of the Antarctic Peninsula in unprecedented temporal and spatial detail. The glider data resolve small-scale exchange processes across the shelf-break front (the Antarctic Slope Front) and the front's biogeochemical signature. GENTOO demonstrated the capability of ocean gliders to play a key role in a future multi-disciplinary Southern Ocean observing system.

  5. Antarctic glaciation caused ocean circulation changes at the Eocene-Oligocene transition.

    Science.gov (United States)

    Goldner, A; Herold, N; Huber, M

    2014-07-31

    Two main hypotheses compete to explain global cooling and the abrupt growth of the Antarctic ice sheet across the Eocene-Oligocene transition about 34 million years ago: thermal isolation of Antarctica due to southern ocean gateway opening, and declining atmospheric CO2 (refs 5, 6). Increases in ocean thermal stratification and circulation in proxies across the Eocene-Oligocene transition have been interpreted as a unique signature of gateway opening, but at present both mechanisms remain possible. Here, using a coupled ocean-atmosphere model, we show that the rise of Antarctic glaciation, rather than altered palaeogeography, is best able to explain the observed oceanographic changes. We find that growth of the Antarctic ice sheet caused enhanced northward transport of Antarctic intermediate water and invigorated the formation of Antarctic bottom water, fundamentally reorganizing ocean circulation. Conversely, gateway openings had much less impact on ocean thermal stratification and circulation. Our results support available evidence that CO2 drawdown--not gateway opening--caused Antarctic ice sheet growth, and further show that these feedbacks in turn altered ocean circulation. The precise timing and rate of glaciation, and thus its impacts on ocean circulation, reflect the balance between potentially positive feedbacks (increases in sea ice extent and enhanced primary productivity) and negative feedbacks (stronger southward heat transport and localized high-latitude warming). The Antarctic ice sheet had a complex, dynamic role in ocean circulation and heat fluxes during its initiation, and these processes are likely to operate in the future.

  6. Biogeography of circum-Antarctic springtails.

    Science.gov (United States)

    McGaughran, Angela; Stevens, Mark I; Holland, Barbara R

    2010-10-01

    We examine the effects of isolation over both ancient and contemporary timescales on evolutionary diversification and speciation patterns of springtail species in circum-Antarctica, with special focus on members of the genus Cryptopygus (Collembola, Isotomidae). We employ phylogenetic analysis of mitochondrial DNA (cox1), and ribosomal DNA (18S and 28S) genes in the programmes MrBayes and RAxML. Our aims are twofold: (1) we evaluate existing taxonomy in light of previous work which found dubious taxonomic classification in several taxa based on cox1 analysis; (2) we evaluate the biogeographic origin of our chosen suite of springtail species based on dispersal/vicariance scenarios, the magnitude of genetic divergence among lineages and the age and accessibility of potential habitat. The dubious taxonomic characterisation of Cryptopygus species highlighted previously is confirmed by our multi-gene phylogenetic analyses. Specifically, according to the current taxonomy, Cryptopygus antarcticus subspecies are not completely monophyletic and neither are Cryptopygus species in general. We show that distribution patterns among species/lineages are both dispersal- and vicariance-driven. Episodes of colonisation appear to have occurred frequently, the routes of which may have followed currents in the Southern Ocean. In several cases, the estimated divergence dates among species correspond well with the timing of terrestrial habitat availability. We conclude that these isotomid springtails have a varied and diverse evolutionary history in the circum-Antarctic that consists of both ancient and recent elements and is reflected in a dynamic contemporary fauna. PMID:20558307

  7. Ecology and living conditions of groundwater fauna

    International Nuclear Information System (INIS)

    This report presents the current state of ecological knowledge and applied research relating to groundwater. A conceptual picture is given of groundwater fauna occurrence in regard to Swedish environmental conditions. Interpretation features for groundwater fauna and applications are outlined. Groundwater is one of the largest and oldest limnic habitats populated by a rich and diverse fauna. Both very old species and species occurring naturally in brackish or salt water can be found in groundwater. Groundwater ecosystems are heterotrophic; the fauna depends on imports from the surface. Most species are meiofauna, 0.3-1 mm. The food chain of groundwater fauna is the same as for relatives in surface water and salt water. Smaller animals graze biofilms and detritus, larger animals act facutatively as predators. A difference is that stygobiotic fauna has become highly adapted to its living space and tolerates very long periods without food. Oxygen is a limiting factor, but groundwater fauna tolerates periods with low oxygen concentrations, even anoxic conditions. For longer periods of time a minimum oxygen requirement of 1 mg/l should be fulfilled. Geographic features such as Quaternary glaciation and very old Pliocene river systems are important for distribution patterns on a large spatial scale, but aquifer characteristics are important on a landscape scale. Area diversity is often comparable to surface water diversity. However, site diversity is low in groundwater. Site specific hydrological exchange on a geological facies level inside the aquifer, e.g. porous, fractured and karstic aquifers as well as the hyporheic zone, controls distribution patterns of groundwater fauna. For a better understanding of controlling factors indicator values are suggested. Different adequate sampling methods are available. They are representative for the aquifer, but a suitable number of monitoring wells is required. The existence of groundwater fauna in Sweden is considered as very

  8. Ecology and living conditions of groundwater fauna

    Energy Technology Data Exchange (ETDEWEB)

    Thulin, Barbara (Geo Innova AB (Sweden)); Hahn, Hans Juergen (Arbeitsgruppe Grundwasseroekologie, Univ. of Koblenz-Landau (Germany))

    2008-09-15

    This report presents the current state of ecological knowledge and applied research relating to groundwater. A conceptual picture is given of groundwater fauna occurrence in regard to Swedish environmental conditions. Interpretation features for groundwater fauna and applications are outlined. Groundwater is one of the largest and oldest limnic habitats populated by a rich and diverse fauna. Both very old species and species occurring naturally in brackish or salt water can be found in groundwater. Groundwater ecosystems are heterotrophic; the fauna depends on imports from the surface. Most species are meiofauna, 0.3-1 mm. The food chain of groundwater fauna is the same as for relatives in surface water and salt water. Smaller animals graze biofilms and detritus, larger animals act facutatively as predators. A difference is that stygobiotic fauna has become highly adapted to its living space and tolerates very long periods without food. Oxygen is a limiting factor, but groundwater fauna tolerates periods with low oxygen concentrations, even anoxic conditions. For longer periods of time a minimum oxygen requirement of 1 mg/l should be fulfilled. Geographic features such as Quaternary glaciation and very old Pliocene river systems are important for distribution patterns on a large spatial scale, but aquifer characteristics are important on a landscape scale. Area diversity is often comparable to surface water diversity. However, site diversity is low in groundwater. Site specific hydrological exchange on a geological facies level inside the aquifer, e.g. porous, fractured and karstic aquifers as well as the hyporheic zone, controls distribution patterns of groundwater fauna. For a better understanding of controlling factors indicator values are suggested. Different adequate sampling methods are available. They are representative for the aquifer, but a suitable number of monitoring wells is required. The existence of groundwater fauna in Sweden is considered as very

  9. Stardust in Antarctic Micrometeorites

    Energy Technology Data Exchange (ETDEWEB)

    Yada, Toru; Floss, Christine; Stadermann, Frank J.; Zinner, E.; Nakamura, T.; Noguchi, T.; Lea, Alan S.

    2008-03-07

    We report the discovery of presolar silicate, oxide (hibonite) and (possibly) SiC grains from four Antarctic micrometeorites. The oxygen isotopic compositions of the eighteen presolar silicate (and one oxide) grains found are consistent with those observed previously in primitive meteorites and interplanetary dust particles, and indicate origins in oxygen-rich red giant or asymptotic giant branch stars. Four grains with anomalous C isotopic compositions were also detected. 12C/13C as well as Si ratios are similar to those of mainstream SiC grains; the N isotopic composition of one grain is also consistent with a mainstream SiC classification. Presolar silicate grains were found in three of the seven AMMs studied, and are heterogeneously distributed within these micrometeorites. Fourteen of the 18 presolar silicate grains and 3 of the 4 C-anomalous grains were found within one AMM, T98G8. The presence of magnesiowüstite, which forms mainly through the decomposition of carbonates, in AMMs without presolar silicates, and its absence in the presolar silicate-bearing micrometeorites, suggests that parent body processes (specifically aqueous alteration) may determine the presence or absence of presolar silicates in Antarctic micrometeorites.

  10. Spatial distribution and abundance of the megabenthic fauna community in Gabes gulf (Tunisia, eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    H. EL LAKHRACH

    2012-12-01

    Full Text Available The aim of this paper is to bring to light the knowledge of marine diversity of invertebrates in Gabes gulf. The spatial distribution of the megabenthic fauna community in Gabes gulf (Tunisia, Eastern Mediterranean Sea, together with the bottom type and vegetation cover, were studied. The abundance of the megabenthic fauna was represented by eight groups: Echinodermata (38%, Crustacea (21%, Tunicata (19%, Mollusca (13%, Porifera (4%, Cnidaria (3%, Bryozoa, and Annelida (2%. It was spatially more concentrated in the coast area of the gulf than in the offshore waters. This area, especially, in Southern Kerkennah, North-est of Gabes and North-east of Djerba appeared to be in a good ecological condition  hosting a variety of species like the paguridsPaguristes eremita and Pagurus cuanensis, the brachyura Medorippe lanata, Inachus doresttensis, the Gastropoda Hexaplex trunculus, Bolinus brandaris, Aporrhais pespelecani, andErosaria turdus, the Bivalvia Fulvia fragilis, the Echinoidea Psammechinus microtuberculatus, Holothuria polii,Ophiothrix fragilis and Antedon mediterranea, and the AscidiaceaAplidium cf. conicum, Didemnum spp, and Microcosmus exasperatus.The species’ compositions of the megabentic fauna community showed clearly that the spatial analysis represented the differences between the community of these two regions (inshore waters and offshore waters. These differences were closely related to peculiar characters of the fauna and biotopes (depth, bottom type and vegetation cover community. The results of the present study should be considered as a necessary starting point for a further analysis of priceless benthic fauna contribution to the marine environment and its organisms.

  11. Metazoan Parasites of Antarctic Fishes.

    Science.gov (United States)

    Oğuz, Mehmet Cemal; Tepe, Yahya; Belk, Mark C; Heckmann, Richard A; Aslan, Burçak; Gürgen, Meryem; Bray, Rodney A; Akgül, Ülker

    2015-06-01

    To date, there have been nearly 100 papers published on metazoan parasites of Antarctic fishes, but there has not yet been any compilation of a species list of fish parasites for this large geographic area. Herein, we provide a list of all documented occurrences of monogenean, cestode, digenean, acanthocephalan, nematode, and hirudinean parasites of Antarctic fishes. The list includes nearly 250 parasite species found in 142 species of host fishes. It is likely that there are more species of fish parasites, which are yet to be documented from Antarctic waters.

  12. Spring Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

  13. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were...

  14. Fall Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Fall Bottom Trawl Survey was initiated in 1963 and covered an area from Hudson Canyon, NY to Nova Scotia, Canada. Throughout the years,...

  15. Summer Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sampling the coastal waters of the Gulf of Maine using the Northeast Fishery Science Center standardized bottom trawl has been problematic due to large areas of...

  16. Relationship Between Estuarine Shellfish Fauna and Physical Environmental Characteristics for Estuary Conservation in Kyushu, Japan

    Directory of Open Access Journals (Sweden)

    Rei Itsukushima

    2015-12-01

    Full Text Available The establishment of a conservation strategy or restoration goal for river estuaries requires knowledge of potential biota or possible habitat characteristics. In this study, we investigated the relationship between estuarine fauna and macro scale physical indicators on Kyushu Island, Japan to provide basic information for estuarine conservation. As a result of the classification of shellfish fauna by similarity, the Kyushu region was divided into three groups, namely, 1 southern Kyushu with high wave exposure, long fetch, and low tidal variation; 2 the Ariake and Yatsushiro seas with low wave exposure, short fetch, and high tidal variation; and 3 northern Kyushu with an intermediate fetch and tidal variation. In addition, a number of sites, such as Nakatsu Port, Sone tideland, and the Honmyou River, were classified into geographically different groups. This is because the physical characteristics of these sites were similar to classified groups or shellfish fauna were significantly altered by artificial impacts. As a result of discriminant analysis, the discrimination hit rate of species inhabiting the inner bay or tidal flat was high, whereas that for species using a wide variety of bottom sediment environment was low. To improve the accuracy of the discriminant model, it is necessary to collect more detailed physical information, such as habitat type, salinity concentration, or grain diameter of bottom sediment. To establish a conservation or restoration strategy, there is a need for classifying taxonomic groups or physical characteristics.

  17. Did the continent and sea have different temperatures in the northern Antarctic Peninsula during the Middle Eocene?

    Directory of Open Access Journals (Sweden)

    A.L. Cione

    2007-12-01

    Full Text Available The Seymour Island beds include a remarkable representation of the continental flora and fauna and marine fauna of Eocene in southern high latitudes. We suggest that, at least during the deposition of the best sampled unit, the Cucullaea I Allomember of the La Meseta Alloformation in the Seymour Island area, a cold temperate terrestrial environment co-existed with relatively warmer temperatures in the adjacent shallow shelf sea. This is suggested by the fish and invertebrate fauna and could have been due to the presence of warmer waters of a current reaching the region from the north. The temperature drop proposed for the time of deposition of the uppermost part of the La Meseta Formation (Submeseta Allomember appears to correspond to the global drop of the end of the Eocene and beginning of Oligocene and not to the establishment of the Antarctic Circumpolar Current.

  18. Charmed Bottom Baryon Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas

    2014-11-01

    The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.

  19. Environmental contamination in Antarctic ecosystems.

    Science.gov (United States)

    Bargagli, R

    2008-08-01

    Although the remote continent of Antarctica is perceived as the symbol of the last great wilderness, the human presence in the Southern Ocean and the continent began in the early 1900s for hunting, fishing and exploration, and many invasive plant and animal species have been deliberately introduced in several sub-Antarctic islands. Over the last 50 years, the development of research and tourism have locally affected terrestrial and marine coastal ecosystems through fuel combustion (for transportation and energy production), accidental oil spills, waste incineration and sewage. Although natural "barriers" such as oceanic and atmospheric circulation protect Antarctica from lower latitude water and air masses, available data on concentrations of metals, pesticides and other persistent pollutants in air, snow, mosses, lichens and marine organisms show that most persistent contaminants in the Antarctic environment are transported from other continents in the Southern Hemisphere. At present, levels of most contaminants in Antarctic organisms are lower than those in related species from other remote regions, except for the natural accumulation of Cd and Hg in several marine organisms and especially in albatrosses and petrels. The concentrations of organic pollutants in the eggs of an opportunistic top predator such as the south polar skua are close to those that may cause adverse health effects. Population growth and industrial development in several countries of the Southern Hemisphere are changing the global pattern of persistent anthropogenic contaminants and new classes of chemicals have already been detected in the Antarctic environment. Although the Protocol on Environmental Protection to the Antarctic Treaty provides strict guidelines for the protection of the Antarctic environment and establishes obligations for all human activity in the continent and the Southern Ocean, global warming, population growth and industrial development in countries of the Southern

  20. Environmental contamination in Antarctic ecosystems.

    Science.gov (United States)

    Bargagli, R

    2008-08-01

    Although the remote continent of Antarctica is perceived as the symbol of the last great wilderness, the human presence in the Southern Ocean and the continent began in the early 1900s for hunting, fishing and exploration, and many invasive plant and animal species have been deliberately introduced in several sub-Antarctic islands. Over the last 50 years, the development of research and tourism have locally affected terrestrial and marine coastal ecosystems through fuel combustion (for transportation and energy production), accidental oil spills, waste incineration and sewage. Although natural "barriers" such as oceanic and atmospheric circulation protect Antarctica from lower latitude water and air masses, available data on concentrations of metals, pesticides and other persistent pollutants in air, snow, mosses, lichens and marine organisms show that most persistent contaminants in the Antarctic environment are transported from other continents in the Southern Hemisphere. At present, levels of most contaminants in Antarctic organisms are lower than those in related species from other remote regions, except for the natural accumulation of Cd and Hg in several marine organisms and especially in albatrosses and petrels. The concentrations of organic pollutants in the eggs of an opportunistic top predator such as the south polar skua are close to those that may cause adverse health effects. Population growth and industrial development in several countries of the Southern Hemisphere are changing the global pattern of persistent anthropogenic contaminants and new classes of chemicals have already been detected in the Antarctic environment. Although the Protocol on Environmental Protection to the Antarctic Treaty provides strict guidelines for the protection of the Antarctic environment and establishes obligations for all human activity in the continent and the Southern Ocean, global warming, population growth and industrial development in countries of the Southern

  1. Is the species flock concept operational? The Antarctic shelf case.

    Directory of Open Access Journals (Sweden)

    Guillaume Lecointre

    Full Text Available There has been a significant body of literature on species flock definition but not so much about practical means to appraise them. We here apply the five criteria of Eastman and McCune for detecting species flocks in four taxonomic components of the benthic fauna of the Antarctic shelf: teleost fishes, crinoids (feather stars, echinoids (sea urchins and crustacean arthropods. Practical limitations led us to prioritize the three historical criteria (endemicity, monophyly, species richness over the two ecological ones (ecological diversity and habitat dominance. We propose a new protocol which includes an iterative fine-tuning of the monophyly and endemicity criteria in order to discover unsuspected flocks. As a result nine « full » species flocks (fulfilling the five criteria are briefly described. Eight other flocks fit the three historical criteria but need to be further investigated from the ecological point of view (here called "core flocks". The approach also shows that some candidate taxonomic components are no species flocks at all. The present study contradicts the paradigm that marine species flocks are rare. The hypothesis according to which the Antarctic shelf acts as a species flocks generator is supported, and the approach indicates paths for further ecological studies and may serve as a starting point to investigate the processes leading to flock-like patterning of biodiversity.

  2. A local metal sources and the influence of the Antarctic Bottom Water on the cobalt-rich crust formatim-New evidence from the data of seawater column chemistry around a seamount%海山当地物源和南极底层水对富钴结壳成矿作用的影响——来自海山周围水柱化学分析的证据

    Institute of Scientific and Technical Information of China (English)

    武光海; 刘捷红

    2012-01-01

    In order to probe seamount Co-rich crusts' metal sources and their ore-forming environment, water column chemistry analyses were done at two sites (one site is just on the seamount slope and the another is relative far away the seamount) around a seamount in the central Pacific Ocean. The results reveal that the water chemical environments of the two sites are similar because of the similar distributions of dissolved oxygen concentration, pH and nutrients concentrations of these sites, two. but the metal element concentrations from the water column are obvious difference between the two sites, and the metal element concentrations at the site on the seamount slope are obvious higher than those of the site relative far away the seamount; the main metal is from the local seamount rocks, maybe related to the low temperature hy-drothermal activity and the water-rock reaction. There are relative high metal concentrations in the bottom water near the seafloor at the two sites although there is the above-mentioned difference. This condition confirms the influence of the Antarctic Bottom Water(AABW) on this area, which is confirmed by the local distributions of the seawater potential temperatures, and shows that the AABW is a main factor to keep the relative strong oxidizing environment in the seawater on the seamount slope and has the ability of transporting partial ore-forming elements. The difference of the two sites maybe hints that there is a local metal source such as low temperature hydrothermal activity in this seamount area.%为了了解海山富钴结壳中金属元素的来源及其形成环境,对中太平洋某海山周围两个站位(一个位于海山斜坡上部,另一个位于海山外围较远处)进行了海水水柱综合水化学分析,发现两个站位溶解氧、pH及营养盐的分布是一致的,反映了两个站位海水化学环境的相似性,而剖面上金属元素含量却存在很大差异,位于海山斜坡上部站位的金属元素含

  3. Regulating Antarctic Tourism and the Precautionary Principle

    NARCIS (Netherlands)

    Bastmeijer, C.J.; Roura, R.

    2004-01-01

    On the basis of an overview of the developments in Antarctic tourism since 1956, this current development note examines the issue of international regulation of Antarctic tourism. After discussing one of the main management issues in respect of Antarctic tourism ¿ the assessment and prevention of cu

  4. Cryptic species diversity in sub-Antarctic islands: A case study of Lepidonotothen.

    Science.gov (United States)

    Dornburg, Alex; Federman, Sarah; Eytan, Ron I; Near, Thomas J

    2016-11-01

    The marine fauna of the Southern Ocean is well known for an impressive adaptive radiation of fishes, the notothenioids. However, when compared to other marine areas, the frigid waters of the Southern Ocean also contain a seemingly large proportion of cryptic species. The documented instances of speciation in the absence of morphological change are largely observed in invertebrate taxa, in particular around peri- and sub-Antarctic islands such as South Georgia, which has been dubbed a cryptic species hotspot. This prevalence of cryptic species raises the question of how generalizable these patterns are for Antarctic vertebrates. Here we examine aspects of genotype and phenotype in an Antarctic notothenioid fish species, Lepidonotothen nudifrons, which is distributed in near shore habitats of the Antarctic Peninsula, South Orkney Islands, South Georgia, and the South Sandwich Islands. The results of our analyses show that L. nudifrons comprises two species. We highlight that cryptic species are phenomena not restricted to invertebrate lineages, raising the possibility that the species diversity of notothenioids and other Southern Ocean fishes is under-described. In addition, our findings raise several questions about the evolutionary origin and maintenance of morphological stasis in one of the most extreme habitats on earth.

  5. Molecular techniques for identifying North Sea fauna

    OpenAIRE

    Knebelsberger, Thomas; Ditzler, Sandra; Laakmann, Silke; Mohrbeck, Inga; Raupach, Michael J.

    2010-01-01

    Accelerated biodiversity assessment is the key to understanding the relationship between biodiversity and ecosystem functioning, especially in times of rapid climate change and habitat destruction. For the marine fauna of the North Sea, morphological species identification is impaired by the small size of many taxa, morphological convergence, intraspecific variation and larval stages which often elude morphological identification. Accordingly, the use of molecular methods...

  6. Signs of hypothetical fauna of Venus

    Science.gov (United States)

    Ksanfomality, Leonid V.

    2014-04-01

    On March 1 and 5, 1982, experiments in television photography instrumented by the landers VENERA-13 and -14, yielded 37 panoramas (or their fragments) of the Venus surface at the landing site. Over the past 31 years, no similar missions have been sent to Venus. Using a modern technique the VENERA panoramas were re-examined. A new analysis of Venusian surface panoramas' details has been made. A few relatively large objects of hypothetical fauna of Venus were found with size ranging from a decimeter to half meter and with unusual morphology. Treated once again VENERA-14 panoramic images revealed `amisada' object about 15 cm in size possessing apparent terramorphic features. The amisada's body stands out with its lizard-like shape against the stone plates close by. The amisada can be included into the list of the most significant findings of the hypothetical Venusian fauna. The amisada's body show slow movements, which is another evidence of the Venusian fauna's very slow style of activity, which appears to be associated with its energy constraints or, and that is more likely, with the properties of its internal medium. The terramorphic features of the Venusian fauna, if they are confirmed, may point out at outstandingly important and yet undiscovered general laws of the animated nature on different planets.

  7. The hawkmoth fauna of Pakistan (Lepidoptera: Sphingidae).

    Science.gov (United States)

    Rafi, Muhammad Ather; Sultan, Amir; Kitching, Ian J; Pittaway, Anthony R; Markhasiov, Maxim; Khan, Muhammad Rafique; Naz, Falak

    2014-01-01

    This study represents the first complete modern account of the Sphingidae of Pakistan and takes the form of an annotated checklist, based on several national collections and those of a number of individuals. Of the 60 species and subspecies found, 14 are new records to the fauna of Pakistan, namely Agnosia orneus, Langia zenzeroides subsp. zenzeroides, Polyptychus trilineatus subsp. trilineatus, Dolbina inexacta, Ambulyx sericeipennis subsp. sericeipennis, Thamnoecha uniformis, Macroglossum belis, Macroglossum stellatarum, Cechetra scotti, Hippotion boerhaviae, Hyles euphorbiae subsp. euphorbiae, Rhagastis olivacea, Rethera brandti subsp. euteles and Theretra latreillii subsp. lucasii. Anambulyx elwesi subsp. kitchingi and Clanis deucalion subsp. thomaswitti are not recognised as valid subspecies and are synonymized with their respective nominotypical subspecies. An additional list is given of 30 taxa which may yet be found in Pakistan as they are present in neighbouring countries close to the border. Of the species/subspecies found, 24 are part of the Palaearctic fauna, 27 are part of the Oriental fauna and nine are Palaeo-Oriental/Palaeotropical. This reconfirms the transitional biogeographical position of the Pakistan fauna. PMID:24870331

  8. Assessing Fish and Motile Fauna around Offshore Windfarms Using Stereo Baited Video.

    Directory of Open Access Journals (Sweden)

    Ross A Griffin

    Full Text Available There remains limited knowledge of how offshore windfarm developments influence fish assemblages, particularly at a local scale around the turbine structures. Considering the existing levels of anthropogenic pressures on coastal fish populations it is becoming increasingly important for developers and environmental regulators to gain a more comprehensive understanding of the factors influencing fish assemblages. Improving our ability to assess such fish populations in close proximity to structures will assist in increasing this knowledge. In the present study we provide the first trial use of Baited Remote Underwater Stereo-Video systems (stereo BRUVs for the quantification of motile fauna in close proximity to offshore wind turbines. The study was conducted in the Irish Sea and finds the technique to be a viable means of assessing the motile fauna of such environments. The present study found a mixture of species including bottom dwellers, motile crustaceans and large predatory fish. The majority of taxa observed were found to be immature individuals with few adult individuals recorded. The most abundant species were the angular crab (Goneplax rhomboides and the small-spotted catshark (Scyliorhinus canicula. Of note in this study was the generally low abundance and diversity of taxa recorded across all samples, we hypothesise that this reflects the generally poor state of the local fauna of the Irish Sea. The faunal assemblages sampled in close proximity to turbines were observed to alter with increasing distance from the structure, species more characteristic of hard bottom environments were in abundance at the turbines (e.g. Homarus gammarus, Cancer pagarus, Scyliorhinus spp. and those further away more characteristic of soft bottoms (e.g. Norwegian Lobster. This study highlights the need for the environmental impacts of offshore renewables on motile fauna to be assessed using targeted and appropriate tools. Stereo BRUVs provide one of those

  9. Assessing Fish and Motile Fauna around Offshore Windfarms Using Stereo Baited Video.

    Science.gov (United States)

    Griffin, Ross A; Robinson, Gary J; West, Ashley; Gloyne-Phillips, Ian T; Unsworth, Richard K F

    2016-01-01

    There remains limited knowledge of how offshore windfarm developments influence fish assemblages, particularly at a local scale around the turbine structures. Considering the existing levels of anthropogenic pressures on coastal fish populations it is becoming increasingly important for developers and environmental regulators to gain a more comprehensive understanding of the factors influencing fish assemblages. Improving our ability to assess such fish populations in close proximity to structures will assist in increasing this knowledge. In the present study we provide the first trial use of Baited Remote Underwater Stereo-Video systems (stereo BRUVs) for the quantification of motile fauna in close proximity to offshore wind turbines. The study was conducted in the Irish Sea and finds the technique to be a viable means of assessing the motile fauna of such environments. The present study found a mixture of species including bottom dwellers, motile crustaceans and large predatory fish. The majority of taxa observed were found to be immature individuals with few adult individuals recorded. The most abundant species were the angular crab (Goneplax rhomboides) and the small-spotted catshark (Scyliorhinus canicula). Of note in this study was the generally low abundance and diversity of taxa recorded across all samples, we hypothesise that this reflects the generally poor state of the local fauna of the Irish Sea. The faunal assemblages sampled in close proximity to turbines were observed to alter with increasing distance from the structure, species more characteristic of hard bottom environments were in abundance at the turbines (e.g. Homarus gammarus, Cancer pagarus, Scyliorhinus spp.) and those further away more characteristic of soft bottoms (e.g. Norwegian Lobster). This study highlights the need for the environmental impacts of offshore renewables on motile fauna to be assessed using targeted and appropriate tools. Stereo BRUVs provide one of those tools, but like

  10. Bottom fauna of dredging and dredge spoil disposal sites of a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Sheeba, P.; Jayalakshmy, K.V.; Devi, S.K.

    . 55. 56. 57. 58. Eriopisa chitkensis Corophium triaenonyx Apseudes chitkensis Apseudes gymnophobium Isopod sp. Anthuridae Decapod sp. Crab Mysid sp. Cumacea sp. Sergestid sp. Alpheid sp. Barnacles Balanus Nudibranchs Gastropod sp. Dentalium sp...

  11. Principles of the Antarctic Treaty

    Science.gov (United States)

    Candidi, M.

    The operation of any base or expedition to Antarctica is regulated by the mutual agreement among nations in the “Antarctic Treaty”. This treaty deals with the major aspects of life in Antarctica and its main principles and provisions are described in what follows.

  12. Special Stamps:Antarctic Scenery

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In July 2002, the State Postal Bureau issued a set of three stamps, whose theme is Antarctic scenery.The first stamp depicts an iceberg. Antarctica is where 90 percent of the world’s ice exists. Each year countless icebergs float majestically through the sea, and are a magnificent scenic feature of Antarctica.

  13. New Vetulicoliids from the Lower Cambrian Guanshan Fauna,Kunming

    Institute of Scientific and Technical Information of China (English)

    LUO Huilin; FU Xiaoping; HU Shixue; LI Yong; CHEN Liangzhong; YOU Ting; LIU Qi

    2005-01-01

    The Guanshan Fauna, a soft-bodied fauna intermediate between the Chengjiang Fauna and the Kaili Fauna and also the Burgess Shale Fauna stratigraphically, consists of trilobites, trilobitoides, Tuzoia, Vetulicola, Paleoscolex, brachiopods and sponges. The discovery and research of this fauna is of great significance in understading the "Cambrian Explosion" and the evolution of early life. The occurrence of vetulicoliids from the Guanshan Fauna not only adds new members to the taxonomic list, but also provides new information to the evolution of this animal group. This paper describe Vetulicola gantoucunensis Luo, Fu et Hu sp. nov. from the Lower Cambrian Wulongqing Formation in the Kunming area. Also presented are the amended description of Vetulicola and the comparisons with related genera within Vetulicoliids. The affinity, distribution, as well as evolution of vetulicoliids are discussed.

  14. SOIL FAUNA CHARACTERIZATION IN Eucalyptus spp. PLANTATIONS

    Directory of Open Access Journals (Sweden)

    Juliana Garlet

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810545Forest soils provide good conditions for the development and the establishment of soil fauna, manly by the deposition of litter. However, monoculture systems conducted in a single substrate by providing food, can promote the development of certain animal groups over others, causing outbreaks of pest species. The aim of this study was to characterize the soil fauna and its relationship with meteorological variables, in plantations of Eucalyptus spp. This study was conducted in six stands of Eucalyptus from three species: Eucalyptus dunni Maiden, Eucalyptus grandis Maiden and Eucalyptus grandis x Eucalyptus urophylla S. T. Blake (clone hybrid and two ages (planted in 2006 and 2007.

  15. Decreasing seagrass density negatively influences associated fauna

    OpenAIRE

    Rosemary M McCloskey; Unsworth, Richard K. F.

    2015-01-01

    Seagrass meadows globally are disappearing at a rapid rate with physical disturbances being one of the major drivers of this habitat loss. Disturbance of seagrass can lead to fragmentation, a reduction in shoot density, canopy height and coverage, and potentially permanent loss of habitat. Despite being such a widespread issue, knowledge of how such small scale change affects the spatial distribution and abundances of motile fauna remains limited. The present study investigated fish and macro...

  16. Investigations of a novel fauna from hydrothermal vents along the Arctic Mid-Ocean Ridge (AMOR) (Invited)

    Science.gov (United States)

    Rapp, H.; Schander, C.; Halanych, K. M.; Levin, L. A.; Sweetman, A.; Tverberg, J.; Hoem, S.; Steen, I.; Thorseth, I. H.; Pedersen, R.

    2010-12-01

    The Arctic deep ocean hosts a variety of habitats ranging from fairly uniform sedimentary abyssal plains to highly variable hard bottoms on mid ocean ridges, including biodiversity hotspots like seamounts and hydrothermal vents. Deep-sea hydrothermal vents are usually associated with a highly specialized fauna, and since their discovery in 1977 more than 400 species of animals have been described. This fauna includes various animal groups of which the most conspicuous and well known are annelids, mollusks and crustaceans. The newly discovered deep sea hydrothermal vents on the Mohns-Knipovich ridge north of Iceland harbour unique biodiversity. The Jan Mayen field consists of two main areas with high-temperature white smoker venting and wide areas with low-temperature seepage, located at 5-700 m, while the deeper Loki Castle vent field at 2400 m depth consists of a large area with high temperature black smokers surrounded by a sedimentary area with more diffuse low-temperature venting and barite chimneys. The Jan Mayen sites show low abundance of specialized hydrothermal vent fauna. Single groups have a few specialized representatives but groups otherwise common in hydrothermal vent areas are absent. Slightly more than 200 macrofaunal species have been identified from this vent area, comprising mainly an assortment of bathyal species known from the surrounding area. Analysis of stable isotope data also indicates that the majority of the species present are feeding on phytodetritus and/or phytoplankton. However, the deeper Loki Castle vent field contains a much more diverse vent endemic fauna with high abundances of specialized polychaetes, gastropods and amphipods. These specializations also include symbioses with a range of chemosynthetic microorganisms. Our data show that the fauna composition is a result of high degree of local specialization with some similarities to the fauna of cold seeps along the Norwegian margin and wood-falls in the abyssal Norwegian Sea

  17. Multibranch Antarctic Seismic Data Library facilitates research

    Science.gov (United States)

    Cooper, Alan K.

    In 1991, investigators from 11 nations involved in Antarctic multichannel seismic (MCS) reflection research sought a way to keep the Antarctic Treaty's promise of open access to data, and in the process to encourage Earth-science research using seismic data. The Antarctic Seismic Data Library System for Cooperative Research (SDLS) was the solution, and is now a recommendation of the Antarctic Treaty Consultative Parties (ATCP). Today—at 12 branches spanning the world—researchers can access over 68,000 km of marine MCS data to use for cooperative research.More than 150,000 km of MCS data have been accumulated since 1976 by 13 countries on nearly 70 cruises. The majority of data now in the library cover the Ross Sea, Wilkes Land, and Prydz Bay sectors of the Antarctic margin, with smaller amounts from the Weddell Sea and the Antarctic Peninsula.

  18. Antarctic tourism and the maritime heritage

    OpenAIRE

    Basberg, Bjørn L.

    2008-01-01

    Maritime activity in the Antarctic region goes back to the 18th Century. It evolved from exploration and discoveries to commercial activities, especially sealing and whaling. Antarctic tourism is a more recent phenomenon, developing gradually from the 1960s. Today, more than 20.000 tourists visit the Antarctic annually – mostly on cruise ships. The paper reviews the historical development of these activities. The main focus is on how the maritime heritage has been dealt with an...

  19. Antarctic skuas recognize individual humans.

    Science.gov (United States)

    Lee, Won Young; Han, Yeong-Deok; Lee, Sang-Im; Jablonski, Piotr G; Jung, Jin-Woo; Kim, Jeong-Hoon

    2016-07-01

    Recent findings report that wild animals can recognize individual humans. To explain how the animals distinguish humans, two hypotheses are proposed. The high cognitive abilities hypothesis implies that pre-existing high intelligence enabled animals to acquire such abilities. The pre-exposure to stimuli hypothesis suggests that frequent encounters with humans promote the acquisition of discriminatory abilities in these species. Here, we examine individual human recognition abilities in a wild Antarctic species, the brown skua (Stercorarius antarcticus), which lives away from typical human settlements and was only recently exposed to humans due to activities at Antarctic stations. We found that, as nest visits were repeated, the skua parents responded at further distances and were more likely to attack the nest intruder. Also, we demonstrated that seven out of seven breeding pairs of skuas selectively responded to a human nest intruder with aggression and ignored a neutral human who had not previously approached the nest. The results indicate that Antarctic skuas, a species that typically inhabited in human-free areas, are able to recognize individual humans who disturbed their nests. Our findings generally support the high cognitive abilities hypothesis, but this ability can be acquired during a relatively short period in the life of an individual as a result of interactions between individual birds and humans.

  20. The fauna of soil nematodes of the rocky pinery

    OpenAIRE

    Gruzdeva L I

    2001-01-01

    The fauna of nematodes of the PetrSU Botanic Garden’s rocky pinery is investigated for the first time. 43 species of soil nematodes are revealed. These are representatives of 6 functional groups (bacteriotrophes, micotrophes, politrophes, predators, obligate and optional plant parasites). In general, the fauna of nematodes of the present biocenosis can be estimated as rather various (Shannon’s variability index H’ = 3.8). Specific diversity of the fauna of nematodes, availability ...

  1. The mammalian fauna from the Central Himalaya, Nepal

    OpenAIRE

    Hem Bahadur Katuwal; Bhaiya Khanal; Khadga Basnet; Bhim Rai; Shiva Devkota

    2013-01-01

    Nepal harbors unique mammalian fauna, but it is poorly studied at higher elevation. Mammalian fauna were recorded in Manaslu Conservation Area, Dudhkunda and Dudhkoshi valley of Solukhumbu district and Kanchenjunga Conservation Area of Nepal during March 2011 to April 2013 along the trail and the study plots from 700m to 4400m a.s.l. Semi-structured interviews were made with local people to understand their behavior and habitats. Altogether, 29 mammalian fauna were recorded. Five species were...

  2. Assessing environmental conditions of Antarctic footpaths to support management decisions.

    Science.gov (United States)

    Tejedo, Pablo; Benayas, Javier; Cajiao, Daniela; Albertos, Belén; Lara, Francisco; Pertierra, Luis R; Andrés-Abellán, Manuela; Wic, Consuelo; Luciáñez, Maria José; Enríquez, Natalia; Justel, Ana; Reck, Günther K

    2016-07-15

    Thousands of tourists visit certain Antarctic sites each year, generating a wide variety of environmental impacts. Scientific knowledge of human activities and their impacts can help in the effective design of management measures and impact mitigation. We present a case study from Barrientos Island in which a management measure was originally put in place with the goal of minimizing environmental impacts but resulted in new undesired impacts. Two alternative footpaths used by tourist groups were compared. Both affected extensive moss carpets that cover the middle part of the island and that are very vulnerable to trampling. The first path has been used by tourists and scientists since over a decade and is a marked route that is clearly visible. The second one was created more recently. Several physical and biological indicators were measured in order to assess the environmental conditions for both paths. Some physical variables related to human impact were lower for the first path (e.g. soil penetration resistance and secondary treads), while other biochemical and microbiological variables were higher for the second path (e.g. β-glucosidase and phosphatase activities, soil respiration). Moss communities located along the new path were also more diverse and sensitive to trampling. Soil biota (Collembola) was also more abundant and richer. These data indicate that the decision to adopt the second path did not lead to the reduction of environmental impacts as this path runs over a more vulnerable area with more outstanding biological features (e.g. microbiota activity, flora and soil fauna diversity). In addition, the adoption of a new route effectively doubles the human footprint on the island. We propose using only the original path that is less vulnerable to the impacts of trampling. Finally from this process, we identify several key issues that may be taken into account when carrying out impact assessment and environmental management decision-making in the

  3. Anti-inflammatory activity in selected Antarctic benthic organisms

    Directory of Open Access Journals (Sweden)

    Juan eMoles

    2014-07-01

    Full Text Available Antarctic benthos was prospected in search for anti-inflammatory activity in polar benthic invertebrates, in two different geographical areas: deep-bottoms of the Eastern Weddell Sea and shallow-waters of the South Shetland Islands. A total of 36 benthic algae and invertebrate species were selected to perform solubility tests in order to test them for anti-inflammatory activity. From these, ethanol extracts of ten species from five different phyla resulted suitable to be studied in cell macrophage cultures (RAW 264.7. Cytotoxicity (MTT method and production of inflammatory mediators (prostaglandin E2, leukotriene B4, interleukin-1 were determined at three extract concentrations (50, 125, 250 g/mL. Bioassays resulted in four different species showing anti-inflammatory activity corresponding to three sponges: Mycale (Oxymycale acerata, Isodictya erinacea, and I. toxophila; and one hemichordate: Cephalodiscus sp. These results show that Antarctic sessile invertebrates may have great value as a source of lead compounds with potential pharmaceutical applications.

  4. JCADM, new directions in Antarctic data management

    Science.gov (United States)

    Campbell, H.; de Bruin, T. F.

    2008-12-01

    The Joint Committee on Antarctic Data Management (JCADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), to assist in the fulfilment of the data management obligations imposed by the Antarctic Treaty (section III.1.c): "Scientific observations and results from Antarctica shall be exchanged and made freely available." JCADM comprises representatives of the National Antarctic Data Centres or national points of contact. Currently 31 nations around the world are represented in JCADM. So far, JCADM has been focussing on the coordination of the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. Currently, JCADM is in a transition phase, moving forward to provide data access. Existing systems and web services technology will be used as much as possible, to increase efficiency and prevent 're-inventing the wheel' This poster will give an overview of this process, the current status and the expected results.

  5. Impact of climate change on Antarctic krill

    NARCIS (Netherlands)

    Florentino De Souza Silva, A.P.; Atkinson, A.; Kawaguchi, S.; Bravo Rebolledo, E.; Franeker, van J.A.

    2012-01-01

    Antarctic krill Euphausia superba (hereafter ‘krill’) occur in regions undergoing rapid environmental change, particularly loss of winter sea ice. During recent years, harvesting of krill has increased, possibly enhancing stress on krill and Antarctic ecosystems. Here we review the overall impact of

  6. Testing oils in antarctic soils

    International Nuclear Information System (INIS)

    The resident seals, whales and penguins in Antarctica's Ross Sea region have only environmentally friendly ways of getting around. In contrast, wherever humans go in the Antarctic and whatever they do, be it research, tourism or fishing, they need fuel for their planes, icebreaker ships, land vehicles and generators. Because of this, petroleum hydrocarbons are the most likely source of pollution in the Antarctic. Accidental oil spills often occur near scientific stations, where storage and refuelling of aircraft and vehicles can result in spills. Spills also occur as a consequence of drilling activities. Dr Jackie Aislabie, a microbiologist from the New Zealand government's research company Landcare Research, is leading a program aimed at understanding how oil spills impact on Antarctic soils. The properties of pristine soils were compared with oil-contaminated soil at three locations: Scott Base, Marble Point and in the Wright Valley at Bull Pass. Soils in the Scott Base area are impacted by the establishment and continuous habitation of the base over 40 years, and a hydrocarbon-contaminated site was sampled near a former storage area for drums of mixed oils. Soil sampled from Marble Point was taken from near the old Marble Point camp, which was inhabited from 1957 to about 1963. Oil stains were visible on the soil surface, and are assumed to have been there for more than 30 years. The samples selected for analysis from the Wright Valley came from a spill site near Bull Pass that occurred during seismic bore-hole drilling activities in 1985. The contamination levels ranged from below detection to just over 29,000 μg/g of soil. Descriptions and analyse results are included into a Geographic Information System and associated soils database

  7. Impacts of marine instability across the East Antarctic Ice Sheet on Southern Ocean dynamics

    Science.gov (United States)

    Phipps, Steven J.; Fogwill, Christopher J.; Turney, Christian S. M.

    2016-09-01

    Recent observations and modelling studies have demonstrated the potential for rapid and substantial retreat of large sectors of the East Antarctic Ice Sheet (EAIS). This has major implications for ocean circulation and global sea level. Here we examine the effects of increasing meltwater from the Wilkes Basin, one of the major marine-based sectors of the EAIS, on Southern Ocean dynamics. Climate model simulations reveal that the meltwater flux rapidly stratifies surface waters, leading to a dramatic decrease in the rate of Antarctic Bottom Water (AABW) formation. The surface ocean cools but, critically, the Southern Ocean warms by more than 1 °C at depth. This warming is accompanied by a Southern Ocean-wide "domino effect", whereby the warming signal propagates westward with depth. Our results suggest that melting of one sector of the EAIS could result in accelerated warming across other sectors, including the Weddell Sea sector of the West Antarctic Ice Sheet. Thus, localised melting of the EAIS could potentially destabilise the wider Antarctic Ice Sheet.

  8. Fauna Europaea - all European animal species on the web

    DEFF Research Database (Denmark)

    de Jong, Yde; Verbeek, Melina; Michelsen, Verner;

    2014-01-01

    Abstract Fauna Europaea is Europe's main zoological taxonomic index, making the scientific names and distributions of all living, currently known, multicellular, European land and freshwater animals species integrally available in one authoritative database. Fauna Europaea covers about 260,000 ta...

  9. The marine Element in the Fauna of the Ganges

    NARCIS (Netherlands)

    Annandale, N.; D.Sc.,

    1922-01-01

    In discussing the aquatic fauna of Europe we are accustomed to divide it into two sections, the marine fauna and that of fresh water. With a few exceptions, such as that of the Decapod Crustacean Palaemonetes varians in brackish water in Northern Europe (and in fresh water in the Mediterranean regio

  10. Combination Features, Paleobiogeographic Affinity and Mass Extinction of the Latest Ordovician (Hirnantian) Rugosan Fauna from Northern Guizhou, China

    Institute of Scientific and Technical Information of China (English)

    HE Xinyi; CHEN Jianqiang; XIAO Jingyi

    2007-01-01

    The rugosan fauna from the Guanyinqiao Bed (latest Ordovician, Hirnantian) of northern Guizhou, China is known to belong to the cold or cool-water type corals. The components of the fauna are solitary corals only, and corallite septa are generally strongly dilated, especially the streptelasmatid corals are dominant comprising 98% of the whole fauna. The Guanyinqiao Bed is rich in rugosans of 18genera, which are streptelasmatid Streptelasma (=Helicelasma), Brachyelasma, Amplexobrachyelasma,Salvadorea, Grewingkia, Borelasma, Crassilasma, Leolasma, Kenophyllum, Ullernelasma,Paramplexoides, Siphonolasma, Pycnactoides, Dalmanophyllum, Bodophyllum, Axiphoria,Lambeophyllum and cystiphyllid Sinkiangolasma. Although this fauna was fairly abundant in a confined area (northern-northeastern Guizhou, southern Sichuan) during the Hirnantian age, the rugosan mass extinction (generic extinction rate 81%) happened at the end of the Hirnantian Stage. It is concluded that the mass extinction is related to the ending of maximum glaciation and ice cap melting in Gondwana in the southern hemisphere in the latest Hirnantian, resulting in rapid global sea-level rise in the earliest Silurian. In the Upper Yangtze Basin, the sea bottom environments were replaced by anoxic and warmer water during that time, so that the cool-water type rugosan became extinct. The present paper attempts to revise some already described rugose coral genera and species (He, 1978,1985) and to supplement a few new forms from the Guanyinqiao Bed. Fourteen species of 12 genera are re-described and illustrated, of which one species-Grewingkia latifossulata is new. As a whole, the rugosan fauna of the Guanyinqiao Bed may be correlated with those contemporaneous of North Europe, Estonia and North America, indicating a close biogeographic affinity to North Europe.

  11. Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.

    Science.gov (United States)

    Huovinen, Pirjo; Ramírez, Jaime; Gómez, Iván

    2016-01-01

    Understanding underwater optics in natural waters is essential in evaluating aquatic primary production and risk of UV exposure in aquatic habitats. Changing environmental conditions related with global climate change, which imply potential contrasting changes in underwater light climate further emphasize the need to gain insights into patterns related with underwater optics for more accurate future predictions. The present study evaluated penetration of solar radiation in six sub-Antarctic estuaries and fjords in Chilean North Patagonian region (39-44°S) and in an Antarctic bay (62°S). Based on vertical diffuse attenuation coefficients (Kd), derived from measurements with a submersible multichannel radiometer, average summer UV penetration depth (z1%) in these water bodies ranged 2-11 m for UV-B (313 nm), 4-27 m for UV-A (395 nm), and 7-30 m for PAR (euphotic zone). UV attenuation was strongest in the shallow Quempillén estuary, while Fildes Bay (Antarctica) exhibited the highest transparency. Optically non-homogeneous water layers and seasonal variation in transparency (lower in winter) characterized Comau Fjord and Puyuhuapi Channel. In general, multivariate analysis based on Kd values of UV and PAR wavelengths discriminated strongly Quempillén estuary and Puyuhuapi Channel from other study sites. Spatial (horizontal) variation within the estuary of Valdivia river reflected stronger attenuation in zones receiving river impact, while within Fildes Bay a lower spatial variation in water transparency could in general be related to closeness of glaciers, likely due to increased turbidity through ice-driven processes. Higher transparency and deeper UV-B penetration in proportion to UV-A/visible wavelengths observed in Fildes Bay suggests a higher risk for Antarctic ecosystems reflected by e.g. altered UV-B damage vs. photorepair under UV-A/PAR. Considering that damage repair processes often slow down under cool temperatures, adverse UV impact could be further

  12. Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.

    Science.gov (United States)

    Huovinen, Pirjo; Ramírez, Jaime; Gómez, Iván

    2016-01-01

    Understanding underwater optics in natural waters is essential in evaluating aquatic primary production and risk of UV exposure in aquatic habitats. Changing environmental conditions related with global climate change, which imply potential contrasting changes in underwater light climate further emphasize the need to gain insights into patterns related with underwater optics for more accurate future predictions. The present study evaluated penetration of solar radiation in six sub-Antarctic estuaries and fjords in Chilean North Patagonian region (39-44°S) and in an Antarctic bay (62°S). Based on vertical diffuse attenuation coefficients (Kd), derived from measurements with a submersible multichannel radiometer, average summer UV penetration depth (z1%) in these water bodies ranged 2-11 m for UV-B (313 nm), 4-27 m for UV-A (395 nm), and 7-30 m for PAR (euphotic zone). UV attenuation was strongest in the shallow Quempillén estuary, while Fildes Bay (Antarctica) exhibited the highest transparency. Optically non-homogeneous water layers and seasonal variation in transparency (lower in winter) characterized Comau Fjord and Puyuhuapi Channel. In general, multivariate analysis based on Kd values of UV and PAR wavelengths discriminated strongly Quempillén estuary and Puyuhuapi Channel from other study sites. Spatial (horizontal) variation within the estuary of Valdivia river reflected stronger attenuation in zones receiving river impact, while within Fildes Bay a lower spatial variation in water transparency could in general be related to closeness of glaciers, likely due to increased turbidity through ice-driven processes. Higher transparency and deeper UV-B penetration in proportion to UV-A/visible wavelengths observed in Fildes Bay suggests a higher risk for Antarctic ecosystems reflected by e.g. altered UV-B damage vs. photorepair under UV-A/PAR. Considering that damage repair processes often slow down under cool temperatures, adverse UV impact could be further

  13. Microbial ecology of Antarctic aquatic systems.

    Science.gov (United States)

    Cavicchioli, Ricardo

    2015-11-01

    The Earth's biosphere is dominated by cold environments, and the cold biosphere is dominated by microorganisms. Microorganisms in cold Southern Ocean waters are recognized for having crucial roles in global biogeochemical cycles, including carbon sequestration, whereas microorganisms in other Antarctic aquatic biomes are not as well understood. In this Review, I consider what has been learned about Antarctic aquatic microbial ecology from 'omic' studies. I assess the factors that shape the biogeography of Antarctic microorganisms, reflect on some of the unusual biogeochemical cycles that they are associated with and discuss the important roles that viruses have in controlling ecosystem function.

  14. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  15. Breakup of Pack Ice, Antarctic Ice Shelf

    Science.gov (United States)

    1991-01-01

    Breakup of Pack Ice along the periphery of the Antarctic Ice Shelf (53.5S, 3.0E) produced this mosaic of ice floes off the Antarctic Ice Shelf. Strong offshore winds, probably associated with strong katabatic downdrafts from the interior of the continent, are seen peeling off the edges of the ice shelf into long filamets of sea ice, icebergs, bergy bits and growlers to flow northward into the South Atlantic Ocean. 53.5S, 3.0E

  16. COMMENT ON AEROSOL EFFECT ON ANTARCTIC OZONE

    OpenAIRE

    イワサカ, ヤスノブ; Yasunobu, IWASAKA; Guang-Yu, SHI

    1987-01-01

    The structure of the aerosol layer disturbed by a cold air was suggested from the lidar measurements at Syowa Station (69°00′S, 39°35′E). The particle layer containing sublayers of spherical or nonspherical aerosols was frequently observed in Antarctic spring. It is a point one sholud not ignore when he discusses aerosol effects on "Antarctic ozone depletion" through radiative processes and heterogeneous chemical reactions.

  17. Role of the meiobenthos in Antarctic ecosystems

    OpenAIRE

    Vanhove, S.; Wittoeck, J; Beghyn, M.; Van Gansbeke, D.; Van Kenhove, A.; Coomans, A.; Vincx, M.

    1997-01-01

    To date meiobenthic research remained a big white spot in the systematic-ecological work on Antarctic zoobenthos. Therefore the relative importance of the meiofauna (organisms within the size range of 38-1000µm) in the Antarctic benthic community has been assessed by a combined field ecology and experimental approach. This was done in two contrasting conditions, e.g. the deep sea and low subtidal, where as to the depth of the water column the benthic characteristics were, respectively, indire...

  18. Hypothetical flora and fauna of Venus

    Science.gov (United States)

    Ksanfomality, L. V.

    2014-12-01

    Hypothetical habitability of some of extrasolar planets is a fundamental question of science. Some of exoplanets possess physical conditions close to those of Venus. Therefore, the planet Venus, with its dense and hot (735 K) oxygen-free atmosphere of CO2, having a high pressure of 9.2 MPa at the surface, can be a natural laboratory for this kind of studies. The only existing data on the planet's surface are still the results obtained by the Soviet VENERA landers in the 1970s and 1980s. The TV experiments of Venera-9 and 10 (October, 1975) and Venera-13 and 14 (March, 1982) delivered 41 panoramas of Venus surface (or their fragments). There have not been any similar missions to Venus in the subsequent 39 and 32 years. In the absence of new landing missions to Venus, the VENERA panoramas have been re-processed. The results of these missions are studied anew. A dozen of relatively large objects, from a decimeter to half a meter in size, with an unusual morphology have been found which moved very slowly or changed slightly their shape. Their emergence by chance could hardly be explained by noise. Certain unusual findings that have similar structure were found in different areas of the planet. This paper presents the last results obtained of a search for hypothetical flora and fauna of Venus.

  19. Met flora meer fauna de stad in trekken

    NARCIS (Netherlands)

    Hoffman, M.H.A.

    2010-01-01

    Meer flora en fauna in de stedelijke omgeving begint met de aanplant van gevarieerd groen. Plant Publicity Holland geeft in een overzicht aan welke bomen, heesters en vaste planten daarvoor geschikt zijn.

