antarctic bottom fauna: Topics by WorldWideScience.org

Sample records for antarctic bottom fauna

Is there a distinct continental slope fauna in the Antarctic?

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Kaiser, Stefanie; Griffiths, Huw J.; Barnes, David K. A.; Brandão, Simone N.; Brandt, Angelika; O'Brien, Philip E.

2011-02-01

The Antarctic continental slope spans the depths from the shelf break (usually between 500 and 1000 m) to ˜3000 m, is very steep, overlain by 'warm' (2-2.5 °C) Circumpolar Deep Water (CDW), and life there is poorly studied. This study investigates whether life on Antarctica's continental slope is essentially an extension of the shelf or the abyssal fauna, a transition zone between these or clearly distinct in its own right. Using data from several cruises to the Weddell Sea and Scotia Sea, including the ANDEEP (ANtarctic benthic DEEP-sea biodiversity, colonisation history and recent community patterns) I-III, BIOPEARL (BIOdiversity, Phylogeny, Evolution and Adaptive Radiation of Life in Antarctica) 1 and EASIZ (Ecology of the Antarctic Sea Ice Zone) II cruises as well as current databases (SOMBASE, SCAR-MarBIN), four different taxa were selected (i.e. cheilostome bryozoans, isopod and ostracod crustaceans and echinoid echinoderms) and two areas, the Weddell Sea and the Scotia Sea, to examine faunal composition, richness and affinities. The answer has important ramifications to the link between physical oceanography and ecology, and the potential of the slope to act as a refuge and resupply zone to the shelf during glaciations. Benthic samples were collected using Agassiz trawl, epibenthic sledge and Rauschert sled. By bathymetric definition, these data suggest that despite eurybathy in some of the groups examined and apparent similarity of physical conditions in the Antarctic, the shelf, slope and abyssal faunas were clearly separated in the Weddell Sea. However, no such separation of faunas was apparent in the Scotia Sea (except in echinoids). Using a geomorphological definition of the slope, shelf-slope-abyss similarity only changed significantly in the bryozoans. Our results did not support the presence of a homogenous and unique Antarctic slope fauna despite a high number of species being restricted to the slope. However, it remains the case that there may be
Bottom fauna of the Malacca Strait

Digital Repository Service at National Institute of Oceanography (India)

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

Bottom fauna of Malacca Strait (connecting the Indian Ocean with Pacific) in the depth range of 80 to 1350 m, is dominated by meiofauna which exceeds macrofauna by 12.5 times in weight and by more than 780 times in population density. Standing crop...
Biogeographical distribution of the benthic thecate hydroids collected during the Spanish Antartida 8611 expedition and comparison between Antarctic and Magellan benthic hydroid faunas

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A. L. Peña Cantero

1999-12-01

Full Text Available The biogeographical distribution of the benthic hydroid species collected during the Spanish Antarctic expedition Antártida 8611 has been studied. An inventory of the Antarctic and Magellan benthic thecate hydroid faunas, along with a comparison between the two, have been also carried out. 104 and 126 species of thecate hydroids have been considered in the Antarctic and Magellan areas, respectively. 72 species (69% of the Antarctic species and 49 (39% of the Magellan species are endemic. 23 species are present both in the Antarctic Region and in the Magellan area, representing 22% and 18% respectively, and indicating an important relationship between both faunas.
Spreading of Antarctic Bottom Water in the Atlantic Ocean

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Morozov, E.; Tarakanov, R. Y.; Zenk, Walter

2012-01-01

This paper describes the transport of bottom water from its source region in the Weddell Sea through the abyssal channels of the Atlantic Ocean. The research brings together the recent observations and historical data. A strong flow of Antarctic Bottom Water through the Vema Channel is analyzed. The mean speed of the flow is 30 cm/s. A temperature increase was found in the deep Vema Channel, which has been observed for 30 years already. The flow of bottom water in the northern part of the Bra...
Morphology of bottom surfaces of glacier ice tongues in the East Antarctic region

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Bianchi, C.; Chiappini, M.; Zirizzotti, A.; Zuccheretti, E. [Istituto Nazionale di Geofisica e Vulcanologia, Rome (Italy); Tabacco, I. E. [Milan Univ., Milan (Italy). Sez. Geofisica; Passerini, A. [Milan Univ. Bicocca, Milan (Italy). Dipt. di Fisica