  20. SOIL FAUNA CHARACTERIZATION IN Eucalyptus spp. PLANTATIONS

    OpenAIRE

    Juliana Garlet; Ervandil Correa Costa; Jardel Boscardin

    2013-01-01

    http://dx.doi.org/10.5902/1980509810545Forest soils provide good conditions for the development and the establishment of soil fauna, manly by the deposition of litter. However, monoculture systems conducted in a single substrate by providing food, can promote the development of certain animal groups over others, causing outbreaks of pest species. The aim of this study was to characterize the soil fauna and its relationship with meteorological variables, in plantations of Eucalyptus spp. This ...

  1. Vegetated fauna overpass enhances habitat connectivity for forest dwelling herpetofauna

    OpenAIRE

    Mel E. McGregor; Steve K. Wilson; Jones, Darryl N.

    2015-01-01

    The ecological impact of roads and traffic is now widely acknowledged, with a variety of mitigation strategies such as purpose designed fauna underpasses and overpasses commonly installed to facilitate animal movement. Despite often being designed for larger mammals, crossing structures appear to enable safe crossings for a range of smaller, ground dwelling species that exhibit high vulnerability to roads. Less attention has been paid to the extent to which fauna overpasses function as habita...

  2. Notes on the Holocene marine fauna of eastern North Greenland

    DEFF Research Database (Denmark)

    Bennike, Ole; Funder, Svend Visby; Hjorth, Christian

    1986-01-01

    A list of invertebrates, notably molluscs, from the raised Holocene marine sedimets in eastern North Greenland is given. The faunas have low diversity, and contain an element of Arctic sublittoral and bathyal species indicative of cold surface water.......A list of invertebrates, notably molluscs, from the raised Holocene marine sedimets in eastern North Greenland is given. The faunas have low diversity, and contain an element of Arctic sublittoral and bathyal species indicative of cold surface water....

  3. THE CICADA FAUNA AS PHYTOPLASMA VECTORS IN ISTRIAN VINEYARDS

    OpenAIRE

    Đanfranko Pribetić

    2009-01-01

    The cicada fauna represents a considerable group of insects in vine-growing. Phytoplasma vine vectors insects are significant. They are fed from the phloem tissues of plants like cicadas from the families Cicadelidae, Coccidae, Fulgoridae and Psyilloidaea. Their phytoplasma is transmitted in a persistent way. Researches on cicada fauna, on the floristic structure of weeds and host plants of vine phytoplasma were done in 2005 and 2006 in Istrian vineyards. The research was being done in 10 vin...

  4. The SCAR Standing Committee on Antarctic Data Management - new directions in access to Antarctic research data

    Science.gov (United States)

    de Bruin, T.

    2009-04-01

    The SCAR Standing Committee on Antarctic Data Management (SC-ADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), to assist in the fulfillment of the data management obligations imposed by the Antarctic Treaty (section III.1.c): "Scientific observations and results from Antarctica shall be exchanged and made freely available." SC-ADM comprises representatives of the National Antarctic Data Centres or national points of contact. Currently 31 nations around the world are represented in SC-ADM. So far, SC-ADM has been focussing on the coordination of the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. Currently, SC-ADM is in a transition phase, moving forward to provide data access. Existing systems and web services technology will be used as much as possible, to increase efficiency and prevent 're-inventing the wheel' This poster will give an overview of this process, the current status and the expected results.

  5. Bottom sediments of Ypacarai Lake

    International Nuclear Information System (INIS)

    Bottom sediments of Ypacarai Lake was investigated with XRF and Mossbauer techniques. The lake of about 120 Km2, is a shallow one, medium deep of about 1.8m. In addition to its use for recreation, its basin has a wide area of influence and of economical significance. Bottom sediments play an important role in the overall distribution of trace elements in the aquatic system and act as a sink for metals. Bottom samples were taken from 5 different sampling stations, selected according to the morphology and population sites in the shore. The concentration of toxic metals was found to be low and no negative ecological impact should be expected. The main metallic ion component is iron (1.69%). Mossbauer studies showed this element appears as Fe+3 and no Fe+2 was detected. It is here suggested that Fe+3 acts as the limiting element which controls eutrophication process

  6. Bottomed analog of Z+(4433)

    International Nuclear Information System (INIS)

    The newly observed Z+(4433) resonance by BELLE is believed to be a tetraquark bound state made up of (cu)(cd). We propose the bottomed analog of this bound state, namely, by replacing one of the charm quarks by a bottom quark, thus forming Zbc0,±,±±. One of the Zbc is doubly charged. The predicted mass of Zbc is around 7.6 GeV. This doubly charged bound state can be detected by its decay into Bc±π±. Similarly, we can also replace both charm quark and antiquark of the Z+(4433) by bottom quark and antiquark, respectively, thus forming Zbb the bottomonium analog of Z+(4433). The predicted mass of Zbb is about 10.7 GeV

  7. Oxygen and evolutionary patterns in the sea: onshore/offshore trends and recent recruitment of deep-sea faunas

    Science.gov (United States)

    Jacobs, D. K.; Lindberg, D. R.

    1998-01-01

    Over the last 15 years a striking pattern of diversification has been documented in the fossil record of benthic marine invertebrates. Higher taxa (orders) tend to originate onshore, diversify offshore, and retreat into deep-water environments. Previous studies attribute this macroevolutionary pattern to a variety of causes, foremost among them the role of nearshore disturbance in providing opportunities for the evolution of novel forms accorded ordinal rank. Our analysis of the post-Paleozoic record of ordinal first appearances indicates that the onshore preference of ordinal origination occurred only in the Mesozoic prior to the Turonian stage of the Cretaceous, a period characterized by relatively frequent anoxic/dysoxic bottom conditions in deeper marine environments. Later, in the Cretaceous and Cenozoic, ordinal origination of benthic organisms did not occur exclusively, or even preferentially, in onshore environments. This change in environmental pattern of ordinal origination roughly correlates with Late Cretaceous: (i) decline in anoxia/dysoxia in offshore benthic environments; (ii) extinction of faunas associated with dysoxic conditions; (iii) increase in bioturbation with the expansion of deep burrowing forms into offshore environments; and (iv) offshore expansion of bryozoan diversity. We also advance a separate argument that the Cenomanian/Turonian and latest Paleocene global events eliminated much of the deep-water benthos. This requires a more recent origin of modern vent and deep-sea faunas, from shallower water refugia, than the Paleozoic or early Mesozoic origin of these faunas suggested by other workers.

  8. Temporal segregation of the Australian and Antarctic blue whale call types (Balaenoptera musculus spp.)

    OpenAIRE

    Tripovich, Joy S.; Klinck, Holger; Nieukirk, Sharon L; Adams, Tempe; Mellinger, David K.; Balcazar, Naysa E.; Klinck, Karolin; Hall, Evelyn J. S.; Tracey L Rogers

    2015-01-01

    We examined recordings from a 15-month (May 2009–July 2010) continuous acoustic data set collected from a bottom-mounted passive acoustic recorder at a sample frequency of 6kHz off Portland, Victoria, Australia (38°33′01″S, 141°15′13″E) off southern Australia. Analysis revealed that calls from both subspecies were recorded at this site, and general additive modeling revealed that the number of calls varied significantly across seasons. Antarctic blue whales were detected more frequently from ...

  9. A dataset from bottom trawl survey around Taiwan

    Directory of Open Access Journals (Sweden)

    Kwang-tsao Shao

    2012-05-01

    Full Text Available Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000–2003, in the waters around Taiwan and Penghu (Pescadore Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw. They have also been published through TaiBIF (http://taibif.tw, FishBase and GBIF (website see below. This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

  10. A dataset from bottom trawl survey around Taiwan.

    Science.gov (United States)

    Shao, Kwang-Tsao; Lin, Jack; Wu, Chung-Han; Yeh, Hsin-Ming; Cheng, Tun-Yuan

    2012-01-01

    Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000-2003, in the waters around Taiwan and Penghu (Pescadore) Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw). They have also been published through TaiBIF (http://taibif.tw), FishBase and GBIF (website see below). This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

  11. Flora y fauna crónica

    Directory of Open Access Journals (Sweden)

    Susana Chávez-Silverman

    2004-01-01

    Full Text Available “Flora & Fauna Crónica” is from the book, Killer Crónicas, which will be published by the University of Wisconsin Press in 2004. This collection of chronicles began in 2000, after Susana was awarded a fellowship by the US National Endowment for the Humanities (NEH for a project on contemporary Argentine women's poetry. She spent thirteen months in Buenos Aires where, in addition to research and writing on her official (academic book, she began to send bilingual, punning “letters from the southern [cone] front” to colleagues and friends by email. Susana says: “Living in Buenos Aires, that gorgeous, turn of the century city in a country on the brink of (economic collapse—home to many of the authors and artists I had long admired (Borges, Cortázar, Alfonsina Storni, Alejandra Pizarnik, and before them the foundational Romantics, Sarmiento and Echeverría—brought out a sense of self, dis/placed yet oddly at home, in a cultural, linguistic and even tangible way. In Buenos Aires, the fragmented parts of me, the voices, cultures, and places inside of me, rubbed up against each other and struck fire. I called my email missives “Crónicas,” inspired by the somewhat rough-hewn, journalistic, often fantastic first-hand accounts sent “home” by the early conquistadores, and refashioned by modern-day counterparts such as Carlos Monsiváis, Elena Poniatowska, and Cristina Pacheco.” One of Susana’s crónicas, “Anniversary Crónica,” inspired by the wedding anniversary of Susana’s parents and by the so-called “Soweto Riots” in South Africa, was recently awarded First prize in Personal Memoir in the Chicano Literary Excellence Contest sponsored by the U.S. national literary magazine el Andar.

  12. Health aspects of Antarctic tourism.

    Science.gov (United States)

    Prociv, P

    1998-12-01

    Increasing numbers of seaborne tourists are visiting Antarctica, with most coming from the United States (3503 in 1996-97), Germany (777), and Australia (680; cf. 356 in 1994-95 and 410 in 1995-96). The impression among travel medicine clinicians is that, each year, more prospective travelers seek advice about the health demands of this type of adventure, mostly relating to fitness for travel, exposure to extreme cold, hazards in ice and snow, and other potential health risks. This is a recent phenomenon. While a regular shipping service had been established between the Falklands and the subantarctic islands of South Georgia and the South Shetlands by 1924, the first documented tourists accompanied an Argentine expedition to the South Orkneys in 1933.1 Commercial airline flights over these islands and the Antarctic Peninsula began in 1956, from Chile, and recreational cruises to the Peninsula began in 1958. Tourist numbers subsequently grew slowly, for what was clearly an exclusive and very expensive undertaking, with few ships available for these hazardous voyages. From 1957 to 1993, 37,000 tourists visited by sea, most seeing only the Peninsula.2 The dramatic recent growth in numbers is a consequence of the collapse of the Soviet Union. The small fleet of ice-strengthened research vessels and working icebreakers, which was made redundant by withdrawal of central government support from isolated communities and military activities along the northern coast of Siberia (and from Antarctic research bases), now accounts for the bulk of charter-cruise tourism to Antarctica, at competitive prices. According to the International Association of Antarctica Tour Operators,3 7322 people traveled to Antarctica on commercially organized voyages in the 1996-97 season, and a record 10,000 shipborne visitors were expected for the 1997-98 season (November-March), traveling mainly from South America to the Peninsula on 15 ice-reinforced vessels, each carrying between 36 and 180

  13. Culture from the Bottom Up

    Science.gov (United States)

    Atkinson, Dwight; Sohn, Jija

    2013-01-01

    The culture concept has been severely criticized for its top-down nature in TESOL, leading arguably to its falling out of favor in the field. But what of the fact that people do "live culturally" (Ingold, 1994)? This article describes a case study of culture from the bottom up--culture as understood and enacted by its individual users.…

  14. Controls and variability of solute and sedimentary fluxes in Antarctic and sub-Antarctic Environments

    Science.gov (United States)

    Zwolinski, Zbigniew

    2015-04-01

    The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). The book comprises five parts. One of them is part about sub-Antarctic and Antarctic Environments. This part "Sub-Antarctic and Antarctic Environments" describes two different environments, namely oceanic and continental ones. Each part contains results of research on environmental drivers and rates of contemporary solute and sedimentary fluxes in selected sites. Apart from describing the environmental conditions of the whole continent of Antarctica and sub-Antarctic islands (Zb.Zwolinski, M.Kejna, A.N.Lastochkin, A.Zhirov, S.Boltramovich) this part of the book characterizes terrestrial polar oases free from multi-year ice and snow covers (Zb.Zwolinski). The detailed results of geoecological and sedimentological research come from different parts of Antarctica. Antarctic continental shelf (E.Isla) is an example of sub-Antarctic oceanic environment. South Shetlands, especially King George Island (Zb.Zwolinski, M.Kejna, G.Rachlewicz, I.Sobota, J.Szpikowski), is an example of sub-Antarctic terrestrial environment. Antarctic Peninsula (G.Vieira, M.Francelino, J.C.Fernandes) and surroundings of McMurdo Dry Valleys (W.B.Lyons, K.A.Welch, J.Levy, A.Fountain, D.McKnight) are examples of Antarctic continental environments. The key goals of the Antarctic and sub-Antarctic book chapters are following: (i) identify the main environmental drivers and rates of contemporary solute and sedimentary fluxes, and (ii) model possible effects of projected climate change on solute and sedimentary fluxes in cold climate environments

  15. What shapes edaphic communities in mineral and ornithogenic soils of Cierva Point, Antarctic Peninsula?

    Science.gov (United States)

    Mataloni, G.; Garraza, G. González; Bölter, M.; Convey, P.; Fermani, P.

    2010-08-01

    Three mineral soil and four ornithogenic soil sites were sampled during summer 2006 at Cierva Point (Antarctic Peninsula) to study their bacterial, microalgal and faunal communities in relation to abiotic and biotic features. Soil moisture, pH, conductivity, organic matter and nutrient contents were consistently lower and more homogeneous in mineral soils. Ornithogenic soils supported larger and more variable bacterial abundances than mineral ones. Algal communities from mineral soils were more diverse than those from ornithogenic soils, although chlorophyll- a concentrations were significantly higher in the latter. This parameter and bacterial abundance were correlated with nutrient and organic matter contents. The meiofauna obtained from mineral soils was homogeneous, with one nematode species dominating all samples. The fauna of ornithogenic soils varied widely in composition and abundance. Tardigrades and rotifers dominated the meiofauna at eutrophic O2, where they supported a large population of the predatory nematode Coomansus gerlachei. At site O3, high bacterial abundance was consistent with high densities of the bacterivorous nematodes Plectus spp. This study provides evidence that Antarctic soils are complex and diverse systems, and suggests that biotic interactions (e.g. competition and predation) may have a stronger and more direct influence on community variability in space and time than previously thought.

  16. Cenozoic Methane-Seep Faunas of the Caribbean Region.

    Directory of Open Access Journals (Sweden)

    Steffen Kiel

    Full Text Available We report new examples of Cenozoic cold-seep communities from Colombia, Cuba, the Dominican Republic, Trinidad, and Venezuela, and attempt to improve the stratigraphic dating of Cenozoic Caribbean seep communities using strontium isotope stratigraphy. Two seep faunas are distinguished in Barbados: the late Eocene mudstone-hosted 'Joes River fauna' consists mainly of large lucinid bivalves and tall abyssochrysoid gastropods, and the early Miocene carbonate-hosted 'Bath Cliffs fauna' containing the vesicomyid Pleurophopsis, the mytilid Bathymodiolus and small gastropods. Two new Oligocene seep communities from the Sinú River basin in Colombia consist of lucinid bivalves including Elongatolucina, thyasirid and solemyid bivalves, and Pleurophopsis. A new early Miocene seep community from Cuba includes Pleurophopsis and the large lucinid Meganodontia. Strontium isotope stratigraphy suggests an Eocene age for the Cuban Elmira asphalt mine seep community, making it the oldest in the Caribbean region. A new basal Pliocene seep fauna from the Dominican Republic is characterized by the large lucinid Anodontia (Pegophysema. In Trinidad we distinguish two types of seep faunas: the mudstone-hosted Godineau River fauna consisting mainly of lucinid bivalves, and the limestone-hosted Freeman's Bay fauna consisting chiefly of Pleurophopsis, Bathymodiolus, and small gastropods; they are all dated as late Miocene. Four new seep communities of Oligocene to Miocene age are reported from Venezuela. They consist mainly of large globular lucinid bivalves including Meganodontia, and moderately sized vesicomyid bivalves. After the late Miocene many large and typical 'Cenozoic' lucinid genera disappeared from the Caribbean seeps and are today known only from the central Indo-Pacific Ocean. We speculate that the increasingly oligotrophic conditions in the Caribbean Sea after the closure of the Isthmus of Panama in the Pliocene may have been unfavorable for such large

  17. 76 FR 9849 - Comprehensive Environmental Evaluations for Antarctic Activities

    Science.gov (United States)

    2011-02-22

    .... SUPPLEMENTARY INFORMATION: Article 3 of Annex I to the Protocol on Environmental Protection to the Antarctic Treaty requires the preparation of a CEE for any proposed Antarctic activity likely to have more than a... Comprehensive Environmental Evaluations for Antarctic Activities SUMMARY: The Department of State gives...

  18. NSF's role in Antarctic environment scrutinized

    Science.gov (United States)

    Bush, Susan

    In the last few years, the National Science Foundation has come under criticism by environmental groups for inadequate stewardship in the U.S. Antarctic Program's environmental issues. Since 1978, NSF was given full responsibility, by Executive Order, for budgeting and managing the entire U.S. national program in Antarctica, including logistics support. NSF has also been responsible for the compliance of the U.S. Antarctic Program with environmental protection measures agreed to by the Antarctic Treaty nations. Specifically under fire by environmentalists have been NSF's maintenance of a land-fill, open-air burning of solid waste, and the removal of toxic substances. According to Peter E. Wilkniss, director of the Division of Polar Programs at NSF, open burning is no longer taking place and will not be allowed in the future.

  19. Antarctic “quiet” site stirs debate

    Science.gov (United States)

    Simarski, Lynn Teo

    Geophysicists from the United States and New Zealand plan to meet in the coming months to assess the electromagnetic pollution of an Antarctic site especially designated for research. U.S. scientists charge that a satellite Earth station erected apparently inside the preserve by New Zealand's Telecom company could interfere with experiments on the ionosphere and magnetosphere (Eos, April 28, 1992). The Site of Special Scientific Interest at Arrival Heights, the only Antarctic preserve specifically for physical science, is located near the U.S. McMurdo and New Zealand Scott bases.Debate over the Telecom facility inter-twines diplomatic and scientific issues. One question is whether the station violates the Antarctic treaty. Secondly, does it actually impair research at the site—or could it harm future experiments? To deepen the imbroglio, those involved from both nations say that transmissions from sources off-site also interfere with research—raising doubts about how pristine the site really is.

  20. The Antarctic cryptoendolithic ecosystem - Relevance to exobiology

    Science.gov (United States)

    Friedmann, E. I.; Ocampo-Friedmann, R.

    1984-01-01

    Cryptoendolithic microorganisms in the Antarctic desert live inside porous sandstone rocks, protected by a thin rock crust. While the rock surface is abiotic, the microclimate inside the rock is comparatively mild. These organisms may have descended from early, pre-glaciation Antarctic life forms and thus may represent the last outpost of life in a gradually deteriorating environment. Assuming that life once arose on Mars, it is conceivable that, following the loss of water, the last of surviving organisms withdrew to similar insulated microenvironments. Because such microscopic pockets have little connection with the outside environment, their detection may be difficult. The chances that the Viking lander could sample cryptoendolithic microorganisms in the Antarctic desert would be infinitesimal.

  1. Solar flare irradiation records in Antarctic meteorites

    Science.gov (United States)

    Goswami, J. N.

    1981-01-01

    The observation of tracks from solar flare heavy nuclei in Antarctic meteorite samples is reported. In an analysis of nuclear track densities in eight L and H chondrites of low metamorphic grade, it was found that two interior specimens of sample 77216, an L-3 chondrite, contain olivine grains with track densities much higher than the average track densities, indicating precompaction irradiation by solar flares in different shielding conditions. Preliminary data from mass spectroscopic analyses show a large excess of noble gases, with a Ne-20/Ne-22 ratio of greater than or equal to 10, indicating the presence of solar-type noble gas. Results of track density measurements in the other Antarctic meteorites range from 10,000 to 4,000,000/sq cm, which is within the range observed in non-Antarctic L-group meteorites

  2. Meteorological observatory for Antarctic data collection

    International Nuclear Information System (INIS)

    In the last years, a great number of automatic weather stations was installed in Antarctica, with the aim to examine closely the weather and climate of this region and to improve the coverage of measuring points on the Antarctic surface. In 1987 the Italian Antarctic Project started to set up a meteorological network, in an area not completely covered by other countries. Some of the activities performed by the meteorological observatory, concerning technical functions such as maintenance of the AWS's and the execution of radio soundings, or relating to scientific purposes such as validation and elaboration of collected data, are exposed. Finally, some climatological considerations on the thermal behaviour of the Antarctic troposphere such as 'coreless winter', and on the wind field, including katabatic flows in North Victoria Land are described

  3. First geomagnetic measurements in the Antarctic region

    Science.gov (United States)

    Raspopov, O. M.; Demina, I. M.; Meshcheryakov, V. V.

    2014-05-01

    Based on data from literature and archival sources, we have further processed and analyzed the results of geomagnetic measurements made during the 1772-1775 Second World Expedition by James Cook and the 1819-1821 overseas Antarctic Expedition by Russian mariners Bellingshausen and Lazarev. Comparison with the GUFM historical model showed that there are systematic differences in the spatial structure of both the declination and its secular variation. The results obtained can serve as a basis for the construction of regional models of the geomagnetic field for the Antarctic region.

  4. Climate Change Influences on Antarctic Bird Populations

    Science.gov (United States)

    Korczak-Abshire, Małgorzata

    2010-01-01

    Rapid changes in the major environmental variables like: temperature, wind and precipitation have occurred in the Antarctic region during the last 50 years. In this very sensitive region, even small changes can potentially lead to major environmental perturbations. Then the climate change poses a new challenge to the survival of Antarctic wildlife. As important bioindicators of changes in the ecosystem seabirds and their response to the climate perturbations have been recorded. Atmospheric warming and consequent changes in sea ice conditions have been hypothesized to differentially affect predator populations due to different predator life-history strategies and substantially altered krill recruitment dynamics.

  5. Flora and Fauna in Roundup Tolerant Fodder Beet Fields

    DEFF Research Database (Denmark)

    Elmegaard, N.; Pedersen, Marianne Bruus

    three times. The results are reported at http://www.sns.dk/natur/bioteknologi/ roundup_art.htm. In 2000, six different fields were visited but only once (in June), in order to examine flora and fauna in field cultivated on different soil types, under different weather conditions and under different....... Thus, the conservation potential in RR-beets can be improved if dosage is reduced. At the studied sites there was a scope for dosage reduction without yield loss. Use of insecticides in fields with delayed weed control will counteract the benefits to the fauna from the herbicide regime. In the present...... study insecticide was only used as seed dressing. A dense and diverse weed flora is believed to benefit the fauna in several ways. Firstly, occurrence and density of the host affect herbivorous insect species thriving on specific weed species. Secondly, the microclimate and habitat structure of weedy...

  6. Characteristic Flora and Fauna of the Kachin State, Northern Myanmar

    International Nuclear Information System (INIS)

    Three biological expeditions was made from June 2003 to June 2004. Altitude is a major factor among the differences of flora and fauna distribution. Hkakaborazi (19296') is a reservoir of glaciers with permanent ice and snow from which rivers. Melikha and Maekha emanate. Ayeyarwaddy river formed from those two rivers and flow beside Myirkyina. Therefore, water quality of each river and their tributaries are cool and fresh. This quality can preserve endemic species. Unknown species of jellyfishes of Ayeyarwaddy river was collected from Myitkyina environ. Also, three different terrestrial habitats namely icy-mountain range, cool temperature and subtropical forest can conserve their characteristic flora and fauna. Flora and fauna distribution is always related to their habitat or environs. Diagnostic features of each species were recorded by photographs. The findings were discussed from conservation point of view.

  7. An annotated checklist of the Greek Stonefly Fauna (Insecta: Plecoptera).

    Science.gov (United States)

    Karaouzas, Ioannis; Andriopoulou, Argyro; Kouvarda, Theodora; Murányi, Dávid

    2016-05-17

    An overview of the Greek stonefly (Plecoptera) fauna is presented as an annotated index of all available published records. These records have resulted in an updated species list reflecting current taxonomy and species distributions of the Greek peninsula and islands. Currently, a total of 71 species and seven subspecies belonging to seven families and 19 genera are reported from Greece. There is high species endemicity of the Leuctridae and Nemouridae, particularly on the Greek islands. The endemics known from Greece comprise thirty species representing 42% of the Greek stonefly fauna. The remaining taxa are typical Balkan and Mediterranean species.

  8. An annotated checklist of the Greek Stonefly Fauna (Insecta: Plecoptera).

    Science.gov (United States)

    Karaouzas, Ioannis; Andriopoulou, Argyro; Kouvarda, Theodora; Murányi, Dávid

    2016-01-01

    An overview of the Greek stonefly (Plecoptera) fauna is presented as an annotated index of all available published records. These records have resulted in an updated species list reflecting current taxonomy and species distributions of the Greek peninsula and islands. Currently, a total of 71 species and seven subspecies belonging to seven families and 19 genera are reported from Greece. There is high species endemicity of the Leuctridae and Nemouridae, particularly on the Greek islands. The endemics known from Greece comprise thirty species representing 42% of the Greek stonefly fauna. The remaining taxa are typical Balkan and Mediterranean species. PMID:27395093

  9. Antarctic Data Management as Part of the IPY Legacy

    Science.gov (United States)

    de Bruin, T.

    2006-12-01

    The Antarctic Treaty states that "scientific observations and results from Antarctica shall be exchanged and made freely available". Antarctica includes the Southern Ocean. In support of this, National Antarctic Data Centres (NADC) are being established to catalogue data sets and to provide information on data sets to scientists and others with interest in Antarctic science. The Joint Committee on Antarctic Data Management (JCADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP). JCADM comprises representatives of the National Antarctic Data Centres. Currently 30 nations around the world are represented in JCADM. JCADM is responsible for the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. JCADM is the Antarctic component of the IPY Data Infrastructure, which is presently being developed. This presentation will give an overview of the organization of Antarctic and Southern Ocean data management with sections on the organizational structure of JCADM, contents of the Antarctic Master Directory, relationships to the SCAR Scientific Research Programmes (SRP) and IPY, international embedding and connections with discipline-based peer organizations like the International Oceanographic Data and Information Exchange Committee (IODE). It will focus primarily on the role that an existing infrastructure as JCADM, may play in the development of the IPY Data Infrastructure and will provide considerations for IPY data management, based on the experiences in Antarctic and oceanographic data management.

  10. Diagnóstico da fauna silvestre em empresas florestais brasileiras Diagnosis of wild fauna in brazilian forest companies

    Directory of Open Access Journals (Sweden)

    Giovanna Debortoli Medeiros

    2009-02-01

    Full Text Available Com o objetivo de conhecer a situação atual da fauna silvestre em empresas florestais brasileiras, foram pesquisadas 42 razões sociais, entre Associadas e Co-Participantes da Sociedade de Investigações Florestais (SIF, as quais possuem plantios florestais próprios. As informações foram obtidas com base em questionário enviado às referidas empresas, via correio eletrônico, sendo as respostas obtidas também por esse mecanismo. Entre os vários resultados, destaca-se o fato de que 90,9% das empresas associadas já realizaram levantamentos qualitativos da fauna silvestre. No entanto, de modo geral há notória carência de infra-estrutura nas empresas pesquisadas para atender a trabalhos específicos de manejo e conservação da fauna silvestre.Forty-two companies, associates and co-participants of the Forest Investigation Society (SIF and owners of private forest plantations, were assessed to determine the current situation of wild fauna in Brazilian forest companies. Information was obtained through a questionnaire sent to and received from the companies by e-mail. One of the several results obtained was that 90.9% of the associate companies had already carried out qualitative surveys on wild fauna stands.. On the other hand, in general, there is a total lack of infrastructure in the surveyed companies, to specifically assist in the management and conservation of wild fauna.

  11. Molecular and morphological analysis of an Antarctic tardigrade, Acutuncus antarcticus

    Directory of Open Access Journals (Sweden)

    Hiroshi Kagoshima

    2013-03-01

    Full Text Available We isolated a species of tardigrade from moss samples collected from Langhovde and Skarvsnes, near Syowa station, East Antarctic, from which we cultured a parthenogenetic strain in Petri dishes with co-occurring cyanobacteria or green algae. This culture was maintained at both 4 and 10ºC, though the latter proved more suitable for growth. Eggs were laid free, rather than in exuviae. We isolated the 18S rRNA sequences from this tardigrade, identical to that of Acutuncus antarcticus from King George island, South Shetland islands. Morphological analyses via both light and scanning electron microscopy also show general agreement with characteristics of A. antarcticus: dorsal and ventral apophyses for the insertion of stylet muscles and dorsal longitudinal thickening on the anterior part of buccal tube; presence of pharyngeal apophyses, two macroplacoids and absence of a microplacoid; the surface structure of egg; and claw shape. Peribuccal lamellae were absent, but six oval swellings surrounded the mouth opening. An additional study of moss pillars from lake Hotoke-ike, Skarvsnes, proved the existence of the same tardigrade taxon living at the bottom of the lake.

  12. Contrasting Arctic and Antarctic sea ice temperatures

    Science.gov (United States)

    Vancoppenolle, Martin; Raphael, Marilyn; Rousset, Clément; Vivier, Frédéric; Moreau, Sébastien; Delille, Bruno; Tison, Jean-Louis

    2016-04-01

    Sea ice temperature affects the sea ice growth rate, heat content, permeability and habitability for ice algae. Large-scale simulations with NEMO-LIM suggest large ice temperature contrasts between the Arctic and the Antarctic sea ice. First, Antarctic sea ice proves generally warmer than in the Arctic, in particular during winter, where differences reach up to ~10°C. Second, the seasonality of temperature is different among the two hemispheres: Antarctic ice temperatures are 2-3°C higher in spring than they are in fall, whereas the opposite is true in the Arctic. These two key differences are supported by the available ice core and mass balance buoys temperature observations, and can be attributed to differences in air temperature and snow depth. As a result, the ice is found to be habitable and permeable over much larger areas and much earlier in late spring in the Antarctic as compared with the Arctic, which consequences on biogeochemical exchanges in the sea ice zone remain to be evaluated.

  13. Relevance of antarctic microbial ecosystems to exobiology

    Science.gov (United States)

    Mckay, Christopher P.

    1993-01-01

    Antarctic microbial ecosystems which provide biological and physical analogs that can be used in exobiology are studied. Since the access to extraterrestrial habitats is extremely difficult, terrestrial analogs represent the best opportunity for both formulation and preliminary testing of hypothesis about life. Antarctica, as one of few suitable environments on earth is considered to be a major locus of progress in exobiology.

  14. Global dynamics of the Antarctic ice sheet

    NARCIS (Netherlands)

    Oerlemans, J.

    2002-01-01

    The total mass budget of the Antarctic ice sheet is studied with a simple axi-symmetrical model. The ice-sheet has a parabolic profile resting on a bed that slopes linearly downwards from the centre of the ice sheet into the ocean. The mean ice velocity at the grounding line is assumed to be proport

  15. A method for treating bottom ash

    NARCIS (Netherlands)

    Rem, P.C.; Van Craaikamp, H.; Berkhout, S.P.M.; Sierhuis, W.; Van Kooy, L.A.

    2007-01-01

    A method for treating bottom ash from a waste incineration plant. The invention relates in particular to a method for treating bottom ash from a domestic waste incineration plant. In accordance with the invention bottom ash having a size ranging up to 2 mm is treated by removing a previously determi

  16. Long-term monitoring of the environmental quality of the Norwegian coastal areas. Soft-bottom. Data report 1995; Langtidsovervaaking av miljoekvaliteten i kystomraadene av Norge. Bloetbunn. Datarapport 1995

    Energy Technology Data Exchange (ETDEWEB)

    Rygg, B.

    1996-02-01

    This report contains data collected in 1995 in a running programme for monitoring the environmental quality off the coast of Norway. Samples from soft-bottom fauna were collected at 17 locations. The species diversity, individuals counts within the species and sediment parameters are tabulated. Analysis is left for the annual report. 3 refs., 1 fig., 21 tabs.

  17. Neogene kinematic history of Nazca-Antarctic-Phoenix slab windows beneath Patagonia and the Antarctic Peninsula

    Science.gov (United States)

    Breitsprecher, Katrin; Thorkelson, Derek J.

    2009-01-01

    The Patagonian slab window is a subsurface tectonic feature resulting from subduction of the Nazca-Antarctic spreading-ridge system (Chile Rise) beneath southern South America. The geometry of the slab window had not been rigorously defined, in part because of the complex nature of the history of ridge subduction in the southeast Pacific region, which includes four interrelated spreading-ridge systems since 20 Ma: first, the Nazca-Phoenix ridge beneath South America, then simultaneous subduction of the Nazca-Antarctic and the northern Phoenix-Antarctic spreading-ridge systems beneath South America, and the southern Phoenix-Antarctic spreading-ridge system beneath Antarctica. Spreading-ridge paleo-geographies and rotation poles for all relevant plate pairs (Nazca, Phoenix, Antarctic, South America) are available from 20 Ma onward, and form the mathematical basis of our kinematic reconstruction of the geometry of the Patagonia and Antarctic slab windows through Neogene time. At approximately 18 Ma, the Nazca-Phoenix-Antarctic oceanic (ridge-ridge-ridge) triple junction enters the South American trench; we recognize this condition as an unstable quadruple junction. Heat flow at this junction and for some distance beneath the forearc would be considerably higher than is generally recognized in cases of ridge subduction. From 16 Ma onward, the geometry of the Patagonia slab window developed from the subduction of the trailing arms of the former oceanic triple junction. The majority of the slab window's areal extent and geometry is controlled by the highly oblique (near-parallel) subduction angle of the Nazca-Antarctic ridge system, and by the high contrast in relative convergence rates between these two plates relative to South America. The very slow convergence rate of the Antarctic slab is manifested by the shallow levels achieved by the slab edge (< 45 km); thus no point on the Antarctic slab is sufficiently deep to generate "normal" mantle-derived arc-type magmas

  18. A checklist of the fish fauna of Greenland waters

    DEFF Research Database (Denmark)

    Møller, Peter R.; Nielsen, Jørgen G.; Knudsen, Steen W.;

    2010-01-01

    Although the Greenland fish fauna has been studied for more than 200 years, new species continue to be discovered. We here take the opportunity of the International Polar Year 2007-08 (IPY) to present an updated check-list of the fishes of Greenland and discuss whether the growing diversity can...

  19. Soil invertebrate fauna affect N2O emissions from soil

    NARCIS (Netherlands)

    Kuiper, I.; Deyn, de G.B.; Thakur, M.P.; Groenigen, van J.W.

    2013-01-01

    Nitrous oxide (N2O) emissions from soils contribute significantly to global warming. Mitigation of N2O emissions is severely hampered by a lack of understanding of its main controls. Fluxes can only partly be predicted from soil abiotic factors and microbial analyses – a possible role for soil fauna

  20. Short notes and reviews The fossil fauna of Mazon Creek

    NARCIS (Netherlands)

    Schultze, Hans-Peter

    1998-01-01

    Review of: Richardson’s Guide to the Fossil Fauna of Mazon Creek, edited by Charles W. Shabica & Andrew A. Hay. Northeastern Illinois University, Chicago, Illinois, 1997: XVIII + 308 pp., 385 figs., 4 tables, 1 faunal list; $75.00 (hard cover) ISBN 0-925065-21-8. Since the last century, the area aro

  1. The mammalian fauna from the Central Himalaya, Nepal

    Directory of Open Access Journals (Sweden)

    Hem Bahadur Katuwal

    2013-07-01

    Full Text Available Nepal harbors unique mammalian fauna, but it is poorly studied at higher elevation. Mammalian fauna were recorded in Manaslu Conservation Area, Dudhkunda and Dudhkoshi valley of Solukhumbu district and Kanchenjunga Conservation Area of Nepal during March 2011 to April 2013 along the trail and the study plots from 700m to 4400m a.s.l. Semi-structured interviews were made with local people to understand their behavior and habitats. Altogether, 29 mammalian fauna were recorded. Five species were recorded new for the areas. Overall, Carnivore species (nine were encountered more, followed by species of the order Cetartiodactyla (seven. The highest number of mammalian fauna (18 was identified from Manaslu Conservation Area whereas the least (11 from Dudhkunda and Dudhkoshi valley. Human wildlife conflict was frequent with Himalayan Goral (Naemorhedus goral, Barking Deer (Muntiacus vaginalis, Himalayan Tahr (Hemitragus jemlahicus, Rhesus Macaque (Macaca mulatta, Nepal Grey Langur (Semnopithecus schistaceus and Himalayan Black Bear (Ursus thibetanus for crop depredation in these areas. Although mammalian research started a long time ago, scenario of comprehensive research is not satisfactory in the Central Himalaya, Nepal.

  2. Pollinating fauna of a phryganic ecosystem: species list

    NARCIS (Netherlands)

    Petanidou, Th.

    1991-01-01

    Studies on the pollination biology of Mediterranean scrub vegetations (maquis and phrygana) are not available as yet on an ecosystem level. To analyse in detail the pollination food web of the phrygana, the vegetation and the pollinator fauna of a phryganic ecosystem near Athens has been continuousl

  3. A Late Pliocene rodent fauna from Alozaina (Malaga, Spain)

    NARCIS (Netherlands)

    Aguilar, J.P.; Michaux, J.; Delannoy, J.J.; Guendon, J.L.

    1993-01-01

    In this paper 11 species of rodents are described, that have been found in the fossiliferous karst fissure of Alozaina (Malaga, Spain). Three species of Stephanomys (Murinae) are present in this fauna: S. thaleri, S. minor, and the new species S. prietaensis. The latter exhibits a lesser degree of e

  4. Benthic fauna around Mauritius island, southwest Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Ansari, Z.A.; Parulekar, A.H.

    Distribution of benthic fauna in the Exclusive Economic Zone of Mauritius was studied during September-October 1987. Mean faunal density (macro+meio) and dry weight biomass was 10848 no.m/2 and 228.8 mg.m/2, respectively. The macrofauna was dominat...

  5. Terrestrial mammal fauna and threatened species in France

    OpenAIRE

    François De Beaufort; Hervé Maurin; Patrick Haffner

    1996-01-01

    Abstract With the passing of time, the terrestrial mammal fauna changed considerably in France: definitive extinctions, temporary disappearances, natural reapparitions, introductions and reintroductions. 21 species are considered as threatened (endangered and vulnerab1e) and two have completely disappeared. However, more precise data are needed for a few of them.

  6. Carboniferous-Permian rugose coral Cyathaxonia faunas in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Cyathaxonia faunas are widely distributed in the Carboniferous and Permian strata in China.The fauna in China contains 12 families and 40 genera,and can be recognized as three episodes from Early Carboniferous to the end-Permian in terms of their occurrence and composition:1) Mississippian;2) Pennsylvanian-Early Permian;3) Middle Permian-Late Permian.They were relatively abundant in episodes 1 and 2.A decrease of family Antiphyllidae and an increase of family Hapsiphyllidae can be observed from Early Carboniferous to the end-Permian.Two case studies are given to illustrate the bio-facies of the Cyathaxonia faunas,which are from the Mississippian of Baoshan,West Yunnan and the Mississippian of Chaohu,South Anhui.In both areas,Cyathaxonia faunas occur just below the large dissepimented solitary and compound coral assemblages in a continuous sequence in a single section,which implies that the occurrence of these small,non-dissepimented solitary corals is not strictly related with Gondwanan or Peri-gondwanan cold water environment,but might be controlled by such benthic conditions as deeper,mud-rich,quieter,and darker sedimentary environments.

  7. A Diverse Tetrapod Fauna at the Base of 'Romer's Gap'.

    Directory of Open Access Journals (Sweden)

    Jason S Anderson

    Full Text Available The lack of fossil tetrapod bearing deposits in the earliest Carboniferous ('Romer's Gap' has provoked some recent discussions regarding the proximal cause, with three explanations being offered: environmental, taphonomic, and collection failure. One of the few, and earliest, windows into this time is the locality of Blue Beach exposed in the Tournaisian deposits at Horton Bluff lying along the Avon River near Hantsport, Nova Scotia, Canada. This locality has long been known but, because the fossils were deposited in high energy settings they are almost always disarticulated, so the fauna has not been described in detail. Recent intensive collection has revealed a diverse assemblage of material, including for the first time associated elements, which permits an evaluation of the faunal constituents at the locality. Although not diagnosable to a fine taxonomic level, sufficient apomorphies are present to identify representatives from numerous clades known from more complete specimens elsewhere. The evidence suggests a diverse fauna was present, including whatcheeriids and embolomeres. A single humerus previously had been attributed to a colosteid, but there is some uncertainty with this identification. Additional elements suggest the presence of taxa otherwise only known from the late Devonian. Depositional biases at the locality favor tetrapod fossils from larger individuals, but indirect evidence from trackways and tantalizing isolated bones evidences the presence of small taxa that remain to be discovered. The fossils from Blue Beach demonstrate that when windows into the fauna of 'Romer's Gap' are found a rich diversity of tetrapods will be shown to be present, contra arguments that suggested this hiatus in the fossil record was due to extrinsic factors such as atmospheric oxygen levels. They also show that the early tetrapod fauna is not easily divisible into Devonian and Carboniferous faunas, suggesting that some tetrapods passed through

  8. PHOTOPROTECTION OF SEA-ICE MICROALGAL COMMUNITIES FROM THE EAST ANTARCTIC PACK ICE(1).

    Science.gov (United States)

    Petrou, Katherina; Hill, Ross; Doblin, Martina A; McMinn, Andrew; Johnson, Robert; Wright, Simon W; Ralph, Peter J

    2011-02-01

    All photosynthetic organisms endeavor to balance energy supply with demand. For sea-ice diatoms, as with all marine photoautotrophs, light is the most important factor for determining growth and carbon-fixation rates. Light varies from extremely low to often relatively high irradiances within the sea-ice environment, meaning that sea-ice algae require moderate physiological plasticity that is necessary for rapid light acclimation and photoprotection. This study investigated photoprotective mechanisms employed by bottom Antarctic sea-ice algae in response to relatively high irradiances to understand how they acclimate to the environmental conditions presented during early spring, as the light climate begins to intensify and snow and sea-ice thinning commences. The sea-ice microalgae displayed high photosynthetic plasticity to increased irradiance, with a rapid decline in photochemical efficiency that was completely reversible when placed under low light. Similarly, the photoprotective xanthophyll pigment diatoxanthin (Dt) was immediately activated but reversed during recovery under low light. The xanthophyll inhibitor dithiothreitol (DTT) and state transition inhibitor sodium fluoride (NaF) were used in under-ice in situ incubations and revealed that nonphotochemical quenching (NPQ) via xanthophyll-cycle activation was the preferred method for light acclimation and photoprotection by bottom sea-ice algae. This study showed that bottom sea-ice algae from the east Antarctic possess a high level of plasticity in their light-acclimation capabilities and identified the xanthophyll cycle as a critical mechanism in photoprotection and the preferred means by which sea-ice diatoms regulate energy flow to PSII. PMID:27021712

  9. Sub-lethal heat stress causes apoptosis in an Antarctic fish that lacks an inducible heat shock response.

    Science.gov (United States)

    Sleadd, Isaac M; Lee, Marissa; Hassumani, Daniel O; Stecyk, Tonya M A; Zeitz, Otto K; Buckley, Bradley A

    2014-08-01

    The endemic fish fauna of the Southern Ocean are cold-adapted stenotherms and are acutely sensitive to elevated temperature. Many of these species lack a heat shock response and cannot increase the production of heat shock proteins in their tissues. However, some species retain the ability to induce other stress-responsive genes, some of which are involved in cell cycle arrest and apoptosis. Here, the effect of heat on cell cycle stage and its ability to induce apoptosis were tested in thermally stressed hepatocytes from a common Antarctic fish species from McMurdo Sound in the Ross Sea. Levels of proliferating cell nuclear antigen were also measured as a marker of progression through the cell cycle. The results of these studies demonstrate that even sub-lethal heat stress can have deleterious impacts at the cellular level on these environmentally sensitive species. PMID:25086982

  10. Brain and sense organ anatomy and histology of two species of phyletically basal non-Antarctic thornfishes of the Antarctic suborder Notothenioidei (Perciformes: Bovichtidae).

    Science.gov (United States)

    Eastman, Joseph T; Lannoo, Michael J

    2007-06-01

    The predominantly non-Antarctic family Bovichtidae is phyletically basal within the perciform suborder Notothenioidei, the dominant component of the Antarctic fish fauna. In this article we focus on the South Atlantic bovichtids Bovichtus diacanthus, the klipfish from tide pools at Tristan da Cunha, and Cottoperca gobio, the frogmouth from the Patagonian shelf and Falkland Islands. We document the anatomy and histology of the brains, olfactory apparatus, retina, and cephalic lateral line system. We also use the microvascular casting agent Microfil to examine ocular vascular structures. We provide detailed drawings of the brains and cranial nerves of both species. Typical of perciforms, the brains of both species have a well-developed tectum and telencephalon and robust thalamic nuclei. The telencephalon of C. gobio is prominently lobed, with the dorsomedial nucleus more conspicuous than in any other notothenioid. The corpus cerebelli is relatively small and upright and, unlike other notothenioids, has prominent transverse sulci on the dorsal and caudal surfaces. Areas for lateral line mechanoreception (eminentia granularis and crista cerebellaris) are also conspicuous but olfactory, gustatory, and somatosensory areas are less prominent. The anterior lateral line nerve complex is larger than the posterior lateral line nerve in B. diacanthus, and in their cephalic lateral line systems both species possess branched membranous tubules (which do not contain neuromasts) with small pores. These are especially complex in B. diacanthus where they become increasingly branched and more highly pored in progressively larger specimens. Superficial neuromasts are sparse. Both species have duplex (cone and rod) retinae that are 1.25-fold thicker and have nearly 5-fold more photoreceptors and than those of most Antarctic notothenioids. Convergence ratios are also high for bovichtids. Bovichtus diacanthus has a yellow intraocular filter in the dorsal aspect of the cornea. Both

  11. BIOCHRONOLOGY OF THE PLEISTOCENE MAMMAL FAUNA FROM PONTE GALERIA (ROME AND REMARKS ON THE MIDDLE GALERIAN FAUNAS

    Directory of Open Access Journals (Sweden)

    CARMELO PETRONIO

    1999-03-01

    Full Text Available Taking into account the fossil mammal material recently discovered at Cava di Breccia (sands outcropping at Ponte Galeria, Rome, the revised fossils from the area and the updated stratigraphical settings of the Ponte Galeria Formation (Rome, the Authors discuss the biochronology of the Middle Galerian faunal assemblages with a new definition of its Faunal Units.1 The mammal fauna of Isernia in our opinion is strongly conditioned by palaeoenvironmental factors and by human influence. The occurrence at Isernia La Pineta of the rodent Arvicola cantiana, which was widespread in Western Europe from 0.6 MA, does not match with the biochronology of the fauna and with the absolute dating (0.736 MA. A new radiometric dating will be useful to determine the age of the Isernia La Pineta local fauna, which can be considered younger than 0.736 MA on the basis of its faunal assemblage.  2 The age of the faunal assemblage of Ponte Galeria is between 0.8 and 0.75 MA, approximately in correspondence with the Brunhes-Matuyama paleomagnetic reversal event. The first occurrence of Bos galerianus and Megaloceros savini testifies a faunal renewal in comparison with the faunal assemblage of Slivia. The megacerine cervids from Ponte Galeria are more primitive than those from Isernia La Pineta and Venosa-Notarchirico. The Ponte Galeria local fauna has to be considered as a distinct Faunal Unit, younger than Slivia F.U. and older than the Isernia La Pineta fauna.  SHORT NOTE

  12. Encouraging Advances Made by Chinese Scientists in Antarctic Research

    Institute of Scientific and Technical Information of China (English)

    Zhang Qingsong

    2003-01-01

    @@ Chinese scientists began involving in the Antarctic research in 1980. As the first step, some 40 Chinese scientists were sent to Antarctic stations of Australia and other countries during the period from 1980 to 1984. Then,China established two Antarctic stations of its own, and purchased an icebreaker, enabling China to carry on its own independent research program both on land and at sea.

  13. Relative Changes in Krill Abundance Inferred from Antarctic Fur Seal

    OpenAIRE

    Tao Huang; Liguang Sun; John Stark; Yuhong Wang; Zhongqi Cheng; Qichao Yang; Song Sun

    2011-01-01

    Antarctic krill Euphausia superba is a predominant species in the Southern Ocean, it is very sensitive to climate change, and it supports large stocks of fishes, seabirds, seals and whales in Antarctic marine ecosystems. Modern krill stocks have been estimated directly by net hauls and acoustic surveys; the historical krill density especially the long-term one in the Southern Ocean, however, is unknown. Here we inferred the relative krill population changes along the West Antarctic Peninsula ...

  14. Satellite-based quantification of the bottom trawling induced sediment resuspension over an entire shelf

    Science.gov (United States)

    Oberle, F. J.; Cheriton, O. M.; Hanebuth, T. J. J.

    2014-12-01

    The effect of bottom trawling activities on continental shelves has been a topic of interest for both fishery resource studies and ecological impact studies for a while. However, the impact of demersal fishing gear was almost exclusively studied from a perspective of its effects on benthic fauna, but recently it has also attracted attention due to its profound impact on sediments. Here we present the first study to quantify the trawling-induced sediment resuspension effect by combining satellite-based spatial patterns of bottom trawling with quantitative measurements of induced sediment plumes. This study examined high-resolution GPS vessel monitoring data from one year (2011-2012) to quantify the sedimentary budget caused by bottom trawling activity for the entire NW Iberian shelf, an area that is widely affected by chronic (continuous and intensive) commercial bottom trawling and is exemplary for many other narrow shelves worldwide. By filtering the GPS data by vessel type, vessel speed, and geometry of the trawl path, we resolved geographically detailed bottom trawling activities with varying local trawling intensities depending both on legal restrictions and bedrock geomorphology. Initial results show that trawling-induced resuspended sediments mark a significant if not dominant factor for a source to sink sedimentary budget, as they are calculated to be approximately two times as large as fluvial sedimentary input to the shelf. Ultimately, these results not only allow for a trawling affected sediment budget but also significantly help with marine management decisions by allowing to predict the mobilization and transport of sediment caused by bottom trawling gear at the level of a specific fishing fleet or ecosystem.

  15. Para que servem os inventários de fauna?

    Directory of Open Access Journals (Sweden)

    Luís Fábio Silveira

    2010-01-01

    Full Text Available Inventários de fauna acessam diretamente a diversidade de uma localidade, em um determinado espaço e tempo. Os dados primários gerados pelos inventários compõem uma das ferramentas mais importantes na tomada de decisões a respeito do manejo de áreas naturais. Entretanto, vários problemas têm sido observados em diversos níveis relacionados aos inventários de fauna no Brasil e vão desde a formação de recursos humanos até a ausência de padronização, de desenho experimental e de seleção de métodos inadequados. São apresentados estudos de caso com mamíferos, répteis, anfíbios e peixes, nos quais são discutidos problemas como variabilidade temporal e métodos para detecção de fauna terrestre, sugerindo que tanto os inventários quanto os programas de monitoramento devam se estender por prazos maiores e que os inventários devem incluir diferentes metodologias para que os seus objetivos sejam plenamente alcançados.Inventories of fauna directly access the diversity of a locality in a certain period of time. The primary data generated by these inventories comprise one of the most important steps in decisions making regarding the management of natural areas. However, several problems have been observed at different levels related to inventories of fauna in Brazil, and range from the training of humans to the lack of standardization of experimental design and selection of inappropriate methods. We present case studies of mammals, reptiles, amphibians and fishes, where they discussed issues such temporal variability and methods for detection of terrestrial fauna, suggesting that both inventories and monitoring programs should be extended for longer terms and that inventories should include different methodologies to ensure that their goals are fully achieved.

  16. Microbial mercury methylation in Antarctic sea ice.

    Science.gov (United States)

    Gionfriddo, Caitlin M; Tate, Michael T; Wick, Ryan R; Schultz, Mark B; Zemla, Adam; Thelen, Michael P; Schofield, Robyn; Krabbenhoft, David P; Holt, Kathryn E; Moreau, John W

    2016-01-01

    Atmospheric deposition of mercury onto sea ice and circumpolar sea water provides mercury for microbial methylation, and contributes to the bioaccumulation of the potent neurotoxin methylmercury in the marine food web. Little is known about the abiotic and biotic controls on microbial mercury methylation in polar marine systems. However, mercury methylation is known to occur alongside photochemical and microbial mercury reduction and subsequent volatilization. Here, we combine mercury speciation measurements of total and methylated mercury with metagenomic analysis of whole-community microbial DNA from Antarctic snow, brine, sea ice and sea water to elucidate potential microbially mediated mercury methylation and volatilization pathways in polar marine environments. Our results identify the marine microaerophilic bacterium Nitrospina as a potential mercury methylator within sea ice. Anaerobic bacteria known to methylate mercury were notably absent from sea-ice metagenomes. We propose that Antarctic sea ice can harbour a microbial source of methylmercury in the Southern Ocean. PMID:27670112

  17. The history of Antarctic Peninsula glaciation

    Science.gov (United States)

    Barker, Peter F.

    2007-01-01

    As Co-Chief Scientist on DSDP Leg 35 in 1974, Cam Craddock (1930-2006) produced the first useful information on Cenozoic Antarctic Peninsula glaciation - an early middle Miocene (15-17 Ma) apparent glacial onset. Subsequent work, onshore and offshore, has greatly extended our knowledge but that early conclusion stands today. Cenozoic Antarctic Peninsula palaeoclimate as presently known is broadly consistent with global palaeoclimate proxies. Initial glacial onset was within the Eocene-Oligocene boundary interval (although earlier, short-lived glaciations have been proposed, from indirect measurements) and the peninsula probably became deglaciated in the earliest Miocene (ca. 24 Ma). The renewed middle Miocene glaciation probably continued to the present and, for the last 9 Myr at least, has persisted through glacial (orbital) cycles, with grounded ice advance to the shelf edge during maxima. Although orbital cyclicity affected earlier AP palaeoclimate also, the level of glaciation through a complete cycle is uncertain.

  18. Total Mercury in Six Antarctic Notothenioid Fishes.

    Science.gov (United States)

    Wintle, Nathan J P; Sleadd, Isaac M; Gundersen, Deke T; Kohl, Kristina; Buckley, Bradley A

    2015-11-01

    We analyzed white muscle samples from six species of Antarctic fish (suborder Notothenioidei) collected in 2011 from McMurdo Sound, Ross Sea, Antarctica, to assess levels of total mercury (THg). Gymnodraco acuticeps and Trematomus bernacchii exhibited the highest concentrations of THg followed by Trematomus pennellii, Trematomus nicolai, Trematomus newnesi and Pagothenia borchgrevinki, (71.3, 53.9±32.1, 45.8±27.3, 37.2±18.6, 35.7±23.6, and 21.9±2.8 ng/g wet weight, respectively). The results from this study suggest that THg has the potential to bioaccumulate from various marine Antarctic ecosystems into biota.

  19. Antarctic Meteorite Classification and Petrographic Database

    Science.gov (United States)

    Todd, Nancy S.; Satterwhite, C. E.; Righter, Kevin

    2011-01-01

    The Antarctic Meteorite collection, which is comprised of over 18,700 meteorites, is one of the largest collections of meteorites in the world. These meteorites have been collected since the late 1970's as part of a three-agency agreement between NASA, the National Science Foundation, and the Smithsonian Institution [1]. Samples collected each season are analyzed at NASA s Meteorite Lab and the Smithsonian Institution and results are published twice a year in the Antarctic Meteorite Newsletter, which has been in publication since 1978. Each newsletter lists the samples collected and processed and provides more in-depth details on selected samples of importance to the scientific community. Data about these meteorites is also published on the NASA Curation website [2] and made available through the Meteorite Classification Database allowing scientists to search by a variety of parameters

  20. Terrestrial age dating of antarctic meteorites

    International Nuclear Information System (INIS)

    During the last three antarctic field seasons, US and Japanese teams have collected several thousand meteorites. The terrestrial age of these objects is of interest because such knowledge enables the setting of lower bounds on the lower age of the ice sheet, provides information about ice movement, and aids understanding of the accumulation mechanism of the meteorites. Terrestrial ages can be established by measuring the decay of radioactive species produced by bombardment of cosmic rays while the objects are in space. After entering the Earth's atmosphere the meteorites essentially are completely shielded from cosmic rays. The radioactive products that exist at saturation values in space then decay exponentially toward zero activity. By the end of 1980, data will be established on 150 to 200 selected samples. With that large a data base we should have a fairly clear picture of the terrestrial age distribution of antarctic meteorites

  1. New and rare cephalopods from the Antarctic waters

    OpenAIRE

    Kubodera,Tsunemi/Okutani,Takeshi

    1986-01-01

    Three species of Antarctic cephalopods, Grimpoteuthis antarctica n. sp., male specimens of Megaleledone senoi TAKI and Gonatus antarcticus LONNBERG are described with some considerations to their systematic status.

  2. Gas chromatography-mass spectrometry analysis of fatty acid profiles of Antarctic and non-Antarctic yeasts.

    Science.gov (United States)

    Bhuiyan, Mohammad; Tucker, David; Watson, Kenneth

    2014-08-01

    The fatty acid profiles of Antarctic (n = 7) and non-Antarctic yeasts (n = 7) grown at different temperatures were analysed by gas chromatography-mass spectrometry. The Antarctic yeasts were enriched in oleic 18:1 (20-60 %), linoleic 18:2 (20-50 %) and linolenic 18:3 (5-40 %) acids with lesser amounts of palmitic 16:0 (Antarctic yeasts (n = 4) were enriched in 18:1 (20-55 %, with R. mucilaginosa at 75-80 %) and 18:2 (10-40 %) with lesser amounts of 16:0 (Antarctic yeasts (enriched in 18:1 and 18:2) and the third to the Antarctic yeasts (enriched in 18:2 and 18:3).

  3. Satellite magnetic anomalies of the Antarctic crust

    Directory of Open Access Journals (Sweden)

    D. E. Alsdorf

    2000-06-01

    Full Text Available Spatially and temporally static crustal magnetic anomalies are contaminated by static core field effects above spherical harmonic degree 12 and dynamic, large-amplitude external fields. To extract crustal magnetic anomalies from the measurements of NASA's Magsat mission, we separate crustal signals from both core and external field effects. In particular, we define Magsat anomalies relative to the degree 11 field and use spectral correlation theory to reduce them for external field effects. We obtain a model of Antarctic crustal thickness by comparing the region's terrain gravity effects to free-air gravity anomalies derived from the Earth Gravity Model 1996 (EGM96. To separate core and crustal magnetic effects, we obtain the pseudo-magnetic effect of the crustal thickness variations from their gravity effect via Poisson's theorem for correlative potentials. We compare the pseudo-magnetic effect of the crustal thickness variations to field differences between degrees 11 and 13 by spectral correlation analysis. We thus identify and remove possible residual core field effects in the Magsat anomalies relative to the degree 11 core field. The resultant anomalies reflect possible Antarctic contrasts due both to crustal thickness and intracrustal variations of magnetization. In addition, they provide important constraints on the geologic interpretation of aeromagnetic survey data, such as are available for the Weddell Province. These crustal anomalies also may be used to correct for long wavelength errors in regional compilations of near-surface magnetic survey data. However, the validity of these applications is limited by the poor quality of the Antarctic Magsat data that were obtained during austral Summer and Fall when south polar external field activity was maximum. Hence an important test and supplement for the Antarctic crustal Magsat anomaly map will be provided by the data from the recently launched Ørsted mission, which will yield coverage

  4. Antarctic terrestrial ecosystems: responses to environmental change

    OpenAIRE

    Convey, Peter

    2006-01-01

    The consequences of climate change are exciting considerable concern worldwide. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. This paper sets out to introduce contemporary ecosystems of the Antarctic, and the factors that have influenced them and their biodiversity over evolutionary timescales. Contemporary climate change processes significant to terrestrial biota, and the biological consequences of these changes seen t...

  5. PSEUDO MAGNETIC ANOMALIES IN THE ANTARCTIC SEA

    OpenAIRE

    マツモト, タケシ; カミヌマ, カツタダ; Takeshi, MATSUMOTO; Katsutada, Kaminuma

    1988-01-01

    Pseudo magnetic anomaly in the Antarctic Sea has been calculated using the gravity data derived from altimetric geoid. Comparison of the pseudo magnetic anomaly thus calculated with the theoretical magnetic anomaly predicted from topography has been made with respect to the large fracture zones composed of short-wavelength ridges and troughs in the Southeastern Pacific, which shows that these two anomalies coincide well with each other. Gravity anomaly calculated from topography only also coi...

  6. Tephrochronology : Methodology and correlations, Antarctic Peninsula Area

    OpenAIRE

    Molén, Mats

    2012-01-01

    Abstract Methods for tephrochronology are evaluated, in the following way: Lake sediments <500 years old from three small Antarctic lakes were analysed for identification of tephras. Subsamples were analysed for a) grain size, and identification and concentration of volcanogenic grains, b) identification of tephra horizons, c) element abundance by EPMA WDS/EDS and LA-ICP-MS, and d) possible correlations between lakes and volcanoes. Volcanogenic minerals and shards were found all through th...

  7. Biodiversity and Sequence of the Middle Triassic Panxian Marine Reptile Fauna,Guizhou Province,China

    Institute of Scientific and Technical Information of China (English)

    JIANG Dayong; Ryosuke MOTANI; HAO Weicheng; Olivier RIEPPEL; SUN Yuanlin; Andrea TINTORI; SUN Zuoyu; Lars SCHMITZ

    2009-01-01

    The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian nlass extinction.Ten marine reptile taxa have been found from the 1.82-2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation,which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles.The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al.,2008 and Lariosaurus hongguoensis Jiang et al.,2006,the ichthyopterygians Xinminosaurus catactes Jiang et al.,2008 and Phalarodon cf.Phalarodon fraasi Merriam,1910,associated with Mixosaurus panxmnensis Jiang et al.,2006,representing a stage of predominance of durophagous taxa.In this bed,the large complete skeletons may reach up to 2.3 m in length,and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom,as well as a rising sea level.The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al.,2006 and the archosaur Qianosuchus mixtus Li et al.,2006,associated with Mixosaurus panxmnensisJiang et al..2006.The fossils in this bed are characterized by its pincering dentition and Iarge overall body size,with the largest possibly exceeding 3 m in length.This bed might represent a time of deepest basin with relatively anoxic condition near the bottom.The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al.,2008,Keichousaurus sp.,the protorosaur Dinocephalosaurus orientalis Li,2003,and the iehthyopterygian Mixosaurus panxlanensis Jiang et al.,2006.In this bed,reptilian taxa characterized by suction feeding appeared,and most are less than 1 m long.This bed corresponds to a period of decreasing water depth.

  8. Measurements of 36Cl in Antarctic meteorites and Antarctic ice using a Van de Graaff accelerator

    International Nuclear Information System (INIS)

    Cosmic-ray produced 36Cl(tsub(1/2) = 3.0 X 105 years) has been measured in four Antarctic meteorites and one sample of Antarctic ice using a tandem Van de Graaff accelerator as an ultrasensitive mass spectrometer with the extremely low background level of 36Cl/Cl -16. Results from this ion counting technique (applied here to extraterrestrial materials for the first time) are used to support a two-stage irradiation model for the Yamato-7301and Allan Hills-76008 meteorites and to show a long terrestrial age (0.7 +- 0.1 m.y.) for Allan Hills-77002. Yamato-7304 has a terrestrial age of less than 0.1 m.y. The 36Cl content of the Antarctic ice sample from the Yamato Mountain area implies that the age of the ice cap at this site is less than one 36Cl half-life. (Auth.)

  9. Antarctic Treaty Summit: Washington, DC (2009)

    Science.gov (United States)

    Berkman, P. A.; Young, O. R.

    2005-12-01

    Advancement in Earth system science and international cooperation have been intertwined with the International Polar Years since 1882. In particular, the 3rd International Polar Year (which was convened as the International Geophysical Year from 1 July 1957 through 31 December 1958) specifically demonstrates the role of science in international policy: Acknowledging the substantial contributions to scientific knowledge resulting from international cooperation in scientific investigation in Antarctica; Convinced that the establishment of a firm foundation for the continuation and development of such cooperation on the basis of freedom of scientific investigation in Antarctica as applied during the International Geophysical Year accords with the interests of science and the progress of all mankind; Preamble, 1959 Antarctic Treaty To commemorate the 50th anniversary of the 1959 Antarctic Treaty and to explore the complexities of the science-policy relationship through the lens of a well-constrained case study, an international and interdisciplinary Antarctic Treaty Summit is being planned for 2009 in Washington, DC in conjunction with the International Polar Year 2007-08 (http://www.ipy.org).

  10. Antarctic Meteorite Classification and Petrographic Database Enhancements

    Science.gov (United States)

    Todd, N. S.; Satterwhite, C. E.; Righter, K.

    2012-01-01

    The Antarctic Meteorite collection, which is comprised of over 18,700 meteorites, is one of the largest collections of meteorites in the world. These meteorites have been collected since the late 1970 s as part of a three-agency agreement between NASA, the National Science Foundation, and the Smithsonian Institution [1]. Samples collected each season are analyzed at NASA s Meteorite Lab and the Smithsonian Institution and results are published twice a year in the Antarctic Meteorite Newsletter, which has been in publication since 1978. Each newsletter lists the samples collected and processed and provides more in-depth details on selected samples of importance to the scientific community. Data about these meteorites is also published on the NASA Curation website [2] and made available through the Meteorite Classification Database allowing scientists to search by a variety of parameters. This paper describes enhancements that have been made to the database and to the data and photo acquisition process to provide the meteorite community with faster access to meteorite data concurrent with the publication of the Antarctic Meteorite Newsletter twice a year.

  11. Mirror seeing of the Antarctic survey telescope

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kaiyuan; LI Zhengyang; YUAN Xiangyan; PEI Chong

    2014-01-01

    Site testing results indicate that Antarctic Dome A is an excellent ground-based astronomical site suitable for observations ranging from visible to infrared wavelengths. However, the harsh environment in Antarctica, especially the very low temperature and atmospheric pressure, always produces frost on the telescopes’ mirrors, which are exposed to the air. Since the Dome A site is still unattended, the Antarctic telescope tubes are always designed to be filled with dry nitrogen, and the outer surfaces of the optical system are heated by an indium-tin oxide thin film. These precautions can prevent the optical surfaces from frosting over, but they degrade the image quality by introducing additional mirror seeing. Based on testing observations of the second Antarctic Survey Telescope (AST3-2) in the Mohe site in China, mirror seeing resulting from the heated aspheric plate has been measured using micro-thermal sensors. Results comparing the real-time atmospheric seeing monitored by the Differential Image Motion Monitor and real-time examinations of image quality agree well.

  12. A paleomagnetic study of the Antarctic Peninsula

    Science.gov (United States)

    Poblete, F.; Arriagada, C.; Roperch, P.

    2009-05-01

    In the Paleozoic, South America, South Africa and Antarctica were part of Gondwana. The Weddell Sea began to form at about 146 Ma, after rifting between the Antarctic Peninsula and southernmost South America. Much uncertainty still exists about the geometrical fit and subsequent drift history between Patagonia and Antarctica. Geophysical and geological data which describe the tectonic history are sparsely distributed and often of poor quality. During the last two years we have collected more than 1000 paleomagnetic samples from 70 sites at several localities (King George Island, Robert Island, Yankee Bay, Half Moon Island, Byers Peninsula and Snow Island) from the South Shetland Islands and Anderson Island in the northern tip of Antarctic Peninsula. Our main objective was to provide first-order constraints on latitudinal displacements and the amount of tectonic rotations as an essential test of published tectonic models. Paleomagnetic results were obtained from 50 sites. All samples from sites in volcanic and intrusive rocks have well-defined univectorial magnetizations. Unfortunately, all sites in late Paleozoic sediments have been remagnetized and the magnetizations are often unstable upon thermal demagnetization. Cretaceous and Cenozoic units display very little apparent polar wander. Results from intrusive rocks of expected Jurassic age do not confirm the expected relative rotation betwen the Antarctic Peninsula and East Antarctica. Further radiometric dating are needed to confirm the age of these units.

  13. Update on terrestrial ages of Antarctic meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Welten, K C; Nishiizumi, K; Caffee, M W

    2000-01-14

    Terrestrial ages of Antarctic meteorites are one of the few parameters that will help us to understand the meteorite concentration mechanism on blue-ice fields. Traditionally, terrestrial ages were determined on the basis of {sup 36}Cl in the metal phase, which has an uncertainty of about 70 ky. For young meteorites (< 40 ky), the terrestrial age is usually and most accurately determined using {sup 14}C in the stone phase. In recent years two methods have been developed which are independent of shielding effects, the {sup 10}Be-{sup 36}Cl/{sup 10}Be method and the {sup 41}Ca/{sup 36}Cl method. These methods have reduced the typical uncertainties in terrestrial ages by a factor of 2, to about 30 ky. The {sup 10}Be-{sup 36}Cl/{sup 10}Be method is quite dependent on the exposure age, which is unknown for most Antarctic meteorites. The authors therefore also attempt to use the relation between {sup 26}Al and {sup 36}Cl/{sup 26}Al to derive a terrestrial age less dependent on the exposure age. The authors have measured the concentrations of cosmogenic {sup 10}Be, {sup 26}Al and {sup 36}Cl in the metal phase of {approximately} 70 Antarctic meteorites, from more than 10 different ice-fields, including many new ones. They then discuss the trends in terrestrial ages of meteorites from different ice-fields.

  14. Skip spawning as a reproductive strategy in Antarctic fish species: the Antarctic silverfish (Pleuragramma antarctica) case study

    OpenAIRE

    Eva Pisano; Stuart Hanchet; Marino Vacchi

    2015-01-01

    The Antarctic silverfish Pleuragramma antarctica (Notothenioidei, Nototheniidae) is the most abundant pelagic fish inhabiting the frigid Antarctic coastal waters. It plays relevant roles in the local ecosystems, where it is often considered a keystone species connecting lower and upper trophic levels within the coastal marine food web. Despite its ecological relevance, and although many aspects of the Antarctic silverfish biology have already been elucidated, knowledge on important components...

  15. Temporal variation in Sargassum Biomass, Hypnea epiphytism and associated fauna

    Directory of Open Access Journals (Sweden)

    Leite Fosca Pedini Pereira

    2003-01-01

    Full Text Available Studies were carried out to investigate the temporal variation in Sargassum biomass, Hypnea epiphytism and associated fauna. There was a marked variation in the biomass of Sargassum and Hypnea among various sampling periods. Low values for Sargassum were recorded in August and November, while the lower value for Hypnea biomass was recorded in August. An inverse relationship was found between Sargassum biomass and the intensity of Hypnea epiphytism. The density of the total fauna associated to Sargassum showed a marked reduction in May. This variation was influenced by the variation patterns of the dominant faunistic groups (Gastropoda, Gammaridea, Isopoda and Caridea. Significant positive relationships were found between the biomass of Sargassum and Sargassum+Hypnea with the total density of all faunistic groups (per macroalgae biomass unit. However, the influence of Hypnea epiphytism on the phytal organisms was not evidenced.

  16. Phylogeography of regional fauna on the Tibetan Plateau: A review

    Institute of Scientific and Technical Information of China (English)

    Shujuan Yang; Hailiang Dong; Fumin Lei

    2009-01-01

    The studies of uplift and glaciations of the Tibetan Plateau are summarized, and a series of recent case studies of the endemic species based on DNA sequences are detailed. In general, these molecular data show that all the organisms originated from Early Pliocene to Late Miocene, and then multi-stages of divergence/speciation occurred within each taxa following their original occupation on the pla-teau, mainly as a result of periodic glacial cycles and geographic isolation. The regional fauna may have undergone several range con-tractions and expansions during the Pleistocene glaciations. However, the population expansion and refugia may vary in space, time, and extent. The regional fauna of the Tibetan Plateau may be combinations of ancient movement from adjacent zoogeographical regions, speciation in situ, and postglacial colonization from adjacent areas. Geomorphic and climatic changes on the plateau definitely have a remarkable influence on the regional and adjacent biogeographic patterns, and the mechanism is very complex.

  17. Antarctic fish in a changing world: metabolic, osmoregulatory and endocrine stress response

    Directory of Open Access Journals (Sweden)

    Pedro Miguel Guerreiro

    2015-10-01

    Full Text Available Fish around Antarctic Peninsula are exposed to the fastest climate change rate in the planet, up to ten times higher than the global average. The evolution in extreme stenothermal isolation was a strong selective pressure for the development of a highly endemic fish fauna, with likely structural and functional constraints. To which extent can coastal notothenioid fish adjust to the conditions forecasted by the models of climate change? Experiments were run in the Arctowski (PL station at Admiralty Bay, King George Island, in 2012/13. Fish, Notothenia rossii and N. coriiceps, were collected by boat at 5-25 meter deep using fishing poles and were transferred to experimental tanks in cold rooms acclimated to natural temperatures (0-2°C. Fish were exposed to rapid/ gradual changes in water temperature or/and salinity (to 6-8°C using thermostat-controlled heaters, to 20-10‰ by addition of freshwater to recirculating tanks, over a period of up to 10 days to evaluate the response of several physiological processes. The stress endocrine axis was tested by injecting known blockers/ agonists of cortisol release and receptors. Exposure to altered conditions had no effect in immediate mortality. Increased temperature reduced overall activity and behavioral response to stimuli, although it had no clear effect on mobilization of energetic substrate. Both cortisol and gene expression of metabolic-related proteins and glucocorticoid- and mineralocorticoid receptors were modified after heat shock, but that the cortisol response to handling was reduced. The rise in temperature induced a dependent decrease in plasma osmolality while increasing branchial Na+/K+-ATPase activity, thus decreasing osmoregulatory efficiency. In conclusion, Antarctic fish are reactive to environmental change, but that their ability to accommodate rapid or adaptive responses may be compromised.

  18. Mammalian fauna of the Temessos National Park, Turkey

    OpenAIRE

    Anna De Marinis; Marco Masseti

    2009-01-01

    The National Park of Termessos, Southern Turkey, is one of the Turkey’s biggest national park not only with its archeological richness but also with its great natural wild life. We provided a checklist of the mammalian fauna of the park on the base of direct observations, interviews and a comparative analysis of the available literature. Sixteen species have been reported in the park. Hedgehogs, hares, porcupines and Persian squirrels and, among flying mammals, Egyptian rousette and Mou...

  19. Soil invertebrate fauna affect N2 O emissions from soil.

    Science.gov (United States)

    Kuiper, Imke; de Deyn, Gerlinde B; Thakur, Madhav P; van Groenigen, Jan Willem

    2013-09-01

    Nitrous oxide (N2 O) emissions from soils contribute significantly to global warming. Mitigation of N2 O emissions is severely hampered by a lack of understanding of its main controls. Fluxes can only partly be predicted from soil abiotic factors and microbial analyses - a possible role for soil fauna has until now largely been overlooked. We studied the effect of six groups of soil invertebrate fauna and tested the hypothesis that all of them increase N2 O emissions, although to different extents. We conducted three microcosm experiments with sandy soil and hay residue. Faunal groups included in our experiments were as follows: fungal-feeding nematodes, mites, springtails, potworms, earthworms and isopods. In experiment I, involving all six faunal groups, N2 O emissions declined with earthworms and potworms from 78.4 (control) to 37.0 (earthworms) or 53.5 (potworms) mg N2 O-N m(-2) . In experiment II, with a higher soil-to-hay ratio and mites, springtails and potworms as faunal treatments, N2 O emissions increased with potworms from 51.9 (control) to 123.5 mg N2 O-N m(-2) . Experiment III studied the effect of potworm density; we found that higher densities of potworms accelerated the peak of the N2 O emissions by 5 days (P < 0.001), but the cumulative N2 O emissions remained unaffected. We propose that increased soil aeration by the soil fauna reduced N2 O emissions in experiment I, whereas in experiment II N2 O emissions were driven by increased nitrogen and carbon availability. In experiment III, higher densities of potworms accelerated nitrogen and carbon availability and N2 O emissions, but did not increase them. Overall, our data show that soil fauna can suppress, increase, delay or accelerate N2 O emissions from soil and should therefore be an integral part of future N2 O studies. PMID:23625707

  20. Quaternary fauna of bats in Spain: Paleoecologic and biogeographic interest

    OpenAIRE

    Sevilla, Paloma

    1989-01-01

    The study of fossil bat material collected in Quaternary localities in Spain has yielded interesting information on the characteristics of this fauna during the Pleistocene and Holocene in Spain. Out of the 25 species of Chiroptera actually living in Spain, 15 have been detected from the Middle Pleistocene onwards: Rhinolophus ferrumequinum, R. euryale, R. mehelyi, R. hipposideros, Myotis myotis, M. bechsteini, M. nattereri, M. emarginatus, Plecotus austriacus, Eptesicus ser...

  1. Data to the Dragonfly Fauna of Lower Neretva River

    OpenAIRE

    Bogdanović, Tomislav; Merdić, Enrich; JMikuska, Jozsef

    2008-01-01

    We present the frst list of dragonfly fauna of the lower Neretva River, comprising 44 species. During the period from June – September from 2003 to 2005 the first systematic investigations of dragonflies of the Lower Neretva river were carried out at 6 locations. The following methods were used: the method of collecting by entomological nets, the method of strolling and observing and the method of taking photographs. On the basis of the collected individuals at different life stages (larvae -...

  2. A review of fish fauna in the Turkish Black Sea

    OpenAIRE

    Keskin, Çetin

    2010-01-01

    Abstract This review showed that a total of 161 fish species inhabit in the Turkish Black Sea according to previous studies. Atlanto-Mediterranean species consisted 62.73% of total fish fauna, 6.83% cosmopolitan, 28.57% endemics and 1.86% introduced species such as, Liza haematocheila, Sphraena obtusata and Salmo salar. For the protection of the fish diversity in the Black Sea needs to establish marine protected areas, get under control of illegal, unreported and unregulated fisheries, region...

  3. Macrobenthic fauna community in the Middle Songkhla Lake, Southern Thailand

    OpenAIRE

    Angsupanich, S.; Charoenpornthip, M.; Siripech, A.

    2005-01-01

    A bimonthly investigation of macrobenthic fauna at the area from Ban Pak Khat to Ban Leam Chong Thanon in the Inner Songkhla Lake from February 1998 to February 1999 was undertaken to determine the species richness and abundance. A total of 7 phyla and 161 species were identified. Annelida (58 species), Arthropoda (64 species) and Mollusca (23 species) were the major phyla while Nemertea (1 species), Platyhelminthes (1 species), Cnidaria (4 species) and Chordata (10 species) were the minor. F...

  4. The ARM West Antarctic Radiation Experiment (AWARE)

    Science.gov (United States)

    Lubin, Dan; Bromwich, David; Vogelmann, Andrew; Verlinde, Johannes; Russell, Lynn

    2016-04-01

    West Antarctica is one of the most rapidly warming regions on Earth, and its changing climate in both atmosphere and ocean is linked to loss of Antarctic ice mass and global sea level rise. The specific mechanisms for West Antarctic Ice Sheet (WAIS) warming are not fully understood, but are hypothesized to involve linkage between moisture from Southern Ocean storm tracks and the surface energy balance over the WAIS, and related teleconnections with subtropical and tropical meteorology. This present lack of understanding has motivated a climate science and cloud physics campaign jointly supported by the US National Science Foundation (NSF) and Department of Energy (DOE), called the Atmospheric Radiation Measurement Program (ARM) West Antarctic Radiation Experiment (AWARE). The DOE's second ARM Mobile Facility (AMF2) was deployed to McMurdo Station on Ross Island in November 2015 and will operate through December 2016. The AMF2 includes (1) cloud research radars, both scanning and zenith, operating in the Ka- and X-bands, (2) high spectral resolution and polarized micropulse lidars, and (3) a suite of shortwave and longwave broadband and spectral radiometers. A second suite of instruments is deployed at the WAIS Divide Ice Camp on the West Antarctic plateau during December 2015 and January 2016. The WAIS instrument suite provides (1) measurement of all surface energy balance components, (2) a polarized micropulse lidar and shortwave spectroradiometer, (3) microwave total water column measurement, and (4) four times daily rawinsonde launches which are the first from West Antarctica since 1967. There is a direct linkage between the WAIS instrument suite and the AMF2 at McMurdo, in that air masses originating in Southern Ocean storm tracks that are driven up over the WAIS often subsequently descend over the Ross Ice Shelf and arrive at Ross Island. Preliminary data are already illustrating the prevalence of mixed-phase clouds and their role in the surface energy balance

  5. On the contribution of the soil fauna to the macropores

    Science.gov (United States)

    Barontini, Stefano; Vitale, Paolo; Comincini, Mattia; Pezzotti, Dario; Peli, Marco; Armiraglio, Stefano; Tomirotti, Massimo; Ranzi, Roberto

    2016-04-01

    Soil fauna play an important role in characterizing the soil structure, and they are one of the main macropore sources, together with roots, swelling and local erosion. In an hydrological perspective, according to most of the authors, macropores are meati with meaningfully small capillary action, that is with a characteristic transverse-length greater than some tens of micrometers. Macropores importance is crucial for the hydrological cycle, as they are seat of preferential flow and they contribute to key hydrological processes, viz infiltration, percolation and subsurface runoff. In the framework of a wider investigation which aims at deepening the comprehension of the role played by the macropores in characterising the soil hydrological response (at spatial scales from the local to the slope one), we present a literature reanalysis focused on the capability of soil fauna to dig nests, holes, burrows, and subsoil tunnels and rooms. Particularly we examinated data about fauna with dimensions ranging from small arthropods and anellids to some big chordates. As a result we present a classification approach which aims at enlightening the hydrological features of the holes, e.g. structure, length, main direction, tortuosity, transverse section, displaced soil volume, hydraulic radius, digging technique, affected soil layers, in view of comparing the hydrological fallouts of different soil diggers.

  6. Perceptual learning: top to bottom.

    Science.gov (United States)

    Amitay, Sygal; Zhang, Yu-Xuan; Jones, Pete R; Moore, David R

    2014-06-01

    Perceptual learning has traditionally been portrayed as a bottom-up phenomenon that improves encoding or decoding of the trained stimulus. Cognitive skills such as attention and memory are thought to drive, guide and modulate learning but are, with notable exceptions, not generally considered to undergo changes themselves as a result of training with simple perceptual tasks. Moreover, shifts in threshold are interpreted as shifts in perceptual sensitivity, with no consideration for non-sensory factors (such as response bias) that may contribute to these changes. Accumulating evidence from our own research and others shows that perceptual learning is a conglomeration of effects, with training-induced changes ranging from the lowest (noise reduction in the phase locking of auditory signals) to the highest (working memory capacity) level of processing, and includes contributions from non-sensory factors that affect decision making even on a "simple" auditory task such as frequency discrimination. We discuss our emerging view of learning as a process that increases the signal-to-noise ratio associated with perceptual tasks by tackling noise sources and inefficiencies that cause performance bottlenecks, and present some implications for training populations other than young, smart, attentive and highly-motivated college students.

  7. Macrobenthic fauna community in the Middle Songkhla Lake, Southern Thailand

    Directory of Open Access Journals (Sweden)

    Angsupanich, S.

    2005-02-01

    Full Text Available A bimonthly investigation of macrobenthic fauna at the area from Ban Pak Khat to Ban Leam Chong Thanon in the Inner Songkhla Lake from February 1998 to February 1999 was undertaken to determine the species richness and abundance. A total of 7 phyla and 161 species were identified. Annelida (58 species, Arthropoda (64 species and Mollusca (23 species were the major phyla while Nemertea (1 species, Platyhelminthes (1 species, Cnidaria (4 species and Chordata (10 species were the minor. Fifty-seven speciesof Polychaete annelids were found. The highest species richness (14 species was in the Nereididae Family, of which Ceratonereis burmensis and Namalycastis indica were predominant. Nephtys sp. and Heteromastus sp. were not so highly abundant but appeared at almost all stations through every sampling month, while Prionospio cirrifera and Pseudopolydora kempi were found in higher densities but with narrower distribution. Ficopomatus sp. and unidentified Terebellidae were not commonly found, but occasionally reached a high density. Amphipods gave the highest species richness (22 species, with Photis longicaudata distributed widely and in all months. Five species of Tanaidaceans were found with Apseudes sapensis the second most dominant (max. 5044 individuals m-2 in February in the overall fauna. Isopoda were not as densely found as tanaidaceans but there were many species (18 species. Cyathura sp.1 was the most dominant isopod. Brachidontes arcuatulus was the most dominant bivalve (max. 29449 individuals m-2 in April, especially at stations with a sand-gravel substrate. The mean density of total macrobenthic fauna among stations ranged from 920 to 10620 ind. m-2 while the monthly densities ranged from 1520 to 6160 ind.m-2. The mean density of macrobenthic fauna was highest in the dry season (April. The species richness among stations ranged from65 to 105 species while varying from 81 to 112 species during the different months. The highest species

  8. BIOCHRONOLOGY OF THE PLEISTOCENE MAMMAL FAUNA FROM PONTE GALERIA (ROME) AND REMARKS ON THE MIDDLE GALERIAN FAUNAS

    OpenAIRE

    CARMELO PETRONIO; RAFFAELE SARDELLA

    1999-01-01

    Taking into account the fossil mammal material recently discovered at Cava di Breccia (sands outcropping at Ponte Galeria, Rome), the revised fossils from the area and the updated stratigraphical settings of the Ponte Galeria Formation (Rome), the Authors discuss the biochronology of the Middle Galerian faunal assemblages with a new definition of its Faunal Units.1) The mammal fauna of Isernia in our opinion is strongly conditioned by palaeoenvironmental factors and by human influence. The oc...

  9. Model decay in the Australia-Antarctic basin

    Energy Technology Data Exchange (ETDEWEB)

    Weijer, Wilbert [Los Alamos National Laboratory; Gille, Sarah T [UCSD; Vivier, Frederic [LOCEAN-IPSL

    2008-01-01

    The barotropic intraseasonal variability in the Australia-Antarctic Basin (AAB) is studied in terms of the excitation and decay of topographically-trapped barotropic modes. The main objective is to reconcile two widely differing estimates of the decay rate of SSH anomalies in the AAB that are assumed to be related to barotropic modes. First, an Empirical Orthogonal Function (EOF) analysis is applied to almost 15 years of altimeter data. The analysis suggests that several modes are involved in the variability of the AAB, each related to distinct areas with (almost) closed contours of potential vorticity. Second, the dominant normal modes of the AAB are determined in a barotropic shallow-water (SW) model. These stationary modes are confined by the closed contours of potential vorticity that surround the eastern AAB, and the crest of the Southeast Indian Ridge. For reasonable values of horizontal eddy viscosity and bottom friction, their decay time scale is of the order of several weeks. Third, the SW model is forced with realistic winds and integrated for several years. Projection of the modal velocity patterns onto the output fields shows that the barotropic modes are indeed excited in the model, and that they decay slowly on the frictional O(3 weeks) time scale. However, the SSH anomalies in the modal areas display rapid O(4 days) decay. Additional analysis shows that this rapid decay reflects the adjustment of unbalanced flow components through the emission of Rossby waves. Resonant excitation of the dominant free modes accounts for about 20% of the SSH variability in the forced model run. Other mechanisms are suggested to explain the region of high SSH variability in the AAB.

  10. Southern elephant seals from Kerguelen Islands confronted by Antarctic Sea ice. Changes in movements and in diving behaviour

    Science.gov (United States)

    Bailleul, Frédéric; Charrassin, Jean-Benoıˆt; Ezraty, Robert; Girard-Ardhuin, Fanny; McMahon, Clive R.; Field, Iain C.; Guinet, Christophe

    2007-02-01

    The behaviour of southern elephant seals from Kerguelen Island ( 49∘50'S, 70∘30'E) was investigated in relation to the oceanographic regions of the Southern Ocean. The oceanographic and the seal behaviour data, including location and diving activity, were collected using a new generation of satellite-relayed devices measuring and transmitting pressure, temperature, and salinity along with locations. Dive duration, maximum diving depth, time spent at the bottom of the dives, and shape of dive profiles were compared between male and female seals, and were related to the oceanographic characteristics of areas prospected by the seals. Most animals travelled to the Antarctic shelf. However, during winter, adult females travelled away from the continent, remained and foraged within the marginal sea-ice zone, while juvenile males remained within the pack ice to forage mainly on the Antarctic shelf. Therefore, as the ice expanded females appeared to shift from benthic to pelagic foraging farther north, while males continued to forage almost exclusively benthically on the continental shelf. This difference is likely related to the different energetic requirements between the two sexes, but also may be related to pregnant females having to return to Kerguelen in early spring in order to give birth and successfully raise their pups, while males can remain in the ice. Our results show an important link between elephant seals and Antarctic sea ice and suggest that changes in sea-ice conditions could strongly affect the behaviour of this species.

  11. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm),

  12. Development of Castables for Gass Tank Bottom

    Institute of Scientific and Technical Information of China (English)

    YUANLin; CHENShengling

    1998-01-01

    The production and use of zircon corundum refractory castables were analyzed.The superior properties and applied effect of castables for glass tank bottom were demonstrated.The results show that those castables have excellent molten glass corrosion resistance (MGCR) and enable glass tank bot-tom to form a seal mass.

  13. Antarctic density stratification and the strength of the circumpolar current during the Last Glacial Maximum

    Science.gov (United States)

    Lynch-Stieglitz, Jean; Ito, Takamitsu; Michel, Elisabeth

    2016-05-01

    The interaction between ocean circulation and biological processes in the Southern Ocean is thought to be a major control on atmospheric carbon dioxide content over glacial cycles. A better understanding of stratification and circulation in the Southern Ocean during the Last Glacial Maximum (LGM) provides information that will help us to assess these scenarios. First, we evaluate the link between Southern Ocean stratification and circulation states in a suite of climate model simulations. While simulated Antarctic Circumpolar Current (ACC) transport varies widely (80-350 Sverdrup (Sv)), it co-varies with horizontal and vertical stratification and the formation of the southern deep water. We then test the LGM simulations against available data from paleoceanographic proxies, which can be used to assess the density stratification and ACC transport south of Australia. The paleoceanographic data suggest a moderate increase in the Southern Ocean stratification and the ACC strength during the LGM. Even with the relatively large uncertainty in the proxy-based estimates, extreme scenarios exhibited by some climate models with ACC transports of greater than 250 Sv and highly saline Antarctic Bottom Water are highly unlikely.

  14. A newly discovered Gigantopithecus fauna from Sanhe Cave, Chongzuo, Guangxi, South China

    Institute of Scientific and Technical Information of China (English)

    JIN ChangZhu; QIN DaGong; PAN WenShi; TANG ZhiLu; LIU JinYi; WANG Yuan; DENG ChengLong; ZHANG YingQi; DONG Wei; TONG HaoWen

    2009-01-01

    Among the most important faunas in the Late Cenozoic, the Gigantopithecus faunas have received:a good deal of attention. The Gigantopithecus fauna recently discovered in Sanhe Cave consists of more than 80 mammal species, including cf. Hominidae, Pongo sp., Hylobates sp., Sinomastodon yangzien-sis, Stegodon preorientalis, Cervavitus fenqii, Dicoryphochoerus ultimus and Sus xiaozhu. It is the southernmost Gigantopithecus fauna found so far in China. Its geological age is estimated to be Early Pleistocene based on the fauna and stratigraphic correlation. The significant increase in the estimated body sizes of Ailuropoda, Gigantopithecus and Tapirus shows that the Sanhe fauna is middle Early Pleistocene, later than those from Wushan and Liucheng (early Early Pleistocene). Paleomagnetic dating of the fossil-bearing strata in Sanhe Cave gives an age of approximately 1.2 Ma. The fauna is characterized by tropical-subtropical forest types, including Pongo sp., Tupaia sp., la sp., Typhlomys intermedius, etc., and it lacks Palaearctic types. It is a typical tropical forest fauna, suggesting an en-vironment with a lush forest and a warm and humid climate. The discovery of the Sanhe Gigantopith-ecus fauna is significant for establishing the chronological stages of the Gigantopithecus faunas in China, and for discussing their origin, evolution and dynamics.

  15. UV radiation and primary production in the Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Krishnakumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

    obtained between pp and the above parameters in the Antarctic sub-surface waters determined at discrete depths of 10, 20, 30 and 40 m. However, when the primary productivity values were normalised for PAR, a more negative effect was noticed at the Antarctic...

  16. Challenges to the Future - Conservation of the Antarctic

    NARCIS (Netherlands)

    Chown, S.L.; Lee, J.E.; Hughes, K.A.; Barnes, J.; Bergstrom, D.M.; Convey, P.; Cowan, D.A.; Crosbie, K.; Dyer, G.; Frenot, Y.; Grant, S.M.; Herr, D.; Kennicutt, M.C.; Lamers, M.A.J.; Murray, A.; Possingham, H.P.; Reid, K.; Riddle, M.J.; Ryan, P.G.; Sanson, L.; Shaw, J.D.; Sparrow, M.D.; Summerhayes, C.; Terauds, A.; Wall, D.H.

    2012-01-01

    The Antarctic Treaty System, acknowledged as a successful model of cooperative regulation of one of the globe's largest commons (1), is under substantial pressure. Concerns have been raised about increased stress on Antarctic systems from global environmental change and growing interest in the regio

  17. The distribution of Fe in the Antarctic Circumpolar Current

    NARCIS (Netherlands)

    Löscher, B.M.; Baar, H.J.W. de; Jong, J.T.M. de; Veth, C.; Dehairs, F.

    1997-01-01

    The large-scale distributions of dissolved and total Fe in surface and deep waters of the Antarctic Circumpolar Current exhibit strong relationships with hydrography and biological processes. The mean dissolved Fe concentrations are low in surface waters of the Antarctic Circumpolar Current (0.31–0.

  18. Transcriptome of the Antarctic brooding gastropod mollusc Margarella antarctica.

    Science.gov (United States)

    Clark, Melody S; Thorne, Michael A S

    2015-12-01

    454 RNA-Seq transcriptome data were generated from foot tissue of the Antarctic brooding gastropod mollusc Margarella antarctica. A total of 6195 contigs were assembled de novo, providing a useful resource for researchers with an interest in Antarctic marine species, phylogenetics and mollusc biology, especially shell production.

  19. Biological studies in the Antarctic waters: A review

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.

    stream_size 12 stream_content_type text/plain stream_name Proc_Workshop_Antarct_Stud_1990_407.pdf.txt stream_source_info Proc_Workshop_Antarct_Stud_1990_407.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

  20. Reaching for the Horizon: Enabling 21st Century Antarctic Science

    Science.gov (United States)

    Rogan-Finnemore, M.; Kennicutt, M. C., II; Kim, Y.

    2015-12-01

    The Council of Managers of National Antarctic Programs' (COMNAP) Antarctic Roadmap Challenges(ARC) project translated the 80 highest priority Antarctic and Southern Ocean scientific questionsidentified by the community via the SCAR Antarctic Science Horizon Scan into the highest prioritytechnological, access, infrastructure and logistics needs to enable the necessary research to answer thequestions. A workshop assembled expert and experienced Antarctic scientists and National AntarcticProgram operators from around the globe to discern the highest priority technological needs includingthe current status of development and availability, where the technologies will be utilized in the Antarctic area, at what temporal scales and frequencies the technologies will be employed,and how broadly applicable the technologies are for answering the highest priority scientific questions.Secondly the logistics, access, and infrastructure requirements were defined that are necessary todeliver the science in terms of feasibility including cost and benefit as determined by expected scientific return on investment. Finally, based on consideration of the science objectives and the mix oftechnologies implications for configuring National Antarctic Program logistics capabilities andinfrastructure architecture over the next 20 years were determined. In particular those elements thatwere either of a complexity, requiring long term investments to achieve and/or having an associated cost that realistically can only (or best) be achieved by international coordination, planning and partnerships were identified. Major trends (changes) in logistics, access, and infrastructure requirements were identified that allow for long-term strategic alignment of international capabilities, resources and capacity. The outcomes of this project will be reported.

  1. Antarctic bacteria inhibit growth of foodborne microorganisms at low temperatures.

    NARCIS (Netherlands)

    A.C. O'Brien; R. Sharp; N.J. Russell; S. Roller

    2004-01-01

    The aim of this study was to identify Antarctic microorganisms with the ability to produce cold-active antimicrobial compounds with potential for use in chilled food preservation. Colonies (4496) were isolated from 12 Antarctic soil samples and tested against Listeria innocua, Pseudomonas fragi and

  2. The oscillations of ship lock bottom

    Directory of Open Access Journals (Sweden)

    N.Yu. Kuzmin

    2012-06-01

    Full Text Available The article deals with the dynamic characteristics of the ship lock. The accurate design relations intended to study the natural and forced vibrations of the bottom of the ship lock are provided. The degree of filling of the lock, as well as the added mass of water is considered. The various coupling conditions of the bottom and walls of buildings are taken into account. A concrete example of the calculation is given.An exact, in the framework of the adopted design scheme, solution of the problem of the own and forced vibrations of the bottom of the ship lock is found. The frequency of the first five tones of vibrations and the associated mass of liquid according to thickness of the structure and coupling conditions of the bottom and sides of the lock are analyzed. A significant effect of liquids on low-frequency part of the spectrum and the dynamic response of the bottom is determined.

  3. Screening of microorganisms from Antarctic surface water and cytotoxicity metabolites from Antarctic microorganisms.

    Science.gov (United States)

    Zheng, Lanhong; Yang, Kangli; Liu, Jia; Sun, Mi; Zhu, Jiancheng; Lv, Mei; Kang, Daole; Wang, Wei; Xing, Mengxin; Li, Zhao

    2016-03-01

    The Antarctic is a potentially important library of microbial resources and new bioactive substances. In this study, microorganisms were isolated from surface water samples collected from different sites of the Antarctic. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay-based cytotoxicity-tracking method was used to identify Antarctic marine microorganism resources for antitumor lead compounds. The results showed that a total of 129 Antarctic microorganism strains were isolated. Twelve strains showed potent cytotoxic activities, among which a Gram-negative, rod-shaped bacterium, designated as N11-8 was further studied. Phylogenetic analysis based on 16S rRNA gene sequence showed that N11-8 belongs to the genus Bacillus. Fermented active products of N11-8 with molecular weights of 1-30 kDa had higher inhibitory effects on different cancaer cells, such as BEL-7402 human hepatocellular carcinoma cells, U251 human glioma cells, RKO human colon carcinoma cells, A549 human lung carcinoma cells, and MCF-7 human breast carcinoma cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. Microscopic observations showed that the fermented active products have inhibitory activity on BEL-7402 cells similar to that of mitomycin C. Further studies indicated that the fermented active products have high pH and high thermal stability. In conclusion, most strains isolated in this study may be developed as promising sources for the discovery of antitumor bioactive substances. The fermented active products of Antarctic marine Bacillus sp. N11- 8 are expected to be applied in the prevention and treatment of cancer.

  4. Emerging spatial patterns in Antarctic prokaryotes

    Directory of Open Access Journals (Sweden)

    Chun Wie eChong

    2015-09-01

    Full Text Available Recent advances in knowledge of patterns of biogeography in terrestrial eukaryotic organisms have led to a fundamental paradigm shift in understanding of the controls and history of life on land in Antarctica, and its interactions over the long term with the glaciological and geological processes that have shaped the continent. However, while it has long been recognized that the terrestrial ecosystems of Antarctica are dominated by microbes and their processes, knowledge of microbial diversity and distributions has lagged far behind that of the macroscopic eukaryote organisms. Increasing human contact with and activity in the continent is leading to risks of biological contamination and change in a region whose isolation has protected it for millions of years at least; these risks may be particularly acute for microbial communities which have, as yet, received scant recognition and attention. Even a matter apparently as straightforward as Protected Area designation in Antarctica requires robust biodiversity data which, in most parts of the continent, remain almost completely unavailable. A range of important contributing factors mean that it is now timely to reconsider the state of knowledge of Antarctic terrestrial prokaryotes. Rapid advances in molecular biological approaches are increasingly demonstrating that bacterial diversity in Antarctica may be far greater than previously thought, and that there is overlap in the environmental controls affecting both Antarctic prokaryotic and eukaryotic communities. Bacterial dispersal mechanisms and colonization patterns remain largely unaddressed, although evidence for regional evolutionary differentiation is rapidly accruing and, with this, there is increasing appreciation of patterns in regional bacterial biogeography in this large part of the globe. In this review, we set out to describe the state of knowledge of Antarctic prokaryote diversity patterns, drawing analogy with those of eukaryote

  5. CHARACTERISTICS OF SLUDGE BOTTOM MESH

    Directory of Open Access Journals (Sweden)

    Kamil Szydłowski

    2016-05-01

    Full Text Available The main aim of the study was to assess the selected heavy metals pollution of bottom sediments of small water bodies of different catchment management. Two ponds located in Mostkowo village were chosen for investigation. The first small water reservoir is surrounded by the cereal fields, cultivated without the use of organic and mineral fertilizers (NPK. The second reservoir is located in a park near rural buildings. Sediment samples were collected by the usage of KC Denmark sediments core probe. Samples were taken from 4 layers of sediment, from depth: 0–5, 5–10, 10–20 and 20–30 cm. Sampling was made once during the winter period (2014 year when ice occurred on the surface of small water bodies, from three points. The material was prepared for further analysis according to procedures used in soil science. The content of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn were determined by atomic absorption spectrometry by usage of ASA ICE 3000 Thermo Scientific after prior digestion in the mixture (5: 1 of concentrated acids (HNO3 and HClO4. Higher pH values ​​were characteristic for sediments of pond located in a park than in pond located within the agricultural fields. In both small water bodies the highest heavy metal concentrations occurred in the deepest points of the research. In the sediments of the pond located within crop fields the highest concentration of cadmium, copper, lead and zinc were observed in a layer of 0–5 cm, wherein the nickel and chromium in a layer of 20–30 cm. In the sediments of the pond, located in the park the highest values ​​occurred at the deepest sampling point in the layer taken form 10–20 cm. Sediments from second reservoir were characterized by the largest average concentrations of heavy metals, except the lead content in sediment form the layer of 10–20 cm. According to the geochemical evaluation of sediments proposed by Bojakowska and Sokołowska [1998], the majority of samples belongs to Ist

  6. Automatic focusing system of BSST in Antarctic

    Science.gov (United States)

    Tang, Peng-Yi; Liu, Jia-Jing; Zhang, Guang-yu; Wang, Jian

    2015-10-01

    Automatic focusing (AF) technology plays an important role in modern astronomical telescopes. Based on the focusing requirement of BSST (Bright Star Survey Telescope) in Antarctic, an AF system is set up. In this design, functions in OpenCV is used to find stars, the algorithm of area, HFD or FWHM are used to degree the focus metric by choosing. Curve fitting method is used to find focus position as the method of camera moving. All these design are suitable for unattended small telescope.

  7. The Antarctic Ozone Hole: An Update

    Science.gov (United States)

    Douglass, Anne R.; Newman, Paul A.; Solomon, Susan

    2014-01-01

    The stratospheric ozone hole, an annual occurrence during austral spring, is caused by heterogeneous conversion of hydrogen chloride and chlorine nitrate to chlorine radicals. These reactions take place of polar stratospheric cloud particles in the cold, isolate Antarctic winter vortex. The chlorine radicals participate in chemical reactions that rapidly deplete ozone when sunlight returns at the end of polar night. International agreements eliminated production of the culprit anthropogenic chlorofluorocarbons in the late 1990s, but due to their long stratospheric lifetime (50-100 years), the ozone hole will continue its annual appearance for years to come.

  8. Fast recession of a West Antarctic glacier

    OpenAIRE

    Rignot, EJ

    1998-01-01

    Satellite radar interferometry observations of Pine Island Glacier, West Antarctica, reveal that the glacier hinge-line position retreated 1.2 ± 0.3 kilometers per year between 1992 and 1996, which in turn implies that the ice thinned by 3.5 ± 0.9 meters per year. The fast recession of Pine Island Glacier, predicted to be a possible trigger for the disintegration of the West Antarctic Ice Sheet, is attributed to enhanced basal melting of the glacier floating tongue by warm ocean waters.

  9. Backarc basin evolution and cordilleran orogenesis: Insights from new ocean-bottom seismograph refraction profiling in Bransfield Strait, Antarctica

    Science.gov (United States)

    Barker, Daniel H. N.; Christeson, Gail L.; Austin, James A., Jr.; Dalziel, Ian W. D.

    2003-02-01

    Bransfield Strait, a backarc basin off the northwestern Antarctic Peninsula, is a modern analog for Cretaceous basins inverted in the compressional tectonic regime that initiated the Andean Cordillera. Eight new refraction ocean-bottom seismograph profiles in the strait demonstrate that crustal thickness in the deep central basin increases from northeast to southwest, from ˜10 km to ˜14 16 km. This confirms multichannel seismic interpretation of upper crustal structures suggesting that the Bransfield basin is opening by northeast to southwest rift propagation within arc crust of the Antarctic Peninsula, a process also recorded in the obducted Cretaceous Rocas Verdes basin of the southernmost Andes. Thinning is most prominent along the axis of the strait, where the crust is ˜9 11 km thick. In contrast, thicknesses beneath the Antarctic Peninsula margin and the inactive South Shetland Islands pedestal are ˜18 km and ˜24 km, respectively. Seismic velocities and thicknesses suggest that new oceanic crust is not yet being generated. Extension is focused along the northwest margin, imparting the physiographic asymmetry to the strait. Comparing the Bransfield basin with the inverted Rocas Verdes basin and intraoceanic counterparts in the western Pacific suggests that rift propagation and trench-side focusing of extension may be fundamental features of young backarc basins. Resultant asymmetry may facilitate observed obduction of backarc basin floor and arc rocks onto continental margins during compressional orogenesis.

  10. Molecular genetic diversity of bacteria in the bottom section of arctic sea ice from the Canada Basin

    Institute of Scientific and Technical Information of China (English)

    LI Huirong; YU Yong; CHEN Bo; ZENG Yinxin; REN Daming

    2005-01-01

    PCR-DGGE approach was used to analyze bacterial diversity in the bottom section of seven arctic sea ice samples colleted from the Canada Basin. Thirty-two 16S rDNA sequences were obtained from prominent DGGE bands. The closest relatives of these sequences are found to be those of cultivated or uncultured bacteria from antarctic or arctic sea ice. Phylogenetic analysis clustered these sequences or phylotypes within α- proteobacteria, γ-proteobacteria and CFB (cytophaga-flexibacter-bacteroides) group. Sequences belonging to γ-proteobacteria were dominant and members of the CFB group were highly abundant. It was suggested that the CFB group was the representative of the bottom section of sea ice samples.

  11. Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes.

    Science.gov (United States)

    García-Palacios, Pablo; Maestre, Fernando T; Kattge, Jens; Wall, Diana H

    2013-08-01

    Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesised litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~ 37%). [corrected]. However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate-driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome-specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large-scale decomposition models.

  12. Pipeline bottoming cycle study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  13. Rapid Access Ice Drill: A New Tool for Exploration of the Deep Antarctic Ice Sheets and Subglacial Geology

    Science.gov (United States)

    Goodge, J. W.; Severinghaus, J. P.

    2014-12-01

    The Rapid Access Ice Drill (RAID) will penetrate the Antarctic ice sheets in order to core through deep ice, the glacial bed, and into bedrock below. This new technology will provide a critical first look at the interface between major ice caps and their subglacial geology. Currently in construction, RAID is a mobile drilling system capable of making several long boreholes in a single field season in Antarctica. RAID is interdisciplinary and will allow access to polar paleoclimate records in ice >1 Ma, direct observation at the base of the ice sheets, and recovery of rock cores from the ice-covered East Antarctic craton. RAID uses a diamond rock-coring system as in mineral exploration. Threaded drill-pipe with hardened metal bits will cut through ice using reverse circulation of Estisol for pressure-compensation, maintenance of temperature, and removal of ice cuttings. Near the bottom of the ice sheet, a wireline bottom-hole assembly will enable diamond coring of ice, the glacial bed, and bedrock below. Once complete, boreholes will be kept open with fluid, capped, and made available for future down-hole measurement of thermal gradient, heat flow, ice chronology, and ice deformation. RAID will also sample for extremophile microorganisms. RAID is designed to penetrate up to 3,300 meters of ice and take sample cores in less than 200 hours. This rapid performance will allow completion of a borehole in about 10 days before moving to the next drilling site. RAID is unique because it can provide fast borehole access through thick ice; take short ice cores for paleoclimate study; sample the glacial bed to determine ice-flow conditions; take cores of subglacial bedrock for age dating and crustal history; and create boreholes for use as an observatory in the ice sheets. Together, the rapid drilling capability and mobility of the drilling system, along with ice-penetrating imaging methods, will provide a unique 3D picture of the interior Antarctic ice sheets.