2001-02-01

During three Antarctic summer campaigns (1995/97/99) Radio Echo Sounding (RES) system data from some glacier ice tongues in the East Antarctic regions between Victoria Land and George 5. Land were collected. The morphology and structure of the bottom surfaces deduced from the electromagnetic interpretation of echo signal were observed. The bottom surfaces at the ice/water interface show either irregular or flat contours or both. Some ice tongues are nearly perfectly flat, others show clear signs of irregularities while three of them have good regular spaced rippled bottom surfaces. The latter structures are well-evident in the longitudinal traverse of the tongues, whereas the transversal paths do not show the same features. This particular shape of the bottom surfaces related to the ablation process and detachment mechanism could be interesting especially to determine some physical characteristics and the possible fracture points of the ice tongues.
Morphology of bottom surfaces of glacier ice tongues in the East Antarctic region

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E. Zuccheretti

2001-06-01

Full Text Available During three Antarctic summer campaigns (1995/97/99 Radio Echo Sounding (RES system data from some glacier ice tongues in the East Antarctic regions between Victoria Land and George V Land were collected. The morphology and structure of the bottom surfaces deduced from the electromagnetic interpretation of echo signal were observed. The bottom surfaces at the ice/water interface show either irregular or flat contours or both. Some ice tongues are nearly perfectly flat, others show clear signs of irregularities while three of them have good regular spaced rippled bottom surfaces. The latter structures are well-evident in the longitudinal traverse of the tongues, whereas the transversal paths do not show the same features. This particular shape of the bottom surfaces related to the ablation process and detachment mechanism could be interesting especially to determine some physical characteristics and the possible fracture points of the ice tongues.
SPREADING OF ANTARCTIC BOTTOM WATER IN THE ATLANTIC OCEAN

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Eugene Morozov

2012-01-01

Full Text Available This paper describes the transport of bottom water from its source region in the Weddell Sea through the abyssal channels of the Atlantic Ocean. The research brings together the recent observations and historical data. A strong flow of Antarctic Bottom Water through the Vema Channel is analyzed. The mean speed of the flow is 30 cm/s. A temperature increase was found in the deep Vema Channel, which has been observed for 30 years already. The flow of bottom water in the northern part of the Brazil Basin splits. Part of the water flows through the Romanche and Chain fracture zones. The other part flows to the North American Basin. Part of the latter flow propagates through the Vema Fracture Zone into the Northeast Atlantic. The properties of bottom water in the Kane Gap and Discovery Gap are also analyzed.
Salmonella infections in Antarctic fauna and island populations of wildlife exposed to human activities in coastal areas of Australia.

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Iveson, J B; Shellam, G R; Bradshaw, S D; Smith, D W; Mackenzie, J S; Mofflin, R G

2009-06-01

Salmonella infections in Antarctic wildlife were first reported in 1970 and in a search for evidence linking isolations with exposure to human activities, a comparison was made of serovars reported from marine fauna in the Antarctic region from 1982-2004 with those from marine mammals in the Northern hemisphere. This revealed that 10 (83%) Salmonella enterica serovars isolated from Antarctic penguins and seals were classifiable in high-frequency (HF) quotients for serovars prevalent in humans and domesticated animals. In Australia, 16 (90%) HF serovars were isolated from marine birds and mammals compared with 12 (86%) HF serovars reported from marine mammals in the Northern hemisphere. In Western Australia, HF serovars from marine species were also recorded in humans, livestock, mussels, effluents and island populations of wildlife in urban coastal areas. Low-frequency S. enterica serovars were rarely detected in humans and not detected in seagulls or marine species. The isolation of S. Enteritidis phage type 4 (PT4), PT8 and PT23 strains from Adélie penguins and a diversity of HF serovars reported from marine fauna in the Antarctic region and coastal areas of Australia, signal the possibility of transient serovars and endemic Salmonella strains recycling back to humans from southern latitudes in marine foodstuffs and feed ingredients.
Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

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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
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean.

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Menezes, Viviane V; Macdonald, Alison M; Schatzman, Courtney