  14. De corticole fauna van platanen: i. Arachniden (Arachnida: Araneae, Pseudoscorpiones, Acari)

    OpenAIRE

    Noordijk, J.; Berg, M.P.

    2001-01-01

    The corticolous fauna of plane trees: I. Arachnids (Arachnida: Araneae, Pseudoscorpiones, Acari) From February until September 2000 an inventory was made of the bark-dwelling arthropod fauna of more than 400 plane trees (Platanus hybrida), all over the Netherlands. Arthropods were collected from bark and under the ‘loose’ bark fragments at a height of 160-175 cm from the ground. Algae, mosses and fungi are important resources for the corticolous fauna. Crevices in the tree trunk and loose bar...

  15. Bottom-strange mesons in hyperonic matter

    OpenAIRE

    Pathak, Divakar; Mishra, Amruta

    2014-01-01

    The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of t...

  16. Capítulo 2. La fauna sobrenatural

    OpenAIRE

    Mayer, Renata; Millones, Luis

    2015-01-01

    Todo libro sagrado, al narrar el origen del mundo y los acontecimientos que rodearon a este suceso, incluye entre sus creaciones primigenias a una fauna y flora muy selectiva, que juega el rol de los seres que acompañan o preceden a la aparición de los humanos. Su importancia es desigual en este continuo drama de creación, formación o construcción del universo; y, en cierta forma, constituyen ensayos de la obra maestra que será la aparición de la pareja primera, que casi siempre repite en ima...

  17. THE EFFECTS OF ULTRAVIOLET-B RADIATION ON ANTARCTIC SEA-ICE ALGAE(1).

    Science.gov (United States)

    Ryan, Ken G; McMinn, Andrew; Hegseth, Else N; Davy, Simon K

    2012-02-01

    The impacts of ultraviolet-B radiation (UVB) on polar sea-ice algal communities have not yet been demonstrated. We assess the impacts of UV on these communities using both laboratory experiments on algal isolates and by modification of the in situ spectral distribution of the under-ice irradiance. In the latter experiment, filters were attached to the upper surface of the ice so that the algae were exposed in situ to treatments of ambient levels of PAR and UV radiation, ambient radiation minus UVB, and ambient radiation minus all UV. After 16 d, significant increases in chl a and cell numbers were recorded for all treatments, but there were no significant differences among the different treatments. Bottom-ice algae exposed in vitro were considerably less tolerant to UVB than those in situ, but this tolerance improved when algae were retained within a solid block of ice. In addition, algae extracted from brine channels in the upper meter of sea ice and exposed to PAR and UVB in the laboratory were much more tolerant of high UVB doses than were any bottom-ice isolates. This finding indicates that brine algae may be better adapted to high PAR and UVB than are bottom-ice algae. The data indicate that the impact of increased levels of UVB resulting from springtime ozone depletion on Antarctic bottom-ice communities is likely to be minimal. These algae are likely protected by strong UVB attenuation by the overlying ice and snow, by other inorganic and organic substances in the ice matrix, and by algal cells closer to the surface. PMID:27009652

  18. Bioaccumulation of heavy metals in fauna from wet detention ponds for stormwater runoff

    DEFF Research Database (Denmark)

    Stephansen, Diana; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild;

    2012-01-01

    Stormwater detention ponds remove pollutants e.g. heavy metals and nutrients from stormwater runoff. These pollutants accumulate in the pond sediment and thereby become available for bioaccumulation in fauna living in the ponds. In this study the bioaccumulation was investigated by fauna samples...... from 5 wet detention ponds for analyses of heavy metal contents. Five rural shallow lakes were included in the study to survey the natural occurrence of heavy metals in water-dwelling fauna. Heavy metal concentrations in water-dwelling fauna were generally found higher in wet detention ponds compared...

  19. CHAMP Magnetic Anomalies of the Antarctic Crust

    Science.gov (United States)

    Kim, Hyung Rae; Gaya-Pique, Luis R.; vonFrese, Ralph R. B.; Taylor, Patrick T.; Kim, Jeong Woo

    2003-01-01

    Regional magnetic signals of the crust are strongly masked by the core field and its secular variations components and hence difficult to isolate in the satellite measurements. In particular, the un-modeled effects of the strong auroral external fields and the complicated- behavior of the core field near the geomagnetic poles conspire to greatly reduce the crustal magnetic signal-to-noise ratio in the polar regions relative to the rest of the Earth. We can, however, use spectral correlation theory to filter the static lithospheric and core field components from the dynamic external field effects. To help isolate regional lithospheric from core field components, the correlations between CHAMP magnetic anomalies and the pseudo magnetic effects inferred from gravity-derived crustal thickness variations can also be exploited.. Employing these procedures, we processed the CHAMP magnetic observations for an improved magnetic anomaly map of the Antarctic crust. Relative to the much higher altitude Orsted and noisier Magsat observations, the CHAMP magnetic anomalies at 400 km altitude reveal new details on the effects of intracrustal magnetic features and crustal thickness variations of the Antarctic.

  20. Extremophiles in an Antarctic Marine Ecosystem

    Science.gov (United States)

    Dickinson, Iain; Goodall-Copestake, William; Thorne, Michael A.S.; Schlitt, Thomas; Ávila-Jiménez, Maria L.; Pearce, David A.

    2016-01-01

    Recent attempts to explore marine microbial diversity and the global marine microbiome have indicated a large proportion of previously unknown diversity. However, sequencing alone does not tell the whole story, as it relies heavily upon information that is already contained within sequence databases. In addition, microorganisms have been shown to present small-to-large scale biogeographical patterns worldwide, potentially making regional combinations of selection pressures unique. Here, we focus on the extremophile community in the boundary region located between the Polar Front and the Southern Antarctic Circumpolar Current in the Southern Ocean, to explore the potential of metagenomic approaches as a tool for bioprospecting in the search for novel functional activity based on targeted sampling efforts. We assessed the microbial composition and diversity from a region north of the current limit for winter sea ice, north of the Southern Antarctic Circumpolar Front (SACCF) but south of the Polar Front. Although, most of the more frequently encountered sequences  were derived from common marine microorganisms, within these dominant groups, we found a proportion of genes related to secondary metabolism of potential interest in bioprospecting. Extremophiles were rare by comparison but belonged to a range of genera. Hence, they represented interesting targets from which to identify rare or novel functions. Ultimately, future shifts in environmental conditions favoring more cosmopolitan groups could have an unpredictable effect on microbial diversity and function in the Southern Ocean, perhaps excluding the rarer extremophiles. PMID:27681902

  1. Solar power for an Antarctic rover

    Science.gov (United States)

    Lever, J. H.; Ray, L. R.; Streeter, A.; Price, A.

    2006-03-01

    Sensors mounted on mobile robots could serve a variety of science missions in Antarctica. Although weather conditions can be harsh, Antarctic snowfields offer unique conditions to facilitate long-distance robot deployment: the absence of obstacles, firm snow with high albedo, and 24 h sunlight during the summer. We have developed a four-wheel-drive, solar-powered rover that capitalizes on these advantages. Analyses and field measurements confirm that solar power reflected from Antarctic snow contributes 30-40% of the power available to a robot consisting of a five-side box of solar panels. Mobility analyses indicate that the 80 kg rover can move at 0.8 m s-1 during clear sky conditions on firm snow into a 5 m s-1 headwind, twice the speed needed to achieve the design target of 500 km in 2 weeks. Local winter tests of the chassis demonstrated good grade-climbing ability and lower than predicted rolling resistance. Tests of the completed robot occurred in Greenland in 2005.

  2. Longitudinal surface structures (flowstripes on Antarctic glaciers

    Directory of Open Access Journals (Sweden)

    N. F. Glasser

    2011-11-01

    Full Text Available Longitudinal surface structures (''flowstripes'' are common on many glaciers but their origin and significance are poorly understood. In this paper we present observations of the development of these longitudinal structures from four different Antarctic glacier systems (the Lambert Glacier/Amery Ice Shelf area, outlet glaciers in the Ross Sea sector, ice-shelf tributary glaciers on the Antarctic Peninsula, and the onset zone of a tributary to the Recovery Glacier Ice Stream in the Filchner Ice Shelf area. Mapping from optical satellite images demonstrates that longitudinal surface structures develop in two main situations: (1 as relatively wide flow stripes within glacier flow units and (2 as relatively narrow flow stripes where there is convergent flow around nunataks or at glacier confluence zones. Our observations indicate that the confluence features are narrower, sharper, and more clearly defined features. They are characterised by linear troughs or depressions on the ice surface and are much more common than the former type. Longitudinal surface structures within glacier flow units have previously been explained as the surface expression of localised bed perturbations but a universal explanation for those forming at glacier confluences is lacking. Here we propose that these features are formed at zones of ice acceleration and extensional flow at glacier confluences. We provide a schematic model for the development of longitudinal surface structures based on extensional flow that can explain their ridge and trough morphology as well as their down-ice persistence.

  3. Extremophiles in an Antarctic Marine Ecosystem

    Directory of Open Access Journals (Sweden)

    Iain Dickinson

    2016-01-01

    Full Text Available Recent attempts to explore marine microbial diversity and the global marine microbiome have indicated a large proportion of previously unknown diversity. However, sequencing alone does not tell the whole story, as it relies heavily upon information that is already contained within sequence databases. In addition, microorganisms have been shown to present small-to-large scale biogeographical patterns worldwide, potentially making regional combinations of selection pressures unique. Here, we focus on the extremophile community in the boundary region located between the Polar Front and the Southern Antarctic Circumpolar Current in the Southern Ocean, to explore the potential of metagenomic approaches as a tool for bioprospecting in the search for novel functional activity based on targeted sampling efforts. We assessed the microbial composition and diversity from a region north of the current limit for winter sea ice, north of the Southern Antarctic Circumpolar Front (SACCF but south of the Polar Front. Although, most of the more frequently encountered sequences  were derived from common marine microorganisms, within these dominant groups, we found a proportion of genes related to secondary metabolism of potential interest in bioprospecting. Extremophiles were rare by comparison but belonged to a range of genera. Hence, they represented interesting targets from which to identify rare or novel functions. Ultimately, future shifts in environmental conditions favoring more cosmopolitan groups could have an unpredictable effect on microbial diversity and function in the Southern Ocean, perhaps excluding the rarer extremophiles.

  4. Interhemispheric coupling and warm Antarctic interglacials

    Directory of Open Access Journals (Sweden)

    P. B. Holden

    2009-12-01

    Full Text Available Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than pre-industrial (CO2 ~280 ppm in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (~3 000 years and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as "Warmer than Present Transients" (WPTs. We here present transient 800 kyr simulations using the intermediate complexity model GENIE-1 which suggest that WPTs could be explained as a consequence of the meltwater-forced slowdown of the Atlantic Meridional Overturning Circulation (AMOC during glacial terminations. It is well known that a slowed AMOC would increase southern Sea Surface Temperature (SST through the bipolar seesaw. Observational data supports this hypothesis, suggesting that the AMOC remained weak throughout the terminations preceding WPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. In order to investigate model and boundary condition uncertainty, we additionally present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP and three snapshot HadCM3 simulations at 130 000 Before Present (BP. These simulations together reproduce both the timing and magnitude of WPTs, and point to the potential importance of an albedo feedback associated with West Antarctic Ice Sheet (WAIS retreat.

  5. Microbial biomass and basal respiration in Sub-Antarctic and Antarctic soils in the areas of some Russian polar stations

    Directory of Open Access Journals (Sweden)

    E. Abakumov

    2014-03-01

    Full Text Available Antarctica is the unique place for pedological investigations. Soils of Antarctica have been studied intensively during the last century. Antarctic logistic provides the possibility to scientists access the terrestrial landscapes mainly in the places of polar stations. That is why the main and most detailed pedological investigations were conducted in Mc Murdo Valleys, Transantarctic Mountains, South Shetland Islands, Larsemann hills and Schirmacher Oasis. Investigations were conducted during the 53rd and 55th Russian Antarctic expeditions on the base of soil pits and samples collected in Sub-Antarctic and Antarctic regions. Soils of diverse Antarctic landscapes were studied with aim to assess the microbial biomass level, basal respiration rates and metabolic activity of microbial communities. The investigation conducted shows that soils of Antarctic are quite different in profile organization and carbon content. In general, Sub-Antarctic soils are characterized by more developed humus (sod organo-mineral horizons as well as the upper organic layer. The most developed organic layers were revealed in peat soils of King-George Island, where its thickness reach even 80 cm. These soils as well as soils under guano are characterized by the highest amount of total organic carbon (TOC 7.22–33.70%. Coastal and continental soils of Antarctic are presented by less developed Leptosols, Gleysols, Regolith and rare Ornhitosol with TOC levels about 0.37–4.67%. The metabolic ratios and basal respiration were higher in Sub-Antarctic soils than in Antarctic ones which can be interpreted as result of higher amounts of fresh organic remnants in organic and organo-mineral horizons. Also the soils of King-George island have higher portion of microbial biomass (max 1.54 mg g−1 than coastal (max 0.26 mg g−1 and continental (max 0.22 mg g−1 Antarctic soils. Sub-Antarctic soils mainly differ from Antarctic ones in increased organic layers thickness and total

  6. Landfilling: Bottom Lining and Leachate Collection

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter;

    2011-01-01

    The critical element of a landfill, which is essential for the protection of the environment in general, and prevention of contamination of the underlying soils and groundwater in particular, is the bottom lining system. The major focus of the bottom lining system development is to prevent leachate...... from entering the groundwater or surface water. The bottom lining system should cover the full footprint area of the landfill, including both the relatively flat bottom and the sideslopes in the case of an excavated configuration. This prevents the lateral migration of leachate from within the landfill...... works together with the overlying leachate management system, also referred to as the leachate collection and removal system (LCRS), which consists of a drainage layer that provides easy horizontal drainage of the leachate to a point of gravitational collection or pumping. Although individual liners...

  7. Sedimentation and near-bottom currents in the South-Western Atlantic

    Science.gov (United States)

    Emelyanov, Emelyan M.

    2008-01-01

    The aims of the paper are: 1) to study the bottom relief and Late Quaternary bottom sediments of the South-Western Atlantic from the Amazon cone to the Vema Channel and Rio Grande Rise, and 2) to reconstruct recent and palaeo-Antarctic near-bottom currents (AABW). For this purpose, we used three main Parasound seismic profiles: 30 cores (up to 500 cm in length), the nanoplankton stratigraphy of 9 cores from the Brazilian lithological profile (along 24 °W), and literature sources. No soft sedimentes were found in the Vema channel; the bottom of the channel is acoustically "hard". Our geological data confirm that AABW flows mainly through this channel. The velocity of this flow should be higher than 100 cm.s-1. Only this strong current is able to rewash not only soft Holocene sediments, but also consolidated Quaternary deposits. Soft layered sediments occur at a depth less than 4200 m in the Hunter channel. Consequently, the AABW is able to flow from the Argentine Basin to the Brazil Basin only at a depth of more than 4200 m in this channel. Brown red clay or yellowish gray miopelagic clay prevail in the Brazil Deep. The age of red clay in the cores is different: Early or Late Pleistocene, or Holocene. Clay was rewashed and re-deposited in many areas of the deep. This means that the hydrodynamics sometimes was very active at a depth of 4000-5000 m in the Brazil Deep. The presence of conturite and turbidite interlayers in the red clay of the S. America continental base confirms the occurrence of a strong jet of the AABW (Deep Western Boundary current - DWBC) here. Antarctic and other diatoms were brought by AABW from Antarctica up to 10-5 °S. An unusual Pleistocene Ethmodiscus rex ooze was discovered at the latitude of 20 °S. Our data confirm the occurrence in the area between 10-5 °S of two mid-oceanic channels, one of them (EMOC) being located on a large sedimentary swell. The AABW in the cross-section from the Amazon River to the MAR flows through the Nara

  8. Time stability of ocean bottom seismometers (OBS)

    OpenAIRE

    Shariat Panahi, Shahram; Manuel Lázaro, Antonio; Corrêa Alegría, Francisco

    2010-01-01

    During the past decades, Ocean Bottom Seismometers (OBS) have played a key role in permanent seismic activity monitoring at sea as well as allowing a better understating of the earth interior. Data collected by the instrument can provide information on the ocean bottom sub-layers down to a depth of 40 km beneath the ocean floor. The accuracy of the results directly depends on the temperature stability of the crystal used as the main time base of the equipment. This paper pre...

  9. [Is the parasite fauna of Poland well recognized?].

    Science.gov (United States)

    Pojmańska, Teresa; Niewiadomska, Katarzyna

    2003-01-01

    The studies of parasite fauna have in Poland a long tradition. Generally the helmint fauna of all groups of vertebrates was more or less examined and as much as over 100 species of Monogenea, almost 400 Digenea, over 250 Cestoda, about 500 Nematoda and 32 Acanthocephala have been recorded. The best recognized are the helminths of fish (especially those of Cyprinidae, Esocidae, Percidae and Salmonidae), frogs examined in various regions of Poland, some birds (especially connected with water environment: Anseriformes, Ciconiformes, Podicipediformes), most of insectivores (although examined only in few localities), European bisons, deers, foxes and wild boars (all under permanent monitoring), as well as domestic animals (cattle, horses, sheeps) and pets. Such groups like some amphibians, reptiles, bats, carniwores, some birds (especially Passeriformes, Charadriiformes, falcons and eagles) need further exploration, as some host species were not the subject of parasitological investigation. In some cases it will be rather difficult goal, as most of these animals are under strict preservation, and only dead (naturally or accidentally) specimens can be autopsied. PMID:16888930

  10. Scorpion fauna and epidemiological aspects of scorpionism in southeastern Iran

    Institute of Scientific and Technical Information of China (English)

    Jalil Nejati; Ehsan Mozafari; Abedin Saghafipour; Malek Kiyani

    2014-01-01

    Objective: To identify the scorpion fauna and classify the epidemiological aspects of scorpionism in an endemic region, Southeast Iran. Methods: Scorpionism data were collected from health centers and hospitals in Sistan-Baluchestan Province during 2010-2011. Specimens were collected at night, using UV light, between May and October 2012.Results:Five species including Odontobuthus odonturus, Hottentotta (Buthotus) jayakari, Compsobuthus matthiesseni, Scorpio maurus and Orthochirus scrobiculosus are reported for the first time from this area. Androctonus crassicauda was the dominant species. In total, 3638 scorpion sting cases were recorded by health system, the majority of which were females. Stings mostly occurred in July and the age group of 15-24 years presented the highest frequency. Scorpionism decreased during 2011 compared with that in 2010 (68.2%). In total, 246 scorpions were collected from two families (Buthidae and Scorpionidae). Conclusions: Based on the results, scorpionism is a serious health problem in this area and increasing knowledge of residents regarding the prevention methods of scorpion stings is recommended. Additional research on the scorpion fauna, their ecological and molecular variety in this part of the country is needed as well as the correlation between scorpions’ species and the clinical signs and symptoms.

  11. Mosquito Fauna (Diptera: Culicidae of Hamedan County, Western Iran.

    Directory of Open Access Journals (Sweden)

    Amir Hossein Zahirnia

    2014-12-01

    Full Text Available This study aimed to identify and determine the larval and adult mosquitoes (Culicidae fauna in Hamedan County, western Iran.It was a cross-sectional study which took place in four area of the Hamedan County. Sampling methods for larvae, pupae and adults were dipping, hand catch, night catch and total catch. Larvae and adult mosquitoes collected and were sent to laboratory of Medical Entomology, Hamedan University of Medical Sciences, Hamedan, Iran for further identification to species level to determination of fauna. Data analysis was performed using SPSS software version19.Three genera and eight species of family Culicidae were collected and identified in Hamedan County, Hamedan Province, West Iran, during May to October 2013. These species included: Culex theileri, Cx. pipiens, Cx. antennatus, Culiseta subochrea, Cs. langiareolata, Anopheles superpictus, An. maculipennis and An. stephensi. The species Cx. antennatus and An. stephensi were reported for the first time in Hamedan County.An. stephensi and Cx. antennatus caught had not been previously recorded in Hamedan Province. Due to vast agricultural activities in the province which provides suitable environment for the establishment of various species of mosquitoes and since many of them are potential vectors of human and domesticated animal pathogens, their ecology needs to be studied extensively.

  12. Bioseguridad en el Manejo de Fauna Silvestre y no Convencional

    Directory of Open Access Journals (Sweden)

    Nestor Varela

    2011-06-01

    Full Text Available La bioseguridad es un conjunto de actuaciones para prevenir la pérdida de la integridad biológica a diversas escalas, estando relacionada como concepto a múltiples campos y disciplinas. En las ciencias de la salud, la bioseguridad hace referencia a la prevención de la contaminación derivada del contacto con órganos o tejidos de origen biológico y microorganismos. Los problemas traumáticos, las reacciones alérgicas o irritativas y las zoonosis son las causas de enfermedad más frecuentes en las personas que manejan fauna, por ello la prevención debe dirigirse prioritariamente al control de estos factores. Las medidas de protección incluyen la higiene personal, el aseo, limpieza y desinfección de las instalaciones, elementos y equipos, el empleo de indumentaria de protección personal, y la adopción de protocolos específicos de acuerdo al nivel de riesgo detectado para las diversas actividades realizadas por el personal. Se describe un código de prácticas generales a varios niveles para personas encargadas del manejo de fauna y se describen los niveles de bioseguridad que se emplean como protocolos ante la ausencia de conocimiento sobre bioriesgo durante la práctica con animales silvestres.

  13. Contribution to the knowledge of the butterfly fauna of Albania

    Directory of Open Access Journals (Sweden)

    Martina Šašić

    2015-03-01

    Full Text Available Albanian insect fauna is one of the least studied in Europe. In 2012 and 2013 surveys were undertaken with the aim of improving the knowledge of the distribution of butterflies, particularly in the southern part of the country. This research has resulted in the publication of three new species records for Albania. Here we add two new species to the list of native butterflies of Albania, Melitaea ornata Christoph, 1893 and Cupido alcetas (Hoffmannsegg, 1804. We recorded a total of 143 species including several confirmations of historical published records. The total number of species has consequently increased to 198, which is comparable with butterfly diversity in neighbouring countries. Unlike its neighbours, Albania has preserved many of its traditional agricultural practices and consequently its rich fauna has been well protected during the last decades. However, with the opening up of the country to outside influences this will undoubtedly change as the process of intensification has already started in more populated coastal areas. It is therefore imperative to identify important butterfly areas in need of conservation and to take decisive measures to preserve traditional agricultural practices.

  14. Butterfly fauna in Mount Gariwang-san, Korea

    Directory of Open Access Journals (Sweden)

    Cheol Min Lee

    2016-06-01

    Full Text Available The aim of this study is to elucidate butterfly fauna in Mt. Gariwang-san, Korea. A field survey was conducted from 2010 to 2015 using the line transect method. A literature survey was also conducted. A total of 2,037 butterflies belonging to 105 species were recorded. In the estimation of species richness of butterfly, 116 species were estimated to live in Mt. Gariwang-san. In butterfly fauna in Mt. Gariwang-san, the percentage of northern species was very high and the percentage of grassland species was relatively higher than that of forest edge species and forest interior species. Sixteen red list species were found. In particular, Mimathyma nycteis was only recorded in Mt. Gariwang-san. When comparing the percentage of northern species and southern species including those recorded in previous studies, the percentage of northern species was found to have decreased significantly whereas that of southern species increased. We suggest that the butterfly community, which is distributed at relatively high altitudes on Mt. Gariwang-san, will gradually change in response to climate change.

  15. Antarctic Treaty Summit to Focus on Global Science Policy Lessons

    Science.gov (United States)

    Berkman, Paul Arthur; Walton, David W. H.; Weiler, C. Susan

    2008-10-01

    The Antarctic Treaty Summit, which will coincide with the fiftieth anniversary of the treaty's signing, will be held at the Smithsonian Institution's National Museum of Natural History, in Washington, D. C., from 30 November to 3 December 2009. The summit will provide an open international forum for scientists, legislators, lawyers, administrators, educators, students, corporate executives, historians, and other members of global civil society to explore science policy achievements from the first 50 years of the Antarctic Treaty. In addition, the summit will complement official government celebrations of the Antarctic Treaty anniversary that do not include public participation.

  16. Antarctic Porifera database from the Spanish benthic expeditions

    OpenAIRE

    Pilar Rios; Javier Cristobo

    2014-01-01

    The information about the sponges in this dataset is derived from the samples collected during five Spanish Antarctic expeditions: Bentart 94, Bentart 95, Gebrap 96, Ciemar 99/00 and Bentart 2003. Samples were collected in the Antarctic Peninsula and Bellingshausen Sea at depths ranging from 4 to 2044 m using va­rious sampling gears.The Antarctic Porifera database from the Spanish benthic expeditions is unique as it provides in­formation for an under-explored region of the Southern Oc...

  17. COMERCIO DE FAUNA SILVESTRE EN COLOMBIA WILDLIFE TRADE IN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Néstor Javier Mancera Rodríguez

    2008-12-01

    Full Text Available Este trabajo ofrece un panorama sobre las actividades relacionadas con el comercio de bienes derivados de las especies de fauna silvestre en Colombia, abordando el tema desde el desarrollo que ha tenido su actividad productiva, el aprovechamiento extractivo, así como la dinámica de su comercio legal e ilegal en el país y el desarrollo y promoción de alternativas productivas sustentadas en su aprovechamiento. Se analizó la información secundaria de entidades como el Ministerio de Ambiente, Vivienda y Desarrollo Territorial, las Corporaciones Autónomas Regionales y Autoridades Ambientales Urbanas, el Instituto Colombiano de Desarrollo Rural-INCODER, las Autoridades Policiales, los Institutos de Investigación, el Departamento Administrativo Nacional de Estadística, la Dirección de Impuestos y Aduanas Nacionales-DIAN, el Ministerio de Comercio, Industria y Turismo, y PROEXPORT. entre otras. En Colombia, el comercio de especies de fauna silvestre está centrado principalmente en la extracción de ejemplares de forma ilegal, lo cual ha generado desequilibrios en las poblaciones naturales y ha repercutido en el deterioro de la dinámica de los ecosistemas. El comercio legal de fauna silvestre se basa en la producción de unas pocas especies entre las que se destacan la babilla (Caiman crocodilus, el chigüiro (Hydrochaeris hydrochaeris, cerca de 200 especies de peces ornamentales y en menor medida el lobo pollero (Tupinambis nigropunctatus, la iguana (Iguana iguana, la boa (Boa constrictor, escarabajos (Dynastes hercules y mariposas. En el país no se tiene información exacta sobre el número de incautaciones realizadas en los operativos de control al tráfico ilegal de fauna, y no existe un conocimiento de la dinámica de este comercio ilegal.This work offers a current view on the activities related to the trade of derived from the wildlife species in Colombia, approaching the topic from the development that has had its productive activity

  18. Adjustment of pigment composition in Desmarestia (Desmarestiaceae species along a sub-Antarctic to Antarctic latitudinal gradient

    Directory of Open Access Journals (Sweden)

    Andrés Mansilla

    2016-08-01

    Full Text Available Photosynthesis at high latitudes demands efficient strategies of light utilization to maintain algal fitness and performance. The fitness, and physiological adaptation, of a plant or algae species depends in part on the abundance and efficiency of the pigments it can produce to utilize the light resource from its environment. We quantified pigment composition and concentration in six species of the brown macroalgal genus Desmarestia, collected from sub-Antarctic sites (Strait of Magellan, Beagle Channel–Cape Horn Province and sites on the Antarctic Peninsula and adjacent islands. Sub-Antarctic Desmarestia species exhibited lower concentrations of chlorophyll a, chlorophyll c and fucoxanthin than endemic Antarctic species. Antarctic samples of D. menziesii and D. antarctica collected along a decreasing latitudinal gradient showed spatial and interspecific differences in light-harvesting pigment composition. Our results suggest distinct physiological adjustments in Desmarestia species in response to heterogeneous abiotic environmental conditions. The marine sub-Antarctic and Antarctic ecosystems are characterized by harsh environments (e.g., extreme irradiance, photoperiod, temperature, salinity to which the physiology of macroalgal species must adapt.

  19. Different adaptations of Chinese winter-over expeditioners during prolonged Antarctic and sub-Antarctic residence

    Science.gov (United States)

    Chen, Nan; Wu, Quan; Li, Hao; Zhang, Tao; Xu, Chengli

    2016-05-01

    Prolonged residence in Antarctica is characterized by exposure to isolated, confined, and extreme (ICE) environment. Winter-over expeditioners at research stations often exhibit a complex of psychophysiological symptoms, which varied by stations and sociocultural backgrounds. To understand the different patterns of psychophysiological responses provoked by environmental stress, we conducted a longitudinal assessment of mood and endocrine function in two groups of Chinese expeditioners who were deployed to sub-Antarctic (Great Wall Station, 62°S, N = 12) and Antarctic (Zhongshan Station, 66°S, N = 16) from December 2003 to 2005. Measures of mood, thyroid function, the levels of plasma catecholamine, and circulating interleukins were obtained at departure from China, mid-winter (Antarctica), end of winter (Antarctica), and return to China, respectively. The Zhongshan Station crew experienced significant increases in fatigue, anger, tension, confusion, and decrease in free thyroxine (FT4), norepinephrine (NE), and epinephrine (E) during the winter, increase in thyrotropin (TSH) and total triiodothyronine (TT3) when returning, whereas their counterparts at Great Wall Station only experienced increased TT3 after deployment. Moreover, compared with the Great Wall Station crew, the Zhongshan Station crew exhibited greater increase in anger, greater decrease in FT4, total thyroxine (TT4), NE and E over the winter, and greater increase in TSH when returning. Chinese expeditioners who lived and worked at the Antarctic station and the sub-Antarctic station for over a year showed different change patterns in mood and endocrine hormones. Negative mood and endocrine dysfunction were positively associated with the severity of environment. The study is a supplement to scientific knowledge on psychophysiological variation under ICE environment, which has certain applied value for the development of preventive countermeasures or interventions.

  20. Different adaptations of Chinese winter-over expeditioners during prolonged Antarctic and sub-Antarctic residence.

    Science.gov (United States)

    Chen, Nan; Wu, Quan; Li, Hao; Zhang, Tao; Xu, Chengli

    2016-05-01

    Prolonged residence in Antarctica is characterized by exposure to isolated, confined, and extreme (ICE) environment. Winter-over expeditioners at research stations often exhibit a complex of psychophysiological symptoms, which varied by stations and sociocultural backgrounds. To understand the different patterns of psychophysiological responses provoked by environmental stress, we conducted a longitudinal assessment of mood and endocrine function in two groups of Chinese expeditioners who were deployed to sub-Antarctic (Great Wall Station, 62°S, N = 12) and Antarctic (Zhongshan Station, 66°S, N = 16) from December 2003 to 2005. Measures of mood, thyroid function, the levels of plasma catecholamine, and circulating interleukins were obtained at departure from China, mid-winter (Antarctica), end of winter (Antarctica), and return to China, respectively. The Zhongshan Station crew experienced significant increases in fatigue, anger, tension, confusion, and decrease in free thyroxine (FT4), norepinephrine (NE), and epinephrine (E) during the winter, increase in thyrotropin (TSH) and total triiodothyronine (TT3) when returning, whereas their counterparts at Great Wall Station only experienced increased TT3 after deployment. Moreover, compared with the Great Wall Station crew, the Zhongshan Station crew exhibited greater increase in anger, greater decrease in FT4, total thyroxine (TT4), NE and E over the winter, and greater increase in TSH when returning. Chinese expeditioners who lived and worked at the Antarctic station and the sub-Antarctic station for over a year showed different change patterns in mood and endocrine hormones. Negative mood and endocrine dysfunction were positively associated with the severity of environment. The study is a supplement to scientific knowledge on psychophysiological variation under ICE environment, which has certain applied value for the development of preventive countermeasures or interventions.

  1. Biomarkers and Microbial Fossils In Antarctic Rocks

    Science.gov (United States)

    Wierzchos, J.; Ascaso, C.

    Lithobiontic microbial communities living within Antarctic rocks are an example of survival in an extremely cold and dry environment. Any unfavourable change in ex- ternal conditions can result in the death and disappearance of microscopic organisms, and this may be followed by the appearance of trace biomarkers and microbial fossils. The extinction of these microorganisms in some zones of the Ross Desert, probably provoked by the hostile environment, might be considered a good terrestrial analogue of the first stage of the disappearance of possible life on early Mars. Granite samples from maritime Antarctica (Granite Harbour) and sandstone rocks from the continental Ross Desert were collected with the aim of searching for biomarkers and microbial fossils at the microscopic level of observation. To this end, a novel in situ applica- tion of scanning electron microscopy with backscattered electron imaging was com- bined with the simultaneous use of X-ray energy dispersive spectroscopy techniques. Our findings confirm the existence of inorganic biomarkers in the form of physico- chemically bioweathered minerals within the granitic rocks. The presence of Fe-rich diagenetic minerals, such as iron hydroxide nanocrystals and biogenic clays around chasmoendolithic hyphae and bacterial cells was also observed. Others biomarkers, including inorganic deposits such as calcium oxalates and silica accumulations, are clear signs of endolithic microorganism activity. The interior of the sandstone rocks (Ross Desert, Mt. Fleming) reveal the presence of microbial fossils of algae and other endolithic microorganisms. These microbial fossils, detected for the first time within Antarctic rocks, contain well preserved and morphologically distinguishable relics of ultrastructural cytoplasm elements, such as cell walls, chloroplast membranes, and oc- casionally, pyrenoids and traces of organic matter. These structures are similar to those observed in live cells also found in Antarctic

  2. Tropical pacing of Antarctic sea ice increase

    Science.gov (United States)

    Schneider, D. P.

    2015-12-01

    One reason why coupled climate model simulations generally do not reproduce the observed increase in Antarctic sea ice extent may be that their internally generated climate variability does not sync with the observed phases of phenomena like the Pacific Decadal Oscillation (PDO) and ENSO. For example, it is unlikely for a free-running coupled model simulation to capture the shift of the PDO from its positive to negative phase during 1998, and the subsequent ~15 year duration of the negative PDO phase. In previously presented work based on atmospheric models forced by observed tropical SSTs and stratospheric ozone, we demonstrated that tropical variability is key to explaining the wind trends over the Southern Ocean during the past ~35 years, particularly in the Ross, Amundsen and Bellingshausen Seas, the regions of the largest trends in sea ice extent and ice season duration. Here, we extend this idea to coupled model simulations with the Community Earth System Model (CESM) in which the evolution of SST anomalies in the central and eastern tropical Pacific is constrained to match the observations. This ensemble of 10 "tropical pacemaker" simulations shows a more realistic evolution of Antarctic sea ice anomalies than does its unconstrained counterpart, the CESM Large Ensemble (both sets of runs include stratospheric ozone depletion and other time-dependent radiative forcings). In particular, the pacemaker runs show that increased sea ice in the eastern Ross Sea is associated with a deeper Amundsen Sea Low (ASL) and stronger westerlies over the south Pacific. These circulation patterns in turn are linked with the negative phase of the PDO, characterized by negative SST anomalies in the central and eastern Pacific. The timing of tropical decadal variability with respect to ozone depletion further suggests a strong role for tropical variability in the recent acceleration of the Antarctic sea ice trend, as ozone depletion stabilized by late 1990s, prior to the most

  3. DICKINSARTELLA FAUNA FROM THE SAIWAN FORMATION (OMAN: A BIVALVE FAUNA TESTIFYING TO THE LATE SAKMARIAN (EARLY PERMIAN CLIMATIC AMELIORATION ALONG THE NORTH-EASTERN GONDWANAN FRINGE.

    Directory of Open Access Journals (Sweden)

    CRISTIANO LARGHI

    2005-11-01

    Full Text Available The transitional faunas of the Permian Huqf succession of Oman make it one of the key-sections for the intercalibration of Early to Middle Permian biostratigraphical scales. The abundance of fossils improved the knowledge of some marine faunas which populated the North-Eastern Gondwanan fringe during times of climatic changes in the Permian. A Sterlitamakian (upper Sakmarian, Lower Permian bivalve fauna from the Saiwan Formation in the Huqf area, informally named "Dickinsartella Fauna", is described in the present paper. The specimens examined were collected from the "Pachycyrtella Bed" (Auctorum, the basal bed of the Formation in its type locality. The Dickinsartella Fauna can be identified for the presence of the new genus Dickinsartella, which dominates the bivalve thanatocoenosis with D. pistacina sp. n. (type species. The bivalve fauna from the Pachycyrtella Bed includes the new species Stutchburia sangallii and Promytilus  mazzolenii, and also Astartella obliqua Dickins, 1963, Nuculopsis cf. bangarraensis Dickins, 1963, ?Oriocrassatella sp., and indeterminable aviculopectinids. This fauna shows a low taxonomic diversity. Nevertheless, some species are represented by a high number of generally well-preserved specimens, i.e. some specimens of S. sangallii sp. n. and A. obliqua show part of the ligament.  The good preservation of the shells permitted the microstructural analysis of D. pistacina sp. n. and S. sangallii sp. n. The microstructure of S. sangallii sp. n. supports the close phylogenetical link between modiomorphids and crassatelloids recognized by some previous authors.The new genus Dickinsartella includes the more recent species belonging to the important Paleozoic Order Cyrtodontida Scarlato & Starobogatov, 1971. The discovery of Dickinsartella gen. n. and other taxa of the Pachycyrtella Bed, present also in the Sakmarian levels of the Carnarvon and Perth Basins in Western Australia,  indicates a wider distribution of the

  4. Review and palaeoecological analysis of the late Tremadocian – early Floian (Early Ordovician cephalopod fauna of the Montagne Noire, France

    Directory of Open Access Journals (Sweden)

    B. Kröger

    2011-02-01

    Full Text Available The Early Ordovician successions of the southern Montagne Noire consist of a thick sequence of predominantly siliciclastic sediments of which the late Tremadocian St. Chinian Formation and the earliest Floian La Maurerie Formation contain a comparatively rich and abundant cephalopod association. The cephalopods of the St. Chinian and La Maurerie Formation are interpreted as generally authochthonous, representing a fauna which originally lived in the open water above the sediments or related to the sea bottom. The cephalopod associations of the St. Chinian and La Maurerie formations are similar to other contemporaneous assemblages known from higher palaeolatitudes and associated with deeper depositional settings. They are composed almost exclusively of longiconic orthocones, in this case predominantly of eothinoceratids and baltocerids. The occurrences of Annbactrocera, and Bactroceras in the St. Chinian Formation are at present the earliest unambiguous reports of the Orthocerida. The available data suggest an initial expansion of orthoceroid cephalopod faunas from open water habitats of high paleo-latitudes, and a subsequent expansion on the carbonate platforms during the Floian. The presence of the eothinoceratid Saloceras in abundance demonstrates the Gondwanan affinity of the assemblage whilst adding further support for the presence of a "Saloceras realm" that may have extended along the margins of East and West Gondwana at least into intermediate latitudes. The following new taxa are proposed: Annbactroceras n. gen., Annbactroceras felinense n. sp., Cyclostomiceras thorali n. sp., Felinoceras n. gen., Felinoceras constrictum n. sp., Lobendoceras undulatum n. sp., Rioceratidae n. fam., Saloceras murvielense n. sp., Thoraloceras n. gen., Thoraloceras bactroceroides n. sp. doi:10.1002/mmng.201000013

  5. De corticole fauna van platanen: ii. Springstaarten, stofluizen, loopkevers (Collembola, Psocoptera, Carabidae)

    NARCIS (Netherlands)

    Noordijk, J.; Berg, M.P.

    2002-01-01

    The corticolous fauna of plane trees: ii. Springtails, barklice and ground beetles (Collembola, Psocoptera, Carabidae) From July 1999 until September 2001 an inventory was made of the bark-dwelling arthropod fauna of 450 plane trees (Platanus x hybrida), spread over 69 localities in the Netherlands.

  6. De springstaart Lepidocyrtus paradoxus nieuw voor de Nederlandse fauna (Hexapoda: Collembola)

    NARCIS (Netherlands)

    Berg, M.P.; Heijerman, T.

    2002-01-01

    The springtail Lepidocyrtus paradoxus new to the Dutch fauna (Hexapoda: Collembola) Lepidocyrtus paradoxus Uzel, 1890 is a central European springtail, which is recorded here as new to the Dutch fauna. The species was collected in high numbers on a site called the Sint Pietersberg (near Maastricht),

  7. De springstaart Isotomurus maculatus nieuw voor de fauna van Nederland (Insecta: Collembola)

    NARCIS (Netherlands)

    Berg, M.P.; Noordijk, J.; Schakel, A.; Bongers, M.

    2001-01-01

    The springtail Isotomurus maculatus new to the fauna of the Netherlands (Insecta: Collembola) Isotomurus maculatus (Schäffer, 1896) is a southern European springtail, which is recorded here as new for the fauna of the Netherlands. Specimens were collected on five sites in different regions of the Ne

  8. Seasonal Trends in Bioaccumulation of Heavy Metals in Fauna of Stormwater Ponds

    DEFF Research Database (Denmark)

    Stephansen, Diana; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild;

    2013-01-01

    Fauna caught in three stormwater ponds, two receiving highway run-off and one receiving runoff from a center for trucks, was analyzed for copper, iron, zinc, cadmium, chromium, and lead. The fauna was monitored from March to October with 1-month intervals to evaluate seasonal trends in bioaccumul...

  9. An Ostracode fauna from the Upper Devonian of the Gildar—Monto region (NW Spain)

    NARCIS (Netherlands)

    Bless, M.J.M.; Michel, M.Ph.

    1967-01-01

    A proliferous ostracode fauna has been recognized, which could be correlated with similar faunas of Thuringen (Germany). The genus Processobairdia is suggested to have been able to swim on account of a.o. the morphology of its carapace. A new species: Processobairdia spinanterocerata is described.

  10. A Middle Devonian atrypid brachiopod fauna from the Cantabrian Mountains, northwestern Spain, and its stratigraphic significance

    NARCIS (Netherlands)

    Struve, W.; Mohanti, M.

    1970-01-01

    This paper records for the first time a rich atrypid brachiopod fauna from the Middle Devonian of the Cantabrian Mountains, Spain. A comparison of the Spanish atrypid fauna with that of Germany reveals a close similarity between the two. Even though the species are not identical, yet a comparison an

  11. De corticole fauna van platanen: i. Arachniden (Arachnida: Araneae, Pseudoscorpiones, Acari)

    NARCIS (Netherlands)

    Noordijk, J.; Berg, M.P.

    2001-01-01

    The corticolous fauna of plane trees: I. Arachnids (Arachnida: Araneae, Pseudoscorpiones, Acari) From February until September 2000 an inventory was made of the bark-dwelling arthropod fauna of more than 400 plane trees (Platanus hybrida), all over the Netherlands. Arthropods were collected from bar

  12. Interactions between microbial-feeding and predatory soil fauna trigger N2O emissions

    NARCIS (Netherlands)

    Thakur, M.P.; Groenigen, van J.W.; Kuiper, I.; Deyn, de G.B.

    2014-01-01

    Recent research has shown that microbial-feeding invertebrate soil fauna species can significantly contribute to N2O emissions. However, in soil food webs microbial-feeding soil fauna interact with each other and with their predators, which affects microbial activity. To date we lack empirical tests

  13. A Comparative Study of Antarctic Arctic and Himalayan Ice

    Directory of Open Access Journals (Sweden)

    R. C. Pathak

    1989-07-01

    Full Text Available Arctic, Antarctic and inaccessible lofty regions of Himalayas,which are geographically diverse areas and have been a constant source of inspiration, envisages a challenging field of study 'by early adventurers and scientists of the world. Characteristics of ice obtained at Arctic and Antarctic do not possess similar properties. Even thesalient properties of snow and ice of western and central Himalayas vary due to its differing free water content. A study has been carriedout based on recent Antarctic Expedition by Indian scientists and the data gathered along litha-tectonic regions of Himalayas and their characteristics have been compared, wkich brings out stratigraphic and metamorphic characteristics of the ice and snow. In the present paper,an analysis of the ice and snow properties of Arctic, Antarctic and Himalayan regions has been presented.

  14. Photosynthesis in a sub-Antarctic shore-zone lichen

    NARCIS (Netherlands)

    Smith, V.; Gremmen, N.J.M.

    2001-01-01

    Photosynthetic responses to moisture, light, temperature, salinity and inorganic nitrogen fertilization are reported for a shore-zone lichen Turgidiusculum complicatulum (formerly Mastodia tesselata), a possible recent introduction to sub-Antarctic Marion Island. Optimum moisture contents for net ph

  15. STRATEGIES AND KINETICS OF PHOTOACCLIMATION IN 3 ANTARCTIC NANOPHYTOFLAGELLATES

    NARCIS (Netherlands)

    BUMA, AGJ; NOORDELOOS, AAM; LARSEN, J

    1993-01-01

    Three Antarctic nanophytoflagellates (two cryptophyte species and a Pyramimonas sp.) were compared for their capacity to photoacclimate and for their kinetic responses in changing photic environments. Division rate, cell size, cellular fluorescence, and chlorophyll a content were measured during ste

  16. Climate Prediction Center (CPC) Daily Antarctic Oscillation Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Antarctic Oscillation (AAO) is a leading teleconnection pattern in the Southern Hemisphere circulation. It is calculated as the first Empirical Orthogonal...

  17. Searching for eukaryotic life preserved in Antarctic permafrost

    DEFF Research Database (Denmark)

    Zucconi, L.; Selbmann, L.; Buzzini, P.;

    2012-01-01

    Fungi and yeasts isolated in pure culture from Antarctic permafrost collected at different depths in the McMurdo Dry Valleys were identified with cultural, physiological and molecular methods. Fungi belonged to the genera Penicillium, Eurotium, Cladosporium, Alternaria, Engyodonthium, Aureobasidium...

  18. German Antarctic Receiving Station (GARS) O'Higgins

    Science.gov (United States)

    Neidhardt, Alexander; Ploetz, Christian; Kluegel, Thomas

    2013-01-01

    In 2012, the German Antarctic Receiving Station (GARS) O'Higgins contributed to the IVS observing program with four observation sessions. Maintenance and upgrades were made, and a new replacement dewar is under construction in the observatory at Yebes, Spain.

  19. Biological invasions in the Antarctic: extent, impacts and implications.

    Science.gov (United States)

    Frenot, Yves; Chown, Steven L; Whinam, Jennie; Selkirk, Patricia M; Convey, Peter; Skotnicki, Mary; Bergstrom, Dana M

    2005-02-01

    Alien microbes, fungi, plants and animals occur on most of the sub-Antarctic islands and some parts of the Antarctic continent. These have arrived over approximately the last two centuries, coincident with human activity in the region. Introduction routes have varied, but are largely associated with movement of people and cargo in connection with industrial, national scientific program and tourist operations. The large majority of aliens are European in origin. They have both direct and indirect impacts on the functioning of species-poor Antarctic ecosystems, in particular including substantial loss of local biodiversity and changes to ecosystem processes. With rapid climate change occurring in some parts of Antarctica, elevated numbers of introductions and enhanced success of colonization by aliens are likely, with consequent increases in impacts on ecosystems. Mitigation measures that will substantially reduce the risk of introductions to Antarctica and the sub-Antarctic must focus on reducing propagule loads on humans, and their food, cargo, and transport vessels.

  20. Joint Antarctic School Expedition - An International Collaboration for High School Students and Teachers on Antarctic Science

    Science.gov (United States)

    Botella, J.; Warburton, J.; Bartholow, S.; Reed, L. F.

    2014-12-01

    The Joint Antarctic School Expedition (JASE) is an international collaboration program between high school students and teachers from the United States and Chile aimed at providing the skills required for establishing the scientific international collaborations that our globalized world demands, and to develop a new approach for science education. The National Antarctic Programs of Chile and the United States worked together on a pilot program that brought high school students and teachers from both countries to Punta Arenas, Chile, in February 2014. The goals of this project included strengthening the partnership between the two countries, and building relationships between future generations of scientists, while developing the students' awareness of global scientific issues and expanding their knowledge and interest in Antarctica and polar science. A big component of the project involved the sharing by students of the acquired knowledge and experiences with the general public. JASE is based on the successful Chilean Antarctic Science Fair developed by Chile´s Antarctic Research Institute. For 10 years, small groups of Chilean students, each mentored by a teacher, perform experimental or bibliographical Antarctic research. Winning teams are awarded an expedition to the Chilean research station on King George Island. In 2014, the Chileans invited US participation in this program in order to strengthen science ties for upcoming generations. On King George Island, students have hands-on experiences conducting experiments and learning about field research. While the total number of students directly involved in the program is relatively small, the sharing of the experience by students with the general public is a novel approach to science education. Research experiences for students, like JASE, are important as they influence new direction for students in science learning, science interest, and help increase science knowledge. We will share experiences with the

  1. Morphogenesis of Antarctic Paleosols: Martian Analogue

    Science.gov (United States)

    Mahaney, W. C.; Dohm, J. M.; Baker, V. R.; Newsom, Horton E.; Malloch, D.; Hancock, R. G. V.; Campbell, Iain; Sheppard, D.; Milner, M. W.

    2001-11-01

    Samples of horizons in paleosols from the Quartermain Mountains of the Antarctic Dry Valleys (Aztec and New Mountain areas) were analyzed for their physical characteristics, mineralogy, chemical composition, and microbiology to determine the accumulation and movement of salts and other soluble constituents and the presence/absence of microbial populations. Salt concentrations are of special interest because they are considered to be a function of age, derived over time, in part from nearby oceanic and high-altitude atmospheric sources. The chemical composition of ancient Miocene-age paleosols in these areas is the direct result of the deposition and weathering of airborne-influxed salts and other materials, as well as the weathering of till derived principally from local dolerite and sandstone outcrops. Paleosols nearer the coast have greater contents of Cl, whereas near the inland ice sheet, nitrogen tends to increase on a relative basis. The accumulation and vertical distribution of salts and other soluble chemical elements indicate relative amounts of movement in the profile over long periods of time, in the order of several million years. Four of the six selected subsamples from paleosol horizons in two ancient soil profiles contained nil concentrations of bacteria and fungi. However, two horizons at depths of between 3 and 8 cm, in two profiles, yielded several colonies of the fungi Beauveria bassiana and Penicillium brevicompactum, indicating very minor input of organic carbon. Beauveria bassiana is often reported in association with insects and is used commercially for the biological control of some insect pests. Penicillium species are commonly isolated from Arctic, temperate, and tropical soils and are known to utilize a wide variety of organic carbon and nitrogen compounds. The cold, dry soils of the Antarctic bear a close resemblance to various present and past martian environments where similar weathering could occur and possible microbial populations

  2. Perspectives on the economic history of the Antarctic region

    OpenAIRE

    Basberg, Bjørn L.

    2005-01-01

    This paper starts out by indicating how the economic history of the Antarctic could be conceptualized, given the peculiarities of the continent and the region (no permanent population, no sovereignty in a traditional sense, extreme remoteness, rigorous climate etc.). Second, it describes the main industries throughout Antarctic history. Third, it examines the quantitative data available on economic activity in the region, suggests how we should proceed to analyse the economic a...

  3. Holocene subsurface temperature variability in the eastern Antarctic continental margin

    OpenAIRE

    Kim, J. H.; Crosta, X.; Willmott, V.; Renssen, H.; Bonnin, J.; Helmke, P.; Schouten, S.; Sinninghe Damsté, J. S.

    2012-01-01

    We reconstructed subsurface (similar to 45-200 m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX86 L). Our results reveal that subsurface temperature changes were probably positively coupled to the variability of warmer, nutrient-rich Modified Circumpolar Deep Water (MCDW, deep water of the Antarctic circumpolar current) intrusion onto the continental shelf. The TEX86 L record, in c...

  4. Obliquity-paced Pliocene West Antarctic ice sheet oscillations

    OpenAIRE

    Naish, T.; Antarctic Research Centre, Victoria University of Wellington, Kelburn Parade, PO Box 600, Wellington 6012, New Zealand; Powell, R.; Department of Geology & Environmental Geosciences, Northern Illinois University, DeKalb, Illinois 60115, USA.; Levy, R.; ANDRILL Science Management Office, University of Nebraska-Lincoln, Lincoln, USA; Wilson, G.; University of Otago, Department of Geology, PO Box 56, Leith Street, Dunedin, Otago 9001, New Zealand; Scherer, R.; Department of Geology & Environmental Geosciences, Northern Illinois University, DeKalb, Illinois 60115, USA.; Talarico, F.; Universita` di Siena, Dipartimento di Scienze delle Terra, Via Laterina 8, I-53100 Siena, Italy; Krissek, L.; Ohio State University, Department of Geological Sciences, 275 Mendenhall Lab, 125 South Oval Mall, Columbus, Ohio 43210, USA; Niessen, F.; Alfred Wegener Institute, Department of Geosciences, Postfach 12 01 6, Am Alten Hafen 26, D-27515 Bremerhaven, Germany; Pompilio, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Wilson, T.; Ohio State University, Department of Geological Sciences, 275 Mendenhall Lab, 125 South Oval Mall, Columbus, Ohio 43210, USA; Carter, L.; Antarctic Research Centre, Victoria University of Wellington, Kelburn Parade, PO Box 600, Wellington 6012, New Zealand; DeConto, R.; Department of Geosciences, 233 Morrell Science Centre, University of Massachusetts, Amherst, Massachusetts 01003-9297, USA; Huybers, P.; Department of Earth and Planetary Sciences, Harvard University, Massachusetts 02138, USA; McKay, R.; Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington - New Zealand; Pollard, D.; Earth and Environmental Systems Institute, 2217 Earth-Engineering Science Bldg, University Park, PA 16802, USA

    2009-01-01

    Thirty years after oxygen isotope records frommicrofossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth’s orbital geometry control the ice ages1, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles2. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the ‘warmer-than- present’ early-Pliocene epoch (̃5–3Myr ago) is needed to better constrain the possibl...

  5. Check list and zoogeographic analysis of the scale insect fauna (Hemiptera: Coccomorpha) of Greece.

    Science.gov (United States)

    Pellizzari, Giuseppina; Chadzidimitriou, Evangelia; Milonas, Panagiotis; Stathas, George J; Kozár, Ferenc

    2015-01-01

    This paper presents an updated checklist of the Greek scale insect fauna and the results of the first zoogeographic analysis of the Greek scale insect fauna. According to the latest data, the scale insect fauna of the whole Greek territory includes 207 species; of which 187 species are recorded from mainland Greece and the minor islands, whereas only 87 species are known from Crete. The most rich families are the Diaspididae (with 86 species), followed by Coccidae (with 35 species) and Pseudococcidae (with 34 species). In this study the results of a zoogeographic analysis of scale insect fauna from mainland Greece and Crete are also presented. Five species, four from mainland Greece and one from Crete are considered to be endemic. Comparison with the scale insect fauna of other countries is provided.