2017-01-01

Southern Ocean abyssal waters, in contact with the atmosphere at their formation sites around Antarctica, not only bring signals of a changing climate with them as they move around the globe but also contribute to that change through heat uptake and sea level rise. A repeat hydrographic line in the Indian sector of the Southern Ocean, occupied three times in the last two decades (1994, 2007, and, most recently, 2016), reveals that Antarctic Bottom Water (AABW) continues to become fresher (0.004 ± 0.001 kg/g decade -1 ), warmer (0.06° ± 0.01°C decade -1 ), and less dense (0.011 ± 0.002 kg/m 3 decade -1 ). The most recent observations in the Australian-Antarctic Basin show a particularly striking acceleration in AABW freshening between 2007 and 2016 (0.008 ± 0.001 kg/g decade -1 ) compared to the 0.002 ± 0.001 kg/g decade -1 seen between 1994 and 2007. Freshening is, in part, responsible for an overall shift of the mean temperature-salinity curve toward lower densities. The marked freshening may be linked to an abrupt iceberg-glacier collision and calving event that occurred in 2010 on the George V/Adélie Land Coast, the main source region of bottom waters for the Australian-Antarctic Basin. Because AABW is a key component of the global overturning circulation, the persistent decrease in bottom water density and the associated increase in steric height that result from continued warming and freshening have important consequences beyond the Southern Indian Ocean.
Tardigrade eggs and exuviae in Antarctic lake sediments: insights into Holocene dynamics and origins of the fauna

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Sandra J. MCINNES

2007-09-01

Full Text Available The preservation of tardigrade eggs and exuviae in Antarctic lake sediments provided an opportunity to assess post-glacial colonisation and Holocene tardigrade dynamics on the southern continent. Tardigrade eggs were recovered from five lakes, two from the maritime Antarctic and three from continental Antarctica. Eggs were identified from the following species: Dactylobiotus cf. ambiguus, Macrobiotus furciger, Macrobiotus blocki, Minibiotus weinerorum and Acutuncus antarcticus. Other, unornamented eggs were also observed. The preservation of some of these eggs in exuviae allowed identification to at least genus. Significant variations were observed in egg abundance within the sediment of each lake, and in one lake a species (Dactylobiotus cf. ambiguus became locally extinct, probably as the result of penguin-associated eutrophication. Tardigrades generally did not become abundant for a considerable period after the lakes’ formation. The presence of an in-part endemic fauna is consistent with slow colonisation from Antarctic sources rather than wind transport from extra-continental sites. Tardigrade eggs appear to be abundant in high-latitude lake sediments, and greater use could be made of these records when evaluating tardigrade dynamics during the Holocene.
A Synoptic View of the Ventilation and Circulation of Antarctic Bottom Water from Chlorofluorocarbons and Natural Tracers

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Purkey, Sarah G.; Smethie, William M.; Gebbie, Geoffrey; Gordon, Arnold L.; Sonnerup, Rolf E.; Warner, Mark J.; Bullister, John L.

2018-01-01

Antarctic Bottom Water (AABW) is the coldest, densest, most prolific water mass in the global ocean. AABW forms at several distinct regions along the Antarctic coast and feeds into the bottom limb of the meridional overturning circulation, filling most of the global deep ocean. AABW has warmed, freshened, and declined in volume around the globe in recent decades, which has implications for the global heat and sea level rise budgets. Over the past three decades, the use of tracers, especially time-varying tracers such as chlorofluorocarbons, has been essential to our understanding of the formation, circulation, and variability of AABW. Here, we review three decades of temperature, salinity, and tracer data and analysis that have led to our current knowledge of AABW and how the southern component of deep-ocean ventilation is changing with time.
78 FR 41959 - Notice of Permit Modification Received Under the Antarctic Conservation Act of 1978

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2013-07-12

... Areas (ASPA) or involving Antarctic Flora and Fauna. Starting in 2013, all new permits issued for ASPA entry or involving Antarctic Flora and Flora require the permittee to submit an annual report to the... Specially Protected Areas (ASPA) or involving Antarctic Flora and Fauna issued prior to 2013 that require...
Chemical evidence of the changes of the Antarctic Bottom Water ventilation in the western Ross Sea between 1997 and 2003

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Rivaro, Paola; Massolo, Serena; Bergamasco, Andrea; Castagno, Pasquale; Budillon, Giorgio

2010-05-01

Data from three Italian CLIMA project cruises between 1997 and 2003 were used to obtain sections of the hydrographic and chemical properties of the main water masses across the shelf break off Cape Adare (western Ross Sea, Antarctica). Dissolved oxygen, nitrate and phosphate data were combined on the basis of the Redfield ratio to obtain the quasi-conservative tracers NO (9[NO 3]+[O 2]), PO (135[PO 4]+[O 2]) and phosphate star PO4* ( PO4*=[PO 4]+[O 2]/175-1.95). In 1997 and 2003 the presence of the High Salinity Shelf Water at the bottom depth near the sill was traced by both physical and chemical measurements. In 2001 the Modified Shelf Water, characterized by warmer temperature and by a lower dissolved oxygen content than High Salinity Shelf Water, was observed at the shelf edge. The distribution of the chemical tracers together with the hydrographic observations showed recently formed Antarctic Bottom Water on the continental slope during all of the cruises. These observations were confirmed by the extended optimum multiparameter analysis. The calculated thickness of the new Antarctic Bottom Water, as well as the tracer content, were variable in time and in space. The estimated volume of the new Antarctic Bottom Water and the export of dissolved oxygen and nutrient associated with the overflowing water were different over the examined period. In particular, a lower (˜55%) export was evidenced in 2001 compared to 1997.
The role of the complete Coriolis force in cross-equatorial transport of the Antarctic Bottom Water