  6. [Determination of parasite fauna of chicken in the Van region].

    Science.gov (United States)

    Orunç, Ozlem; Biçek, Kamile

    2009-01-01

    The aim of this study was to determine the parasite fauna of the chicken in Van Province in 2002 and 2003. The material of the present study included endoparasites and ectoparasites determined by rutine parasitological examinations. Direct, flotation and sedimentation techniques for endoparasites were used. The total of endoparasites and ectoparasites were determined as 85% and 76% respectively. The ratios of endoparasites obtained from the chicken were coccidial oocystis 65%, Echinostoma spp. 2%, Davania proglottina 8%, Raillietina spp. 10%, Trichostrongylus tenuis 4%, Dispharynx nasuta 1%, Ascaridia galli 13%, Heterakis gallinarum 15%, Capillaria spp. 30% whereas ratios of ectoparasites were Goniocotes hologaster 32%, Lipeurus heteragraphus 6%, Eomenacanthus stramineus 42%, Menacanthus cornutus 11%, Menopon gallinae 22%.

  7. Cenomanian-Coniacian Upper Cretaceous foraminiferal fauna of Lithuania

    Science.gov (United States)

    Aleksienė, Agnė

    2010-12-01

    Foraminiferal assemblages form a unique fauna succession from the Cenomanian to Maastrichtian stages in Lithuania; the Cenomanian-Coniacian succession is discussed in this paper. The first Cretaceous planktonic foraminifera species appeared in the Early Cenomanian. The Cenomanian planktonic foraminiferal association consists of the relatively abundant genus Hedbergella. However, Cenomanian planktonic foraminifera are rare compared to benthic; the latter are numerous, and their assemblage contains various calcareous and agglutinated species. As a result of environmental changes, foraminiferal assemblages gradually changed as well. The newly formed deep-water niches in the Turonian allowed spreading the keeled forms of planktonic foraminifera. Taxonomically, Turonian-Coniacian foraminiferal assemblages are mainly composed of species of the following genera: Praeglobotruncana, Helvetoglobotruncana, Dicarinella, Marginotruncana.

  8. Checklist of spider fauna of FR Peshawar, FATA, Pakistan

    Directory of Open Access Journals (Sweden)

    F. Perveen

    2012-03-01

    Full Text Available The spiders are known as poisonous arthropods, but they also act as the predator or biological pests control agent. Their 23 species belonging to 15 genera and 09 families were reported during 2009-2010 from FR Peshawar, FATA, Pakistan. The reported families Clubionidae, Scytodidae and Sprassidae covered each 4%, Araneidae, Gnaphosidae, Pholicidae and Salticidae each 9%, Thomisidae 13% and Lycosidae 43% biodiversity of spiders of FATA. However, the largest spider collected was huntsman, Isopoda tuhodnigra (Barrion with total body length 15.80+-0.83 mm. Moreover, the smallest spider was wolf spider, Pardosa birmanica (Simon with total body length 4.20+-1.30 mm. Further, the crab spiders, Thomisus pugilis (Stoliczka, T. spectabilis (Doleschall and Diaea evanida (Thorell were the most colorful species belonging to family Thomisidae. A detail study is required for further exploration of spider fauna of FATA.

  9. Helminth fauna of Talpa spp. in the Palaearctic Realm.

    Science.gov (United States)

    Ribas, A; Casanova, J C

    2006-03-01

    The helminth fauna of the genus Talpa in the Palaearctic Realm is reviewed. Several helminth species reported in Talpa spp. by a number of authors are discussed, with reference to host specificity, parasite biology, and host ethology, ecology and phylogeny. Twelve species of cestodes were found, two of which exhibit stenoxenous specificity (Staphylocystis bacillaris and Multitesticulata filamentosa). Only three species of trematodes, Ityogonimus lorum, Ityogonimus ocreatus and Combesia macrobursata, are exclusive parasites of Talpa spp. The largest group are nematodes, with 37 species. Species of Tricholinstowia are parasites of holarctic talpids and several species of distinct genera, such as Capillaria, Soboliphyme and Trichuris, are found only in Talpa spp. Only acanthocephalans of the genus Moniliformis have been reported in moles of the genus Talpa. On the basis of these helminthological findings, the close phylogenetic relationship between moles (Talpidae) and shrews (Soricidae) supports the separation of the ordinal levels Soricomorpha and Erinaceomorpha.

  10. Soil salinization as a stress factor for soil fauna

    OpenAIRE

    Duarte, Gabriel Alexandre Isidoro

    2011-01-01

    A existência de condições desfavoráveis no solo (p.e. um agente químico) pode influenciar a presença de organismos de solo ou parâmetros do ciclo de vida tais como a reprodução da fauna do solo num local específico. Logo, a resposta de evitamento e o sucesso reprodutivo de organismos em locais contaminados pode ser utilizada como uma primeira ferramenta de avaliação de risco ecológico, já que respostas negativas de evitamento ou reprodução significam que deverá haver algum...

  11. Phlebotomine fauna in a rural area of the Brazilian Pantanal

    Directory of Open Access Journals (Sweden)

    Braga-Miranda Lourdislene Costa

    2006-01-01

    Full Text Available The aim of the study was to identify among the phlebotomine fauna potential leishmaniasis vectors. The study was carried out in Corumbá county, State of Mato Grosso do Sul, Mid-West Brazil (18º59'S, 56º39'W. Sand fly captures were undertaken fortnightly with automatic light traps at 11 sites in forested environments and anthropic areas from April 2001 to July 2003. A total of only 41 specimens were captured. Thirty-one percent of the specimens were captured in forests and 68.3% in anthropic areas. The predominance of non-anthropophilic groups and the low density of N. whitmani, a known cutaneous leishmaniasis vector, does not seem to indicate any actual risk of the transmission of this disease in the study area.

  12. Bioactive natural products from Chinese marine flora and fauna

    Institute of Scientific and Technical Information of China (English)

    Zhen-fang ZHOU; Yue-wei GUO

    2012-01-01

    In recent decades,the pharmaceutical application potential of marine natural products has attracted much interest from both natural product chemists and pharmacologists.Our group has long been engaged in the search for bioactive natural products from Chinese marine flora (such as mangroves and algae) and fauna (including sponges,soft corals,and mollusks),resulting in the isolation and characterization of numerous novel secondary metabolites spanning a wide range of structural classes and various biosynthetic origins.Of particular interest is the fact that many of these compounds show promising biological activities,including cytotoxic,antibacterial,and enzyme inhibitory effects- By describing representative studies,this review presents a comprehensive summary regarding the achievements and progress made by our group in the past decade.Several interesting examples are discussed in detail.

  13. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    Science.gov (United States)

    Chown, Steven L

    2012-01-01

    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  14. Transcriptomics and comparative analysis of three antarctic notothenioid fishes.

    Directory of Open Access Journals (Sweden)

    Seung Chul Shin

    Full Text Available For the past 10 to 13 million years, Antarctic notothenioid fish have undergone extraordinary periods of evolution and have adapted to a cold and highly oxygenated Antarctic marine environment. While these species are considered an attractive model with which to study physiology and evolutionary adaptation, they are poorly characterized at the molecular level, and sequence information is lacking. The transcriptomes of the Antarctic fishes Notothenia coriiceps, Chaenocephalus aceratus, and Pleuragramma antarcticum were obtained by 454 FLX Titanium sequencing of a normalized cDNA library. More than 1,900,000 reads were assembled in a total of 71,539 contigs. Overall, 40% of the contigs were annotated based on similarity to known protein or nucleotide sequences, and more than 50% of the predicted transcripts were validated as full-length or putative full-length cDNAs. These three Antarctic fishes shared 663 genes expressed in the brain and 1,557 genes expressed in the liver. In addition, these cold-adapted fish expressed more Ub-conjugated proteins compared to temperate fish; Ub-conjugated proteins are involved in maintaining proteins in their native state in the cold and thermally stable Antarctic environments. Our transcriptome analysis of Antarctic notothenioid fish provides an archive for future studies in molecular mechanisms of fundamental genetic questions, and can be used in evolution studies comparing other fish.

  15. Effect of Antarctic solar radiation on sewage bacteria viability

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, K.A. [National Environment Research Council, Cambridge (United Kingdom). British Antarctic Survey

    2005-06-01

    The majority of coastal Antarctic research stations discard untreated sewage waste into the near-shore marine environment. However, Antarctic solar conditions are unique, with ozone depletion increasing the proportion of potentially damaging ultraviolet-B (UV-B) radiation reaching the marine environment. This study assessed the influence of Antarctic solar radiation on the viability of Escherichia coli and sewage microorganisms at Rothera Research Station, Adelaide Island, Antarctic Peninsula. Cell viability decreased with increased exposure time and with exposure to shorter wavelengths of solar radiation. Cell survival also declined with decreasing cloud cover, solar zenith angle and ozone column depth. However, particulates in sewage increased the persistence of viable bacteria. Ultraviolet radiation doses over Rothera Point were highest during the austral summer. During this time, solar radiation may act to partially reduce the number of viable sewage-derived microorganisms in the surface seawater around Antarctic outfalls. Nevertheless, this effect is not reliable and every effort should be made to fully treat sewage before release into the Antarctic marine environment. (author)

  16. Impact of Long-Term Fertilization on Cropland Soil Fauna Community at Loess Soil, Shannxi, China

    Institute of Scientific and Technical Information of China (English)

    LIN Ying-hua; YANG Xue-yun; ZHANG Fu-dao; GU Qiao-zhen; SUN Ben-hua; MA Lu-jun

    2005-01-01

    The relationship between long-term fertilization and cropland soil fauna was studied at the station's experiment research network for soil fertility and fertilizers in Loess soil of Shannxi Provincefrom Jul. 2001 to Oct. 2002. Six types of long-term fertilizer were carried out for this study including non-fertilizer (CK), abandonment (ABAND), nitrogenous and phosphors and potassium fertilizers combined (NPK), straw and NPK (SNPK), organic material and NPK (MNPK) and 1.5 times MNPK (1.5MNPK). 72 soil samples were collected and 5 495 species of cropland soil fauna obtained by handsorting and Cobb methods at 4 times, belonging to 6 Phyla, 11 Classes, 22 Orders, 2 Superfamilies, 61 Families and 35 Genera. The result showed that different fertilizer had significantly impacted on the cropland soil fauna (F = 2.24, P<0.007). The number of the cropland soil fauna was related to the soil physicochemical properties caused by long-term fertilization. The result by principal component analysis, focusing on the number of 15 key soil fauna species group's diversity, evenness of community and the total soil fauna individuals indicated that the effects of SNPK, NPK, MNPK and 1.5MNPK were significantly different from that of the cropland soil fauna, in which, SNPK and NPK had the positive effect on cropland soil fauna, and MNPK and 1.5 MNPK had the negative affect, others could not be explained. By principal component I,the synthetic effect of different fertilization on the total soil fauna individuals and the group was most significant, and the effect was little on evenness and diversity. By value of eigenvectors, the maximum one was 9.6248, and the minimum one was -1.0904, that means the 6 types of fertilization did not affect evenly the cropland soil fauna.

  17. Possible Signs of Fauna and Flora on Venus

    Science.gov (United States)

    Ksanfomality, Leonid V.; Selivanov, Arnold S.; Gektin, Yuryi M.

    2015-08-01

    Habitability of planets is a fundamental question of science. Some of exoplanets possess physical conditions close to those of Venus. The planet Venus, despite its dense and hot (735 K) oxygen-free atmosphere of CO2, having a high pressure of 9.2 MPa at the surface, can be a natural laboratory for this kind of studies. The only existing data on the planet’s surface are still the results obtained by the Soviet VENERA landers.The TV experiments of Venera-9 and 10 (October, 1975) and Venera-13 and 14 (March, 1982) delivered 41 panoramas of Venus surface (or their fragments). The experiments were of extreme technical complexity. There have not been any similar missions to Venus in the subsequent 40 and 33 years. In the absence of new landing missions to Venus, the VENERA panoramas have been re-processed by modern means. The results of these missions are studied anew. A dozen of relatively large objects, from a decimeter to half a meter in size, with an unusual morphology have been found which moved very slowly or changed slightly their shape. Certain unusual findings that have a structure similar to the Earth’ fauna and flora were found in different areas of the planet. There are more then 30 papers on the topic published in 2012-2014 (e.g., “Acta Astronautica”, 2014, V. 105, pp. 521-533). Due to the availability of up to eight duplicates of the images obtained and their low level of masking noise, the VENERA archive panoramas permit identifying and exploring some types of hypothetical life forms of Venus. Analysis of treated once again VENERA panoramic images revealed objects that might indicate the presence of about 12 hypothetical forms of Venusian flora and fauna. Among them is ‘amisada’ that stands out with its unusual lizard shape against the stone plates surrounding it.

  18. Parasites of the Antarctic toothfish (Dissostichus mawsoni Norman, 1937 (Perciformes, Nototheniidae in the Pacific sector of the Antarctic

    Directory of Open Access Journals (Sweden)

    Ilya I. Gordeev

    2016-06-01

    Full Text Available The Antarctic toothfish (Dissostichus mawsoni Norman, 1937 is one of the main target species of commercial fisheries in the Antarctic. It is an endemic and is found along the shelf of Antarctica, as well as on the slopes of seamounts, underwater elevations and islands in the sub-Antarctic. It feeds on a variety of fish and cephalopods and can be an intermediate/paratenic host of some helminthes, whose final hosts are whales, seals, large rays and sharks. This article presents new data on toothfish infection in the Pacific sector of the Antarctic. Specimens were examined during commercial longline fishing in the Ross Sea and the Amundsen Sea in January–February 2013. Fourteen species of parasites were found using standard parasitological methods and genetic analysis.

  19. A Late Miocene-Pliocene Antarctic Deepwater Record of Cyclic Iron Reduction Events (ODP Leg 178 Site 1095)

    Science.gov (United States)

    Hepp, D. A.; Moerz, T.

    2007-12-01

    The Pacific margin off the Antarctic Peninsula is very sensitive to climate and ice-sheet volume changes. Climatic variations on the continental shelf control regional sedimentary processes and foster the build-up of giant deep- sea sediment drifts. These drifts represent the most proximal continuous sedimentary recorders for West Antarctic ice sheet evolution and glacial-interglacial cyclicity pattern. Sediment physical, geochemical records and x-ray images derived from ODP Site 1095 (Drift 7) were used to identify pattern in glacial-interglacial cyclicity and associated sedimentary and diagenetic processes during late Miocene and Pliocene. Two boundary types dividing half-cycles have been recognized: (1) interglacial-to-glacial transitions are characterized by a sharp boundary and abrupt change in lithology; (2) glacial-to-interglacial transitions can described as a gradual change from a full glacial to a full interglacial stage. A prominent feature of the glacial-to-interglacial transition is the loss of the magnetic susceptibility signal, caused by diagenetic alteration and demagnetization of magnetic iron minerals in a suboxic to anoxic sediment environment. Similar redox processes are described for organic carbon rich Madeira abyssal plain turbidites and Mediterranean sapropels, but are uncommon for vented Circum- Antarctic deep-sea sediments. Iron reduction zones were coupled to the ice sheet collapse at the end of deglaciation phases. Ice sheet collapse and meltwater formation weaken the bottom water formation and convection, but foster short living diatom blooms resulting in high fluxes of organic matter to the seafloor. Iron reduction zones were observed in sixty-four zones of ODP Site 1095 cores. Thus, the sedimentary record of Drift 7 affords an unique opportunity to study cyclic iron reduction events at long time-scales. The occurrence and intensity of those 'diagenetic zones' reflect long-term trends of global climate change and the related

  20. ATOMIZATION CAUSED BY BOTTOM FLOW ENERGY DISSIPATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Bottom flow energy dissipation is one of the common energydissipation methods for flood-releasing structures with high water head. Measures of this energy dissipation depend mainly on the turbulent action of hydraulic jump.In this paper, the physical process and the calculating methods of the atomization caused by bottom flow energy dissipation were studied, the computation models of atomization quantity for the self-aerated flow in overflow and hydraulic jump regions are presented, and the main results are of theoretical and practical significance for the hydraulic and electric engineering.

  1. North Atlantic Deep Water and Antarctic Bottom Water: Their Interaction and Influence on Modes of the Global Ocean Circulation

    OpenAIRE

    Brix, Holger

    2001-01-01

    Interhemispheric signal transmission in the Atlantic Ocean connects the deep water production regions of both hemispheres. The nature of these interactions and large scale responses to perturbations on time scales of years to millenia have been investigated using a global general circulation model based on the primitive equations coupled to a dynamic-thermodynamic sea ice model with a viscous-plastic rheology. The coupled model reproduces many aspects of today´s oceanic circulation. Testing t...

  2. A Middle-Late Devonian fish fauna from the Sierra de Perijá, western Venezuela, South America

    Directory of Open Access Journals (Sweden)

    G. C. Young

    2002-01-01

    Full Text Available A new Devonian fossil fish fauna from the region of Caño Colorado between the Rio Palmar and Rio Socuy, Sierra de Perijá, Venezuela, comes from two localities and several horizons within the Campo Chico Formation, dated on plants and spores as Givetian-Frasnian in age. Placoderms are most common, with the antiarch Bothriolepis perija n. sp., showing affinity with species from the Aztec fish fauna of Victoria Land, Antarctica. A second antiarch, Venezuelepis mingui n.g. n.sp., is also closely related to an Antarctic species, which is reassigned to this new genus. Fragmentary remains of a phyllolepid placoderm show similarity to the genus Austrophyllolepis from southeastern Australia. Chondrichthyan spines are provisionally referred to the Antarctilamnidae, and acanthodian remains include spines of the widespread taxon Machaeracanthus. Osteichthyans are represented by osteolepid and dipnoan scales and teeth, and scales lacking cosmine which may belong to another major taxon. This fauna has provided the first Devonian record from South America of three major fish groups: antiarch and phyllolepid placoderms, and dipnoans. These are widely distributed on most other continents. Although invertebrates and plants from the same sequence closely resemble those of eastern North America, the endemic elements in the fish fauna indicate Gondwana affinities. Phyllolepid placoderms are common in Givetian-Frasnian strata of Australia and Antarctica, but are only known from the Famennian in the Northern Hemisphere. The new phyllolepid occurrence extends their range across the northern margin of Palaeozoic Gondwana. The age and affinities of this new fish fauna are consistent with a model of biotic dispersal between Gondwana and Euramerica at or near the Frasnian-Famennian boundary. A narrow marine barrier separating northern and southern continental landmasses is indicated, in contrast to the wide equatorial ocean for the Late Devonian postulated from

  3. 24 CFR 3285.804 - Bottom board repair.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Bottom board repair. 3285.804....804 Bottom board repair. (a) The bottom board covering must be inspected for any loosening or areas... to be replaced prior to closure and repair of the bottom board. (b) Any splits or tears in the...

  4. Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials

    Directory of Open Access Journals (Sweden)

    P. B. Holden

    2010-07-01

    Full Text Available Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than preindustrial (CO2~280 ppm in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (~3000 years and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as "Warmer than Present Transients" (WPTs. We present a series of experiments to investigate the impact of deglacial meltwater on the Atlantic Meridional Overturning Circulation (AMOC and Antarctic temperature. It is well known that a slowed AMOC would increase southern sea surface temperature (SST through the bipolar seesaw and observational data suggests that the AMOC remained weak throughout the terminations preceding WPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. We present two 800 kyr transient simulations using the Intermediate Complexity model GENIE-1 which demonstrate that meltwater forcing generates transient southern warming that is consistent with the timing of WPTs, but is not sufficient (in this single parameterisation to reproduce the magnitude of observed warmth. In order to investigate model and boundary condition uncertainty, we present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP and three snapshot HadCM3 simulations at 130 000 BP. Only with consideration of the possible feedback of West Antarctic Ice Sheet (WAIS retreat does it become possible to simulate the magnitude of observed warming.

  5. Bottomonia: open bottom strong decays and spectrum

    Directory of Open Access Journals (Sweden)

    Santopinto E.

    2014-05-01

    Full Text Available We present our results for the bottomonium spectrum with self energy corrections. The bare masses used in the calculation are computed within Godfrey and Isgur’s relativized quark model. We also discuss our results for the open bottom strong decay widths of higher bottomonia in the 3P0 pair-creation model.

  6. Spectroscopy and decays of charm and bottom

    Energy Technology Data Exchange (ETDEWEB)

    Butler, J.N.

    1997-10-01

    After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.

  7. Bottom-up approach to silicon nanoelectronics

    OpenAIRE

    Mizumita, Hiroshi; Oda, S

    2005-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920) International audience This paper presents a brief review of our recent work investigating a novel bottom-up approach to realize silicon based nanoelectronics. We discuss fabrication technique, electronic properties and device applications of silicon nanodots as a building block for nanoscale silicon devices.

  8. CEOs: Gulf crisis hits hospitals' bottom line.

    Science.gov (United States)

    Johnsson, J

    1990-12-01

    Hospital CEOs say the Persian Gulf crisis could hit them hard where it counts. In fact, hospitals are already seeing some adverse impact from events in the Middle East. From fundraising to plant management to strategic planning, the confrontations in the Gulf are having an impact on the hospital's bottom line.

  9. Spectroscopy and decays of charm and bottom

    International Nuclear Information System (INIS)

    After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays

  10. Coil in bottom part of splitter magnet

    CERN Multimedia

    1976-01-01

    Radiation-resistant coil being bedded into the bottom part of a splitter magnet. This very particular magnet split the beam into 3 branches, for 3 target stations in the West-Area. See Annual Report 1975, p.176, Figs.14 and 15.

  11. Bottom-up organic integrated circuits

    NARCIS (Netherlands)

    Smits, Edsger C. P.; Mathijssen, Simon G. J.; van Hal, Paul A.; Setayesh, Sepas; Geuns, Thomas C. T.; Mutsaers, Kees A. H. A.; Cantatore, Eugenio; Wondergem, Harry J.; Werzer, Oliver; Resel, Roland; Kemerink, Martijn; Kirchmeyer, Stephan; Muzafarov, Aziz M.; Ponomarenko, Sergei A.; de Boer, Bert; Blom, Paul W. M.; de Leeuw, Dago M.

    2008-01-01

    Self- assembly - the autonomous organization of components into patterns and structures(1) - is a promising technology for the mass production of organic electronics. Making integrated circuits using a bottom- up approach involving self- assembling molecules was proposed(2) in the 1970s. The basic b

  12. Early Silurian(Telychian)rugose coral fauna of Daguan area, northeast Yunnan Province,China

    Institute of Scientific and Technical Information of China (English)

    CHEN Jianqiang; HE Xinyi; TANG Lan

    2006-01-01

    Study on rugose coral fauna of the Sifengya Formation(early Telyehian)and Daluzhai Formation (mid-late Telychian)in Daguan area,northeast Yunnan Province,China was carded out.Rugose coral fauna of the Sifengya Formation included 18 genera and 34 species,while Daluzhai Formation with nine genera,ten species.We described rugose coral fauna(12 genera,19 species)including one new genus and five new species,i.e.Protoketophyllum daguanense gen.et sp.nov..Crassilasma huanggexiense sp.nov.,Pseudophaulactis heae sp.nov.,P.convolutus sp.nov.,and Shensiphyllum minor sp.nov..The characteristics and geological significance of rugose coral fauna of Sifengya Formation and Daluzhai Formation were analyzed.Particularly,mgose coral fauna of the Sifengya Formation represent early Telychian rugosan fauna in the Upper Yangtze region and improve the sequences of early Silurian(Llandovery)mgose coral assemblages in Yangtze region.It is therefore very meaningful to further analyze radiation period of rugose coral fauna in such epoch.

  13. Sequence of the Cenozoic Mammalian Faunas of the Linxia Basin in Gansu, China

    Institute of Scientific and Technical Information of China (English)

    DENG Tao; WANG Xiaoming; NI Xijun; LIU Liping

    2004-01-01

    In the Linxia Basin on the northeast margin of the Tibetan Plateau, the Cenozoic strata are very thick and well exposed. Abundant mammalian fossils are discovered in the deposits from the Late Oligocene to the Early Pleistocene.The Dzungariotheriurn fauna comes from the sandstones of the Jiaozigou Formation, including many representative Late Oligocene taxa. The Platybelodon fauna comes from the sandstones of the Dongxiang Formation and the conglomerates of the Laogou Formation, and its fossils are typical Middle Miocene forms, such as Hemicyon, Amphicyon, Platybelodon,Choerolophodon, Anchitherium, and Hispanotherium. The Hipparion fauna comes from the red clay of the Liushu and Hewangjia Formations, and its fossils can be distinctly divided into four levels, including three Late Miocene levels and one Early Pliocene level. In the Linxia Basin, the Hipparion fauna has the richest mammalian fossils. The Equus fauna comes from the Wucheng Loess, and it is slightly older than that of the classical Early Pleistocene Nihewan Fauna. The mammalian faunas from the Linxia Basin provide the reliable evidence to divide the Cenozoic strata of this basin and correlate them with European mammalian sequence.

  14. Bio-optical properties of Antarctic pack ice in the early austral spring

    Science.gov (United States)

    Fritsen, Christian H.; Wirthlin, Eric D.; Momberg, Diane K.; Lewis, Michael J.; Ackley, Stephen F.

    2011-05-01

    Pack ice in the Bellingshausen Sea contained moderate to high stocks of microalgal biomass (3-10 mg Chl a m -2) spanning the range of general sea-ice microalgal microhabitats (e.g., bottom, interior and surface) during the International Polar Year (IPY) Sea Ice Mass Balance in the Antarctic (SIMBA) studies. Measurements of irradiance above and beneath the ice as well as optical properties of the microalgae therein demonstrated that absorption of photosynthetically active radiation (PAR) by particulates (microalgae and detritus) had a substantial influence on attenuation of PAR and irradiance transmission in areas with moderate snow covers (0.2-0.3 m) and more moderate effects in areas with low snow cover. Particulates contributed an estimated 25 to 90% of the attenuation coefficients for the first-year sea ice at wavelengths less than 500 nm. Strong ultraviolet radiation (UVR) absorption by particulates was prevalent in the ice habitats where solar radiation was highest—with absorption coefficients by ice algae often being as large as that of the sea ice. Strong UVR-absorption features were associated with an abundance of dinoflagellates and a general lack of diatoms—perhaps suggesting UVR may be influencing the structure of some parts of the sea-ice microbial communities in the pack ice during spring. We also evaluated the time-varying changes in the spectra of under-ice irradiances in the austral spring and showed dynamics associated with changes that could be attributed to coupled changes in the ice thickness (mass balance) and microalgal biomass. All results are indicative of radiation-induced changes in the absorption properties of the pack ice and highlight the non-linear, time-varying, bio-physical interactions operating within the Antarctic pack ice ecosystem.

  15. DMSP and DMS cycling within Antarctic sea ice during the winter-spring transition

    Science.gov (United States)

    Damm, E.; Nomura, D.; Martin, A.; Dieckmann, G. S.; Meiners, K. M.

    2016-09-01

    This study describes within-ice concentrations of dimethylsulfoniopropionate (DMSP), its degradation product dimethylsulphide (DMS), as well as nutrients and chlorophyll a, that were sampled during the Sea Ice Physics and Ecosystems eXperiment-2 (SIPEX-2) in 2012. DMSP is a methylated substrate produced in large amounts annually by ice-associated microalgae, while DMS plays a significant role in carbon and sulphur cycling in the Southern Ocean. In the East Antarctic study area between 115-125°E and 64-66°S, ice and slush cores, brine, under-ice seawater and zooplankton (Antarctic krill) samples were collected at 6 ice stations. The pack-ice was characterised by high snow loading which initiated flooding events and triggered nutrient supply to the sea-ice surface, while variation in ice conditions influenced sea-ice permeability. This ranged from impermeable surface and middle sections of the sea ice, to completely permeable ice cores at some stations. Chlorophyll a maxima shifted from the sea-ice surface horizon at the first station to the sea ice bottom layer at the last station. Highest DMSP concentrations were detected in brine samples at the sea-ice surface, reflecting a mismatch with respect to the distribution of chlorophyll a. Our data suggest enhanced DMSP production by sea-ice surface algal communities and its release into brine during freezing and melting, which in turn is coupled to flooding events early in the season. A time-cycle of DMS production by DMSP degradation and DMS efflux is evident at the sea ice-snow interface when slush is formed during melt. Seawater under the ice contained only low concentrations of DMSP and DMS, even when brine drainage was evident and the sea ice became permeable. We postulate that in situ grazing by zooplankton may act as sink for the DMSP produced early in the season.

  16. Antarctic Single Frames = Frame Level Records of Antarctica Photos: 1946 - 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Aerial photographs of Antarctica from the United States Antarctic Resource Center (USARC) and the British Antarctic Survey (BAS) are maintained in this collection....

  17. Redox conditions and trace metal cycling in coastal sediments from the maritime Antarctic

    Science.gov (United States)

    Monien, Patrick; Lettmann, Karsten Alexander; Monien, Donata; Asendorf, Sanja; Wölfl, Anne-Cathrin; Lim, Chai Heng; Thal, Janis; Schnetger, Bernhard; Brumsack, Hans-Jürgen

    2014-09-01

    Redox-sensitive trace metals (Mn, Fe, U, Mo, Re), nutrients and terminal metabolic products (NO3-, NH4+, PO43-, total alkalinity) were investigated for the first time in pore waters of Antarctic coastal sediments. The results of this study reveal a high spatial variability in redox conditions in surface sediments from Potter Cove, King George Island, western Antarctic Peninsula. Particularly in the shallower areas of the bay the significant correlation between sulphate depletion and total alkalinity, the inorganic product of terminal metabolism, indicates sulphate reduction to be the major pathway of organic matter mineralisation. In contrast, dissimilatory metal oxide reduction seems to be prevailing in the newly ice-free areas and the deeper troughs, where concentrations of dissolved iron of up to 700 μM were found. We suggest a combination of several factors to be responsible for the domination of metal oxide reduction over sulphate reduction in these areas. These include the increased accumulation of fine-grained material with high amounts of reducible metal oxides, a reduced availability of metabolisable organic matter and an enhanced physical and biological disturbance by bottom water currents, ice scouring and burrowing organisms. Based on modelled iron fluxes we calculate the contribution of the Antarctic shelf to the pool of potentially bioavailable iron (Feb) to be 6.9 × 103 to 790 × 103 t yr-1. Consequently, these shelf sediments would provide an Feb flux of 0.35-39.5 mg m-2 yr-1 (median: 3.8 mg m-2 yr-1) to the Southern Ocean. This contribution is in the same order of magnitude as the flux provided by icebergs and significantly higher than the input by aeolian dust. For this reason suboxic shelf sediments form a key source of iron for the high nutrient-low chlorophyll (HNLC) areas of the Southern Ocean. This source may become even more important in the future due to rising temperatures at the WAP accompanied by enhanced glacier retreat and the

  18. Compared sub-bottom profile interpretation in fjords of King George Island and Danco Coast, Antarctica

    Science.gov (United States)

    Rodrigo, C.; Vilches, L.; Vallejos, C.; Fernandez, R.; Molares, R.

    2015-12-01

    The fjords of the South Shetland Islands (Antarctica) and Danco Coast (Antarctic Peninsula) represent climatic transitional areas (subpolar to polar). The analysis of the distribution of sub-bottom facies helps to understand the prevailing sedimentary and climatic processes. This work seeks to characterize and compare the fjord seismic facies, of the indicated areas, to determine the main sedimentary processes in these regions. Compressed High-Intensity Radiated Pulse (CHIRP) records from 3.5 kHz sub-bottom profiler were obtained from the cruise: NBP0703 (2007); and pinger 3.5 kHz sub-bottom profiler records from the cruises: ECA-50 INACH (2014), and First Colombian Expedition (2015). Several seismic facies were recognized in all studied areas with some variability on their thickness and extent, and indicate the occurrence of similar sedimentary processes. These are: SSD facies (strong to weak intensity, stratified, draped sheet external shape), is interpreted as sedimentary deposits originated from suspended sediments from glaciar plumes and/or ice-rafting. This facies, in general, is thicker in the fjords of King George Island than in the larger fjords of the Danco Coast; on the other hand, within the Danco Coast area, this facies is thinner and more scarce in the smaller fjords and bays. MCM facies (moderate intensity, chaotic and with mounds) is associated with moraine deposits and/or basement. This is present in all areas, being most abundant in the Danco Coast area. WIC facies (weak intensity and chaotic) is interpreted as debris flows, which are present in both regions, but is most common in small fjords or bays in the Danco Coast, perhaps due to higher slopes of the seabed. In this work we discuss the influence of local climate, sediment plumes from the glaciers and other sedimentary processes on the distribution and geometry of the identified seismic facies.

  19. Diversity and Distribution of Avian Fauna of Swat, Khyber Pakhtunkhwa, Pakistan

    OpenAIRE

    Amir Jan Pathan; Shahroz Khan; Naveed Akhtar; Kausar Saeed

    2014-01-01

    This survey was conducted from January 2013 to December 2013 to explore the avian fauna of Swat valley and to find out the major threats to the avian fauna of the area as it was neglected for years. Direct and indirect methods were used in the study by visiting the field and by interviewing the local peoples and hunters about the current and past status of the avian fauna of the area. During the current study direct and indirect methods were used. A total of 138 species were recorded belongin...

  20. A Standards System for the Protection and Utilization of Wild Fauna and Flora in China

    Institute of Scientific and Technical Information of China (English)

    Zhang Xinjie

    2007-01-01

    This paper analyzed the current state of protection and utilization of wild fauna and flora and its standardization. The principles needed to establish a standardized system for the protection and utilization of wild fauna and flora were put forward. A comprehensive standards system consisting of the basic standards, technical regulations, and various other standards related to products, epidemic disease prevention and control,first-aid and propagation, viewing and hunting was proposed. Such a standards system will play an important role for wild fauna and flora protection and utilization in China.

  1. Soil fauna in forest and coffee plantations from the Sierra Nevada de Santa Mar ta, Colombia

    International Nuclear Information System (INIS)

    Two research stations (M inca, 700 m altitude and Maria Ter esa, 790 m altitude) were established in the Sierra Nevada de Santa Mar ta in places to study the soil fauna associated with forest and coffee plantations. Soil fauna was collected using pitfall and Bailer's traps. Samples were taken from litter as well as from horizons 0, A and B. individuals collected were identified to family level. Diversity, abundance and frequency indexes were used to compare fauna composition at both sites. Significant differences were found between the two research sites as well as with data from other high altitude forest in the Sierra Nevada de Santa Mar ta

  2. Distribution of metals in fauna, flora and sediments of wet detention ponds and natural shallow lakes

    DEFF Research Database (Denmark)

    Stephansen, D.A.; Nielsen, A.H.; Hvitved-Jacobsen, T.;

    2014-01-01

    Fauna, flora, and sediment were collected from 9 wet detention ponds receiving stormwater runoff and 11 small natural shallow lakes. The fauna and flora samples were sorted into species or groups of species and, together with sediments, analyzed for aluminum, copper, iron, zinc, arsenic, cadmium......, chromium, nickel, lead, and phosphorus. There was a trend toward the studied wet detention ponds being more polluted by metals than the lakes. For the fauna this trend was statistically significant for all metals, while it for the plants was statistically significant for most of the metals...

  3. Cathodic protection for the bottoms of above ground storage tanks

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, John P. [Tyco Adhesives, Norwood, MA (United States)

    2004-07-01

    Impressed Current Cathodic Protection has been used for many years to protect the external bottoms of above ground storage tanks. The use of a vertical deep ground bed often treated several bare steel tank bottoms by broadcasting current over a wide area. Environmental concerns and, in some countries, government regulations, have introduced the use of dielectric secondary containment liners. The dielectric liner does not allow the protective cathodic protection current to pass and causes corrosion to continue on the newly placed tank bottom. In existing tank bottoms where inadequate protection has been provided, leaks can develop. In one method of remediation, an old bottom is covered with sand and a double bottom is welded above the leaking bottom. The new bottom is welded very close to the old bottom, thus shielding the traditional cathodic protection from protecting the new bottom. These double bottoms often employ the use of dielectric liner as well. Both the liner and the double bottom often minimize the distance from the external tank bottom. The minimized space between the liner, or double bottom, and the bottom to be protected places a challenge in providing current distribution in cathodic protection systems. This study examines the practical concerns for application of impressed current cathodic protection and the types of anode materials used in these specific applications. One unique approach for an economical treatment using a conductive polymer cathodic protection method is presented. (author)

  4. THE CICADA FAUNA AS PHYTOPLASMA VECTORS IN ISTRIAN VINEYARDS

    Directory of Open Access Journals (Sweden)

    Đanfranko Pribetić

    2009-12-01

    Full Text Available The cicada fauna represents a considerable group of insects in vine-growing. Phytoplasma vine vectors insects are significant. They are fed from the phloem tissues of plants like cicadas from the families Cicadelidae, Coccidae, Fulgoridae and Psyilloidaea. Their phytoplasma is transmitted in a persistent way. Researches on cicada fauna, on the floristic structure of weeds and host plants of vine phytoplasma were done in 2005 and 2006 in Istrian vineyards. The research was being done in 10 vineyards on 11 localities. Cicade collecting was done with an entomological net by means of yellow sticky plates using an exhauster and a method of clonting. The collected cicadas were identified by means of binoculars and keys to identify species while the presence of phytoplasmas BN and Fd was defined by means of molecular analysis (PCR, RFLP. Listing and identifying the floristic structure of weeds were being cloned in the explored vineyards by means of keys to identify species. Samples of plant materials were taken for the analysis using PCR method by checking visually the typical symptoms caused by phytoplasma. Cicadas identifying and molecular analyses were being done at the Viticulture Institute for Research in Conegliano – Italy. During the researches, 243 insect samples were collected. Of the above mentioned number cicadas of 40 genus were identified in 207 samples. On the list of the floristic structure of Weeds 105 species of 36 families were identified. Corylus avellana L and Clematis vitalba L species were included in this list. These species showed sigus of phytoplasma disease and they were found near the explored vineyards. These two species were analysed on the presence for FD and BN phytoplasmas. The PCR method used in the molecular research on the presence of Fd and BN phytoplasmas was done on 34 insect samples and 22 plant samples. None of the mentioned sample was positive for FD and BN. The phytoplasma BN was found in the vine leaves of

  5. Complex Geodetic Research in Ukrainian Antarctic Station "Academician Vernadsky" (Years 2002 - 2005, 2013-2014)

    Science.gov (United States)

    Tretyak, Kornyliy; Hlotov, Volodymyr; Holubinka, Yuriy; Marusazh, Khrystyna

    2016-06-01

    In this paper is given an information about complex geodetic research in Ukrainian Antarctic station "Academician Vernadsky". Research were carried by Lviv polytechnic scientists, during Antarctic expeditions in years 2002 - 2005, 2013, 2014. Main objectives of the studies were: (a) study of the islands glaciers surface volumes changes in Antarctic archipelago and Antarctic Peninsula using terestrial laser scaning and digital terrestrial stereophotogrammetry survey; (b) investigation of Penola strain tectonic fault, using the results of precise GNSS observations.

  6. Skip spawning as a reproductive strategy in Antarctic fish species: the Antarctic silverfish (Pleuragramma antarctica case study

    Directory of Open Access Journals (Sweden)

    Eva Pisano

    2015-11-01

    Full Text Available The Antarctic silverfish Pleuragramma antarctica (Notothenioidei, Nototheniidae is the most abundant pelagic fish inhabiting the frigid Antarctic coastal waters. It plays relevant roles in the local ecosystems, where it is often considered a keystone species connecting lower and upper trophic levels within the coastal marine food web. Despite its ecological relevance, and although many aspects of the Antarctic silverfish biology have already been elucidated, knowledge on important components of its life cycle, including the reproductive features, is still poor. The available data on the reproduction of the Antarctic silverfish remains fragmentary and, in particular, information on the silverfish from the Ross Sea is lacking, in spite of the intensive ecological studies on this unique region and the fact that the only known nursery ground for this species is located in Terra Nova Bay (Ross Sea where hatching occurs under the sea-ice. We present the here first description of the reproductive features of Antarctic silverfish from fish sampled in late Summer (mid February 2008 in the Ross Sea. The gross reproductive traits are consistent with those reported from other Antarctic sectors but, interestingly, widespread follicular atresia has been detected in the fish examined. The intensity and prevalence of such a follicular degenerative process suggest that skip spawning (not all adults spawn every year could be a reproductive strategy of this Antarctic species. Such an hypothesis is discussed both on the short-term and on the evolutionary time-scale. Overall, the data presented also contribute to support the acknowledgment that skip-spawning is a diffuse phenomenon in fishes.

  7. Prospects for surviving climate change in Antarctic aquatic species

    Directory of Open Access Journals (Sweden)

    Peck Lloyd S

    2005-06-01

    Full Text Available Abstract Maritime Antarctic freshwater habitats are amongst the fastest changing environments on Earth. Temperatures have risen around 1°C and ice cover has dramatically decreased in 15 years. Few animal species inhabit these sites, but the fairy shrimp Branchinecta gaini typifies those that do. This species survives up to 25°C daily temperature fluctuations in summer and passes winter as eggs at temperatures down to -25°C. Its annual temperature envelope is, therefore around 50°C. This is typical of Antarctic terrestrial species, which exhibit great physiological flexibility in coping with temperature fluctuations. The rapidly changing conditions in the Maritime Antarctic are enhancing fitness in these species by increasing the time available for feeding, growth and reproduction, as well as increasing productivity in lakes. The future problem these animals face is via displacement by alien species from lower latitudes. Such invasions are now well documented from sub-Antarctic sites. In contrast the marine Antarctic environment has very stable temperatures. However, seasonality is intense with very short summers and long winter periods of low to no algal productivity. Marine animals grow slowly, have long generation times, low metabolic rates and low levels of activity. They also die at temperatures between +5°C and +10°C. Failure of oxygen supply mechanisms and loss of aerobic scope defines upper temperature limits. As temperature rises, their ability to perform work declines rapidly before lethal limits are reached, such that 50% of populations of clams and limpets cannot perform essential activities at 2–3°C, and all scallops are incapable of swimming at 2°C. Currently there is little evidence of temperature change in Antarctic marine sites. Models predict average global sea temperatures will rise by around 2°C by 2100. Such a rise would take many Antarctic marine animals beyond their survival limits. Animals have 3 mechanisms for

  8. Ionospheric irregularities at Antarctic using GPS measurements

    Indian Academy of Sciences (India)

    Sunita Tiwari; Amit Jain; Shivalika Sarkar; Sudhir Jain; A K Gwal

    2012-04-01

    The purpose of this work is to study the behaviour of the ionospheric scintillation at high latitude during geomagnetically quiet and disturbed conditions which is one of the most relevant themes in the space weather studies. Scintillation is a major problem in navigation application using GPS and in satellite communication at high latitudes. Severe amplitude fading and strong scintillation affect the reliability of GPS navigational system and satellite communication. To study the effects of the ionospheric scintillations, GPS receiver installed at Antarctic station Maitri (Geog. 70.76°S; 11.74°E) was used. The data is collected by using GISTM 4004A, NOVATEL’S GPS receiver during March 2008. Studies show that percentage occurrence of phase scintillation is well correlated with geomagnetic activity during the observation period. The result also shows that very intense scintillations can degrade GPS based location determination due to loss of lock of satellites. These findings indicate that the dependence of scintillations and irregularity occurrence on geomagnetic activity is associated with the magnetic local time (MLT). Large number of patches are reported and their activity depends on the magnetic activity index.

  9. Iodine monoxide in the Antarctic snowpack

    Directory of Open Access Journals (Sweden)

    U. Platt

    2009-11-01

    Full Text Available Recent ground-based and space borne observations suggest the presence of significant amounts of iodine monoxide in the boundary layer of Antarctica, which are expected to have an impact on the ozone budget and might contribute to the formation of new airborne particles. So far, the source of these iodine radicals has been unknown. This paper presents long-term measurements of iodine monoxide at the German Antarctic research station Neumayer, which indicate that the snowpack is the main source for iodine radicals. The measurements have been performed using multi-axis differential optical absorption spectroscopy (MAX-DOAS. Using a coupled atmosphere-snowpack radiative transfer model, the comparison of the signals observed from scattered skylight and from light reflected by the snowpack yields several ppb of iodine monoxide in the upper layers of the sunlit snowpack throughout the year. Snow pit samples from Neumayer Station contain up to 700 ng/l of total iodine, representing a sufficient reservoir for these extraordinarily high IO concentrations.

  10. Iodine monoxide in the Antarctic snowpack

    Directory of Open Access Journals (Sweden)

    U. Frieß

    2010-03-01

    Full Text Available Recent ground-based and space borne observations suggest the presence of significant amounts of iodine monoxide in the boundary layer of Antarctica, which are expected to have an impact on the ozone budget and might contribute to the formation of new airborne particles. So far, the source of these iodine radicals has been unknown. This paper presents long-term measurements of iodine monoxide at the German Antarctic research station Neumayer, which indicate that high IO concentrations in the order of 50 ppb are present in the snow interstitial air. The measurements have been performed using multi-axis differential optical absorption spectroscopy (MAX-DOAS. Using a coupled atmosphere – snowpack radiative transfer model, the comparison of the signals observed from scattered skylight and from light reflected by the snowpack yields several ppb of iodine monoxide in the upper layers of the sunlit snowpack throughout the year. Snow pit samples from Neumayer Station contain up to 700 ng/l of total iodine, representing a sufficient reservoir for these extraordinarily high IO concentrations.

  11. Automated detection of Antarctic blue whale calls.

    Science.gov (United States)

    Socheleau, Francois-Xavier; Leroy, Emmanuelle; Pecci, Andres Carvallo; Samaran, Flore; Bonnel, Julien; Royer, Jean-Yves

    2015-11-01

    This paper addresses the problem of automated detection of Z-calls emitted by Antarctic blue whales (B. m. intermedia). The proposed solution is based on a subspace detector of sigmoidal-frequency signals with unknown time-varying amplitude. This detection strategy takes into account frequency variations of blue whale calls as well as the presence of other transient sounds that can interfere with Z-calls (such as airguns or other whale calls). The proposed method has been tested on more than 105 h of acoustic data containing about 2200 Z-calls (as found by an experienced human operator). This method is shown to have a correct-detection rate of up to more than 15% better than the extensible bioacoustic tool package, a spectrogram-based correlation detector commonly used to study blue whales. Because the proposed method relies on subspace detection, it does not suffer from some drawbacks of correlation-based detectors. In particular, it does not require the choice of an a priori fixed and subjective template. The analytic expression of the detection performance is also derived, which provides crucial information for higher level analyses such as animal density estimation from acoustic data. Finally, the detection threshold automatically adapts to the soundscape in order not to violate a user-specified false alarm rate. PMID:26627784

  12. Blowing Snow Over the Antarctic Plateau

    Science.gov (United States)

    Mahesh, Ashwin; Eager, Rebecca; Campbell, James R.; Spinhirne, James D.

    2002-01-01

    Studies of blowing snow over Antarctica have been limited greatly by the remoteness and harsh conditions of the region. Space-based observations are also of lesser value than elsewhere, given the similarities between ice clouds and snow-covered surfaces, both at infrared and visible wavelengths. It is only in recent years that routine ground-based observation programs have acquired sufficient data to overcome the gap in our understanding of surface blowing snow. In this paper, observations of blowing snow from visual observers' records as well as ground-based spectral and lidar programs at South Pole station are analyzed to obtain the first climatology of blowing snow over the Antarctic plateau. Occurrence frequencies, correlation with wind direction and speed, typical layer heights, as well as optical depths are determined. Blowing snow is seen in roughly one third of the visual observations and occurs under a narrow range of wind directions. The near-surface layers typically a few hundred meters thick emit radiances similar to those from thin clouds. Because blowing snow remains close to the surface and is frequently present, it will produce small biases in space-borne altimetry; these must be properly estimated and corrected.

  13. Freezing in the Antarctic limpet, Nacella concinna.

    Science.gov (United States)

    Hawes, T C; Worland, M R; Bale, J S

    2010-08-01

    The process of organismal freezing in the Antarctic limpet, Nacella concinna, is complicated by molluscan biology. Internal ice formation is, in particular, mediated by two factors: (a) the provision of an inoculative target for ice formation in the exposed mucus-secreting foot; and (b) osmoconformity to the marine environment. With regard to the first, direct observations of the independent freezing of pedal mucus support the hypothesis that internal ice formation is delayed by the mucal film. As to the second, ice nucleation parametrics of organismal tissue (head, midgut, gonad, foot) and mucus in both inter- and subtidal populations were characterized by high melting points (range=-4.61 to -6.29 degrees C), with only c.50% of a given sample osmotically active. At this stage it would be premature to ascribe a cryo-adaptive function to the mucus as the protective effects are more readily attributed to the physical properties of the secretion (i.e. viscosity) and their corresponding effects on the rate of heat transfer. As it is difficult to thermally distinguish between the freezing of mucus and the rest of the animal, the question as to whether it is tolerant of internal as well as external ice formation remains problematic, although it may be well suited to the osmotic stresses of organismal freezing. PMID:20599885

  14. Responses of Antarctic Oscillation to global warming

    Science.gov (United States)

    Feng, S.

    2015-12-01

    The Antarctic Oscillation (AAO) is the major annular mode dominates the spatiotemporal variability of the atmospheric circulation in the Southern Hemisphere. This study examined the sensitivity of AAO to future warming by analyzing the outputs of 34 state-of-the-art climate models participating in phase 5 of the Coupled Model Intercomparion Project (CMIP5). The model simulations include the stabilized (RCP4.5) and business as usual (RCP8.5) scenarios as well as the idealized 1% per year increase in atmospheric CO2 to quadrupling (1pctCO2) and an instantaneous quadrupling of CO2 (abrupt4xCO2). We show that the CMIP5 models on average simulate increases in the AAO in every season by 2100 under the RCP4.5 and RCP8.5 scenarios. However, due to the impacts of ozone, aerosol and land use changes, the amplitudes of the projected changes in AAO to future climate scenarios are quit different on different seasons. After the impact of ozone, aerosol and land use changes were removed; it was found that the impact of greenhouse gases (GHGs) on AAO is similar on all seasons. The increases of AAO are accelerating following the increase of GHGs. Our results are also consistent with the simulations of 1pctCO2 and abrupt4xCO2.

  15. Iron isotopes in bottom waters from the Bransfield Strait: Implications for deep water Fe supply

    Science.gov (United States)

    Stichel, Torben; Homoky, William; Connelly, Douglas; Klar, Jessica; Mills, Rachel

    2015-04-01

    Iron (Fe) is an important micro-nutrient in the global ocean. However, its low bioavailability due to poor solubility in oxygenated waters, leads to a strongly limiting character of this trace metal as a nutrient. The major sources of Fe to seawater are largely known (i.e. aeolian dust deposition, riverine and groundwater input, seawater-sediment interaction, and hydrothermal vents) but the relative significance of these sources to the marine Fe supply are not yet well quantified. Areas with low atmospheric inputs, such as the Southern Ocean, are severely Fe limited in surface waters. Here, strong upwelling and a deeply penetrating surface mixed layer fuel one of the largest biogeochemical cycles of trace metals in the global ocean. One significant pathway to bottom waters is the benthic flux of trace metals from hydrothermal systems, where Fe can be stabilised in the water column by different dissolved species. For example, benthic fauna, such as tube-worms, may enhance transportation of dissolved trace metals from pore waters through oxic surface layers of sediments into the deep ocean. Concentrations of total dissolvable Fe (DFe) in these bottom waters have been reported to be significantly higher than surrounding seawater (Aquilina et al., 2014). Here we present DFe isotope composition of bottom water from the Hook Ridge, a shallow (~1100m) sediment covered volcanic feature within a rifted margin. On the basis of Fe isotopes we will determine whether Fe is released by non-reductive dissolution from poorly oxygenated sediments via the presence of tubeworms Sclerolinum spec. This will help to evaluate whether benthic fluxes from hydrothermal fields can be a major source of bioavailable Fe to the deep Southern Ocean. References: Aquilina, A., Homoky, W.B., Hawkes, J. A., Lyons, T.W., Mills, R. a., 2014. Hydrothermal sediments are a source of water column Fe and Mn in the Bransfield Strait, Antarctica. Geochim. Cosmochim. Acta 137, 64-80. doi:10.1016/j.gca.2014.04.003

  16. Bivalves Antárticos e Subantárticos coletados durante as Expedições Científicas Brasileiras à Antártica I a IX (1982-1991 Antarctic and Subantarctic bivalves collected during the Scientific, Brazilian Expeditions to Antarctica I-IX (1982-1991

    Directory of Open Access Journals (Sweden)

    Walter Narchi

    2002-09-01

    Full Text Available The bivalves collected in the Western Antarctic and Subantarctic waters by scientists of the Instituto Oceanográfico - USP during the Scientific Brazilian Expeditions to Antarctical-IX are characterised through its conchiliological features, illustrated and their occurrence plotted in maps. A species of bivalve collected by scuba divers of the IO-USP on the Napier Rock, Admiralty Bay, King George Island during the Expeditions XV and XVI is also considered in this work. The material identified is representative of 25 species distributed among three families and four genera of Protobranchia, three farnilies and five genera of Pteriornorpha, five families and six genera of Heterodonta, and four families and four genera of Anomalo desmata. The main scope of this work is to provide searchers dealing with macrobenthic fauna with an ease identification guide to the bivalved molluscs of the sampled region.

  17. Levoglucosan and phenols in Antarctic marine, coastal and plateau aerosols.

    Science.gov (United States)

    Zangrando, Roberta; Barbaro, Elena; Vecchiato, Marco; Kehrwald, Natalie M; Barbante, Carlo; Gambaro, Andrea

    2016-02-15

    Due to its isolated location, Antarctica is a natural laboratory for studying atmospheric aerosols and pollution in remote areas. Here, we determined levoglucosan and phenolic compounds (PCs) at diverse Antarctic sites: on the plateau, a coastal station and during an oceanographic cruise. Levoglucosan and PCs reached the Antarctic plateau where they were observed in accumulation mode aerosols (with median levoglucosan concentrations of 6.4 pg m(-3) and 4.1 pg m(-3), and median PC concentrations of 15.0 pg m(-3) and 7.3 pg m(-3)). Aged aerosols arrived at the coastal site through katabatic circulation with the majority of the levoglucosan mass distributed on larger particulates (24.8 pg m(-3)), while PCs were present in fine particles (34.0 pg m(-3)). The low levoglucosan/PC ratios in Antarctic aerosols suggest that biomass burning aerosols only had regional, rather than local, sources. General acid/aldehyde ratios were lower at the coastal site than on the plateau. Levoglucosan and PCs determined during the oceanographic cruise were 37.6 pg m(-3) and 58.5 pg m(-3) respectively. Unlike levoglucosan, which can only be produced by biomass burning, PCs have both biomass burning and other sources. Our comparisons of these two types of compounds across a range of Antarctic marine, coastal, and plateau sites demonstrate that local marine sources dominate Antarctic PC concentrations. PMID:26674690

  18. Antarctic ecosystems as models for extraterrestrial surface habitats

    Science.gov (United States)

    Wynn-Williams, D. D.; Edwards, H. G. M.