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Stewart, Andrew; Dellar, Paul

2010-05-01

We investigate the equatorial crossing of the Antarctic Bottom Water using a shallow water model that includes the complete Coriolis force. Most theoretical models of the atmosphere and ocean neglect the component of the Coriolis force associated with the horizontal component of the Earth's rotation vector, the so-called traditional approximation. This approximation is typically justified on the basis that ratio of the ocean depth to the Rossby radius of deformation is negligibly small, H-Rd ≪ 1. However, the steep topography and weak stratification in the abyssal ocean magnify the role of the non-traditional component of the Coriolis force. This is most pronounced in equatorial regions, where the traditional component of the Coriolis force is weakest and the non-traditional component is strongest. The inclusion of the complete Coriolis force gives rise to a range of very long sub-inertial waves, whose frequencies lie below the inertial frequency, in the two-layer shallow water equations. These waves have a dramatically different structure to their traditional counterparts, particularly when the stratification is weak. We focus on the flow of the Antarctic Bottom Water from the Brazil Basin in the western South Atlantic to the Guiana Basin in the western North Atlantic. In this region, the current traverses a deep channel directed westwards and very slightly northwards across the equator. Previous attempts to model this flow have struggled to explain why the cross-equatorial transport is so high, with around 2.0-2.2 Sv exiting at the northern end of the channel. We present analytical and numerical solutions of the non-traditional shallow water equations for the cross-equatorial flow of the Antarctic Bottom Water. We obtain analytical solutions by considering the steady-state flow of a single layer of shallow water through a northwesterly channel with a simple geometry. We assume zero potential vorticity, as it may be shown that fluid whose potential vorticity q
New model and field data on estimates of Antarctic Bottom Water flow through the deep Vema Channel

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Frey, D. I.; Fomin, V. V.; Diansky, N. A.; Morozov, E. G.; Neiman, V. G.

2017-05-01

We used a numerical model of the ocean circulation with a high spatial resolution to obtain estimates of the kinematic characteristics of Antarctic Bottom Water flow through the abyssal Vema Channel in the southwestern part of the Atlantic Ocean. The results of simulations correspond to the data of direct velocity measurements made at several locations in the channel. The high horizontal and vertical resolution of the model in the bottom layer allowed us to study in detail the hydrodynamics of this flow over its entire length.
Measuring Zonal Transport Variability of the Antarctic Circumpolar Current Using GRACE Ocean Bottom Pressure

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Makowski, J.; Chambers, D. P.; Bonin, J. A.

2012-12-01

Previous studies have suggested that ocean bottom pressure (OBP) can be used to measure the transport variability of the Antarctic Circumpolar Current (ACC). Using OBP data from the JPL ECCO model and the Gravity Recovery and Climate Experiment (GRACE), we examine the zonal transport variability of the ACC integrated between the major fronts between 2003-2010. The JPL ECCO data are used to determine average front positions for the time period studies, as well as where transport is mainly zonal. Statistical analysis will be conducted to determine the uncertainty of the GRACE observations using a simulated data set. We will also begin looking at low frequency changes and how coherent transport variability is from region to region of the ACC. Correlations with bottom pressure south of the ACC and the average basin transports will also be calculated to determine the probability of using bottom pressure south of the ACC as a means for describing the ACC dynamics and transport.
Influence of internal tides on Antarctic Bottom Water propagation through abyssal channels