    2000-09-01

    Surface habitats in Antarctic deserts are near the limits of life on Earth and resemble those hypothesized for early Mars. Cyanobacteria dominate the transient riverbeds, stromatolitic sediments in ice-covered lakes, and endolithic communities in translucent rock. There is still no direct evidence of photosynthetic life on early Mars, but cyanobacteria are amongst the earliest microbes detectable in the fossil record for analogous habitats on Earth. Key biomolecules persist in Antarctic microbial habitats, even after extinction by excessive low temperatures, desiccation and UV-B stress within the Ozone Hole. Pigments (or their fossil residues), such as chlorophyll and the UV-protectants scytonemin, carotene and quinones, are good biomarkers. To show not only their presence but also their micro-spatial distribution in situ, we describe the use of FT-Raman spectroscopy with 1064 nm excitation to avoid autofluorescence from the pigments. We report not only the diversity of biomolecules that we have diagnosed from their unique Raman spectra of Antarctic cyanobacterial communities, but also their functional stratification in endolithic communities. Our analyses of Antarctic habitats show the potential of this remote, non-intrusive technique to probe for buried biomolecules on future Mars missions and in Antarctic Lake Vostok, >4 km beneath the Central Ice Sheet, with implications for the putative analogous sub-ice ocean on Europa.

  19. Levoglucosan and phenols in Antarctic marine, coastal and plateau aerosols.

    Science.gov (United States)

    Zangrando, Roberta; Barbaro, Elena; Vecchiato, Marco; Kehrwald, Natalie M; Barbante, Carlo; Gambaro, Andrea

    2016-02-15

    Due to its isolated location, Antarctica is a natural laboratory for studying atmospheric aerosols and pollution in remote areas. Here, we determined levoglucosan and phenolic compounds (PCs) at diverse Antarctic sites: on the plateau, a coastal station and during an oceanographic cruise. Levoglucosan and PCs reached the Antarctic plateau where they were observed in accumulation mode aerosols (with median levoglucosan concentrations of 6.4 pg m(-3) and 4.1 pg m(-3), and median PC concentrations of 15.0 pg m(-3) and 7.3 pg m(-3)). Aged aerosols arrived at the coastal site through katabatic circulation with the majority of the levoglucosan mass distributed on larger particulates (24.8 pg m(-3)), while PCs were present in fine particles (34.0 pg m(-3)). The low levoglucosan/PC ratios in Antarctic aerosols suggest that biomass burning aerosols only had regional, rather than local, sources. General acid/aldehyde ratios were lower at the coastal site than on the plateau. Levoglucosan and PCs determined during the oceanographic cruise were 37.6 pg m(-3) and 58.5 pg m(-3) respectively. Unlike levoglucosan, which can only be produced by biomass burning, PCs have both biomass burning and other sources. Our comparisons of these two types of compounds across a range of Antarctic marine, coastal, and plateau sites demonstrate that local marine sources dominate Antarctic PC concentrations.

  20. The spatial extent and dynamics of the Antarctic Cold Reversal

    Science.gov (United States)

    Pedro, Joel B.; Bostock, Helen C.; Bitz, Cecilia M.; He, Feng; Vandergoes, Marcus J.; Steig, Eric J.; Chase, Brian M.; Krause, Claire E.; Rasmussen, Sune O.; Markle, Bradley R.; Cortese, Giuseppe

    2016-01-01

    Antarctic ice cores show that a millennial-scale cooling event, the Antarctic Cold Reversal (14,700 to 13,000 years ago), interrupted the last deglaciation. The Antarctic Cold Reversal coincides with the Bølling-Allerød warm stage in the North Atlantic, providing an example of the inter-hemispheric coupling of abrupt climate change generally referred to as the bipolar seesaw. However, the ocean-atmosphere dynamics governing this coupling are debated. Here we examine the extent and expression of the Antarctic Cold Reversal in the Southern Hemisphere using a synthesis of 84 palaeoclimate records. We find that the cooling is strongest in the South Atlantic and all regions south of 40° S. At the same time, the terrestrial tropics and subtropics show abrupt hydrologic variations that are significantly correlated with North Atlantic climate changes. Our transient global climate model simulations indicate that the observed extent of Antarctic Cold Reversal cooling can be explained by enhanced northward ocean heat transport from the South to North Atlantic, amplified by the expansion and thickening of sea ice in the Southern Ocean. The hydrologic variations at lower latitudes result from an opposing enhancement of southward heat transport in the atmosphere mediated by the Hadley circulation. Our findings reconcile previous arguments about the relative dominance of ocean and atmospheric heat transports in inter-hemispheric coupling, demonstrating that the spatial pattern of past millennial-scale climate change reflects the superposition of both.

  1. The Antarctic ozone depletion caused by Erebus volcano gas emissions

    Science.gov (United States)

    Zuev, V. V.; Zueva, N. E.; Savelieva, E. S.; Gerasimov, V. V.

    2015-12-01

    Heterogeneous chemical reactions releasing photochemically active molecular chlorine play a key role in Antarctic stratospheric ozone destruction, resulting in the Antarctic ozone hole. Hydrogen chloride (HCl) is one of the principal components in these reactions on the surfaces of polar stratospheric clouds (PSCs). PSCs form during polar nights at extremely low temperatures (lower than -78 °C) mainly on sulfuric acid (H2SO4) aerosols, acting as condensation nuclei and formed from sulfur dioxide (SO2). However, the cause of HCl and H2SO4 high concentrations in the Antarctic stratosphere, leading to considerable springtime ozone depletion, is still not clear. Based on the NCEP/NCAR reanalysis data over the last 35 years and by using the NOAA HYSPLIT trajectory model, we show that Erebus volcano gas emissions (including HCl and SO2) can reach the Antarctic stratosphere via high-latitude cyclones with the annual average probability Pbarann. of at least ∼0.235 (23.5%). Depending on Erebus activity, this corresponds to additional annual stratospheric HCl mass of 1.0-14.3 kilotons (kt) and SO2 mass of 1.4-19.7 kt. Thus, Erebus volcano is the natural and powerful source of additional stratospheric HCl and SO2, and hence, the cause of the Antarctic ozone depletion, together with man-made chlorofluorocarbons.

  2. Relative changes in krill abundance inferred from Antarctic fur seal.

    Directory of Open Access Journals (Sweden)

    Tao Huang

    Full Text Available Antarctic krill Euphausia superba is a predominant species in the Southern Ocean, it is very sensitive to climate change, and it supports large stocks of fishes, seabirds, seals and whales in Antarctic marine ecosystems. Modern krill stocks have been estimated directly by net hauls and acoustic surveys; the historical krill density especially the long-term one in the Southern Ocean, however, is unknown. Here we inferred the relative krill population changes along the West Antarctic Peninsula (WAP over the 20th century from the trophic level change of Antarctic fur seal Arctocephalus gazella using stable carbon (δ(13C and nitrogen (δ(15N isotopes of archival seal hairs. Since Antarctic fur seals feed preferentially on krill, the variation of δ(15N in seal hair indicates a change in the proportion of krill in the seal's diets and thus the krill availability in local seawater. For the past century, enriching fur seal δ(15N values indicated decreasing krill availability. This is agreement with direct observation for the past ∼30 years and suggests that the recently documented decline in krill populations began in the early parts of the 20th century. This novel method makes it possible to infer past krill population changes from ancient tissues of krill predators.

  3. Excited bottom and bottom-strange mesons in the quark model

    Science.gov (United States)

    Lü, Qi-Fang; Pan, Ting-Ting; Wang, Yan-Yan; Wang, En; Li, De-Min

    2016-10-01

    In order to understand the possible q q ¯ quark-model assignments of the BJ(5840 ) and BJ(5960 ) recently reported by the LHCb Collaboration, we evaluate mass spectra, strong decays, and radiative decays of bottom and bottom-strange mesons in a nonrelativistic quark model. Comparing these predictions with the relevant experimental results, we suggest that the BJ(5840 ) and BJ(5960 ) can be identified as the B (2 1S0) and B (1 3D3) , respectively, and the B (5970 ) reported by the CDF Collaboration can be interpreted as the B (2 3S1) or B (1 3D3) . Further precise measurements of the width, spin and decay modes of the B (5970 ) are needed to distinguish these two assignments. These predictions of bottom and bottom-strange mesons can provide useful information to further experimental investigations.

  4. Excited bottom and bottom-strange mesons in the quark model

    CERN Document Server

    Lü, Qi-Fang; Wang, Yan-Yan; Wang, En; Li, De-Min

    2016-01-01

    In order to understand the possible $q\\bar{q}$ quark-model assignments of the $B_J(5840)$ and $B_J(5960)$ recently reported by the LHCb Collaboration, we evaluate mass spectra, strong decays, and radiative decays of bottom and bottom-strange mesons in a nonrelativistic quark model. Comparing these predictions with the relevant experimental results, we suggest that the $B_J(5840)$ and $B_J(5960)$ can be identified as $B(2^1S_0)$ and $B(1^3D_3)$, respectively, and the $B(5970)$ reported by the CDF Collaboration can be interpreted as $B(2^3S_1)$ or $B(1^3D_3)$. Further precise measurements of the width, spin and decay modes of the $B(5970)$ are needed to distinguish these two assignments. These predictions of bottom and bottom-strange mesons can provide useful information to further experimental investigations.

  5. 78 FR 51213 - Notice of Permits Issued Under the Antarctic Conservation Act of 1978

    Science.gov (United States)

    2013-08-20

    ... Protocol on Environmental Protection to the Antarctic Treaty done at Madrid on October 4, 1991. The NSF is... Notice of Permits Issued Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of document availability under the Antarctic Conservation of 1978, as amended by...

  6. 76 FR 63329 - U.S. Antarctic Program Blue Ribbon Panel Review; Notice of Meeting

    Science.gov (United States)

    2011-10-12

    ... the Antarctic Treaty. Agenda: First meeting of the Panel to present the Panel with an overview of... U.S. Antarctic Program Blue Ribbon Panel Review; Notice of Meeting In accordance with Federal... following meeting: Name: U.S. Antarctic Program Blue Ribbon Panel Review (76826). Date/Time: November...

  7. 78 FR 41959 - Notice of Permit Modification Received Under the Antarctic Conservation Act of 1978

    Science.gov (United States)

    2013-07-12

    ... Modification Requested: The Foundation must report to the Antarctic Treaty annually, no later than June 1 on... Notice of Permit Modification Received Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of permit modification under the Antarctic Conservation Act of...

  8. 77 FR 20852 - U.S. Antarctic Program Blue Ribbon Panel Review; Notice of Meeting

    Science.gov (United States)

    2012-04-06

    ... the Antarctic Treaty. Agenda: Present the Panel with additional programmatic information related to... U.S. Antarctic Program Blue Ribbon Panel Review; Notice of Meeting In accordance with Federal... following meeting: Name: U.S. Antarctic Program Blue Ribbon Panel Review, 76826. Date/Time: April 20,...

  9. 77 FR 1743 - U.S. Antarctic Program Blue Ribbon Panel; Notice of Meeting

    Science.gov (United States)

    2012-01-11

    ... sound, safe, innovative, affordable, sustainable, and consistent with the Antarctic Treaty. Agenda... U.S. Antarctic Program Blue Ribbon Panel; Notice of Meeting In accordance with Federal Advisory...: Name: U.S. Antarctic Program Blue Ribbon Panel Review, 76826. Date/Time: January 24, 2012, 8 a.m. to...

  10. 77 FR 9707 - U.S. Antarctic Program Blue Ribbon Panel Review; Notice of Meeting

    Science.gov (United States)

    2012-02-17

    ..., innovative, affordable, sustainable, and consistent with the Antarctic Treaty. Agenda: Present the Panel with... U.S. Antarctic Program Blue Ribbon Panel Review; Notice of Meeting In accordance with Federal... following meeting: Name: U.S. Antarctic Program Blue Ribbon Panel Review, 76826. Date/Time: March 5, 2012,...

  11. 78 FR 41960 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

    Science.gov (United States)

    2013-07-12

    ... Environmental Protocol to the Antarctic Treaty. All other wastes would be packaged and removed to the yacht for... Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of Permit Applications Received under the Antarctic Conservation Act...

  12. Obliquity paced contourite cyclicity in Antarctic sediments from the Wilkes Land (Site U1356) during Late Oligocene

    Science.gov (United States)

    Salabarnada, Ariadna; Escutia, Carlota; Nelson, C. Hans; Roehl, Ursula; Jimenez-Espejo, Francisco; Evangelinos, Dimitris; Ikehara, Minoru; McKay, Robert; Lopez, Adrian

    2016-04-01

    Our study on sediment cores from IODP Expedition 318 Site U1356 off the east Antarctic Wilkes Land margin comprises the interval from 641 meters below seafloor (mbsf) to 688 mbsf. Based on the age model, this section spans approximately 1 myr (between 26.2 and 25.2 Ma) during the Late Oligocene. Sediment cores were studied using a detailed facies analyses, X-Ray computed tomography (CT-scans), Scanning electron microscope (SEM) images, X-Ray Fluorescence (XRF) core-scanner data at 2cm resolution, and geochemical mapping. Sedimentary facies during the Late Oligocene are characterized by an alternation between scarcely bioturbated green claystones with variable silty laminations and highly bioturbated pale-brown silty-claystones with carbonate. In agreement, Magnetic Susceptibility (MS) and XRF analyses show a cyclical variation. Low magnetic susceptibility and high Barium (Ba) content characterizes the laminated facies. In contrast, highly bioturbated facies show high MS and high content in Zr/Ti. SEM images reveal that both facies present evidences of current reworking features. We interpret sedimentation during the Late Oligocene in the Wilkes Land margin to be dominated by bottom-currents of varying intensities during glacial and interglacial cycles. Spectral analyses of the XRF Ba and Zr/Ti scans, point to the observed cyclicity (i.e., laminated vs. bioturbated facies) to be paced by obliquity. In addition, the lack of Ice Rafted Debris (IRD) within the studied interval points to a reduced continental East Antarctic Ice Sheet (EAIS).

  13. [Origin of Lepidoptera fauna of the Southern Transural region].

    Science.gov (United States)

    Utkin, N A

    2000-01-01

    The butterfly fauna of the Southern Transural region began mainly through the migration of insects from the Urals and Kazakhstan, since the end of the Cretaceous Period to the end of Paleogen, the Transural region was covered by an epiplatform sea. As this sea was retreating, the first regions of dry land appeared, which had boundaries with Kazakhstan and the Urals. They were the first to be populated by Lepidoptera. During the Pleocene and then after the Pleistocene cooling events, insects settled generally along the valley of the Tobol River and the Turgai depression, because these territories belong to intrazonal elements. At the present time, the greatest species diversity among insects in the southern Transural area is observed specifically in the Turgai depression and in areas directly adjacent to it. This territory is mainly occupied by populations unique to the Transural regions and belonging to the following species: Mantis religiosa (praying mantis), Saga pedo, Parnassius apollo (apollo), Neolycaena rhymnus, Hyponephele lupina (oriental meadow brown), Chazara persephone (dark rockbrown), Epicallia villica (cream-spot tiger), etc. PMID:11042964

  14. Mammalian fauna of the Temessos National Park, Turkey

    Directory of Open Access Journals (Sweden)

    Anna De Marinis

    2009-12-01

    Full Text Available The National Park of Termessos, Southern Turkey, is one of the Turkey’s biggest national park not only with its archeological richness but also with its great natural wild life. We provided a checklist of the mammalian fauna of the park on the base of direct observations, interviews and a comparative analysis of the available literature. Sixteen species have been reported in the park. Hedgehogs, hares, porcupines and Persian squirrels and, among flying mammals, Egyptian rousette and Mouse-eared bat have been recorded. Carnivores are represented by Golden jackal, Wolf, Red fox, Stone marten, Badger, Otter and Wild cat. Very recently (2005 the presence of the Caracal in the park has been confirmed, whereas no signs of the presence of the Lynx were detected. The last Anatolian leopards seems to have definitively disappeared from the region. The occurrence in the area of striped hyaenas and brown bears is documented up to a few decades ago. The Park is regarded as the only geographical range in the whole world where the European or Common fallow deer has persisted as a native form. Other ungulates too, such as Wild goat and Wild boar are dispersed within the boundary of the park. Management implications are discussed.

  15. [Origin of Lepidoptera fauna of the Southern Transural region].

    Science.gov (United States)

    Utkin, N A

    2000-01-01

    The butterfly fauna of the Southern Transural region began mainly through the migration of insects from the Urals and Kazakhstan, since the end of the Cretaceous Period to the end of Paleogen, the Transural region was covered by an epiplatform sea. As this sea was retreating, the first regions of dry land appeared, which had boundaries with Kazakhstan and the Urals. They were the first to be populated by Lepidoptera. During the Pleocene and then after the Pleistocene cooling events, insects settled generally along the valley of the Tobol River and the Turgai depression, because these territories belong to intrazonal elements. At the present time, the greatest species diversity among insects in the southern Transural area is observed specifically in the Turgai depression and in areas directly adjacent to it. This territory is mainly occupied by populations unique to the Transural regions and belonging to the following species: Mantis religiosa (praying mantis), Saga pedo, Parnassius apollo (apollo), Neolycaena rhymnus, Hyponephele lupina (oriental meadow brown), Chazara persephone (dark rockbrown), Epicallia villica (cream-spot tiger), etc.

  16. "MOSQUITO FAUNA OF IRAN I- AEDES (DIPTERA: CULICIDAE "

    Directory of Open Access Journals (Sweden)

    M.Zaim

    1984-06-01

    Full Text Available Biological research of all kinds on mosquitoes must be built upon a foundation of correct identification and sound classification. Except for the anopheline vectors of malaria, relatively little is known about other mosquitoes in Iran and other countries in Southwest Asia. In view of this a comprehensive study on the mosquito fauna of Iran has started since 1981. In this report the list of the Aedes species of Iran is updated. Previous studies by Iranian and foreign investigators have revealed the occurrence of 6 Aedes species in Iran. Ae. vexans, Ae. geniculatus, Ae. caballus, Ae. Caspius, Ae pulchritarsis and Ae. aegypti. In the present study not only all named species, except one, were recollected but 5 additional species were also captured which formerly have not been know to occur in Iran. These species are Ae. Vittatus, Ae. echinus, Ae. detritus, Ae. flavescens, and Ae. leucomelas. Ae. aegypti has not been collected in Iran since the previous report in 1946. The present list of 10 species should not be regarded as final since other species, which occur in neighboring countries, may eventually be found in Iran.

  17. Connectivity controls on the late Miocene eastern Mediterranean fish fauna

    Science.gov (United States)

    Agiadi, Konstantina; Antonarakou, Assimina; Kontakiotis, George; Kafousia, Nefeli; Moissette, Pierre; Cornée, Jean-Jacques; Manoutsoglou, Emmanouil; Karakitsios, Vasileios

    2016-06-01

    Environmental change significantly affects the production of fish resources and their dependent societies. The paleontological record offers unique insight into the effects of long-term paleoenvironmental variability on the fish species' distributions and abundances. In the present study, we investigate the late Miocene (7.5-6.5 Ma) fish assemblages of the Potamida section in western Crete (eastern Mediterranean). The determined fish taxa are examined in a paleobiogeographic context, with regard to their geographic and stratigraphic distribution from the early Miocene (~13 Ma) through today. In addition, present-day ecological data are used to reconstruct the paleoenvironmental conditions in the study area. Planktonic foraminifer biostratigraphy significantly improves the earlier dating of the studied sequence. The late Miocene fish fauna of Potamida includes 35 taxa (seven in open nomenclature) from 13 teleost families. The eastern Mediterranean biostratigraphic and geographic distribution of 32 taxa is significantly expanded into the Tortonian, whereas 13 species are recorded for the first time from the Messinian. Four stages are distinguished in the area's paleoenvironmental evolution. (1) The Potamida area was an open marine environment with depths exceeding 150 m between ~7.5-7.45 Ma. (2) Between 7.45-7.36 Ma, the results suggest depths between 300-400 m. (3) The depositional depth increases between 7.36-7.28 Ma to 400-550 m. (4) Later on, approximately between 6.8-6.6 Ma, the depth is again estimated around 100-150 m.

  18. Parasitic fauna in hybrid tambacu from fish farms

    Directory of Open Access Journals (Sweden)

    Ronilson Macedo Silva

    2013-08-01

    Full Text Available The objective of this work was to evaluate the parasitic fauna of hybrid tambacu (Colossoma macropomum x Piaractus mesopotamicus from fish farms and the host-parasite relationship. A hundred and fourteen fish were collected from four fish farms in Macapá, in the state of Amapá, Brazil, 80.7% of which were infected by: Ichthyophthirius multifiliis (Ciliophora; Piscinoodinium pillulare (Dinoflagellida; Anacanthorus spatulatus, Notozothecium janauachensis, and Mymarothecium viatorum (Monogenoidea; Neoechinorhynchus buttnerae (Acanthocephala; Cucullanus colossomi (Nematoda; Perulernaea gamitanae (Lernaeidae; and Proteocephalidae larvae (Cestoda. A total of 8,136,252 parasites were collected from the examined fish. This is the first record of N. buttnerae, C. colossomi, N. janauachensis, M. viatorum, and Proteocephalidae for hybrid tambacu in Brazil. Ichthyophthirius multifiliis was the most prevalent parasite, whereas endohelminths were the less. A positive correlation was observed between number of I. multifiliis and total length and weight of fish, as well as between number of P. gamitanae and total length. The infection by I. multifiliis had association with the parasitism by Monogenoidea. Low water quality contributes to high parasitism of hybrid tambacu by ectoparasites, which, however, does not influence the relative condition factor of fish.

  19. Larval habitats of mosquito fauna in Osogbo metropolis, Southwestern Nigeria

    Institute of Scientific and Technical Information of China (English)

    Monsuru Adebayo Adeleke; Wasiu Olalekan Adebimpe; AbdulWasiu Oladele Hassan; Sunday Olukayode Oladejo; Ismail Olaoye; Ganiyu Olatunji Olatunde; Taiwo Adewole

    2013-01-01

    Objective:To determine the larval habitats of mosquito fauna and possible impact of land use/land cover changes on the epidemiology of mosquito-borne diseases in Osogbo metropolis, Southwestern, Nigeria. Methods: All accessible larval habitats were surveyed between May and September, 2011 in Osogbo metropolis while Land Use/ Land cover of the city was analyzed using 2 Lansat Multispectral Scanner satellite imagery of SPOT 1986 and LANDSAT TM 2009. Results:A total of six species namely, Aedes aegypti, Aedes albopictus, Aedes vittatus, Anopheles gambiae complex, Culex quinquefasciatus and Eretmapodite chrysogaster were encountered during the study. The occurrence and contribution of disused tyres was significantly higher (P0.05). The accessible land use/land covered of the study area between 1986 and 2009 showed that the wet land coverage and settlement area increased from 0.19 to 9.09 hectare and 1.00 to 2.01 hectare respectively while the forest area decreased from 60.18 to 50.14 hectare. Conclusion: The contribution of the habitats coupled with the increasing rate of flooded environment which could provide ample breeding sites for mosquitoes call for sustained environmental sanitation and management in Osogbo metropolis.

  20. The groundwater invertebrate fauna of the Channel Islands

    Directory of Open Access Journals (Sweden)

    Lee R.F.D. Knight

    2015-05-01

    Full Text Available The Channel Islands are a small archipelago of British dependencies just off the coast of Normandy at the western end of the English Channel. There were only three records for stygobitic Crustacea [Niphargus fontanus Bate, 1859 and N. kochianus Bate, 1859 from Jersey and N. aquilex Schiődte, 1855 from Guernsey] from the archipelago and no systematic survey has been carried out of the islands for their groundwater fauna till present. Recently sampling was carried out in wells, boreholes and springs on the four largest islands, Jersey, Guernsey, Alderney and Sark during February 2012. Niphargus aquilex was widespread across all four islands and did not appear to be restricted to any particular geology. Niphargus ladmiraulti was present in large numbers in a single borehole on Jersey, the first record of this species from the archipelago. Niphargus kochianus was collected from two sites on Alderney and the syncarid Antrobathynella stammeri (Jakobi, 1954 from two sites on the west coast of Jersey. The records for A. stammeri are new for the Channel Islands and possibly represent the first records of this species from the French bio-geographical area. The presence of N. fontanus on the islands was not confirmed. Several species of stygophilic Cyclopoida were also recorded during the survey along with epigean freshwater invertebrate taxa, which were mostly present in springs and shallow wells close to surface streams.

  1. Dynamics of Soil Fauna in Da Hinggan Mountains, Northeast China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xueping; SUN Yuan; HUANG Lirong

    2009-01-01

    The dynamics of soil animals was studied in seven representative forest communities in the north of the Da Hinggan Mountains, Northeast China. The results indicate that it was distinctive in the changes of the numbers of soil animals and groups and diversity in relationship with seasons for macrofauna and torso-micro fauna in the study area. The numbers of the observed soil animals in different months were: October>August>June. Group number was larger in August and October, but smaller in June. The change of diversity index in different months was: August>June>October. The biomass for macrofanna in different months was: October>June>August. The composition and number of each functional group was relatively stable. In the community of the predominant soil environment, the percentage of saprophagous animals was higher than carnivorous animals and herbivorous animals. The dynamics changes of saprophagous and carnivorous animals were distinctive, increasing from June to October, while the change of herbivorous animals was unremarkable.

  2. Modelling the Constraints of Spatial Environment in Fauna Movement Simulations: Comparison of a Boundaries Accurate Function and a Cost Function

    Science.gov (United States)

    Jolivet, L.; Cohen, M.; Ruas, A.

    2015-08-01

    Landscape influences fauna movement at different levels, from habitat selection to choices of movements' direction. Our goal is to provide a development frame in order to test simulation functions for animal's movement. We describe our approach for such simulations and we compare two types of functions to calculate trajectories. To do so, we first modelled the role of landscape elements to differentiate between elements that facilitate movements and the ones being hindrances. Different influences are identified depending on landscape elements and on animal species. Knowledge were gathered from ecologists, literature and observation datasets. Second, we analysed the description of animal movement recorded with GPS at fine scale, corresponding to high temporal frequency and good location accuracy. Analysing this type of data provides information on the relation between landscape features and movements. We implemented an agent-based simulation approach to calculate potential trajectories constrained by the spatial environment and individual's behaviour. We tested two functions that consider space differently: one function takes into account the geometry and the types of landscape elements and one cost function sums up the spatial surroundings of an individual. Results highlight the fact that the cost function exaggerates the distances travelled by an individual and simplifies movement patterns. The geometry accurate function represents a good bottom-up approach for discovering interesting areas or obstacles for movements.

  3. MODELLING THE CONSTRAINTS OF SPATIAL ENVIRONMENT IN FAUNA MOVEMENT SIMULATIONS: COMPARISON OF A BOUNDARIES ACCURATE FUNCTION AND A COST FUNCTION

    Directory of Open Access Journals (Sweden)

    L. Jolivet

    2015-08-01

    Full Text Available Landscape influences fauna movement at different levels, from habitat selection to choices of movements’ direction. Our goal is to provide a development frame in order to test simulation functions for animal’s movement. We describe our approach for such simulations and we compare two types of functions to calculate trajectories. To do so, we first modelled the role of landscape elements to differentiate between elements that facilitate movements and the ones being hindrances. Different influences are identified depending on landscape elements and on animal species. Knowledge were gathered from ecologists, literature and observation datasets. Second, we analysed the description of animal movement recorded with GPS at fine scale, corresponding to high temporal frequency and good location accuracy. Analysing this type of data provides information on the relation between landscape features and movements. We implemented an agent-based simulation approach to calculate potential trajectories constrained by the spatial environment and individual’s behaviour. We tested two functions that consider space differently: one function takes into account the geometry and the types of landscape elements and one cost function sums up the spatial surroundings of an individual. Results highlight the fact that the cost function exaggerates the distances travelled by an individual and simplifies movement patterns. The geometry accurate function represents a good bottom-up approach for discovering interesting areas or obstacles for movements.

  4. Preliminary research on the transmission path of nssSO2-4- and NO-3 in Antarctic ice sheet

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The main sources of nssSO24- and NO-3 were summarized in this paper. By analyzing the spatial distribution features of major ions in Antarctic ice sheet and studying on the different time of the same volcanic event recorded by different ice cores from different regions in Antarctica, this paper intends to study the transmission path of nssSO24- and NO-3. Results show that nssSO24- and NO-3 are transmitted to the ice sheet through long distance and high altitude. The procedure of the transmission is that nssSO24- and NO-2 are transmitted to the level between the top of troposphere and the bottom of stratosphere, then subsided to the ice sheet surface and spread to other regions.

  5. Measurement of bottom-reflected sound in bottom-limited propagation environment

    Science.gov (United States)

    Hahn, Jooyoung; Park, Joungsoo

    2016-07-01

    To study the bottom reflection of underwater acoustic sound in a bottom-limited propagation environment, an experiment was conducted using four transmitting sounds in the form of a continuous wave from 1 to 6 kHz. The site of the experiment was a continental shelf region off the east coast of Korea where the bottom was composed of sandy mud. The mean water depth was 1100 m in the experiment area. Oceanographic data and acoustic data were collected simultaneously during the experiment. It was found that the sound pressure level decreased by 90 dB to 3.4 km and there is little frequency dependence because a strong direct path contributes more than a bottom-reflected path in sound pressure level. At a range between 6 and 7 km, there is a strong bottom-reflected ray path and frequency dependence exists because the bottom reflection loss varies with frequency at a given grazing angle. Sound pressure levels increase as the range increases between 6 and 7 km by 5.4, 1.9, 1.7, and 1.5 dB at frequencies of 1000, 2490, 3990, and 5490 Hz, respectively.

  6. A proposal to study the insect fauna of Walnut Creek National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — It is the purpose of this proposed study to identify target insect fauna on the Walnut Creek National Wildlife Refuge by completing comprehensive surveys of remnant...

  7. PARASITIC AND SYMBIONIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) COLLECTED FROM THE CALOOSAHATCHEE RIVER AND ESTUARY, FLORIDA

    Science.gov (United States)

    Studies of oysters, Crassostrea virginica, collected from ten sites in the Caloosahatchee River and Estuary, Florida, revealed a varied parasite and symbiotic fauna that have never been reported from this area. Organisms observed included ovacystis virus infecting gametes...

  8. Three New Rhizopulvinaria Species (Homoptera: Coccoidea: Coccidae) for Scale Insect Fauna of Turkey

    OpenAIRE

    Kaydan, Mehmet Bora

    2002-01-01

    Three Rhizopulvinaria species, Rhizopulvinaria pyrethri Borchsenius, Rhizopulvinaria turkestanica (Archangelskaya), and Rhizopulvinaria viridis Borchsenius, were identified on wild flora in eastern Anatolia in 1997. All of them are new records for the Turkish scale insect fauna.

  9. The Quaternary faunas and climatic fluctuation in the tropical zone of China

    Institute of Scientific and Technical Information of China (English)

    HUANGZhenguo; ZHANGWeiqiang

    2003-01-01

    About 70 examples of Quaternary fauna in China's tropics are enumerated in this paper. Of which about 40% of the examples can be found even in cooling stages, showing the smaller amplitude of climatic fluctuation during Quaternary. According to the temporal and spatial distribution of tropical faunas, the following characters of climate variation can be evidenced: two main cycles in Early Pleistocene, three main cycles in Middle Pleistocene, two main cycles in Late Pleistocene and Holocene Megathermal. The drop in temperature during the Latest Glacial Period and Neoglaciation has not endangered the existence of tropical faunas. With influence of cooling fluctuation during historical period, some faunas have removed southwards progressively, but disappearance of these animals in China's tropics was mainly the result of artificial factors.

  10. Benthic fauna of Kakinada bay and backwaters, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rathod, V.; Ansari, Z.A.; Parulekar, A.H.

    . Nematodes, polychaetes, foraminifera and turbellarians were the major groups constituting the bulk of meiofauna, both in the backwaters and near-shore region. Macrofaunal diversity was higher in the near-shore region. Impoverishment of fauna...

  11. A late Burdigalian bathyal mollusc fauna from the Vienna Basin (Slovakia)

    Science.gov (United States)

    Harzhauser, Mathias; Mandic, Oleg; Schlögl, Jan

    2011-06-01

    This is the first record of a bathyal mollusc fauna from the late Early Miocene of the Central Paratethys. The assemblage shows clear affinities to coeval faunas of the Turin Hills in the Mediterranean area and the Aquitaine Basin in France. The overall biostratigraphic value of the assemblage is hard to estimate due to the general very poor knowledge of Miocene bathyal faunas. Several species, however, are known from deep water deposits of the Middle Miocene Badenian stage as well. This implies Early Miocene roots of parts of the Middle Miocene deep water fauna and suggests a low turnover for bathyal mollusc communities at the Early-Middle Miocene boundary. The nassariid gastropod Nassarius janschloegli Harzhauser nov. sp. and the naticid gastropod Polinices cerovaensis Harzhauser nov. sp. are introduced as new species.

  12. Stabilization of bottom sediments from Rzeszowski Reservoir

    Directory of Open Access Journals (Sweden)

    Koś Karolina

    2015-06-01

    Full Text Available The paper presents results of stabilization of bottom sediments from Rzeszowski Reservoir. Based on the geotechnical characteristics of the tested sediments it was stated they do not fulfill all the criteria set for soils in earth embankments. Therefore, an attempt to improve their parameters was made by using two additives – cement and lime. An unconfined compressive strength, shear strength, bearing ratio and pH reaction were determined on samples after different time of curing. Based on the carried out tests it was stated that the obtained values of unconfined compressive strength of sediments stabilized with cement were relatively low and they did not fulfill the requirements set by the Polish standard, which concerns materials in road engineering. In case of lime stabilization it was stated that the tested sediments with 6% addition of the additive can be used for the bottom layers of the improved road base.

  13. Constructing bottom barriers with met grouting

    Energy Technology Data Exchange (ETDEWEB)

    Shibazaki, M.; Yoshida, H. [Chemical Grouting Company, Tokyo (Japan)

    1997-12-31

    Installing a bottom barrier using conventional high pressure jetting technology and ensuring barrier continuity is challenging. This paper describes technology that has been developed and demonstrated for the emplacement of bottom barriers using pressures and flow rates above the conventional high pressure jetting parameters. The innovation capable of creating an improved body exceeding 5 meters in diameter has resulted in the satisfying connection and adherence between the treated columns. Besides, the interfaces among the improved bodies obtain the same strength and permeability lower than 1 x 10{sup -7} cm/sec as body itself. A wide variety of the thickness and the diameter of the improved mass optimizes the application, and the method is nearing completion. The paper explains an aspect and briefs case histories.

  14. Race-To-The-Bottom Tariff Cutting

    OpenAIRE

    Vézina, Pierre-Louis

    2010-01-01

    This paper provides an empirical assessment of race-to-the-bottom unilateralism. It suggests that decades of unilateral tariff cutting in Asia's emerging economies have been driven by a competition to attract FDI from Japan. Using spatial econometrics, I show that tariffs on parts and components, a crucial locational determinant for Japanese firms, converged across countries following a contagion pattern. Tariffs followed those of competing countries if the latter were lower, if FDI jealousy ...

  15. How Service Innovation Boosts Bottom Lines

    OpenAIRE

    Claude Legrand; Rob LaJoie

    2013-01-01

    In the national quest for ground-breaking R&D discoveries and inventions, service innovation is frequently ignored at considerable cost to an organization’s bottom line and a nation’s productivity. For the fact is that innovation applied systematically to all activities outside of R&D can make the difference between uninspiring results and substantial growth in every sector. Many countries, in particular in Europe, have recognized the importance of service innovation and are devoting consider...

  16. Bottoming out-Sign of Stabilization

    Institute of Scientific and Technical Information of China (English)

    Dennis K. Zhao

    2009-01-01

    @@ Production Rose from its Nadir Apart from individual data report.CNTAC was a lot more focused on an overall review of textile industry as a whole to illustrate economic behavior for the first five months."sign of stabilization,bottoming out"are the key words emphatically voiced as a token of encou ragement,for the important economic indexes are indeed encouraging as compa red with this fi rst quarter.

  17. ABOUT THE INTERNATIONAL GIS WORKSHOPON ANTARCTIC KING GEORGE ISLAND

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@With rapid scientific development and further exploration towards the nature, the human kind hopes to serve themselves by mastering the natural law. Countries all over the world set much value on the study of Antarctica and have obtained plenty and substantial achievements. So as to strengthen mutual understanding among the countries in Antarctic surveying and mapping and share the achievements, the "International GIS Workshop on Antarctic King George Island", Wuhan, July 6th~7th, 2000 was successfully held in the Lecture Hall of the National Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS). It was jointly held by the National Research Center on Antarctic Surveying and Mapping and LIESMARS, and sponsored by the National Polar Region Inspection Office, National Natural Scientific Foundation Committee, the State Bureau of Surveying and Mapping, the former Wuhan Technical University of Surveying and Mapping.

  18. Genetics differentiation between Arctic and Antarctic monothalamous foraminiferans

    DEFF Research Database (Denmark)

    Pawlowski, Jan; Majewski, Wojciech; Longet, David;

    2008-01-01

    Monothalamous (single-chambered) foraminifers are a major component of the benthic meiofauna in high latitude regions. Several morphologically similar species are common in the Arctic and Antarctic. However, it is uncertain whether these morphospecies are genetically identical, or whether...... their accurate identification is compromised by a lack of distinctive morphological features. To determine the relationship between Arctic and Antarctic species, we have compared SSU rDNA sequences of specimens belonging to four morphotaxa: Micrometula, Psammophaga, Gloiogullmia, and one morphospecies...... Hippocrepinella hirudinea from western Svalbard (Arctic) and McMurdo Sound (Antarctic). Wherever possible, we include in our analyses representatives of these taxa from the deep Arctic and Southern Oceans, as well as from Northern European fjords. We found that in all cases, the bipolar populations were clearly...

  19. Terrestrial 81Kr-Kr ages of Antarctic meteorites

    International Nuclear Information System (INIS)

    The production rate of 38Ar in meteorites-P(38)-has been determined, as a function of the sample's chemical composition, from 81Kr-Kr exposure ages of four eucrite falls. The cosmogenic 78Kr/83Kr ratio is used to estimate the shielding dependence of P(38). From the ''true'' 38Ar exposure ages and the apparent 81Kr-Kr exposure ages of nine Antarctic eucrite finds, terrestrial ages are calculated. The distribution of terrestrial ages of Allan Hills meteorites is discussed. Meteorites from this blue ice field have two sources: Directly deposited falls and meteorites transported to the Allan Hills inside the moving Antarctic ice sheet. During the surface residence time meteorites decompose due to weathering processes. The weathering ''half-life'' is about 1.6 x 105 a. From the different age distributions of Allan Hills and Yamato meteorites, it is concluded that meteorite concentrations of different Antarctic ice fields need different explanations. (author)

  20. Holocene subsurface temperature variability in the eastern Antarctic continental margin

    Science.gov (United States)

    Kim, Jung-Hyun; Crosta, Xavier; Willmott, Veronica; Renssen, Hans; Bonnin, Jérôme; Helmke, Peer; Schouten, Stefan; Sinninghe Damsté, Jaap S.

    2012-03-01

    We reconstructed subsurface (˜45-200 m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX86L). Our results reveal that subsurface temperature changes were probably positively coupled to the variability of warmer, nutrient-rich Modified Circumpolar Deep Water (MCDW, deep water of the Antarctic circumpolar current) intrusion onto the continental shelf. The TEX86L record, in combination with previously published climatic records, indicates that this coupling was probably related to the thermohaline circulation, seasonal variability in sea ice extent, sea temperature, and wind associated with high frequency climate dynamics at low-latitudes such as internal El Niño Southern Oscillation (ENSO). This in turn suggests a linkage between centennial ENSO-like variability at low-latitudes and intrusion variability of MCDW into the eastern Antarctic continental shelf, which might have further impact on ice sheet evolution.

  1. Bottom-strange mesons in hyperonic matter

    CERN Document Server

    Pathak, Divakar

    2014-01-01

    The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of their medium mass on baryonic density and strangeness content of the medium. Certain aspects of these in-medium interactions are similar to those observed for the strange-charmed mesons in a preceding investigation, such as the lifting of mass-degeneracy of $B_S^0$ and ${\\bar B}_S^0$ mesons in hyperonic matter, while the same is respected in vacuum as well as in nuclear matter. In general, however, there is a remarkable distinction between the two species, even though the formalism predicts a completely analogous in-medium...

  2. Optimal Design of Round Bottomed Triangle Channels

    Directory of Open Access Journals (Sweden)

    Ayman T. Hameed

    2013-05-01

    Full Text Available     In optimal design concept, the geometric dimensions of a channel cross-section are determined in a manner to minimize the total construction costs. The Direct search optimization method by using MATALAB is used to solve the resulting channel optimization models for a specified flow rate, roughness coefficient and longitudinal slope. The developed optimization models are applied to design the round bottomed triangle channel and trapezoidal channels to convey a given design flow considering various design scenarios However, it also can be extended to other shapes of channels. This method optimizes the total construction cost by minimizing the cross-sectional area and wetted perimeter per unit length of the channel. In the present study, it is shown that for all values of side slope, the total construction cost in the round bottomed triangle cross-section are less than those of trapezoidal cross-section for the same values of discharge. This indicates that less excavation and a lining are involved and therefore implies that the round bottomed triangle cross-section is more economical than trapezoidal cross-section.

  3. Isotopic dating of the Chengjiang Fauna-bearing horizon in Central Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Twenty black shale samples, which are free from the influence of weathering, were collected from the Chengjiang Fauna-bearing horizon, central Yunnan Province, yielding a Pb-Pb isochron age of 534±60 Ma. Although this age is younger than both the Rb-Sr isochron age and 40Ar-39Ar age, it should represent the lower isotopic age limit of the Chengjiang Fauna.

  4. Contribution to the knowledge of the butterfly fauna of Montenegro (Lepidoptera: Rhopalocera):

    OpenAIRE

    Švara, Vid; Verovnik, Rudi; Zakšek, Barbara

    2015-01-01

    During the years 2009 to 2013, three visits to Montenegro were made to study the spring and early summer butterfly fauna. The focus of our study was on the south-western part of the country, especially the coastal region. A total of 31 localities were visited and some interesting observations were made. Altogether 112 species were recorded, confirming high diversity of the butterfly fauna of this country. Among the observed species, the following are rare or local in Montenegro: Papilio alexa...

  5. Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow.

    Directory of Open Access Journals (Sweden)

    Shu Liao

    Full Text Available Dissolved organic carbon (DOC and total dissolved nitrogen (TDN are generally considered important active biogeochemical pools of total carbon and nitrogen. Many studies have documented the contributions of soil fauna to litter decomposition, but the effects of the soil fauna on labile substances (i.e., DOC and TDN in litter during early decomposition are not completely clear. Therefore, a field litterbag experiment was carried out from 13th November 2013 to 23rd October 2014 in an alpine forest and an alpine meadow located on the eastern Tibetan Plateau. Litterbags with different mesh sizes were used to provide access to or prohibit the access of the soil fauna, and the concentrations of DOC and TDN in the foliar litter were measured during the winter (the onset of freezing, deep freezing and thawing stage and the growing season (early and late. After one year of field incubation, the concentration of DOC in the litter significantly decreased, whereas the TDN concentration in the litter increased. Similar dynamic patterns were detected under the effects of the soil fauna on both DOC and TDN in the litter between the alpine forest and the alpine meadow. The soil fauna showed greater positive effects on decreasing DOC concentration in the litter in the winter than in the growing season. In contrast, the dynamics of TND in the litter were related to seasonal changes in environmental factors, rather than the soil fauna. In addition, the soil fauna promoted a decrease in litter DOC/TDN ratio in both the alpine forest and the alpine meadow throughout the first year of decomposition, except for in the late growing season. These results suggest that the soil fauna can promote decreases in DOC and TDN concentrations in litter, contributing to early litter decomposition in these cold biomes.

  6. Chondrichthyan Fauna from the Pirabas Formation, Miocene of Northern Brazil, with Comments on Paleobiogeography

    Directory of Open Access Journals (Sweden)

    Márcia Aparecida Fernandes dos Reis

    2005-09-01

    Full Text Available The chondrichthyan fauna from the Pirabas Formation is redescribed. Only thirteen nominal taxa are considered valid. From these taxa, ten were reassigned to extant taxa (Carcharhinus sorrah, Carcharhinus perezii, Galeocerdo cuvier, Rhizoprionodon lalandii, Sphyrna sp., Hemipristis elongatus, Carcharodon carcharias, Isurus oxyrinchus, Nebrius ferrugineus, and indeterminate Myliobatidae, confirming the Neogene age of this formation. This elasmofauna is compared with other Caribbean and African Tertiary faunas.

  7. On the fauna of centipedes (Chilopoda, Myriapoda inhabiting Serbia and Montenegro

    Directory of Open Access Journals (Sweden)

    Mitić Bojan M.

    2002-01-01

    Full Text Available This paper presents our recent knowledge concerning the fauna of centipedes (Chilopoda in Serbia and Montenegro. In this study 5 species are considered as new for the fauna of Serbia, but only one for Montenegro. There exist 42 centipede species and subspecies in Serbia, and 43 species and subspecies in Montenegro; these have been classified into 13 genera and 8 families (Serbia and into 17 genera and 8 families (Montenegro.

  8. Freshwater invertebrate fauna of Nuku Hiva island (French Polynesia) : data during a rainy season

    OpenAIRE

    Fossati, Odile; Gibon, François-Marie; Danigo, Anne-Hélène

    1992-01-01

    The streams of Nuku-Hiva Island, Marquesas Archipelago, were sampled during the rainy season in June 1990. The invertebrate fauna was scarce and had a low diversity. Gastropoda and Decapoda accounted for the major part of the biomass. Insects were represented by #Simuliidae$, #Chironomidae$ and a few #Ceratopogonidae$, #Coleoptera$ and #Zygoptera$. #Oligochaeta$ were numerically important. The role of insularity and the effects of hydraulic conditions on this fauna are briefly discussed. (Rés...

  9. The Benthic Macroinvertebrate Fauna of Sarikum Lake and Spring Waters (Sinop)

    OpenAIRE

    Akbulut, Mehmet; Oztürk, Mehmet; Öztürk, Meral

    2002-01-01

    Abstract In this study, the community composition of benthic macroinvertebrate fauna from Sarikum Lake and spring waters were investigated monthly between June 1995 and May 1996. Physico-chemical parameters of the sampling stations were measured. The fauna were represented with 26 species belonging to 6 systematic groups (Gastropoda, Bivalvia, Insecta (larvae), Crustacea, Polychaete and Turbellaria classis). Insecta was found as predominant in respect to species diversity. The species b...

  10. Crustacean fauna of a mussel cultivated raft system in the Black Sea

    Directory of Open Access Journals (Sweden)

    Murat Sezgin

    2013-06-01

    Full Text Available The aim of the current study was to make a faunistic analysis of the crustaceans associated with cultivated mussels grown on ropes. Mussel samples from 30 cm ropes were collected from rope-grown mussel beds by hand. The crustacean fauna associated with mussel population were quantified. The density of crustacean fauna associated with mussels was significantly greater within rope-grown mussel assemblages than on other biotopes around.

  11. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    Directory of Open Access Journals (Sweden)

    Steven L Chown

    2012-01-01

    Full Text Available The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  12. Antarctic Porifera database from the Spanish benthic expeditions.

    Science.gov (United States)

    Rios, Pilar; Cristobo, Javier

    2014-01-01

    THE INFORMATION ABOUT THE SPONGES IN THIS DATASET IS DERIVED FROM THE SAMPLES COLLECTED DURING FIVE SPANISH ANTARCTIC EXPEDITIONS: Bentart 94, Bentart 95, Gebrap 96, Ciemar 99/00 and Bentart 2003. Samples were collected in the Antarctic Peninsula and Bellingshausen Sea at depths ranging from 4 to 2044 m using various sampling gears. The Antarctic Porifera database from the Spanish benthic expeditions is unique as it provides information for an under-explored region of the Southern Ocean (Bellingshausen Sea). It fills an information gap on Antarctic deep-sea sponges, for which there were previously very few data. This phylum is an important part of the Antarctic biota and plays a key role in the structure of the Antarctic marine benthic community due to its considerable diversity and predominance in different areas. It is often a dominant component of Southern Ocean benthic communities. The quality of the data was controlled very thoroughly with GPS systems onboard the R/V Hesperides and by checking the data against the World Porifera Database (which is part of the World Register of Marine Species, WoRMS). The data are therefore fit for completing checklists, inclusion in biodiversity pattern analysis and niche modelling. The authors can be contacted if any additional information is needed before carrying out detailed biodiversity or biogeographic studies. The dataset currently contains 767 occurrence data items that have been checked for systematic reliability. This database is not yet complete and the collection is growing. Specimens are stored in the author's collection at the Spanish Institute of Oceanography (IEO) in the city of Gijón (Spain). The data are available in GBIF. PMID:24843257

  13. Antarctic Porifera database from the Spanish benthic expeditions

    Directory of Open Access Journals (Sweden)

    Pilar Rios

    2014-04-01

    Full Text Available The information about the sponges in this dataset is derived from the samples collected during five Spanish Antarctic expeditions: Bentart 94, Bentart 95, Gebrap 96, Ciemar 99/00 and Bentart 2003. Samples were collected in the Antarctic Peninsula and Bellingshausen Sea at depths ranging from 4 to 2044 m using va­rious sampling gears.The Antarctic Porifera database from the Spanish benthic expeditions is unique as it provides in­formation for an under-explored region of the Southern Ocean (Bellingshausen Sea. It fills an information gap on Antarctic deep-sea sponges, for which there were previously very few data.This phylum is an important part of the Antarctic biota and plays a key role in the structure of the Antarctic marine benthic community due to its considerable diversity and predominance in different areas. It is often a dominant component of Southern Ocean benthic communities.The quality of the data was controlled very thoroughly with GPS systems onboard the R/V Hesperides and by checking the data against the World Porifera Database (which is part of the World Register of Marine Species, WoRMS. The data are therefore fit for completing checklists, inclusion in biodivers­ity pattern analysis and niche modelling. The authors can be contacted if any additional information is needed before carrying out detailed biodiversity or biogeographic studies.The dataset currently contains 767 occurrence data items that have been checked for systematic reliability. This database is not yet complete and the collection is growing. Specimens are stored in the author’s collection at the Spanish Institute of Oceanography (IEO in the city of Gijón (Spain. The data are available in GBIF.

  14. Antarctic Ozone Hole on September 17, 2001

    Science.gov (United States)

    2002-01-01

    Satellite data show the area of this year's Antarctic ozone hole peaked at about 26 million square kilometers-roughly the size of North America-making the hole similar in size to those of the past three years, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA). Researchers have observed a leveling-off of the hole size and predict a slow recovery. Over the past several years the annual ozone hole over Antarctica has remained about the same in both its size and in the thickness of the ozone layer. 'This is consistent with human-produced chlorine compounds that destroy ozone reaching their peak concentrations in the atmosphere, leveling off, and now beginning a very slow decline,' said Samuel Oltmans of NOAA's Climate Monitoring and Diagnostics Laboratory, Boulder, Colo. In the near future-barring unusual events such as explosive volcanic eruptions-the severity of the ozone hole will likely remain similar to what has been seen in recent years, with year-to-year differences associated with meteorological variability. Over the longer term (30-50 years) the severity of the ozone hole in Antarctica is expected to decrease as chlorine levels in the atmosphere decline. The image above shows ozone levels on Spetember 17, 2001-the lowest levels observed this year. Dark blue colors correspond to the thinnest ozone, while light blue, green, and yellow pixels indicate progressively thicker ozone. For more information read: 2001 Ozone Hole About the Same Size as Past Three Years. Image courtesy Greg Shirah, GSFC Scientific Visualization Studio, based on data from the TOMS science team

  15. Microbiology and Geochemistry of Antarctic Paleosols

    Science.gov (United States)

    Mahaney, W. C.; Malloch, D.; Hancock, R. G. V.; Campbell, I. B.; Sheppard, D.

    2000-08-01

    Samples of ancient soils from horizons in paleosols from the Quartermain Mountains (Aztec and New Mountain areas of the Antarctic Dry Valleys) were analyzed for their chemical composition and microbiology to determine the accumulation and movement of salts and other soluble constituents. The salt concentrations are of special interest because they are considered to be a function of age, derived in part from nearby oceanic and high altitude atmospheric sources. The geochemistry of ancient Miocene-age paleosols in these areas is the direct result of the deposition and weathering of till, derived principally from dolerite and sandstone source rock, in association with airborne-influxed salts. Paleosols nearer the coast have greater contents of chlorine, and farther inland near the Inland Ice Sheet, nitrogen tends to increase on a relative basis. The accumulation and vertical distribution of salts and other soluble chemical elements indicate relative amounts of movement in the profile over long periods of time, to the order of several million years. Iron, both in total concentration and in the form of various extracts, indicates it can be used as a geochronometer to assess the buildup of goethite plus hematite over time in the paleosols. Trends for ferrihydrite, a partially soluble Fe-hydroxide, shows limited profile translocation that might be related to the movement of salt. Six of the eight selected subsamples from paleosol horizons in three soil profiles contained nil concentrations of bacteria and fungi. However, two horizons at depths of between three to eight centimeters yielded several colonies of the fungi Beauveria bassiana and Penicillium spp., indicating some input of organic carbon. Beauveria bassiana is often reported in association with insects and is used commercially for the biological control of some insect pests. Penicillium species are commonly isolated from Arctic, temperate and tropical soils and are known to utilize a wide variety of organic

  16. Running PILOT: operational challenges and plans for an Antarctic Observatory

    Science.gov (United States)

    McGrath, Andrew; Saunders, Will; Gillingham, Peter; Ward, David; Storey, John; Lawrence, Jon; Haynes, Roger

    2008-07-01

    We highlight the operational challenges and planned solutions faced by an optical observatory taking advantage of the superior astronomical observing potential of the Antarctic plateau. Unique operational aspects of an Antarctic optical observatory arise from its remoteness, the polar environment and the unusual observing cycle afforded by long continuous periods of darkness and daylight. PILOT is planned to be run with remote observing via satellite communications, and must overcome both limited physical access and data transfer. Commissioning and lifetime operations must deal with extended logistics chains, continual wintertime darkness, extremely low temperatures and frost accumulation amidst other challenging issues considered in the PILOT operational plan, and discussed in this presentation.