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Morozov, Eugene

2010-05-01

Antarctic Bottom Water (AABW) propagates in the Atlantic Ocean from the Weddell Sea to the north through narrow passages in submarine ridges. Submarine ridges are regions of strong internal tide generation in the ocean that causes mixing and eventually AABW loses its distinguishing properties such as low temperature and salinity. The Vema Fracture Zone (11 N) and Romanche Fracture Zone (equator) in the Mid-Atlantic Ridge (MAR) are pathways for AABW to the Northeast Atlantic. The deep basin of the Northeast Atlantic (Canary Basin and Gambia Abyssal Plain) are filled with the bottom water propagating through the Vema FZ rather than through the equatorial fracture zones because strong internal tides and mixing over the slopes of the MAR near the equator cause warming of AABW and decrease of its density. Further propagation of AABW through the Kane Gap is low. Recent field measurements in the fracture zones confirm this concept based on modeling results. Results of recent cruises are presented.
Polychaetes from Aysen Fjord, Chile: distribution, abundance and biogeographical comparison with the shallow soft-bottom polychaete fauna from Antarctica and the Magellan Province

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J. I. Cañete

1999-12-01

Full Text Available This paper analyzes the composition, abundance and biogeographical relationship of the benthic polychaetes collected in three shallow subtidal locations (mouth of Cuervo and Condor rivers and Acantilada Bay from Aysen Fjord, AF, Chile (45ºS, 73ºW, and provides a comparison with data on shallow soft-bottom polychaetes from Antarctica and other locations of the Magellan Province: Dalcahue Channel, DC (42º22´S, 73º39´W, Puerto Cisnes, Puyuhuapi Channel, PC (44º43´S, 72º42´W and Magellan Straits, MS. AF polychaete fauna comprises 38 species, the macrobenthic taxon being most representative in terms of abundance and species richness. The importance of polychaetes seems to be higher in fjords than in channels. Low numbers of common species were detected among DC, PC, MS and AF, indicating differences along the influence area of the Cape Horn Current or along the Magellan Province. The polychaetes from AF show low affinities with Antarctica; maximum number of common species was observed with the Antarctic Peninsula, whereas the lowest values were recorded from locations in the Ross and Weddell Seas. Coincidence in some ecological attributes between AF and Antarctica indicate that polychaetes may play an important and similar ecological role in both environments.
Influence of Ross Sea Bottom Water changes on the warming and freshening of the Antarctic Bottom Water in the Australian-Antarctic Basin

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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.

Revision of Eocene Antarctic carpet sharks (Elasmobranchii, Orectolobiformes) from Seymour Island, Antarctic Peninsula.

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Engelbrecht, Andrea; Mörs, Thomas; Reguero, Marcelo A; Kriwet, Jürgen

2017-01-01

Seymour Island, Antarctic Peninsula, was once called the 'Rosetta Stone' of Southern Hemisphere palaeobiology, because this small island provides the most complete and richly fossiliferous Palaeogene sequence in Antarctica. Among fossil marine vertebrate remains, chondrichthyans seemingly were dominant elements in the Eocene Antarctic fish fauna. The fossiliferous sediments on Seymour Island are from the La Meseta Formation, which was originally divided into seven stratigraphical levels, TELMs 1-7 (acronym for Tertiary Eocene La Meseta) ranging from the upper Ypresian (early Eocene) to the late Priabonian (late Eocene). Bulk sampling of unconsolidated sediments from TELMs 5 and 6, which are Ypresian (early Eocene) and Lutetian (middle Eocene) in age, respectively, yielded very rich and diverse chondrichthyan assemblages including over 40 teeth of carpet sharks representing two new taxa, Notoramphoscyllium woodwardi gen. et sp. nov. and Ceolometlaouia pannucae gen. et sp. nov. Two additional teeth from TELM 5 represent two different taxa that cannot be assigned to any specific taxon and thus are left in open nomenclature. The new material not only increases the diversity of Eocene Antarctic selachian faunas but also allows two previous orectolobiform records to be re-evaluated. Accordingly, Stegostoma cf. faciatum is synonymized with Notoramphoscyllium woodwardi gen. et sp. nov., whereas Pseudoginglymostoma cf. brevicaudatum represents a nomen dubium . The two new taxa, and probably the additional two unidentified taxa, are interpreted as permanent residents, which most likely were endemic to Antarctic waters during the Eocene and adapted to shallow and estuarine environments.
Antarctic Bottom Water temperature changes in the western South Atlantic from 1989 to 2014

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Johnson, Gregory C.; McTaggart, Kristene E.; Wanninkhof, Rik

2014-12-01

Warming of abyssal waters in recent decades contributes to global heat uptake and sea level rise. Repeat oceanographic section data in the western South Atlantic taken mostly in 1989 (1995 across the Scotia Sea), 2005, and 2014 are used to quantify warming in abyssal waters that spread northward through the region from their Antarctic origins in the Weddell Sea. While much of the Scotia Sea warmed between 1995 and 2005, only the southernmost portion, on the north side of the Weddell Gyre, continued to warm between 2005 and 2014. The abyssal Argentine Basin also warmed between 1989 and 2005, but again only the southernmost portion continued to warm between 2005 and 2014, suggesting a slowdown in the inflow of the coldest, densest Antarctic Bottom Waters into the western South Atlantic between 1989 and 2014. In contrast, the abyssal waters of the Brazil Basin warmed both between 1989 and 2005 and between 2005 and 2014, at a rate of about 2 m°C yr-1. This warming is also assessed in terms of the rates of change of heights above the bottom for deep isotherms in each deep basin studied. These results, together with findings from previous studies, suggest the deep warming signal observed in the Weddell Sea after the mid-1970s Weddell Polynya was followed by abyssal warming in the Argentine Basin from the late 1970s through about 2005, then warming in the deep Vema Channel from about 1992 through at least 2010, and warming in the Brazil Basin from 1989 to 2014.
On the origin and evolution of Antarctic Peracarida (Crustacea, Malacostraca

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Angelika Brandt

1999-12-01

Full Text Available The early separation of Gondwana and the subsequent isolation of Antarctica caused a long evolutionary history of its fauna. Both, long environmental stability over millions of years and habitat heterogeneity, due to an abundance of sessile suspension feeders on the continental shelf, favoured evolutionary processes of preadapted taxa, like for example the Peracarida. This taxon performs brood protection and this might be one of the most important reasons why it is very successful (i.e. abundant and diverse in most terrestrial and aquatic environments, with some species even occupying deserts. The extinction of many decapod crustaceans in the Cenozoic might have allowed the Peracarida to find and use free ecological niches. Therefore the palaeogeographic, palaeoclimatologic, and palaeo-hydrographic changes since the Palaeocene (at least since about 60 Ma ago and the evolutionary success of some peracarid taxa (e.g. Amphipoda, Isopoda led to the evolution of many endemic species in the Antarctic. Based on a phylogenetic analysis of the Antarctic Tanaidacea, Sieg (1988 demonstrated that the tanaid fauna of the Antarctic is mainly represented by phylogenetically younger taxa, and data from other crustacean taxa led Sieg (1988 to conclude that the recent Antarctic crustacean fauna must be comparatively young. His arguments are scrutinized on the basis of more recent data on the phylogeny and biodiversity of crustacean taxa, namely the Ostracoda, Decapoda, Mysidacea, Cumacea, Amphipoda, and Isopoda. This analysis demonstrates that the origin of the Antarctic fauna probably has different roots: an adaptive radiation of descendants from old Gondwanian ancestors was hypothesized for the isopod families Serolidae and Arcturidae, an evolution and radiation of phylogenetically old taxa in Antarctica could also be shown for the Ostracoda and the amphipod family Iphimediidae. A recolonization via the Scotia Arc appears possible for some species, though it is
Bottom current deposition in the Antarctic Wilkes Land margin during the Oligocene

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Salabarnada, Ariadna; Escutia, Carlota; Nelson, Hans C.; Evangelinos, Dimitris; López-Quirós, Adrián

2017-04-01

Sediment cores collected from the Antarctic Wilkes Land continental rise at IODP site 1356 provide evidence for bottom current sedimentation taking place since the early Oligocene (i.e., 33.6 Ma) (Escutia et al., 2011). Correlation between site 1356 sediments and the regional grid of multichannel seismic reflection profiles, complemented with bathymetric data, allow us to differentiate a variety of contourite deposits resulting from the interaction between bottom currents and seafloor paleomorphologies. Contourite deposits are identified based on the seismic signature, reflector configuration and geometry of the depositional bodies as elongated-mounded drifts, giant mounded drifts, confined drifts, infill drifts, plastered drifts, sediment waves, and moats. Based on the spatial and temporal distribution of these deposits, we differentiate three phases in contourite deposition in this margin: Phase 1) from 33.6-28 Ma sheeted drift morphologies dominate, related to high-energy deposits associated with fast flowing currents during the early Oligocene; Phase 2) At around 28 Ma, mounded drift morphologies and moat channels start forming. Continued intensification of contour currents results in larger contourite morphologies such as giant mounded drifts and moats forming around structural heights present in the Wilkes Land basin (e.g, the Adelie Rift Block). Phase 3) A shift in current configuration is recorded at around 15 Ma above regional unconformity WL-U5, which marks the Oligocene-Miocene Transition. This change is shown by a migration to the North of the drift crests and by a dominance of down-slope sedimentation processes that is indicated by mass transport deposits and channel levee formation. We interpret the evolution of the contourite deposits during the Oligocene in this margin to be driven by changes in the intensity of bottom current activity over time resulting from ice sheet growth, evolution of bottom morphology and related changes in paleoceanographic
Studies of evolutionary temperature adaptation: muscle function and locomotor performance in Antarctic fish.