  17. Temperature-dependent enthalpy of oxygenation in Antarctic fish hemoglobins

    DEFF Research Database (Denmark)

    Fago, A.; Wells, R.M.G.; Weber, Roy E.

    1997-01-01

    The effect of temperature on the oxygen-binding properties of the hemoglobins of three cold-adapted Antarctic fish species, Dissostichus mawsoni, Pagothenia borchgrevinki and Trematomus, sp., has been investigated under different pH values and buffer conditions. A clear non linear van't Hoff plot...... literature data for the enthalpy of oxygenation in Antarctic fish hemoglobins derives from the use of the nonintegrated (linearized) form of the van't Hoff equation over different temperature ranges. The general assumption that a low heat of oxygenation in hemoglobins from polar animals represents...

  18. Laboratory study of nitrate photolysis in Antarctic snow

    DEFF Research Database (Denmark)

    Berhanu, Tesfaye A.; Meusinger, Carl; Erbland, Joseph;

    2014-01-01

    in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry," J. Chem. Phys. 140, 244305 (2014)]) is to characterize nitrate photochemistry and improve the interpretation of the nitrate ice core record. Naturally occurring stable isotopes in nitrate (15N, 17O, and 18O) provide......Atmospheric nitrate is preserved in Antarctic snow firn and ice. However, at low snow accumulation sites, post-depositional processes induced by sunlight obscure its interpretation. The goal of these studies (see also Paper I by Meusinger et al. [" Laboratory study of nitrate photolysis...

  19. Deep and bottom water export from the Southern Ocean to the Pacific over the past 38 million years

    Science.gov (United States)

    van de Flierdt, T.; Frank, M.; Halliday, A.N.; Hein, J.R.; Hattendorf, B.; Gunther, D.; Kubik, P.W.

    2004-01-01

    The application of radiogenic isotopes to the study of Cenozoic circulation patterns in the South Pacific Ocean has been hampered by the fact that records from only equatorial Pacific deep water have been available. We present new Pb and Nd isotope time series for two ferromanganese crusts that grew from equatorial Pacific bottom water (D137-01, "Nova," 7219 m water depth) and southwest Pacific deep water (63KD, "Tasman," 1700 m water depth). The crusts were dated using 10Be/9Be ratios combined with constant Co-flux dating and yield time series for the past 38 and 23 Myr, respectively. The surface Nd and Pb isotope distributions are consistent with the present-day circulation pattern, and therefore the new records are considered suitable to reconstruct Eocene through Miocene paleoceanography for the South Pacific. The isotope time series of crusts Nova and Tasman suggest that equatorial Pacific deep water and waters from the Southern Ocean supplied the dissolved trace metals to both sites over the past 38 Myr. Changes in the isotopic composition of crust Nova are interpreted to reflect development of the Antarctic Circumpolar Current and changes in Pacific deep water circulation caused by the build up of the East Antarctic Ice Sheet. The Nd isotopic composition of the shallower water site in the southwest Pacific appears to have been more sensitive to circulation changes resulting from closure of the Indonesian seaway. Copyright 2004 by the American Geophysical Union.

  20. Laser microdissection-based analysis of the Y sex chromosome of the Antarctic fish Chionodraco hamatus (Notothenioidei, Channichthyidae

    Directory of Open Access Journals (Sweden)

    Ennio Cocca

    2015-02-01

    Full Text Available Microdissection, DOP-PCR amplification and microcloning were used to study the large Y chromosome of Chionodraco hamatus, an Antarctic fish belonging to the Notothenioidei, the dominant component of the Southern Ocean fauna. The species has evolved a multiple sex chromosome system with digametic males showing an X1YX2 karyotype and females an X1X1X2X2 karyotype. Fluorescence in situ hybridization, performed with a painting probe made from microdissected Y chromosomes, allowed a deeper insight on the chromosomal rearrangement, which underpinned the fusion event that generated the Y. Then, we used a DNA library established by microdissection and microcloning of the whole Y chromosome of Ch. hamatus for searching sex-linked sequences. One clone provided preliminary information on the presence on the Y chromosome of the CHD1 gene homologue, which is sex-linked in birds but in no other vertebrates. Several clones from the Y-chromosome mini-library contained microsatellites and transposable elements, one of which mapped to the q arm putative fusion region of the Y chromosome. The findings confirm that interspersed repetitive sequences might have fostered chromosome rearrangements and the emergence of the Y chromosome in Ch. hamatus. Detection of the CHD1 gene in the Y sex-determining region could be a classical example of convergent evolution in action.

  1. Reading the complex skipper butterfly fauna of one tropical place.

    Directory of Open Access Journals (Sweden)

    Daniel H Janzen

    Full Text Available BACKGROUND: An intense, 30-year, ongoing biodiversity inventory of Lepidoptera, together with their food plants and parasitoids, is centered on the rearing of wild-caught caterpillars in the 120,000 terrestrial hectares of dry, rain, and cloud forest of Area de Conservacion Guanacaste (ACG in northwestern Costa Rica. Since 2003, DNA barcoding of all species has aided their identification and discovery. We summarize the process and results for a large set of the species of two speciose subfamilies of ACG skipper butterflies (Hesperiidae and emphasize the effectiveness of barcoding these species (which are often difficult and time-consuming to identify. METHODOLOGY/PRINCIPAL FINDINGS: Adults are DNA barcoded by the Biodiversity Institute of Ontario, Guelph, Canada; and they are identified by correlating the resulting COI barcode information with more traditional information such as food plant, facies, genitalia, microlocation within ACG, caterpillar traits, etc. This process has found about 303 morphologically defined species of eudamine and pyrgine Hesperiidae breeding in ACG (about 25% of the ACG butterfly fauna and another 44 units indicated by distinct barcodes (n = 9,094, which may be additional species and therefore may represent as much as a 13% increase. All but the members of one complex can be identified by their DNA barcodes. CONCLUSIONS/SIGNIFICANCE: Addition of DNA barcoding to the methodology greatly improved the inventory, both through faster (hence cheaper accurate identification of the species that are distinguishable without barcoding, as well as those that require it, and through the revelation of species "hidden" within what have long been viewed as single species. Barcoding increased the recognition of species-level specialization. It would be no more appropriate to ignore barcode data in a species inventory than it would be to ignore adult genitalia variation or caterpillar ecology.

  2. Checklist of butterfly fauna of Kohat, Khyber Pakhtunkhwa, Pakistan

    Directory of Open Access Journals (Sweden)

    Farzana Perveen

    2012-09-01

    Full Text Available The butterflies play dual role, firstly as the pollinator, carries pollen from one flower to another and secondly their larvae act as the pest, injurious to various crops. Their 21 species were identified belonging to 3 different families from Kohat, Pakistan during September-December 2008. The reported families Namphalidae covered 33%, Papilionidae 10%, and Pieridae 57% biodiversity of butterflies of Kohat. In Namphalidae included: species belonging to subfamily Nymphalinae, Indian fritillary, Argynnis hyperbius Linnaeus; common castor, Ariadne merione (Cramer; painted lady, Cynthia cardui (Linnaeus; peacock pansy, Junonia almanac Linnaeus; blue pansy, J. orithya Linnaeus; common leopard, Phalantha phalantha (Drury; species belonging to subfamily Satyrinae, white edged rock brown, Hipparchia parisatis (Kollar. In Papilionidae included: subfamily Papilioninae, lime butterfly, Papilio demoleus Linnaeus and common mormon, Pa. polytes Linnaeus. In Pieridae included: subfamily Coliaclinae, dark clouded yellow, Colias croceus (Geoffroy; subfamily Coliadinae, lemon emigrant, Catopsilia pomona Fabricius; little orange tip, C. etrida Boisduval; blue spot arab,Colotis protractus Butler; common grass yellow, Eumera hecab (Linnaeus; common brimstone, Gonepteryx rhamni (Linnaeus; yellow orange tip, Ixias pyrene Linnaeus; subfamily Pierinae, pioneer white butterfly, Belenoi aurota Bingham; Murree green-veined white, Pieris ajaka Moore; large cabbage white, P. brassicae Linnaeus; green-veined white, P. napi (Linnaeus; small cabbage white, P. rapae Linnaeus. The wingspan of collected butterflies, minimum was 25 mm of C. etrida which was the smallest butterfly, however, maximum was 100 mm of P. demoleus and P. polytes which were the largest butterflies. A detail study is required for further exploration of butterflies' fauna of Kohat.

  3. Imperfect isolation: factors and filters shaping Madagascar's extant vertebrate fauna.

    Directory of Open Access Journals (Sweden)

    Karen E Samonds

    Full Text Available Analyses of phylogenetic topology and estimates of divergence timing have facilitated a reconstruction of Madagascar's colonization events by vertebrate animals, but that information alone does not reveal the major factors shaping the island's biogeographic history. Here, we examine profiles of Malagasy vertebrate clades through time within the context of the island's paleogeographical evolution to determine how particular events influenced the arrival of the island's extant groups. First we compare vertebrate profiles on Madagascar before and after selected events; then we compare tetrapod profiles on Madagascar to contemporary tetrapod compositions globally. We show that changes from the Mesozoic to the Cenozoic in the proportions of Madagascar's tetrapod clades (particularly its increase in the representation of birds and mammals are tied to changes in their relative proportions elsewhere on the globe. Differences in the representation of vertebrate classes from the Mesozoic to the Cenozoic reflect the effects of extinction (i.e., the non-random susceptibility of the different vertebrate clades to purported catastrophic global events 65 million years ago, and new evolutionary opportunities for a subset of vertebrates with the relatively high potential for transoceanic dispersal potential. In comparison, changes in vertebrate class representation during the Cenozoic are minor. Despite the fact that the island's isolation has resulted in high vertebrate endemism and a unique and taxonomically imbalanced extant vertebrate assemblage (both hailed as testimony to its long isolation, that isolation was never complete. Indeed, Madagascar's extant tetrapod fauna owes more to colonization during the Cenozoic than to earlier arrivals. Madagascar's unusual vertebrate assemblage needs to be understood with reference to the basal character of clades originating prior to the K-T extinction, as well as to the differential transoceanic dispersal advantage of

  4. Impacts of Soil Fauna on Litter Decomposition at Different Succession Stages of Wetland in Sanjiang Plain, China

    Institute of Scientific and Technical Information of China (English)

    WU Haitao; LU Xianguo; JIANG Ming; BAO Xiao

    2009-01-01

    Litter decomposition is the key process in nutrient recycling and energy flow. The present study examined the impacts of soil fauna on decomposition rates and nutrient fluxes at three succession stages of wetland in the Sanji-ang Plain, China using different mesh litterbags. The results show that in each succession stage of wetland, soil fauna can obviously increase litter decomposition rates. The average contribution of whole soil fauna to litter mass loss was 35.35%. The more complex the soil fauna group, the more significant the role of soil fauna. The average loss of three types of litter in the 4mm mesh litterbags was 0.3-4.1 times that in 0.058mm ones. The decomposition function of soil fauna to litter mass changed with the wetland succession. The average contribution of soil fauna to litter loss firstly de-creased from 34.96% (Carex lasiocapa) to 32.94% (Carex meyeriana), then increased to 38.16% (Calamagrosties an-gustifolia). The contributions of soil fauna to litter decomposition rates vary according to the litter substrata, soil fauna communities and seasons. Significant effects were respectively found in August and July on C angustifolia and C lasiocapa, while in June and August on C. Meyeriana. Total carbon (TC), total nitrogen (TN) and total phosphorus (TP) contents and the C/N and C/P ratios of decaying litter can be influenced by soil fauna. At different wetland succession stages, the effects of soil fauna on nutrient elements also differ greatly, which shows the significant difference of in-fluencing element types and degrees. Soil fauna communities strongly influenced the TC and TP concentrations of C meyeriana litter, and TP content of C lasiocapa. Our results indicate that soil fauna have important effects on litter decomposition and this influence will vary with the wetland succession and seasonal variation.

  5. Characterising Antarctic and Southern Ocean Lithosphere with Magnetic and Gravity Imaging of East Antarctic Rift Systems

    Science.gov (United States)

    Vaughan, A. P.; Kusznir, N. J.; Ferraccioli, F.; Jordan, T. A.; Purucker, M. E.; Golynsky, A. V.; Rogozhina, I.

    2012-12-01

    Since the International Geophysical Year (1957), a view has prevailed that the lithospheric structure of East Antarctica is relatively homogeneous, forming a geological block of largely cratonic nature, consisting of a mosaic of Precambrian terranes, stable since the Pan-African orogeny ~500 million years ago. Recent recognition of a continental-scale rift system cutting the East Antarctic interior indicates that this is incorrect, and has crystallised an alternative view of much more recent geological activity with important implications for tectonic reconstructions and controls on ice sheet formation and stability. The newly defined East Antarctic Rift System appears to extend from at least the South Pole to the continental margin at the Lambert Rift, a distance of 2500 km. This is comparable in scale to the well-studied East African rift system. New analysis of RadarSat data pioneered by Golynsky & Golynsky indicates that further rift zones may extend the East Antarctic Rift System into widely distributed extension zones within the continent. We have carried out a pilot study, using a newly developed gravity inversion technique with existing public domain satellite data, which shows that East Antarctica consists of distinct crustal thickness provinces with anomalously thick areas separated by thin, possibly rifted crust and overall high average thickness. Understanding the nature of crustal thickness in East Antarctica is critical because: 1) Better understanding of crustal thickness in Antarctica, especially along the ocean-continent transition (OCT), will make it possible to improve the plate reconstruction fit between Antarctica, Australia and India in Gondwana and also refine constraints on how and when these continents separated; 2) crustal thickness provinces can be used to aid supercontinent reconstructions and provide new assessments of the influence of basement architecture and mechanical properties on rifting processes; 3) tracking rift zones through

  6. Contrasting time trends of organic contaminants in Antarctic pelagic and benthic food webs.

    Science.gov (United States)

    van den Brink, Nico W; Riddle, Martin J; van den Heuvel-Greve, Martine; van Franeker, Jan Andries

    2011-01-01

    We demonstrate that pelagic Antarctic seabirds show significant decreases in concentrations of some persistent organic pollutants. Trends in Adélie penguins and Southern fulmars fit in a general pattern revealed by a broad literature review. Downward trends are also visible in pelagic fish, contrasting sharply with steady or increasing concentrations in Antarctic benthic organisms. Transfer of contaminants between Antarctic pelagic and benthic food webs is associated with seasonal sea-ice dynamics which may influence the balance between the final receptors of contaminants under different climatic conditions. This complicates the predictability of future trends of emerging compounds in the Antarctic ecosystem, such as of the brominated compounds that we detected in Antarctic petrels. The discrepancy in trends between pelagic and benthic organisms shows that Antarctic biota are still final receptors of globally released organic contaminants and it remains questionable whether the total environmental burden of contaminants in the Antarctic ecosystem is declining.

  7. Persistent organohalogen contaminant burdens in Antarctic krill (Euphausia superba) from the eastern Antarctic sector: A baseline study

    International Nuclear Information System (INIS)

    A baseline for persistent organohalogen compound (POC) accumulation in the Antarctic keystone species, Antarctic krill (Euphausia superba) has been established for a 50 deg. longitudinal range of the eastern Antarctic sector. Samples of adult krill, caught from 12 sites distributed between 30 deg. and 80 deg. E (60-70 deg. S), were analysed for > 100 organohalogen compounds including chlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated organic compounds and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs). Organochlorine pesticides dominated measured krill contaminant burdens with hexachlorobenzene (HCB) as the single most abundant compound quantified. Krill HCB concentrations were comparable to those detected at this trophic level in both the Arctic and temperate northwest Atlantic, lending support for the hypothesis that HCB will approach global equilibrium at a faster rate than other POCs. Para, para'-dichlorodiphenylethene (p,p'-DDE) was detected at notable concentrations. Measurements of DDT and its degradation products provide an important baseline for monitoring the temporal and geographical influence of renewed, DDT usage for malaria-control in affected southern hemisphere countries. In contrast to the Arctic, PCBs did not feature prominently in contaminant burdens of Antarctic krill. The major commercial polybrominated diphenyl ether (PBDE) congeners -99 and -47 were quantified at low background levels with clear concentration spikes observed at around 70 deg. E , in the vicinity of modern, active research stations. The likelihood that local anthropogenic activities are supplementing low PBDE levels, delivered otherwise primarily via long range environmental transport, is discussed. The suspected naturally occurring brominated organic compound, 2,4,6-tribromoanisole (TBA), was a ubiquitous contaminant in all samples whereas the only PCDD/Fs quantifiable were trace levels of octachlorodibenzo-p-dioxin (OCDD) and 1,2,3

  8. Community structures of soil fauna in reclaimed copper mine tailings and suburb forest land

    Directory of Open Access Journals (Sweden)

    Yongheng Zhu

    2012-11-01

    Full Text Available Soil fauna were very important for the ecological reconstruction of mine tailings. We investigated community characteristics of soil fauna at two sites, including reclamated copper-mine-tailings (RCMT and suburb forest land of reclamated copper-mine-tailings (SFL in Tongling City to test and illustrate the value of soil fauna for mitigating the impacts of heavy metal pollution. In the spring of 2011, we established four transects (150 m at the two sites and collected soil samples of macro-, meso- and micro- soil fauna from four depths (0–5 cm, 5–10 cm, 10–15 cm, 15–20 cm at 13 30 cm× 30 cm sampling quadrats. Our results showed that at RCMT, the Acarina, Collembola and Nematoda were dominant groups; the Formicidae, Coleoptera larvae, Oligochaeta, Diptera larvae and Diplura were frequent groups; and the additional 16 groups were less commonly encountered. While at SFL the Collembola and Acarina were dominant groups and the Nematoda and Oligochaeta were frequent groups. Overall abundance of soil fauna at RCMT were significantly less than that of SFL (F=20.65, P<0.01, and number of faunal groups were lower at RCMT (F=5.88, P<0.05. We did not find a significant difference between the density of macro-soil fauna at RCMT and SFL, but found that the density of meso- and micro- soil fauna at RCMT was significantly lower than that of SFL (F=29.99, P<0.01. The Shannon-Wiener diversity index (H at RCMT was higher than that of SFL (F=24.06, P<0.01, but DG diversity index was lower at RCMT compared to SFL (F=4.75, P<0.05. There was evident surface aggregation of soil fauna at RCMT, especially in the differences between the first layer and the other layers of the soil profile (Find.=17.80, Fgro.=33.33, P<0.01. Redundancy analysis indicated that soil macro-, dry-type, wet-type meso- and micro-fauna at different habitats were differentially affected by various environmental factors. At reclaimed land with higher copper concentrations, we found a higher

  9. PRELIMINARY PALAEOSYNECOLOGICAL ANALYSES ON THE UPPER ANISIAN (MIDDLE TRIASSIC)QINGYAN FAUNA%中三叠世青岩生物群的群体古生态学初步研究

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Qingyan fauna (Upper Anisian, Middle Triassic) was found from a section located at about 30km south of Guiyang, the provincial capital of Guizhou Province, SW China. Here yields abundant well-preserved and highly diversed fossils, involving 16-17 groups of organisms, among which gastropods, frachiopods and bivalves are dominant. Some macrofossils are a eommon sight here including corals, sponges, crinoids, scaphapods, ammonoids, nautilids, bryozoaus and echinoids. whereas others such as porifers, cnidarians and annelids are rare in occurrence but visible sometimes. Among microfossils abounded in this fauna, snch groups as ostracods, foraminiferans and calcareous algae were analysed.   After a palaeosynecologic study combining with palaeogeographic analyses we believe that the Qingyan fauna might have developed in an environment of a protected shallow marine habitat, which was lacated at a position of the upper part of basin slope. The sea bottom was fine-grained and stable. The rates of sedimentation were generally relatively low. The water was relatively deep and the organisms lived in the photic zone above the storm wave base and below the fair-weather wave base.   Epibenthic forms are the main groups in this primarily benthic fauna. Shallow burrowing in fauna and semiinfauna form smaller portions. In traphic habits, suspension-feeders are the dominant group. In a ddition, there are herbivores (gastropods), detritus-feeders, scavengers, and omnivores, a few deposit-feeders and few micro- and macro-carnivores.   The high percentage of suspension-feeders in the fauna indicates that the water was clean and clear, gently moving, and rich in oxygen and nutrients. The highly diverse associations, especially bivalves and gastropods, most probablyre present selics of community which had lived in patches of macroalgae.%根据群体古生态学的初步研究,认为青岩生物群的富集是因为发育一个较为特殊的生态环境,即位于斜坡

  10. Vector-like bottom quarks in composite Higgs models

    DEFF Research Database (Denmark)

    Gillioz, M.; Grober, R.; Kapuvari, A.;

    2014-01-01

    , and we test the compatibility with the electroweak precision observables. In particular we evaluate the constraint from the Z coupling to left-handed bottom quarks. General formulae have been derived which include the effects of new bottom partners in the loop corrections to this coupling and which can...... of the left-handed top and bottom quarks....

  11. A new kind of bottom quark factory

    International Nuclear Information System (INIS)

    We describe a novel method of producing large numbers of B mesons containing bottom quarks. It is known that one should analyze at least 109 B meson decays to elucidate the physics of CP violation and rare B decay modes. Using the ultra high energy electron beams from the future generation of electron linear colliders, we Compton backscatter low energy laser beams off these electron beams. From this process, we produce hot photons having energy hundreds of GeV. Upon scattering these hot photons onto stationary targets, we show that it is possible to photoproduce and measure the necessary 109 B mesons per year. 24 refs., 4 figs

  12. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2007-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearized versions of the model are analyzed and show large variations in system gains at steady state as function of load whereas gain variations near the desired bandwidth are small. An analysis...... showed substantial improvement compared to a decentralized scheme based on sequential loop closing. Similar or better result is expected to be obtainable using a full Multiple input Multiple output scheme. Furthermore closed loop simulations, applying a linear controller to the nonlinear plant model...... on states and control signals should be considered....

  13. Rankine bottoming cycle safety analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, G.A.

    1980-02-01

    Vector Engineering Inc. conducted a safety and hazards analysis of three Rankine Bottoming Cycle Systems in public utility applications: a Thermo Electron system using Fluorinal-85 (a mixture of 85 mole % trifluoroethanol and 15 mole % water) as the working fluid; a Sundstrand system using toluene as the working fluid; and a Mechanical Technology system using steam and Freon-II as the working fluids. The properties of the working fluids considered are flammability, toxicity, and degradation, and the risks to both plant workers and the community at large are analyzed.

  14. TEMPERATURE REQUIREMENTS AND BIOGEOGRAPHY OF ANTARCTIC, ARCTIC AND AMPHIEQUATORIAL SEAWEEDS

    NARCIS (Netherlands)

    WIENCKE, C; BARTSCH, [No Value; BISCHOFF, B; PETERS, AF; BREEMAN, AM

    1994-01-01

    The temperature requirements for growth and survival of cold water seaweeds from both Hemispheres are compared and discussed in relation to the climatic history of the various regions and in relation to the origin of amphiequatorial distribution patterns. Endemic Antarctic species are most strongly

  15. Conclusions: Multiple dimensions of human engagement with the Antarctic environment

    NARCIS (Netherlands)

    Liggett, D.; Lamers, M.A.J.; Tin, T.; Maher, P.T.

    2014-01-01

    The future scenarios developed by the contributors to this volume communicate a strong message. They concur that existing environmental management practices and the current system of governance are insufficient to meet the obligations set out under the Madrid Protocol to protect the Antarctic enviro

  16. Spatial-temporal characters of Antarctic sea ice variation

    Institute of Scientific and Technical Information of China (English)

    Ma Lijuan; Lu Longhua; Bian Lingen

    2004-01-01

    Using sea ice concentration dataset covering the period of 1968-2002 obtained from the Hadley Center of UK, this paper investigates characters of Antarctic sea ice variations .The finding demonstrates that the change of mean sea-ice extent is almost consistent with that of sea-ice area, so sea-ice extent can be chosen to go on this research. The maximum and the minimum of Antarctic sea ice appear in September and February respectively. The maximum and the maximal variation of sea ice appear in Weddell Sea and Ross Sea, while the minimum and the minimal variation of sea-ice appear in Antarctic Peninsula. In recent 35 years, as a whole, Antarctic sea ice decreased distinctly. Moreover, there are 5 subdivision characteristic regions considering their different variations. Hereinto, the sea-ice extent of Weddell Sea and Ross Sea regions extends and area increases, while the sea-ice extent of the other three regions contracts and area decreases. They are all of obvious 2-4 years and 5-7 years significant oscillation periods. It is of significance for further understanding the sea-ice-air interaction in Antarctica region and discussing the relationship between sea-ice variation and atmospheric circulation.

  17. Emplacement of Antarctic ice sheet mass affects circumpolar ocean flow

    NARCIS (Netherlands)

    Rugenstein, M.; Stocchi, P.; van der Heydt, A.; Brinkhuis, H.

    2014-01-01

    During the Cenozoic the Antarctic continent experienced large fluctuations in ice-sheet volume. We investigate the effects of Glacial Isostatic Adjustment (GIA) on Southern Ocean circulation for the first continental scale glaciation of Antarctica (~ 34 Myr) by combining solid Earth and ocean dynami

  18. 77 FR 5403 - Conservation of Antarctic Animals and Plants

    Science.gov (United States)

    2012-02-03

    ... (ASPA), Antarctic Specially Managed Areas (ASMA) and Historical Sites or Monuments (HSM). These... managed area (ASMA 7) and five historical sites and monuments in Antarctica (HSM 83-87). Public... Specially Managed Areas (ASMA). Detailed maps and descriptions of the sites and complete management...

  19. A novel Antarctic microbial endolithic community within gypsum crusts.

    Science.gov (United States)

    Hughes, Kevin A; Lawley, Blair

    2003-07-01

    A novel endolithic microbial habitat is described from a climatically extreme site at Two Step Cliffs, Alexander Island, Antarctic Peninsula (71 degrees 54'S, 68 degrees 13'W). Small endolithic colonies (endolithic communities are less extensive than those of the Dry Valleys, continental Antarctica, probably owing to only recent deglaciation (<7000 year ago). PMID:12823188

  20. Microbial ecology and biogeochemistry of continental Antarctic soils

    Science.gov (United States)

    Cowan, Don A.; Makhalanyane, Thulani P.; Dennis, Paul G.; Hopkins, David W.

    2014-01-01

    The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbor microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths) possess a genetic capacity for nitrogen and carbon cycling, polymer degradation, and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities. PMID:24782842

  1. Local scaling characteristics of Antarctic surface layer turbulence

    Directory of Open Access Journals (Sweden)

    S. Basu

    2010-03-01

    Full Text Available Over the past years, several studies have validated Nieuwstadt's local scaling hypothesis by utilizing turbulence observations from the mid-latitude, nocturnal stable boundary layers. In this work, we probe into the local scaling characteristics of polar, long-lived stable boundary layers by analyzing turbulence data from the South Pole region of the Antarctic Plateau.

  2. Oxygen Isotopes and Origin of Opal in an Antarctic Ureilite

    Science.gov (United States)

    Downes, H.; Beard, A. D.; Franchi, I. A.; Greenwood, R. C.

    2016-08-01

    Fragments of opal (SiO2.nH2O) in several internal chips of a single Antarctic polymict ureilite meteorite Elephant Moraine (EET) 83309 have been studied by NanoSIMS to determine their oxygen isotope compositions and hence constrain their origin.

  3. Size selection of Antarctic krill (Euphausia superba) in trawls

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Herrmann, Bent; Iversen, Svein A.;

    2014-01-01

    Trawlers involved in the Antarctic krill (Euphausia superba) fishery use different trawl designs, and very little is known about the size selectivity of the various gears. Size selectivity quantifies a given trawl's ability to catch different sizes of a harvested entity, and this information...

  4. Antarctic Cenozoic climate history from sedimentary records: ANDRILL and beyond.

    Science.gov (United States)

    McKay, R M; Barrett, P J; Levy, R S; Naish, T R; Golledge, N R; Pyne, A

    2016-01-28

    Mounting evidence from models and geological data implies that the Antarctic Ice Sheet may behave in an unstable manner and retreat rapidly in response to a warming climate, which is a key factor motivating efforts to improve estimates of Antarctic ice volume contributions to future sea-level rise. Here, we review Antarctic cooling history since peak temperatures of the Middle Eocene Climatic Optimum (approx. 50 Ma) to provide a framework for future initiatives to recover sediment cores from subglacial lakes and sedimentary basins in Antarctica's continental interior. While the existing inventory of cores has yielded important insights into the biotic and climatic evolution of Antarctica, strata have numerous and often lengthy time breaks, providing a framework of 'snapshots' through time. Further cores, and more work on existing cores, are needed to reconcile Antarctic records with the more continuous 'far-field' records documenting the evolution of global ice volume and deep-sea temperature. To achieve this, we argue for an integrated portfolio of drilling and coring missions that encompasses existing methodologies using ship- and sea-ice-/ice-shelf-based drilling platforms as well as recently developed seafloor-based drilling and subglacial access systems. We conclude by reviewing key technological issues that will need to be overcome.

  5. Pioneering work of CAS researchers in Antarctic expedition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The first observatory at Dome A On 12 January, China scientific expedition to Antarctica succeeded for a second time in climbing up to Dome A, the highest Antarctic icecap peak. A similar feat was made by Chinese scientists about three years ago in January 2005, leaving first human footprints there.

  6. Recent Rapid Regional Climate Warming on the Antarctic Peninsula

    Science.gov (United States)

    Vaughan, D. G.; Marshall, G. J.; Connolley, W. M.; Parkinson, C.; Mulvaney, R.; Hodgson, D. A.; King, J. C.; Pudsey, C. J.; Turner, J.

    2002-12-01

    The Intergovernmental Panel on Climate Change (IPCC) confirmed that global warming was 0.6 ñ 0.2 degrees C during the 20th Century and cited increases in greenhouse gases as a likely contributor. But this average conceals the complexity of observed climate change, which is seasonally biased, decadally variable and geographically patchy. In particular, over the last 50 years three high-latitude areas have undergone recent rapid regional (RRR) warming ? substantially more rapid than the global mean. We discuss the spatial and temporal significance of RRR warming in one area, the Antarctic Peninsula. New analyses of station records show no ubiquitous polar amplification of global warming but significant RRR warming on the Antarctic Peninsula. We investigate the likelihood that this could be amplification of a global warming, and use climate-proxy data to indicate that this RRR warming on the Antarctic Peninsula is unprecedented over the last two millennia and unlikely to be a natural mode of variability. We can show a strong connection between RRR warming and reduced sea-ice duration in an area on the west of the Antarctic Peninsula, but here we cannot yet distinguish cause and effect. Thus for the present we cannot determine which process causes the RRR warming, and until the mechanism initiating and sustaining it is understood, and is convincingly reproduced in climate models, we lack a sound basis for predicting climate change in this region over the coming century.

  7. Biochemical composition of Antarctic zooplankton from the Indian Ocean sector

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Parulekar, A.H.

    variations and ranged between 8.02 and 29.9% (x = 19.57 + or - 6.25). Values for carbohydrate content varied from 11.01 to 27.65% (x = 19.62 + or - 4.80). Higher accumulation of lipids in Antarctic zooplankton during phytoplankton blooms (austral summer...

  8. Occurrence of a taurine derivative in an antarctic glass sponge.

    Science.gov (United States)

    Carbone, Marianna; Núñez-Pons, Laura; Ciavatta, M Letizia; Castelluccio, Francesco; Avila, Conxita; Gavagnin, Margherita

    2014-04-01

    The n-butanol extract of an Antarctic hexactinellid sponge, Anoxycalyx (Scolymastra) joubini, was found to contain a taurine-conjugated anthranilic acid, never reported so far either as a natural product or by synthesis. The compound was inactive against human cancer cells in an in vitro growth inhibitory test, and also showed no antibacterial activity. PMID:24868857

  9. Molecular evolution of hemoglobins of Antarctic fishes (Notothenioidei)

    NARCIS (Netherlands)

    Stam, W.T.; Beintema, J.J; D Avino, R.; Tamburrini, M.; di Prisco, G.

    1997-01-01

    Amino acid sequences of alpha- and beta-chains of human hemoglobin and of hemoglobins of coelacanth and 24 teleost fish species, including 11 antarctic and two temperate Notothenioidei, were analyzed using maximum parsimony. Trees were derived for the alpha- and beta-chains separately and for tandem

  10. Microbial ecology and biogeochemistry of continental Antarctic soils

    Directory of Open Access Journals (Sweden)

    Don A Cowan

    2014-04-01

    Full Text Available The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbour microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths possess a genetic capacity for nitrogen and carbon cycling, polymer degradation and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities.

  11. Holocene subsurface temperature variability in the eastern Antarctic continental margin

    NARCIS (Netherlands)

    Kim, J.H.; Crosta, X.; Willmott, V.; Renssen, H.; Bonnin, J.; Helmke, P.; Schouten, S.; Sinninghe Damsté, J.S.

    2012-01-01

    We reconstructed subsurface (similar to 45-200 m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX86 L). Our results reveal that subsurface temperature changes were probably positively coupl

  12. Holocene subsurface temperature variability in the eastern Antarctic continental margin

    NARCIS (Netherlands)

    Kim, J.H.; Crosta, X.; Willmott, V.; Renssen, H.; Bonnin, J; Helmke, P.; Schouten, S.; Sinnighe Damsté, J.S.

    2012-01-01

    1] We reconstructed subsurface (∼45–200 m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX86L). Our results reveal that subsurface temperature changes were probably positively coupled to th

  13. Occurrence of a taurine derivative in an antarctic glass sponge.

    Science.gov (United States)

    Carbone, Marianna; Núñez-Pons, Laura; Ciavatta, M Letizia; Castelluccio, Francesco; Avila, Conxita; Gavagnin, Margherita

    2014-04-01

    The n-butanol extract of an Antarctic hexactinellid sponge, Anoxycalyx (Scolymastra) joubini, was found to contain a taurine-conjugated anthranilic acid, never reported so far either as a natural product or by synthesis. The compound was inactive against human cancer cells in an in vitro growth inhibitory test, and also showed no antibacterial activity.

  14. On the interpretation of stable isotopes in Antarctic precipitation

    NARCIS (Netherlands)

    Helsen, M.M.

    2006-01-01

    Polar ice caps contain valuable information about the earth's climate. This thesis investigates the extent to which meteorological data are stored in the composition of snow in order to improve the interpretation of deep ice cores from the Antarctic ice cap. It is demonstrated that annual temperatur

  15. Evaluating Wind Power Potential in the Spanish Antarctic Base (BAE)

    International Nuclear Information System (INIS)

    The objective of the work is to model wind field in the surroundings of the Spanish Antarctic Base (BAE in the following). The need of such a work comes from the necessity of an energy source able to supply the energy demand in the BAE during the Antarctic winter. When the BAE is in operation (in the Antarctic summer) the energy supply comes from a diesel engine. In the Antarctic winter the base is closed, but the demand of energy supply is growing up every year because of the increase in the number of technical and scientific machines that remain in the BAE taking different measurements. For this purpose the top of a closed hill called Pico Radio, not perturbed by close obstacles, has been chosen as the better site for the measurements. The measurement station is made up with a sonic anemometer and a small wind generator to supply the energy needed by the sensors head heating of the anemometer. This way, it will be also used as a proof for the suitability of a wind generator in the new chosen site, under those special climatic conditions.(Author) 3 refs

  16. A multivariate analysis of Antarctic sea ice since 1979

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes Neto, Newton de; Evangelista, Heitor [Universidade do Estado do Rio de Janeiro (Uerj), LARAMG - Laboratorio de Radioecologia e Mudancas Globais, Maracana, Rio de Janeiro, RJ (Brazil); Tanizaki-Fonseca, Kenny [Universidade do Estado do Rio de Janeiro (Uerj), LARAMG - Laboratorio de Radioecologia e Mudancas Globais, Maracana, Rio de Janeiro, RJ (Brazil); Universidade Federal Fluminense (UFF), Dept. Analise Geoambiental, Inst. de Geociencias, Niteroi, RJ (Brazil); Penello Meirelles, Margareth Simoes [Universidade do Estado do Rio de Janeiro (UERJ)/Geomatica, Maracana, Rio de Janeiro, RJ (Brazil); Garcia, Carlos Eiras [Universidade Federal do Rio Grande (FURG), Laboratorio de Oceanografia Fisica, Rio Grande, RS (Brazil)

    2012-03-15

    Recent satellite observations have shown an increase in the total extent of Antarctic sea ice, during periods when the atmosphere and oceans tend to be warmer surrounding a significant part of the continent. Despite an increase in total sea ice, regional analyses depict negative trends in the Bellingshausen-Amundsen Sea and positive trends in the Ross Sea. Although several climate parameters are believed to drive the formation of Antarctic sea ice and the local atmosphere, a descriptive mechanism that could trigger such differences in trends are still unknown. In this study we employed a multivariate analysis in order to identify the response of the Antarctic sea ice with respect to commonly utilized climate forcings/parameters, as follows: (1) The global air surface temperature, (2) The global sea surface temperature, (3) The atmospheric CO{sub 2} concentration, (4) The South Annular Mode, (5) The Nino 3, (6) The Nino (3 + 4, 7) The Nino 4, (8) The Southern Oscillation Index, (9) The Multivariate ENSO Index, (10) the Total Solar Irradiance, (11) The maximum O{sub 3} depletion area, and (12) The minimum O{sub 3} concentration over Antarctica. Our results indicate that western Antarctic sea ice is simultaneously impacted by several parameters; and that the minimum, mean, and maximum sea ice extent may respond to a separate set of climatic/geochemical parameters. (orig.)

  17. Antarctic and Southern Ocean influences on Late Pliocene global cooling

    NARCIS (Netherlands)

    McKay, R.; Naish, T.; Carter, L.; Riesselman, C.; Dunbar, R.; Sjunneskog, C.; Winter, D.; Sangiorgi, F.; Warren, C.; Pagani, M.; Schouten, S.; Willmott, V.; Levy, R.; DeConto , R.M.; Powell, R.D.

    2012-01-01

    The influence of Antarctica and the Southern Ocean on Late Pliocene global climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1

  18. Maneuver simulation model of an experimental hovercraft for the Antarctic

    Science.gov (United States)

    Murao, Rinichi

    Results of an investigation of a hovercraft model designed for Antarctic conditions are presented. The buoyancy characteristics, the propellant control system, and simulation model control are examined. An ACV (air cushion vehicle) model of the hovercraft is used to examine the flexibility and friction of the skirt. Simulation results are presented which show the performance of the hovercraft.

  19. Spatial and Temporal Distribution of the Cryptospirifer Fauna (Middle Permian Brachiopods) in the Tethyan Realm and Its Paleogeographic Implications

    Institute of Scientific and Technical Information of China (English)

    JIN Xiaochi; ZHAN Lipei

    2008-01-01

    The middle Permian Cryptospirifer fauna (brachiopod) has hitherto been found in more than 30 localities in the Yangtze Platform, South China. Examination of data from various localities shows that it occurs stratigraphically in three intervals in the range from the upper Kungurian to Wordian.In the Baoshan block in western Yunnan the fauna occurs in the basal part of the Daaozi Formation and is of possibly an early Wordian age. Outside China the Cryptospirifer fauna has been reported from central and northwest Iran and central Turkey, where the fauna may have an age around the Wordian\\Capitanian boundary. Rapid global warming since the late Early Permian and possession of other suitable environmental factors such as proper substrate, clastic input and water depth enabled the Gondwana-derived Baoshan Block and related tectono-stratigraphic units in Iran and Turkey to host the Cryptospirifer fauna, a fauna evolved in the Yangtze Platform that is a type area of the Cathaysian province.

  20. Influence of Antarctic Ice Sheet Lowering on the Southern Hemisphere Climate: Model Experiments Mimicking the Mid-Miocene

    Science.gov (United States)

    Justino, Flavio; Stordal, Frode

    2013-04-01

    Conditions in Antarctica have varied substantially in the Earth's climate history. During the early Miocene (23-17 Ma), as suggested by records from the Ocean Drilling Program (ODP) Sites 1090 and 1218, the ice volume was approximately 50%-125% of its present-day values. It has been argued that the rapid Cenozoic glaciation of Antarctica was induced by a decline in atmospheric CO2 from 4 times to 2 times preindustrial atmospheric level over a 10-Myr period. Minor contributions to this glaciation have also been associated with the opening of Southern Ocean gateways between Antarctica and the Australia-Tasmanian Passage, and Antarctica and the South America-Drake Passage, although it has been argued that the total amount of water owing in the Drake passage during the Eocene/Oligocene boundary may have been insufficient for reducing the poleward heat transport. The AIS is responsible for the greater amount of reflected solar radiation in the SH, and has significantly influenced meridional circulation due to its role in the characterization of the latitudinal thermal gradient. Moreover significant interaction between the polar and tropical regions through the link between the ENSO and West Antarctica has been demonstrated. It has been suggested that warming episodes during the Miocene were closely related to small changes in the Southern Ocean's freshwater balance. Paleorecords (ODP Sites 1090 and 1218) have also been utilized to disentangle the nature of deep-sea water mass. The analyses have demonstrated that warmer bottom water coexisted with increased production of Antarctic Bottom Water during the Plio-Pleistocene (1.6Ma) compared to today. We have investigated impacts of changes to the AIS topography on the climate system by using a coupled climate model, an Earth Model of Intermediate Complexity (EMIC), namely Speedy-Ocean (SPEEDO). We have designed experiments to inter-compare the nature of the atmospheric and oceanic circulation under modern conditions and

  1. Latitudinal trends and temporal shifts in the catch composition of bottom trawls conducted on the eastern Bering Sea shelf

    Science.gov (United States)

    Stevenson, Duane E.; Lauth, Robert R.

    2012-06-01

    Latitudinal species diversity gradients are well known in both terrestrial and aquatic ecosystems throughout the world. However, trends in relative abundance and other shifts in community structure with latitude, which can be more sensitive to environmental shifts such as climate change, have received less attention. Here we investigate latitudinal trends in the seafloor community of the eastern Bering Sea using catches of fishes and epibenthic invertebrates in bottom trawl surveys conducted from 1982 to 2010. Our results indicate that the overall biomass of the epibenthic community declines with increasing latitude in the eastern Bering Sea. This latitudinal trend is primarily driven by declining fish catches in the northern Bering Sea, which in turn reflects changes in the structure of the fish community. The fish fauna in northern latitudes is increasingly dominated by gadids, though the species composition of the gadid fauna also changes with latitude, with smaller species becoming more common in the north. The biomass of the invertebrate megafauna remains relatively consistent throughout the eastern Bering Sea, but invertebrates make up a larger proportion of the catch in bottom trawls conducted at higher latitudes. The epibenthic invertebrate megafauna in the eastern Bering Sea is composed primarily of sea stars (Asteriidae) and oregoniid crabs (Chionoecetes and Hyas), though no clear latitudinal trends in the invertebrate community are evident. Limited trawl data from the eastern Chukchi Sea indicate that the fish community farther north is even more heavily dominated by gadids, and the epibenthic invertebrate community is dominated by asteriid sea stars. Temperature data from bottom trawl surveys in the southeastern Bering Sea over the past decade indicate that there was a distinct temperature shift around 2005, and the relatively warm years of 2001-2005 were followed by five relatively cold years. This shift in the summer temperature regime of the Bering

  2. Comparative phylogeography of the western Indian Ocean reef fauna

    Science.gov (United States)

    Borsa, Philippe; Durand, Jean-Dominique; Chen, Wei-Jen; Hubert, Nicolas; Muths, Delphine; Mou-Tham, Gérard; Kulbicki, Michel

    2016-04-01

    Assessing patterns of connectivity at the community and population levels is relevant to marine resource management and conservation. The present study reviews this issue with a focus on the western Indian Ocean (WIO) biogeographic province. This part of the Indian Ocean holds more species than expected from current models of global reef fish species richness. In this study, checklists of reef fish species were examined to determine levels of endemism in each of 10 biogeographic provinces of the Indian Ocean. Results showed that the number of endemic species was higher in the WIO than in any other region of the Indian Ocean. Endemic species from the WIO on the average had a larger body size than elsewhere in the tropical Indian Ocean. This suggests an effect of peripheral speciation, as previously documented in the Hawaiian reef fish fauna, relative to other sites in the tropical western Pacific. To explore evolutionary dynamics of species across biogeographic provinces and infer mechanisms of speciation, we present and compare the results of phylogeographic surveys based on compilations of published and unpublished mitochondrial DNA sequences for 19 Indo-Pacific reef-associated fishes (rainbow grouper Cephalopholis argus, scrawled butterflyfish Chaetodon meyeri, bluespot mullet Crenimugil sp. A, humbug damselfish Dascyllus abudafur/Dascyllus aruanus, areolate grouper Epinephelus areolatus, blacktip grouper Epinephelus fasciatus, honeycomb grouper Epinephelus merra, bluespotted cornetfish Fistularia commersonii, cleaner wrasse Labroides sp. 1, longface emperor Lethrinus sp. A, bluestripe snapper Lutjanus kasmira, unicornfishes Naso brevirosris, Naso unicornis and Naso vlamingii, blue-spotted maskray Neotrygon kuhlii, largescale mullet Planiliza macrolepis, common parrotfish Scarus psicattus, crescent grunter Terapon jarbua, whitetip reef shark Triaenodon obesus) and three coastal Indo-West Pacific invertebrates (blue seastar Linckia laevigata, spiny lobster

  3. Charmed bottom baryon spectroscopy from lattice QCD

    CERN Document Server

    Brown, Zachary S; Meinel, Stefan; Orginos, Kostas

    2014-01-01

    We calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with $J^P = \\frac12^+$ and $J^P = \\frac32^+$. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limit and to the physical pion mass using $SU(4|2)$ heavy-hadron chiral perturbation theory including $1/m_Q$ and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.

  4. The petroleum industry improving the bottom line

    International Nuclear Information System (INIS)

    The oil and gas exploration and production business environment has presented many challenges over the last decade, notably price volatility and rising costs. Managing the margin and changing a company's cost structure to improve the bottom line is a major issue with company executives. The experiences of Oryx Energy Company since its spinoff from Sun Company in 1988 are used as an example of a company makeover. A generalized exploration and production income statement is employed to present industry cost/portfolio relationships and strategies for improving the bottom line. At Oryx, three major strategies were set in place to enhance shareholder value: an increased emphasis on applied technology, including horizontal drilling, advanced 3-dimensional seismic prospecting, and intensive use of interactive computer workstations; international expansion; and an emphasis on the U.S. Gulf of Mexico, deemphasizing the onshore U.S. and the gas processing business. Specific strategies are outlined in the areas of increasing revenues, reducing production cost and exploration expense, and controlling general and administrative expenses. 8 refs., 18 figs., 2 tabs

  5. Long Wave Dynamics along a Convex Bottom

    CERN Document Server

    Didenkulova, Ira; Soomere, Tarmo

    2008-01-01

    Long linear wave transformation in the basin of varying depth is studied for a case of a convex bottom profile in the framework of one-dimensional shallow water equation. The existence of travelling wave solutions in this geometry and the uniqueness of this wave class is established through construction of a 1:1 transformation of the general 1D wave equation to the analogous wave equation with constant coefficients. The general solution of the Cauchy problem consists of two travelling waves propagating in opposite directions. It is found that generally a zone of a weak current is formed between these two waves. Waves are reflected from the coastline so that their profile is inverted with respect to the calm water surface. Long wave runup on a beach with this profile is studied for sine pulse, KdV soliton and N-wave. Shown is that in certain cases the runup height along the convex profile is considerably larger than for beaches with a linear slope. The analysis of wave reflection from the bottom containing a s...

  6. Bottom-up holographic approach to QCD

    International Nuclear Information System (INIS)

    One of the most known result of the string theory consists in the idea that some strongly coupled gauge theories may have a dual description in terms of a higher dimensional weakly coupled gravitational theory — the so-called AdS/CFT correspondence or gauge/gravity correspondence. The attempts to apply this idea to the real QCD are often referred to as “holographic QCD” or “AdS/QCD approach”. One of directions in this field is to start from the real QCD and guess a tentative dual higher dimensional weakly coupled field model following the principles of gauge/gravity correspondence. The ensuing phenomenology can be then developed and compared with experimental data and with various theoretical results. Such a bottom-up holographic approach turned out to be unexpectedly successful in many cases. In the given short review, the technical aspects of the bottom-up holographic approach to QCD are explained placing the main emphasis on the soft wall model

  7. Bottom-up holographic approach to QCD

    Energy Technology Data Exchange (ETDEWEB)

    Afonin, S. S. [V. A. Fock Department of Theoretical Physics, Saint Petersburg State University, 1 ul. Ulyanovskaya, 198504 (Russian Federation)

    2016-01-22

    One of the most known result of the string theory consists in the idea that some strongly coupled gauge theories may have a dual description in terms of a higher dimensional weakly coupled gravitational theory — the so-called AdS/CFT correspondence or gauge/gravity correspondence. The attempts to apply this idea to the real QCD are often referred to as “holographic QCD” or “AdS/QCD approach”. One of directions in this field is to start from the real QCD and guess a tentative dual higher dimensional weakly coupled field model following the principles of gauge/gravity correspondence. The ensuing phenomenology can be then developed and compared with experimental data and with various theoretical results. Such a bottom-up holographic approach turned out to be unexpectedly successful in many cases. In the given short review, the technical aspects of the bottom-up holographic approach to QCD are explained placing the main emphasis on the soft wall model.

  8. Heavy Exotic Molecules with Charm and Bottom

    CERN Document Server

    Liu, Yizhuang

    2016-01-01

    We revisit the formation of pion-mediated heavy-light exotic molecules with both charm and bottom and their chiral partners under the general strictures of both heavy-quark and chiral symmetry. The chiral exotic partners with good parity formed using the $(0^+, 1^+)$ multiplet are about twice more bound than their primary exotic partners formed using the $(0^-,1^-)$ multiplet. The chiral couplings across the multiplets $(0^\\pm, 1^\\pm)$ cause the chiral exotic partners to unbind, and the primary exotic molecules to be about twice more bound, for $J\\leq 1$. Our multi-channel coupling results show that only the charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify as the reported neutral $X(3872)$. Also, the bottom isotriplet exotic with $J^{PC}=1^{+-}$ binds, which we identify as a mixture of the reported charged exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound isosinglet with $J^{PC}=1^{++}$ is suggested as a possible neutral $X_b(10532)$ not yet reported.

  9. Multibaryons with strangeness, charm and bottom

    Energy Technology Data Exchange (ETDEWEB)

    Kopeliovich, V.B. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Inst. Yadernykh Issledovanij; Durham Univ. (United Kingdom). Dept. of Mathematical Sciences; Zakrzewski, W.J. [Durham Univ. (United Kingdom). Dept. of Mathematical Sciences

    2000-12-01

    The spectra of baryonic systems with strangeness, charm and bottom are considered within a ''rigid oscillator'' version of the bound state soliton model. The static properties of multiskyrmions, of baryon number up to B=8, are calculated using the recently suggested rational map ansaetze as starting field configurations. The property of binding of flavoured mesons by an SU(2) skyrmion is proved rigorously within this model. Binding energy estimates are made of the states with largest isospin which can appear as negatively charged nuclear fragments and for states with zero isospin - fragments of ''flavoured'' nuclear matter. It is shown that for all types of flavour and for vertical stroke F vertical stroke {<=}2 the isoscalar baryonic systems have a better chance to be stable against strong and electromagnetic interactions than those with nonzero isospin. Baryonic systems with charm or bottom quantum numbers are found to be bound more than strange baryonic systems. (orig.)

  10. Evidence for widespread endemism among Antarctic micro-organisms

    Science.gov (United States)

    Vyverman, Wim; Verleyen, Elie; Wilmotte, Annick; Hodgson, Dominic A.; Willems, Anne; Peeters, Karolien; Van de Vijver, Bart; De Wever, Aaike; Leliaert, Frederik; Sabbe, Koen

    2010-08-01

    Understanding the enormous diversity of microbes, their multiple roles in the functioning of ecosystems, and their response to large-scale environmental and climatic changes, are at the forefront of the international research agenda. In Antarctica, where terrestrial and lacustrine environments are predominantly microbial realms, an active and growing community of microbial ecologists is probing this diversity and its role in ecosystem processes. In a broader context, this work has the potential to make a significant contribution to the long-standing debate as to whether microbes are fundamentally different from macroorganisms in their biogeography. According to the ubiquity hypothesis, microbial community composition is not constrained by dispersal limitation and is solely the result of species sorting along environmental gradients. However, recent work on several groups of microalgae is challenging this view. Global analyses using morphology-based diatom inventories have demonstrated that, in addition to environmental harshness, geographical isolation underlies the strong latitudinal gradients in local and regional diversity in the Southern hemisphere. Increasing evidence points to a strong regionalization of diatom floras in the Antarctic and sub-Antarctic regions, mirroring the biogeographical regions that have been recognized for macroorganisms. Likewise, the application of molecular-phylogenetic techniques to cultured and uncultured diversity revealed a high number of Antarctic endemics among cyanobacteria and green algae. Calibration of these phylogenies suggests that several clades have an ancient evolutionary history within the Antarctic continent, possibly dating back to 330 Ma. These findings are in line with the current view on the origin of Antarctic terrestrial metazoa, including springtails, chironomids and mites, with most evidence suggesting a long history of geographic isolation on a multi-million year, even pre-Gondwana break-up timescale.