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Franklin, C E

1998-09-01

1. Studies of evolutionary temperature adaptation of muscle and locomotor performance in fish are reviewed with a focus on the Antarctic fauna living at subzero temperatures. 2. Only limited data are available to compare the sustained and burst swimming kinematics and performance of Antarctic, temperate and tropical species. Available data indicate that low temperatures limit maximum swimming performance and this is especially evident in fish larvae. 3. In a recent study, muscle performance in the Antarctic rock cod Notothenia coriiceps at 0 degree C was found to be sufficient to produce maximum velocities during burst swimming that were similar to those seen in the sculpin Myoxocephalus scorpius at 10 degrees C, indicating temperature compensation of muscle and locomotor performance in the Antarctic fish. However, at 15 degrees C, sculpin produce maximum swimming velocities greater than N. coriiceps at 0 degree C. 4. It is recommended that strict hypothesis-driven investigations using ecologically relevant measures of performance are undertaken to study temperature adaptation in Antarctic fish. Recent detailed phylogenetic analyses of the Antarctic fish fauna and their temperate relatives will allow a stronger experimental approach by helping to separate what is due to adaptation to the cold and what is due to phylogeny alone.
Spatio-temporal distribution of soft-bottom epibenthic fauna on the Cilician shelf (Turkey, Mediterranean Sea

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Erhan Mutlu

2008-12-01

Full Text Available Spatio-temporal distribution of epifauna collected with a sledge was studied on the Cilician shelf of the Mediterranean Sea. There were two different communities: the shallow community was restricted to water at 5 and 10 m deep with sandy bottom inhabited abundantly by Conomurex persicus, Arnoglossus laterna and Murex trunculus. Conomurex persicus, an introduced tropical species predominated the shallow zone and distinguished it from the deep zone. The deep community (25-150 m lacked shallow water species and was dominated by Arnoglossus laterna, Goneplax rhomboides and Parapenaeus longirostris. Seasonality was not a major factor in the epibenthic community structure of the entire shelf, but it is in the shallow waters. Bottom depth was main factor for structuring the community on the shelf. Sediment size and organic content is also a controlling factor for the\tdistribution of the epibenthic fauna. Rev. Biol. Trop. 56 (4: 1919-1946. Epub 2008 December 12.Se estudió la distribución espacio-temporal de la epifauna recolectada con un trineo en la plataforma de Armenia Menor, Mar Mediterráneo. Hubo dos comunidades diferentes: una comunidad de aguas someras entre los 5 y 10 metros de profundidad con fondo arenoso\thabitado en forma abundante por Conomurex persicus, Arnoglossus laterna y Murex trunculus. Conomurex persicus, una especie tropical introducida, predominó en la zona de aguas someras, y la diferenció de la zona profunda. La comunidad profunda (25-150 m no presentaba especies de aguas someras y estaba dominada por Arnoglossus laterna, Goneplax rhomboides y Parapenaeus longirostris. La estacionalidad no fue un factor importante en la estructura de la comunidad epibentónica presente en toda la plataforma, pero sí lo fue en las aguas someras. La profundidad del fondo del mar fue el factor principal en la estructura de la comunidad en la plataforma. El tamaño del sedimento y el contenido de\tmateria orgánica es\ttambién un factor que
Freshwater invertebrates of sub-Antarctic Marion Island | Dartnall ...

African Journals Online (AJOL)

The aquatic species include five platyhelminthes, a gastrotrich, three tardigrades, 28 rotifers, six nematodes, two annelids and 11 arthropods. Most are familiar species that have been recorded on other sub-Antarctic islands. The invertebrate faunas of the various freshwater habitats were basically similar in species ...
Antarctic crabs: invasion or endurance?

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Huw J Griffiths

Full Text Available 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
The alien terrestrial invertebrate fauna of the High Arctic archipelago of Svalbard: potential implications for the native flora and fauna

OpenAIRE

Stephen J. Coulson

2015-01-01

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 spec...
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.
Temporal, spatial and substrate-dependent variations of Danish hard-bottom macrofauna

DEFF Research Database (Denmark)

Dahl, L.; Dahl, K.