  11. Fundamental differences between Arctic and Antarctic ozone depletion.

    Science.gov (United States)

    Solomon, Susan; Haskins, Jessica; Ivy, Diane J; Min, Flora

    2014-04-29

    Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions. The deep Antarctic "hole" contrasts with the generally weaker depletions observed in the warmer Arctic. An unusually cold Arctic stratospheric season occurred in 2011, raising the question of how the Arctic ozone chemistry in that year compares with others. We show that the averaged depletions near 20 km across the cold part of each pole are deeper in Antarctica than in the Arctic for all years, although 2011 Arctic values do rival those seen in less-depleted years in Antarctica. We focus not only on averages but also on extremes, to address whether or not Arctic ozone depletion can be as extreme as that observed in the Antarctic. This information provides unique insights into the contrasts between Arctic and Antarctic ozone chemistry. We show that extreme Antarctic ozone minima fall to or below 0.1 parts per million by volume (ppmv) at 18 and 20 km (about 70 and 50 mbar) whereas the lowest Arctic ozone values are about 0.5 ppmv at these altitudes. At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica. The data show that the lowest ozone values are associated with temperatures below -80 °C to -85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles. PMID:24733920

  12. Evaluation of the biological toxicity of lfuorine in Antarctic krill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ling; LU Xiaoqi; WANG Zhangmin; QIN Liqiang; LIN Zhiqin; YUAN Linxi; ZHANG Wen; YIN Xuebin

    2014-01-01

    Antarctic krill is a potentially nutritious food source for humans, but lfuorine (F) toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups with different dietary regimens:a control group, a krill treatment group (150 mg·kg-1 F), and a sodium lfuoride (NaF) treatment group (150 mg·kg-1 F). After three months, F concentrations in feces, plasma, and bone were determined, and the degree of dental and skeletal lfuorosis was assessed. The F concentrations in plasma and bone from the krill treatment group were 0.167 0±0.020 4 mg.L-1 and 2 709.8±301.9 mg·kg-1, respectively, compared with 0.043 8±0.005 5 mg·L-1 and 442.4±60.7 mg·kg-1, respectively, in samples from the control group. Concentrations of F in plasma and bone in the krill treatment group were higher than in the control group, but lower than in the NaF treatment group. The degree of dental lfuorosis in the krill treatment group was moderate, compared with severe in the NaF treatment group and normal in the control group. The degree of skeletal lfuorosis did not change signiifcantly in any group. These results showed that the toxicity of F in Antarctic krill was lower than for an equivalent concentration of F in NaF, but it was toxic for rats consuming krill in large quantities. To conclude, we discuss possible reasons for the reduced toxicity of F in Antarctic krill. The present study provides a direct toxicological reference for the consideration of Antarctic krill for human consumption.

  13. Aspects of the microvertebrate fauna of the Early Cretaceous (Barremian) Wessex Formation of the Isle of Wight, southern England

    OpenAIRE

    Sweetman, Steve

    2007-01-01

    Until this study, the microvertebrate fauna of the Early Cretaceous (Barremian) Wessex Formation of the Isle of Wight, southern England,was virtually unknown. A comprehensive survey of potentially productive horizons was undertaken using bulk screening techniques and this yielded an unexpectedly diverse microvertebrate fauna together with fragmentary but significant remains of hitherto unknown elements of the associated macro-fauna. At least forty one previously unrecorded tetrapod taxa have ...

  14. Bottom water production variability in the Ross Sea slope during the Late-Pleistocene-Holocene as revealed by benthic foraminifera and sediment geochemistry

    Science.gov (United States)

    Asioli, A.; Langone, L.; Tateo, F.; Giannossi, M. L.; Giglio, F.; Summa, V.; Piva, A.; Ridente, D.; Trincardi, F.

    2009-04-01

    The Antarctic area produces bottom waters that ventilate the vast majority of the deep basins in the rest of the world ocean. The rate of formation in the source area and the strength of these cold bottom waters affect their flow toward the equator and are key factors affecting the Global Thermohaline Circulation during modern and past climate conditions. We present the results of a multidisciplinary study carried out on a core collected in 2377m of water depth on the slope off the Drygalski Basin (Ross Sea), along the modern path of the bottom waters. The goal of this research is to detect a qualitative signal of possible changes in the rate of bottom water production during the Late Pleistocene-Holocene by integrating micropaleontological and geochemical proxies. The micropaleontological signal is represented by the quantitative and qualitative variations of the agglutinated benthic foraminifera assemblages, while the amount of TOC, nitrogen, δ13C, δ15N, biogenic silica, CaCO3 in the sediment, along with the bulk rock mineralogy, provide information on the paleoproductivity and allow reconstruction of changes in the paleocirculation. The chronology is supported by 14C AMS datings on organic matter. Although this study is still in progress, the results obtained allow the following observations: 1) the Holocene sequence includes a major turnover around 8-8.5 calib kyr BP, leading to reduced nutrient utilization, probably reflecting an increased nutrient supply induced by an enhanced Upper Circumpolar Deep Water upwelling; 2) within this general context, the total concentration of benthic foraminifera preserved in the fossil component records millennial scale cycles of variable amplitude after 8.5 calib kyr BP and to present time. This oscillatory trend is paralleled by other parameters, such as the magnetic susceptibility, the dry density, the sheet silicates and the δ15N; 3) minima in foraminifera concentration reflect relatively increased dissolution, weaker

  15. Microbial biomass and soil fauna during the decomposition of cover crops in no-tillage system

    Directory of Open Access Journals (Sweden)

    Luciano Colpo Gatiboni

    2011-08-01

    Full Text Available The decomposition of plant residues is a biological process mediated by soil fauna, but few studies have been done evaluating its dynamics in time during the process of disappearance of straw. This study was carried out in Chapecó, in southern Brazil, with the objective of monitoring modifications in soil fauna populations and the C content in the soil microbial biomass (C SMB during the decomposition of winter cover crop residues in a no-till system. The following treatments were tested: 1 Black oat straw (Avena strigosa Schreb.; 2 Rye straw (Secale cereale L.; 3 Common vetch straw (Vicia sativa L.. The cover crops were grown until full flowering and then cut mechanically with a rolling stalk chopper. The soil fauna and C content in soil microbial biomass (C SMB were assessed during the period of straw decomposition, from October 2006 to February 2007. To evaluate C SMB by the irradiation-extraction method, soil samples from the 0-10 cm layer were used, collected on eight dates, from before until 100 days after residue chopping. The soil fauna was collected with pitfall traps on seven dates up to 85 days after residue chopping. The phytomass decomposition of common vetch was faster than of black oat and rye residues. The C SMB decreased during the process of straw decomposition, fastest in the treatment with common vetch. In the common vetch treatment, the diversity of the soil fauna was reduced at the end of the decomposition process.

  16. Assessing the Fauna Diversity of Marudu Bay Mangrove Forest, Sabah, Malaysia, for Future Conservation

    Directory of Open Access Journals (Sweden)

    Mohamed Zakaria

    2015-04-01

    Full Text Available Mangrove is an evergreen, salt tolerant plant community, which grows in inter-tidal coastal zones of tropical and subtropical regions of the world. They are ecologically important for many fauna species and are rich in food resources and consist of many different vegetation structures. They serve as ideal foraging and nursery grounds for a wide array of species such as birds, mammals, reptiles, fishes and aquatic invertebrates. In spite of their crucial role, around 50% of mangrove habitats have been lost and degraded in the past two decades. The fauna diversity of mangrove habitat at Marudu Bay, Sabah, East Malaysia was examined using various methods: i.e. aquatic invertebrates by swap nets, fish by angling rods and cast nets, reptiles, birds, and mammals through direct sighting. The result showed that Marudu Bay mangrove habitats harbored a diversity of fauna species including 22 aquatic invertebrate species (encompassing 11 crustacean species, six mollusk species and four worm species, 36 fish species, 74 bird species, four reptile species, and four mammal species. The wide array of fauna species could be due to the availability of complex vegetation structures, sheltered beaches and tidal mudflats, which are rich in food resources and also offer safe foraging and breeding grounds for them. These heterogeneous habitats must be protected in a sustainable way in order to ensure the continued presence of aquatic and terrestrial fauna species for future generations.

  17. Acadian biospeleology: composition and ecology of cave fauna of Nova Scotia and southern New Brunswick, Canada.

    Directory of Open Access Journals (Sweden)

    Moseley Max

    2007-01-01

    Full Text Available The vertebrate and invertebrate fauna, environment and habitats of caves and disused mines in Nova Scotia and southern NewBrunswick are provisionally catalogued and described, based on field collections made over many years. The area was glaciatedand the subterranean fauna consists of non-troglobites all of which have arrived and colonised the caves during or following finalrecession of the Pleistocene glaciers. The statistical composition of the fauna at the higher taxonomic level is similar to that inOntario, but is less species rich and there are some notable ecological and other differences. Porcupine dung accumulations are animportant habitat in the region, constituting a cold-temperate analogue of the diverse guano habitats of southern and tropical caves.Parietal assemblages are, as in other cold temperate regions, an important component of the invertebrate fauna but here includespecies derived directly from dung communities: another parallel with tropical guano caves. An unanticipated finding is the numberof non-indigenous species now utilising local caves. These appear to have colonised unfilled ecological niches, suggesting thatpost-glacial recolonisation of the subterranean habitat in Nova Scotia has been relatively delayed. Finally the general and regionalsignificance of the subterranean fauna is briefly discussed.

  18. At-Sea Distribution and Prey Selection of Antarctic Petrels and Commercial Krill Fisheries

    Science.gov (United States)

    Descamps, Sébastien; Tarroux, Arnaud; Cherel, Yves; Delord, Karine; Godø, Olaf Rune; Kato, Akiko; Krafft, Bjørn A.; Lorentsen, Svein-Håkon; Ropert-Coudert, Yan; Skaret, Georg; Varpe, Øystein

    2016-01-01

    Commercial fisheries may impact marine ecosystems and affect populations of predators like seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausia superba that is projected to increase further. Comparing distribution and prey selection of fishing operations versus predators is needed to predict fishery-related impacts on krill-dependent predators. In this context, it is important to consider not only predators breeding near the fishing grounds but also the ones breeding far away and that disperse during the non-breeding season where they may interact with fisheries. In this study, we first quantified the overlap between the distribution of the Antarctic krill fisheries and the distribution of a krill dependent seabird, the Antarctic petrel Thalassoica antarctica, during both the breeding and non-breeding season. We tracked birds from the world biggest Antarctic petrel colony (Svarthamaren, Dronning Maud Land), located >1000 km from the main fishing areas, during three consecutive seasons. The overall spatial overlap between krill fisheries and Antarctic petrels was limited but varied greatly among and within years, and was high in some periods during the non-breeding season. In a second step, we described the length frequency distribution of Antarctic krill consumed by Antarctic petrels, and compared this with results from fisheries, as well as from diet studies in other krill predators. Krill taken by Antarctic petrels did not differ in size from that taken by trawls or from krill taken by most Antarctic krill predators. Selectivity for specific Antarctic krill stages seems generally low in Antarctic predators. Overall, our results show that competition between Antarctic petrels and krill fisheries is currently likely negligible. However, if krill fisheries are to increase in the future, competition with the Antarctic petrel may occur, even with birds breeding thousands of kilometers away. PMID:27533327

  19. At-Sea Distribution and Prey Selection of Antarctic Petrels and Commercial Krill Fisheries.

    Science.gov (United States)

    Descamps, Sébastien; Tarroux, Arnaud; Cherel, Yves; Delord, Karine; Godø, Olaf Rune; Kato, Akiko; Krafft, Bjørn A; Lorentsen, Svein-Håkon; Ropert-Coudert, Yan; Skaret, Georg; Varpe, Øystein

    2016-01-01

    Commercial fisheries may impact marine ecosystems and affect populations of predators like seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausia superba that is projected to increase further. Comparing distribution and prey selection of fishing operations versus predators is needed to predict fishery-related impacts on krill-dependent predators. In this context, it is important to consider not only predators breeding near the fishing grounds but also the ones breeding far away and that disperse during the non-breeding season where they may interact with fisheries. In this study, we first quantified the overlap between the distribution of the Antarctic krill fisheries and the distribution of a krill dependent seabird, the Antarctic petrel Thalassoica antarctica, during both the breeding and non-breeding season. We tracked birds from the world biggest Antarctic petrel colony (Svarthamaren, Dronning Maud Land), located >1000 km from the main fishing areas, during three consecutive seasons. The overall spatial overlap between krill fisheries and Antarctic petrels was limited but varied greatly among and within years, and was high in some periods during the non-breeding season. In a second step, we described the length frequency distribution of Antarctic krill consumed by Antarctic petrels, and compared this with results from fisheries, as well as from diet studies in other krill predators. Krill taken by Antarctic petrels did not differ in size from that taken by trawls or from krill taken by most Antarctic krill predators. Selectivity for specific Antarctic krill stages seems generally low in Antarctic predators. Overall, our results show that competition between Antarctic petrels and krill fisheries is currently likely negligible. However, if krill fisheries are to increase in the future, competition with the Antarctic petrel may occur, even with birds breeding thousands of kilometers away.

  20. At-Sea Distribution and Prey Selection of Antarctic Petrels and Commercial Krill Fisheries.

    Science.gov (United States)

    Descamps, Sébastien; Tarroux, Arnaud; Cherel, Yves; Delord, Karine; Godø, Olaf Rune; Kato, Akiko; Krafft, Bjørn A; Lorentsen, Svein-Håkon; Ropert-Coudert, Yan; Skaret, Georg; Varpe, Øystein

    2016-01-01

    Commercial fisheries may impact marine ecosystems and affect populations of predators like seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausia superba that is projected to increase further. Comparing distribution and prey selection of fishing operations versus predators is needed to predict fishery-related impacts on krill-dependent predators. In this context, it is important to consider not only predators breeding near the fishing grounds but also the ones breeding far away and that disperse during the non-breeding season where they may interact with fisheries. In this study, we first quantified the overlap between the distribution of the Antarctic krill fisheries and the distribution of a krill dependent seabird, the Antarctic petrel Thalassoica antarctica, during both the breeding and non-breeding season. We tracked birds from the world biggest Antarctic petrel colony (Svarthamaren, Dronning Maud Land), located >1000 km from the main fishing areas, during three consecutive seasons. The overall spatial overlap between krill fisheries and Antarctic petrels was limited but varied greatly among and within years, and was high in some periods during the non-breeding season. In a second step, we described the length frequency distribution of Antarctic krill consumed by Antarctic petrels, and compared this with results from fisheries, as well as from diet studies in other krill predators. Krill taken by Antarctic petrels did not differ in size from that taken by trawls or from krill taken by most Antarctic krill predators. Selectivity for specific Antarctic krill stages seems generally low in Antarctic predators. Overall, our results show that competition between Antarctic petrels and krill fisheries is currently likely negligible. However, if krill fisheries are to increase in the future, competition with the Antarctic petrel may occur, even with birds breeding thousands of kilometers away. PMID:27533327

  1. Distribution and morphological features of the antarctic species of CALANUS and The euphausiid fauna of the antarctic and notal regions; 22 February 1955 to 17 June 1958 (NODC Accession 0000922)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data contains abundance, length, and life history data of four species of Calanus copepods. The data is a compilation of 3 cruises of the MV OB carried out by...

  2. Peach Bottom test element program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Saurwein, J.J.; Holzgraf, J.F.; MIller, C.M.; Myers, B.F.; Wallroth, C.F.

    1982-11-01

    Thirty-three test elements were irradiated in the Peach Bottom high-temperature gas-cooled reactor (HTGR) as part of the testing program for advanced HTGRs. Extensive postirradiation examinations and evaluations of 21 of these irradiation experiments were performed. The test element irradiations were simulated using HTGR design codes and data. Calculated fuel burnups, power profiles, fast neutron fluences, and temperatures were verified via destructive burnup measurements, gamma scanning, and in-pile thermocouple readings corrected for decalibration effects. Analytical techniques were developed to improve the quality of temperature predictions through feedback of nuclear measurements into thermal calculations. Dimensional measurements, pressure burst tests, diametral compression tests, ring-cutting tests, strip-cutting tests, and four-point bend tests were performed to measure residual stress, strain, and strength distributions in H-327 graphite structures irradiated in the test elements.

  3. Peach Bottom test element program. Final report

    International Nuclear Information System (INIS)

    Thirty-three test elements were irradiated in the Peach Bottom high-temperature gas-cooled reactor (HTGR) as part of the testing program for advanced HTGRs. Extensive postirradiation examinations and evaluations of 21 of these irradiation experiments were performed. The test element irradiations were simulated using HTGR design codes and data. Calculated fuel burnups, power profiles, fast neutron fluences, and temperatures were verified via destructive burnup measurements, gamma scanning, and in-pile thermocouple readings corrected for decalibration effects. Analytical techniques were developed to improve the quality of temperature predictions through feedback of nuclear measurements into thermal calculations. Dimensional measurements, pressure burst tests, diametral compression tests, ring-cutting tests, strip-cutting tests, and four-point bend tests were performed to measure residual stress, strain, and strength distributions in H-327 graphite structures irradiated in the test elements

  4. Designing the organisational chart from the bottom

    DEFF Research Database (Denmark)

    Giangreco, Antonio; Carugati, Andrea

    This is the first of a two-case series (408-026-1 and 408-027-1). Marco Ginola was hired as the Human Resources (HR) Director of a large municipality in central Italy. The organisation had gone through a phase of major expansion which left problems in co-ordination, integration, delegation...... and control. Marco had been called in because of his reputation for being an effective innovator with unconventional ideas for the public sector. Previously, during his long career in the civil service, Marco proved to be an effective leader and negotiator who was open to other people's view points. He would...... share any significant and final decisions with his employees, rather than merely imposing his own personal choice. After spending some time in the organisation, he put into action a bottom up method to redesign the structure of the HR department. He decided to temporarily suspend the existing internal...

  5. BC Hydro triple bottom line report 2002

    International Nuclear Information System (INIS)

    British Columbia Hydro (BC Hydro) published this document which measures the environmental, social and economic performance of the company. It is a complement to BC Hydro's 2002 Annual Report. The report was prepared to better understand the company's business in terms of its commitment to being an environmentally, socially, and economically responsible company (the three bottom lines). BC Hydro proved its ability to integrate the three bottom lines in decision making processes by carefully examining the environmental, social and economical impacts of programs such as Power Smart, Green and Alternative Energy, and Water Use Planning. All indicators point to BC Hydro achieving its commitment of providing a minimum of 10 per cent of new demand through 2010 with new green energy sources. Water Use Plans were developed for hydroelectric generating stations, and they should all be in place by 2003. Efficiencies realised through the Power Smart program offset the increases in greenhouse gas associated with increased energy demand. Juvenile sturgeon raised in a hatchery were released into the Columbia River in May 2002. The completion of a 40-kilometre trail on the Sunshine Coast was helped by a financial contribution from BC Hydro in the amount of 23,000 dollars. Safety improvements were implemented at eight facilities, such as dam remediation, dam surveillance and instrumentation updates. Scholarships were awarded across the province, along with additional donations to non-profit organizations. Co-op positions were provided for 150 students. Internal energy efficiency programs were successful. Planning is under way for significant maintenance work and equipment replacement projects as the transmission and distribution infrastructure ages. The number of reported indicators was expanded this year. In turn, they were aligned with the revised Global Reporting Initiative (GRI) guidelines. tabs

  6. Macroalgal assemblages of disturbed coastal detritic bottoms subject to invasive species

    Science.gov (United States)

    Klein, Judith C.; Verlaque, Marc

    2009-04-01

    Characteristic flora and fauna that are highly sensitive to disturbances colonize coastal detritic bottoms in the Mediterranean Sea. In the present study, a comparison of the assemblage composition and colonization by invasive macroalgae was made between two coastal detritic macrophyte assemblages, one dominated by rhodoliths (free-living non-geniculate Corallinales) and the other dominated by fleshy algae, in an area that has been exposed to important levels of anthropogenic disturbance, mainly pollution (including changed sedimentation regimes) in the recent past (bay of Marseilles, France). In comparison with less strongly impacted Mediterranean regions, the macrophyte assemblages in the bay of Marseilles were characteristic in terms of species identity and richness of coastal detritic macrophyte assemblages. However, extremely low species abundance (cover) was observed. As far as invasive species were concerned, Caulerpa racemosa var. cylindracea was only abundant in the rhodolith assemblage whereas the two invasive Rhodophyta Asparagopsis armata and Womersleyella setacea were mainly found in the fleshy algae assemblage. The seasonality observed in the Rhodolith assemblage seemed to be related to the development of C. racemosa var. cylindracea and did not follow the typical pattern of other Mediterranean assemblages. This study represents the first study of coastal detritic assemblages invaded by C. racemosa var. cylindracea.

  7. Zoogeography of the bottom Foraminifera of the West-African coast

    Directory of Open Access Journals (Sweden)

    V. Mikhalevich

    2008-03-01

    Full Text Available The sediment samples from the continental shelf of West-Equatorial Africa (from the Strait of Gibraltar to the Niger estuary, depths ranging from 0 to 69 m were found to contain 176 bottom foraminiferal species. For the majority of them (126 species, their areas of occurrences were mapped and the peculiar features of the geographical range and distribution were studied. The species natural habitats were established based on the taxonomical revision of the species in study all over the World Ocean based on the collections of the Zoological Institute RAS and wide literary data. The method of perforated cards was used to mark the geographical locations of all of the species studied. In order to establish the species geographic zonal distribution (together with their depth habitat the five characteristic groups of the species were separated: 1. pan-oceanic (cosmopolitan, 2. widely spread tropical-boreal, 3. tropical-law boreal, 4. tropical-subtropical, 5. tropical. The percent of the species of each group among the species composition was established for the fauna of each station and for the whole region.

  8. Arctic and Antarctic Sea Ice Changes and Impacts (Invited)

    Science.gov (United States)

    Nghiem, S. V.

    2013-12-01

    The extent of springtime Arctic perennial sea ice, important to preconditioning summer melt and to polar sunrise photochemistry, continues its precipitous reduction in the last decade marked by a record low in 2012, as the Bromine, Ozone, and Mercury Experiment (BROMEX) was conducted around Barrow, Alaska, to investigate impacts of sea ice reduction on photochemical processes, transport, and distribution in the polar environment. In spring 2013, there was further loss of perennial sea ice, as it was not observed in the ocean region adjacent to the Alaskan north coast, where there was a stretch of perennial sea ice in 2012 in the Beaufort Sea and Chukchi Sea. In contrast to the rapid and extensive loss of sea ice in the Arctic, Antarctic sea ice has a trend of a slight increase in the past three decades. Given the significant variability in time and in space together with uncertainties in satellite observations, the increasing trend of Antarctic sea ice may arguably be considered as having a low confidence level; however, there was no overall reduction of Antarctic sea ice extent anywhere close to the decreasing rate of Arctic sea ice. There exist publications presenting various factors driving changes in Arctic and Antarctic sea ice. After a short review of these published factors, new observations and atmospheric, oceanic, hydrological, and geological mechanisms contributed to different behaviors of sea ice changes in the Arctic and Antarctic are presented. The contribution from of hydrologic factors may provide a linkage to and enhance thermal impacts from lower latitudes. While geological factors may affect the sensitivity of sea ice response to climate change, these factors can serve as the long-term memory in the system that should be exploited to improve future projections or predictions of sea ice changes. Furthermore, similarities and differences in chemical impacts of Arctic and Antarctic sea ice changes are discussed. Understanding sea ice changes and

  9. Carbon redistribution during interrill erosion in subtropical forests: Effects of leaf litter diversity and soil fauna

    Science.gov (United States)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2016-04-01

    Soil erosion is crucial for degradation of carbon (C) from their pools in the soil. If C of the eroded sediment and runoff are not only related to soil pools but also resulting additively from decomposition of litter cover, the system gets more complex. The role of these amounts for C cycling in a forest environment is not yet known properly and thus, the aim of this study was to investigate the role of leaf litter diversity, litter cover and soil fauna on C redistribution during interrill erosion. We established 96 runoff plots that were deployed with seven domestic leaf litter species resulting in none species (bare ground), 1-species, 2-species and 4-species mixtures. Every second runoff plot was equipped with a fauna extinction feature to investigate the role of soil meso- and macrofauna. Erosion processes were initiated using a rainfall simulator at two time steps (summer 2012 and autumn 2012) to investigate the role of leaf litter decomposition on C redistribution. C fluxes during 20 min rainfall simulation were 99.13 ± 94.98 g/m². C fluxes and C contents both were affected by soil fauna. C fluxes were higher with presence of soil fauna due to loosening and slackening of the soil surface rather than due to faster decomposition of leaves. In contrast, C contents were higher in the absence of soil fauna possibly resulting from a missing dilution effect in the top soil layer. Leaf litter diversity did not affect C fluxes, but indirectly affected C contents as it increased the soil fauna effect with higher leaf litter diversity due to superior food supply. Initial C contents in the soil mainly determined those of the eroded sediment. For future research, it will be essential to introduce a long-term decomposition experiment to get further insights into the processes of C redistribution.

  10. Preliminary Response of Soil Fauna to Simulated N Deposition in Three Typical Subtropical Forests

    Institute of Scientific and Technical Information of China (English)

    XU Guo-Liang; MO Jiang-Ming; ZHOU Guo-Yi; FU Sheng-Lei

    2006-01-01

    A field-scale experiment arranged in a complete randomized block design with three N addition treatments including a control (no addition of N), a low N (5 g m-2 year-1), and a medium N (10 g m-2 year-1) was performed in each of the three typical forests, a pine (Pinus massoniana Lamb.) forest (PF), a pine-broadleaf mixed forest (MF) and a mature monsoon evergreen broadleaf forest (MEBF), of the Dinghushan Biosphere Reserve in subtropical China to study the response of soil fauna community to additions of N. Higher NH4+ and NO3- concentrations and a lower soil pH occurred in the medium N treatment of MEBF, whereas the NO3- concentration was the lowest in PF after the additions of N. The response of the density, group abundance and diversity index of soil fauna to addition of N varied with the forest type,and all these variables decreased with increasing N under MEBF but the trend was opposite under PF. The N treatments had no significant effects on these variables under MF. Compared with the control plots, the medium N treatment had significant negative effect on soil fauna under MEBF. The group abundance of soil fauna increased significantly with additions of higher N rates under PF. These results suggested that the response of soil fauna to N deposition varied with the forest type and N deposition rate, and soil N status is one of the important factors affecting the response of soil fauna to N deposition.

  11. Host diversity and latitude drive the trematode diversity patterns in the European freshwater fauna

    DEFF Research Database (Denmark)

    Thieltges, David W.; Hof, Christian; Dehling, D. Matthias;

    2011-01-01

    faunas. Results Latitude or first intermediate host richness had no effect on trematode richness, but definitive host richness was a strong predictor of trematode richness, among both allogenic and autogenic parasites. We found that beta diversity of trematode faunas within latitudinal bands decreased...... gradient in beta diversity reflects patterns observed in free-living species and probably results from recolonization in the aftermath of the ice ages. The similar beta-diversity patterns of allogenic and autogenic trematodes and the increasing proportion of autogenic trematodes with increasing latitude...

  12. Effects of of Habitats and Pesticides on Aerobic Capacity and Survival of Soil Fauna

    Institute of Scientific and Technical Information of China (English)

    G. TRIPATHI; B. M. SHARMA

    2005-01-01

    Objective Faunal health is largely dependent on their soil environment and available litter quality. So the effects of different soil habitats and pesticides on citrate synthase (CS) activity of soil fauna and its population were studied. Methods The soil animals were collected from different pedoecosystems for habitat study. Whereas Vigna radiata based system was selected for pesticidal observations. The field was divided into five equal plots for control and treatment of γ-BHC, quinalphos, carbaryl and cypermethrin. Soil fauna was collected by quadrat method and extracted by Tullgren funnel. Individuals of a species having similar sizes were collected for the estimation of CS activity. They were homogenized and fractions were obtained by differential centrifugation. The activity of CS was assayed spectrophotometrically. Results Citrate synthase (CS) activity of beetle (Rasphytus fregi), woodlouse (Porcellio laevis) and centipede (Scolopendra morsitans) varied significantly with respect to changes in different soil habitats. Though the CS activity of R. fregi, P. laevis, and S. morsitans differed among themselves but the highest activity of CS in these animals was in V. radiata and lowest in A. nilotica based pedoecosystem. The aerobic capacity of centipede was maximum followed by woodlouse and beetle. The treatment of γ-BHC, quinalphos, carbaryl and cypermethrin significantly reduced the CS activity of these animals. γ-BHC showed maximum reduction in CS activity indicating highly toxic effect of organochlorine on aerobic metabolism of soil fauna. However, minimum reduction was observed in response to carbaryl (in beetle) or cypermethrin (in woodlouse/centipede) leading to impairment of aerobic capacity. The differences in pesticide effects might be assigned to the differences in chemical nature of pesticides and their interactions with below-ground fauna. Treatment of γ-BHC and quinalphos reduced the population of Acari, Coleoptera, Collembola, other

  13. Mosquitoes of Istria, a contribution to the knowledge of Croatian mosquito fauna (Diptera, Culicidae)

    OpenAIRE

    MERDIĆ, Enrih; BOCA, IVANA; SUDARIĆ BOGOJEVIĆ, MIRTA; LANDEKA, Nediljko

    2008-01-01

    Background and Purpose: Although Istria was endemic of malaria up to the mid 20th century, the mosquito fauna was studied in detail. Our investigation of mosquitoes in Istria, a very specific region with a highly diverse breeding site types, was conducted in order to gain insights into the mosquito fauna and abundance, as well as to establish the possible presence of new species. Material and Methods: The sampling took place from May to September over a seven-year period, from 1999 to ...

  14. Radiometric dating of the extinction of the large Pleistocene fauna in Peru

    International Nuclear Information System (INIS)

    The discovery in northern Peru of fossil deposits belonging to large mammals allows the dating of the extinction of this fauna. The method based on disequilibrium within the uranium family (230Th/234U) was used. The extinction occurred at the end of the Pleistocene and is contemporaneous with the beginning of the deglaciation. Moreover, this dating, compared with results of excavations of palaeo-indian ''Paijan'' sites, indicates that human groups in Peru did not play a significant role in extinction of this large fauna. (authors). 26 refs., 1 tab

  15. Dragonflies and damselflies (Insecta: Odonata of Nagaland, with an addition to the Indian odonate fauna

    Directory of Open Access Journals (Sweden)

    Shantanu Joshi

    2014-10-01

    Full Text Available We surveyed odonates in the districts of Kohima, Peren and Wokha in the state of Nagaland, northeastern India, during April and May 2012 and May 2013.  We recorded 69 species, including 43 additions to the known odonates of Nagaland, and one addition—Calicnemia erythromelas Selys, 1891—to the Indian odonate fauna. The known odonate fauna of Nagaland now consists of 90 species in 53 genera and 14 families.  We also describe for the first time the female of Coeliccia schmidti, and partially, a heterochromatic form of the female Ischnura mildredae.

  16. Estudio de la triquinelosis en la fauna silvestre del noroeste español

    OpenAIRE

    Rodríguez Rodríguez, María Estrella

    2016-01-01

    La triquinelosis en España se considera una zoonosis endémica cuyo ciclo doméstico está aparentemente controlado, pero todos los años aparecen brotes en humana relacionados con el consumo de carne de cerdo y jabalí sin control sanitario. En este sentido, la fauna silvestre actúa de reservorio de Trichinella spp., especialmente el jabalí y los carnívoros. Para conocer la situación epidemiológica actual de Trichinella spp. en la fauna silvestre de Galicia, hemos realizado el estudio más ampl...

  17. Published data and new records to the fauna of Eupelmidae (Insecta: Hymenoptera in Bulgaria

    Directory of Open Access Journals (Sweden)

    MIROSLAV ANTOV

    2015-11-01

    Full Text Available This study presents information about published data on eupelmid fauna of Bulgaria and new records of 16 species distributed in the country. Some of them are reared from Cynipidae (Hymenoptera galls on Quercus, Rosa, Hypecoum, as well as from Cecidomyiidae (Diptera developing in stems of Eryngium campestre L. Other species are reared from pods of Astragalus glycyphyllos L. and seeds of Dianthus giganteus dʼUrv. New host associations are established. As a result of the study 4 species and 1 genus are new to the fauna of Bulgaria.

  18. Early Carboniferous Radiolarian Fauna from Heiyingshan South of the Tianshan Mountains and Its Geotectonic Significance

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Abundant and well-preserved fossil radiolarians found from the Artencasher Formation, Heiyingshan of Baicheng County, Xinjiang Uygur Autonomous Region, are identified, including 15 species and 2 unnamed species in 9 genera. The fauna is dominated by the Family Entactiniidae of Spumellaria. According to the faunal characteristics, the radiolarians may be divided into five assemblages, namely, the Triaenosphaera sicarius, Entatinosphaera palimbola, Entactinia vulgaris, Belowea cf. variabilis and Archocyrtium sp assemblages. The fauna may be correlated with that from the Early Carboniferous of Frankenwald and Rein in Germany. Thus, ophiolite was formed in the Carboniferous, while the age of collision between the Ili plate and the Tarim plate is Early Carboniferous.

  19. Insect fauna in soil at different grassland ecosystems at Sobral, state of Ceará, Brazil

    OpenAIRE

    Gislane dos Santos Sousa; Silvia Cristenia da Silva Xavier; Petronio Emanuel Timbó Braga

    2013-01-01

    The aim of this study was perform a surveillance of the insect fauna in soil in three grassland ecosystems of experimental farm Vale do Acaraú of Universidade Estadual Vale do Acaraú at Sobral, state of Ceará, Brazil, by the using of traps soil, with fortnightly collections, from March 2011 to February 2012. To characterize the insect fauna established a distribution pattern, whereas the rates of occurrence and dominance of species grouped by order, as an indicator of the frequency and the oc...

  20. Amino Acids as a Source of Organic Nitrogen in Antarctic Endolithic Microbial Communities

    Science.gov (United States)

    McDonald, G. D.; Sun, H. J.

    2002-12-01

    In the Antarctic Dry Valleys, cryptoendolithic microbial communities occur within porous sandstone rocks. Current understanding of the mechanisms of physiological adaptation of these communities to the harsh Antarctic environment is limited, because traditional methods of studying microbial physiology are very difficult to apply to organisms with extremely low levels of metabolic activity. In order to fully understand carbon and nitrogen cycling and nutrient uptake in cryptoendolithic communities, and the metabolic costs that the organisms incur in order to survive, it is necessary to employ molecular geochemical techniques such as amino acid analysis in addition to physiological methods. Low-molecular-weight biomolecules such as amino acids can be used as tracers of carbon and nitrogen uptake and loss by microbial communities living in solid-state matrices such as rock or sediment. We have measured the concentrations and D/L ratios for several amino acids as a function of depth in a large sandstone boulder. Concentrations of both free and bound amino acids decrease by more than two orders of magnitude from the surface to the visible base of the community (approximately 1.2 cm depth), while the D/L ratios of the amino acids increase from near zero to 0.2 or greater over the same depth interval. We interpret these data as an indication that one or more community members are selectively scavenging L-amino acids as the amino acids are transported through the rock by intermittently percolating meltwater. This is consistent with the known preference of lichens for amino acids as nitrogen sources rather than inorganic nitrogen under conditions of nutrient limitation. It is not yet clear whether there is also a contribution to amino acid uptake from heterotropic bacteria associated with the cryptoendolithic community. The increase in D/L ratios with depth observed in the rock is too great to be attributable solely to the natural occurrence of D-amino acids in bacteria

  1. Arctic sea-ice ridges—Safe heavens for sea-ice fauna during periods of extreme ice melt?

    Science.gov (United States)

    Gradinger, Rolf; Bluhm, Bodil; Iken, Katrin

    2010-01-01

    The abundances and distribution of metazoan within-ice meiofauna (13 stations) and under-ice fauna (12 stations) were investigated in level sea ice and sea-ice ridges in the Chukchi/Beaufort Seas and Canada Basin in June/July 2005 using a combination of ice coring and SCUBA diving. Ice meiofauna abundance was estimated based on live counts in the bottom 30 cm of level sea ice based on triplicate ice core sampling at each location, and in individual ice chunks from ridges at four locations. Under-ice amphipods were counted in situ in replicate ( N=24-65 per station) 0.25 m 2 quadrats using SCUBA to a maximum water depth of 12 m. In level sea ice, the most abundant ice meiofauna groups were Turbellaria (46%), Nematoda (35%), and Harpacticoida (19%), with overall low abundances per station that ranged from 0.0 to 10.9 ind l -1 (median 0.8 ind l -1). In level ice, low ice algal pigment concentrations (3 m where abundances were up to 42-fold higher compared with level ice. We propose that the summer ice melt impacted meiofauna and under-ice amphipod abundance and distribution through (a) flushing, and (b) enhanced salinity stress at thinner level sea ice (less than 3 m thickness). We further suggest that pressure ridges, which extend into deeper, high-salinity water, become accumulation regions for ice meiofauna and under-ice amphipods in summer. Pressure ridges thus might be crucial for faunal survival during periods of enhanced summer ice melt. Previous estimates of Arctic sea ice meiofauna and under-ice amphipods on regional and pan-Arctic scales likely underestimate abundances at least in summer because they typically do not include pressure ridges.

  2. Mitochondrial plasticity in response to changing abiotic factors in Antarctic fish and cephalopods

    OpenAIRE

    Strobel, Anneli

    2013-01-01

    Antarctic species possess very low metabolic rates and poor capacities to change their physiological state, thus making them extremely vulnerable to changing environmental conditions. Mitochondria are a key element in shaping whole organism energy turnover and functional capacity. In my study, the effects of rising temperature and increased seawater PCO2 on the energy metabolism were compared between various nototheniids from sub-Antarctic and cold-temperate and Antarctic waters, and between ...

  3. Relative Changes in KrillAbundance Inferred from Antarctic Fur Seal

    OpenAIRE

    Huang, T.; Sun, L; Stark, John M.; Wang, Y.; Cheng, Z.; Yang, Q.; Sun, S.

    2011-01-01

    Antarctic krill Euphausia superba is a predominant species in the Southern Ocean, it is very sensitive to climate change, and it supports large stocks of fishes, seabirds, seals and whales in Antarctic marine ecosystems. Modern krill stocks have been estimated directly by net hauls and acoustic surveys; the historical krill density especially the long-term one in the Southern Ocean, however, is unknown. Here we inferred the relative krill population changes along the West Antarctic Peninsula ...

  4. Pressure drop evaluation in fuel assembly bottom nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Sydney da Silva; Brittes, Luiz Henrique A. [Industrias Nucleares do Brasil S.A. (INB), Resende, RJ (Brazil)]. E-mails: sydney@inb.gov.br; brittes@inb.gov.br; Navarro, Moyses A. [Centro de Desenvolvimento de Energia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: navarro@cdtn.br

    2007-07-01

    Experiments were conducted in order to assess the pressure drop through an anti-debris bottom nozzle relatively to a standard bottom nozzle of a nuclear fuel assembly. Two kinds of experiments have been performed: one using bottom nozzles connected with the lower part of a Fuel Assembly (containing two spacer grids) and another one using the bottom nozzle alone. Reynolds numbers ranging from 10500 . 95000 have been employed, temperatures ranging from 40 . 55 deg C and pressures up to 4 bar. Results have shown that the pressure drop coefficients of the anti-debris nozzle referring to the whole lower region of the Fuel Assembly were {approx} 13% (for Re {approx_equal} 95000) till {approx} 17% (for Re {approx_equal} 10500) higher than the coefficients for standard bottom nozzle. This difference increases up to 118% when the pressure drop coefficients of the bottom nozzle alone are considered. (author)

  5. DINSAR measurement of glacier motion in Antarctic Grove Mountain

    Institute of Scientific and Technical Information of China (English)

    CHENG Xiao; LI XiaoWen; SHAO Yun; LI Zhen

    2007-01-01

    Grove Mountain is an important nunatak region on East Antarctic Glacier that blocks the ice flow toward Lambert Glacier. The existence of nunataks and subglacial mountains leads to complex ice flow patterns, which are difficult to be measured by conventional ground-based methods. In this study, several JERS-1 and ERS-1/2 SAR images covering this area are used for 3-pass and 4-pass differential interferometric processing. The ice flow field of Grove Mountain and the eastern zone are derived and validated with related knowledge. The research shows that DINSAR is an effective method for measuring complex ice flow in Antarctic inland glacier. L-band DINSAR is more suitable for mid or fast ice flow than C-band over this region.

  6. Definition of Arctic and Antarctic Sea Ice Variation Index

    Institute of Scientific and Technical Information of China (English)

    Chen Hongxia; Liu Na; Pan Zengdi; Zhang Qinghua

    2004-01-01

    It is well known that varying of the sea ice not only in the Antarctic but also in the Arctic has an active influence on the globe atmosphere and ocean. In order to understand the sea ice variation in detail, for the first time, an objective index of the Arctic and Antarctic sea ice variation is defined by projecting the monthly sea ice concentration anomalies poleward of 20°N or 20°S onto the EOF (empirical orthogonal function)-1 spatial pattern. Comparing with some work in former studies of polar sea ice, the index has the potential for clarifying the variability of sea ice in northern and southern high latitudes.

  7. On the manoeuvering simulation of an Antarctic hovercraft

    Science.gov (United States)

    Murao, R.; Nojiri, T.

    Since 1981 an experimental hovercraft for the Antarctic has been tested in Japan's Antarctic station Syowa. During tests on the ice field near Syowa station, it was experienced that the yaw response of this craft is very sensitive to certain ice conditions. In this report, we deal with course keeping of the craft in relative crosswinds and with the maneuvering simulation while turning. Maneuvering at large yaw angle is required to generate the effective centripetal force in turning. The trajectories based on pulse steering are obtained. The course stability is very dependent upon the friction between skirts and ground, and generally not good on smooth flat ice. It is shown, however, that the rudder automatic control provides good course stability independent of ice conditions. The trajectories obtained from the simulation show that the use of a combination of rudder control and puff ports produces quick turning.

  8. Results and perspectives of tectonomagnetic investigations in the Western Antarctic

    Directory of Open Access Journals (Sweden)

    Ihor O. Chobotok

    2009-06-01

    Full Text Available The results of long-term (1998-2005 yrs. tectonomagnetic investigations in the Western Antarctic near the location
    of Ukrainian Antarctic Station «Academic Vernadsky» are reviewed. The peculiarities of the Earth’s
    anomalous magnetic field and its dynamic temporal variations (tectonomagnetic anomalies were studied using
    the newly founded tectonomagnetic polygon. Near the Argentine Archipelago intensive tectonomagnetic effects
    up to -2.8 nT/year were determined. Their spatial-temporal structure agrees with tectonic structure elements. We
    suggest that the nature of such effects is caused by a piezomagnetic effect under the influence of stretching tectonic
    forces (few bars per year in sub-latitudinal direction. Perspectives of tectonomagnetic investigations in the
    region are discussed.

  9. Windblown Pliocene diatoms and East Antarctic Ice Sheet retreat

    Science.gov (United States)

    Scherer, Reed P.; DeConto, Robert M.; Pollard, David; Alley, Richard B.

    2016-01-01

    Marine diatoms in tillites along the Transantarctic Mountains (TAMs) have been used to suggest a diminished East Antarctic Ice Sheet (EAIS) during Pliocene warm periods. Updated ice-sheet modelling shows significant Pliocene EAIS retreat, creating marine embayments into the Wilkes and Aurora basins that were conducive to high diatom productivity and rapid accumulation of diatomaceous sediments. Here we show that subsequent isostatic uplift exposed accumulated unconsolidated marine deposits to wind erosion. We report new atmospheric modelling utilizing Pliocene climate and derived Antarctic landscapes indicating that prevailing mid-altitude winds transported diatoms towards the TAMs, dominantly from extensive emerged coastal deposits of the Aurora Basin. This result unifies leading ideas from competing sides of a contentious debate about the origin of the diatoms in the TAMs and their link to EAIS history, supporting the view that parts of the EAIS are vulnerable to relatively modest warming, with possible implications for future sea-level rise. PMID:27649516

  10. The 1988 Antarctic ozone depletion - Comparison with previous year depletions

    Science.gov (United States)

    Schoeberl, Mark R.; Stolarski, Richard S.; Krueger, Arlin J.

    1989-01-01

    The 1988 spring Antarctic ozone depletion was observed by TOMS to be substantially smaller than in recent years. The minimum polar total ozone values declined only 15 percent during September 1988, compared to nearly 50 percent during September 1987. At southern midlatitudes, exceptionally high total ozone values were recorded beginning in July 1988. The total integrated southern hemispheric ozone increased rapidly during the Austral spring, approaching 1980 levels during October. The high midlatitude total ozone values were associated with a substantial increase in eddy activity as indicated by the standard deviation in total ozone in the zonal band 30-60 deg S. Mechanisms through which the increased midlatitude eddy activity could disrupt the formation of the Antarctic ozone hole are briefly discussed.

  11. Antarctic springtime ozone depletion computed from temperature observations

    Science.gov (United States)

    Rosenfield, Joan E.; Schoeberl, Mark R.; Newman, Paul A.

    1988-01-01

    An observationally based, mechanistic dynamical model is used to simulate the decline of total ozone during September and October for the years 1979 through 1986. Vertical velocities derived from observed stratospheric temperature changes and computed radiative heating rates are used to advect an ozone mixing ratio profile during the Antarctic spring period. An early August 1982 Syowa balloonsonde ozone profile is used to initialize the computations. The model reasonably simulates the September and October changes in total ozone, considering the uncertainties in the observed data and the radiative heating. The simulated decline is found to be very sensitive to the choice of initial ozone profile and to small changes in the radiative heating. The results of this study suggest that the dynamical hypothesis of the Antarctic ozone depletion is both quantitatively credible and consistent with the observed temperature changes.

  12. Ozone depletion - Ultraviolet radiation and phytoplankton biology in Antarctic waters

    Science.gov (United States)

    Smith, R. C.; Prezelin, B. B.; Baker, K. S.; Bidigare, R. R.; Boucher, N. P.; Coley, T.; Karentz, D.; Macintyre, S.; Matlick, H. A.; Menzies, D.

    1992-01-01

    The near-50-percent thinning of the stratospheric ozone layer over the Antarctic, with increased passage of mid-UV radiation to the surface of the Southern Ocean, has prompted concern over possible radiation damage to the near-surface phytoplankton communities that are the bases of Antarctic marine ecosystems. As the ozone layer thinned, a 6-week study of the marginal ice zone of the Bellingshousen Sea in the austral spring of 1990 noted sea-surface and depth-dependent ratios of mid-UV irradiance to total irradiance increased, and mid-UV inhibition of photosynthesis increased. A 6-12 percent reduction in primary production associated with ozone depletion was estimated to have occurred over the course of the present study.

  13. The South Atlantic in the Fine-Resolution Antarctic Model

    Directory of Open Access Journals (Sweden)

    D. P. Stevens

    Full Text Available The geographical area covered by the Fine-Resolution Antarctic Model (FRAM includes that part of the South Atlantic south of 24°S. A description of the dynamics and thermodynamics of this region of the model is presented. Both the mean and eddy fields in the model are in good agreement with reality, although the magnitude of the transients is somewhat reduced. The heat flux is northward and in broad agreement with many other estimates. Agulhas eddies are formed by the model and propagate westward into the Atlantic providing a mechanism for fluxing heat from the Indian Ocean. The confluence of the Brazil and Falkland currents produces a strong front and a large amount of mesoscale activity. In the less stratified regions to the south, topographic steering of the Antarctic circumpolar current is important.

  14. Paleogeographic controls on the onset of the Antarctic circumpolar current

    Science.gov (United States)

    Hill, Daniel J.; Haywood, Alan M.; Valdes, Paul J.; Francis, Jane E.; Lunt, Daniel J.; Wade, Bridget S.; Bowman, Vanessa C.

    2013-10-01

    of the Antarctic Circumpolar Current (ACC) during the Cenozoic is controversial in terms of timing and its role in major climate transitions. Some propose that the development of the ACC was instrumental in the continental scale glaciation of Antarctica and climate cooling at the Eocene/Oligocene boundary. Here we present climate model results that show that a coherent ACC was not possible during the Oligocene due to Australasian paleogeography, despite deep water connections through the Drake Passage and Tasman Gateway and the initiation of Antarctic glaciation. The simulations of ocean currents compare well to paleoenvironmental records relating to the physical oceanography of the Oligocene and provide a framework for understanding apparently contradictory dating of the initiation of the ACC. We conclude that the northward motion of the Australasian land masses and the reconfiguration of the Tasman Seaway and Drake Passage are necessary preconditions for the formation of a strong, coherent ACC.

  15. Sarmatian vertebrate marine fauna assemblage from Dacian Basin with Paratethyan affinities - a comparative case study between Buzau Land (Carpathian Foredeep) and South Dobrogea, Romania

    Science.gov (United States)

    Iftode, Silvia Gabriela; Stoica, Marius

    2015-04-01

    At the Badenian/Sarmatian boundary (12.7 Ma), the Paratethys domain experienced a new moment in its evolution. Restricted connections between the Paratethys and the open seas (Mediterranean or/alternatively Indian Ocean) that occured at this boundary interval led to the decreasing of water salinity, strong faunal endemism and the onset of anoxic/disoxic conditions in the internal parts of Paratethyan Basins (like the actual Black Sea). The low oxigen bottom conditions in the Volhynian - Early Bessarabian favorised the preservation of fish and mammal marine fauna like Cetaceans, Pinnipeds and Sirenids. The purpose of this study is to compare both areas - Buzău Land and South Dobrogea, Romania taking into account the palaecological changes in the Eastern Paratethys Basin. This aspect can be very well noticed in the Carpathian Foredeep zone (Buzău - Rîmnicului - Milcov Valleys, Buzău Land) where fish and cetaceans (Cetotherium sp.) remains are frequent in thick sandstone and blackish shale deposits. Several terrestrial mammal remains were also found in Kherssonian (the late Sarmatian - senso lato) terrestrial deposits, related to a regressive moment. In South Dobrogea we have studied Lower Bessarabian deposits formed in shallow marginal facies, close to the shoreline or around small islands. The littoral sandy facies preserved a rich fossil assemblage composed of seal and marine birds remains. Vertebrate marine fauna dominated by pinnipeds - Phoca pontica, cetaceans - Delphinidae, Cetotheriidae, teleost fish and pelagic birds were also found near Credința and Ciobănița localities. Based on the fossil assemblage found so far in the Lower Bessarabian formations from Buzău Land and South Dobrogea, the environments were similar in both areas. Part of the research leading to these results has received funding from EEA Financial Mecanism 2009 - 2014 under the GeoSust project contract no 22 SEE/30.06.2014.

  16. The micromammal fauna from the upper Oligocene of Sayatón 6, Madrid Basin, Prov. of Guadalajara, Spain

    NARCIS (Netherlands)

    Daams, R.

    1989-01-01

    The extremely poor rodent fauna of Sayatón 6 is described. Only three species are present, of which two are new: Adelomyarion alberti sp. nov. (Cricetidae) and Peridyromys columbarii sp. nov. (Gliridae). The third species, Rhodanomys transiens, places the age of the fauna in the Late Oligocene.

  17. Tabulate Corals after the Frasnian/Famennian Crisis: A Unique Fauna from the Holy Cross Mountains, Poland.

    Science.gov (United States)

    Zapalski, Mikołaj K; Berkowski, Błażej; Wrzołek, Tomasz

    2016-01-01

    Famennian tabulate corals were very rare worldwide, and their biodiversity was relatively low. Here we report a unique tabulate fauna from the mid- and late Famennian of the western part of the Holy Cross Mountains (Kowala and Ostrówka), Poland. We describe eight species (four of them new, namely ?Michelinia vinni sp. nov., Thamnoptychia mistiaeni sp. nov., Syringopora kowalensis sp. nov. and Syringopora hilarowiczi sp. nov.); the whole fauna consists of ten species (two others described in previous papers). These corals form two assemblages-the lower, mid-Famennian with Thamnoptychia and the upper, late Famennian with representatives of genera ?Michelinia, Favosites, Syringopora and ?Yavorskia. The Famennian tabulates from Kowala represent the richest Famennian assemblage appearing after the F/F crisis (these faunas appear some 10 Ma after the extinction event). Corals described here most probably inhabited deeper water settings, near the limit between euphotic and disphotic zones or slightly above. At generic level, these faunas show similarities to other Devonian and Carboniferous faunas, which might suggest their ancestry to at least several Carboniferous lineages. Tabulate faunas described here represent new recruits (the basin of the Holy Cross mountains was not a refuge during the F/F crisis) and have no direct evolutionary linkage to Frasnian faunas from Kowala. The colonization of the seafloor took place in two separate steps: first was monospecific assemblage of Thamnoptychia, and later came the diversified Favosites-Syringopora-Michelinia fauna. PMID:27007689

  18. Transient Temperature Analysis for Industrial AC Arc Furnace Bottom

    Institute of Scientific and Technical Information of China (English)

    (U)nal (C)amdal1; Murat Tun(c)

    2004-01-01

    Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the transient temperature variation at the bottom of the EAF was investigated. The transient temperature analysis was carried out using MATLAB computer program. T=T(r, t) for different bottom lining layers was depicted.

  19. Antarctic Ice Sheet and Radar Altimetry: A Review

    OpenAIRE

    Frédérique Rémy; Soazig Parouty

    2009-01-01

    International audience Altimetry is probably one of the most powerful tools for ice sheet observation. Our vision of the Antarctic ice sheet has been deeply transformed since the launch of the ERS1 satellite in 1991. With the launch of ERS2 and Envisat, the series of altimetric observations now provides 19 years of continuous and homogeneous observations that allow monitoring of the shape and volume of ice sheets. The topography deduced from altimetry is one of the relevant parameters reve...

  20. First record of Babesia sp. in Antarctic penguins.

    Science.gov (United States)

    Montero, Estrella; González, Luis Miguel; Chaparro, Alberto; Benzal, Jesús; Bertellotti, Marcelo; Masero, José A; Colominas-Ciuró, Roger; Vidal, Virginia; Barbosa, Andrés

    2016-04-01

    This is the first reported case of Babesia sp. in Antarctic penguins, specifically a population of Chinstrap penguins (Pygoscelis antarctica) in the Vapour Col penguin rookery in Deception Island, South Shetlands, Antarctica. We collected peripheral blood from 50 adult and 30 chick Chinstrap penguins. Examination of the samples by microscopy showed intraerythrocytic forms morphologically similar to other avian Babesia species in 12 Chinstrap penguin adults and seven chicks. The estimated parasitaemias ranged from 0.25×10(-2)% to 0.75×10(-2)%. Despite the low number of parasites found in blood smears, semi-nested PCR assays yielded a 274 bp fragment in 12 of the 19 positive blood samples found by microscopy. Sequencing revealed that the fragment was 97% similar to Babesia sp. 18S rRNA from Australian Little Penguins (Eudyptula minor) confirming presence of the parasite. Parasite prevalence estimated by microscopy in adults and chicks was higher (24% vs. 23.3%, respectively) than found by semi-nested PCR (16% vs. 13.3% respectively). Although sampled penguins were apparently healthy, the effect of Babesia infection in these penguins is unknown. The identification of Babesia sp. in Antarctic penguins is an important finding. Ixodes uriae, as the only tick species present in the Antarctic Peninsula, is the key to understanding the natural history of this parasite. Future work should address the transmission dynamics and pathogenicity of Babesia sp. in Chinstrap penguin as well as in other penguin species, such as Gentoo penguin (Pygoscelis papua) and Adélie penguin (Pygoscelis adeliae), present within the tick distribution range in the Antarctic Peninsula.