2002-01-01

Detailed knowledge of the Danish hard-bottom fauna is at present limited because of sampling problems. In this study, two different sampling units were used to yield quantitative results of the fauna on two stone reefs in Kattegat: natural holdfasts of Laminaria digitata and plastic pan-scourers ......Detailed knowledge of the Danish hard-bottom fauna is at present limited because of sampling problems. In this study, two different sampling units were used to yield quantitative results of the fauna on two stone reefs in Kattegat: natural holdfasts of Laminaria digitata and plastic pan...... on the Shannon-Wiener diversity index, and it showed a high degree of spatial and temporal variation. ANOSIM analyses showed a significant difference in species compositions between both sampling location, time and substrate type. The plastic pan-scourers proved to be a valuable substrate for quantitative...... investigations of the fauna. In contrast, the Laminaria holdfasts were too small and variable to be suitable for such studies...
Biodiversity of Antarctic echinoids: a comprehensive and interactive database

Directory of Open Access Journals (Sweden)

Bruno David

2005-12-01

Full Text Available Eighty-one echinoid species are present south of the Antarctic Convergence, and they represent an important component of the benthic fauna. “Antarctic echinoids” is an interactive database synthesising the results of more than 100 years of Antarctic expeditions, and comprising information about all echinoid species. It includes illustrated keys for determination of the species, and information about their morphology and ecology (text, illustrations and glossary and their distribution (maps and histograms of bathymetrical distribution; the sources of the information (bibliography, collections and expeditions are also provided. All these data (taxonomic, morphologic, geographic, bathymetric… can be interactively queried in two main ways: (1 display of listings that can be browsed, sorted according to various criteria, or printed; and (2 interactive requests crossing the different kinds of data. Many other possibilities are offered, and an on-line help file is also available.
SUGGESTIONS OF SCENARIOS FOR RESTORING LONGITUDINAL CONNECTIVITY TO SUSTAIN FISH FAUNA MIGRATION UPSTREAM AND DOWNSTREAM OF APAHIDA BOTTOM SILL

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Razvan VOICU

2016-12-01

Full Text Available Rivers and their corridors form complex ecosystems that include adjacent land, flora and fauna and the actual courses of water. Given the ecological criteria for prioritizing the rehabilitation of longitudinal continuity of watercourses recommended by the International Commission for Protection of the Danube River (ICPDR (Appendix 1 and starting from the analysis of the Management Plan to ensure longitudinal continuity of watercourses in Some?-Tisa River Area (Annex 9.17.a in BMP – Basin Management Plan there have been proposed several scenarios in order to facilitate fish species migration above the bottom sill from Apahida. The selected case study is focused on the mentioned discharge or bottom sill in Apahida town (hm 985 located 45 m downstream of the bridge located at the intersection of two streets; this bottom sill is 0.8 m high and was built in order to correct the slope, to reduce erosion and to enhance water oxygenation. Currently the bottom sill is supervised by Some?-Tisa River Basin Water Administration, Cluj SGA. One of the important migratory fish species in the study area is the Common Nase (Chondrostoma nasus protected by Bern Convention (Appendix III; barbel (Barbus barbus- rare species, protected Habitats Directive (Annex V,annex 4A of Low nr.462 and Red List of RBDD; bream (Abramis brama bream (Abramis brama - IUCN Red List of Threatened Species. The water catchment area of the Apahida commune in Cluj County blocks migration of various species of migratory fish such as: Common Nase (Chondrostoma nasus protected by the Bern Convention (Appendix III; Barbel (Barbus barbus - rare species, protected Habitats Directive (Annex V, Annex 4A of Low No 462 and Red List of RBDD; Bream (Abramis brama Bream (Abramis brama - IUCN Red List of Threatened Species. To help the three species of fish come the solutions proposed in this article.
types and abundance of arthropod fauna in relation to physico ...

African Journals Online (AJOL)

DJFLEX

TYPES AND ABUNDANCE OF ARTHROPOD FAUNA IN RELATION ... The occurrence of arthropods associated with the bottom sediment of Warri River was investigated, and samples were collected ..... to analysis of the vegetation on Danish.
The impact of tourists on Antarctic tardigrades: an ordination-based model

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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.
Response of benthic fauna to experimental bottom fishing

NARCIS (Netherlands)

Sciberras, Marija; Hiddink, Jan Geert; Jennings, Simon; Szostek, Claire L.; Hughes, Kathryn M.; Kneafsey, Brian; Clarke, Leo J.; Ellis, Nick; Rijnsdorp, Adriaan D.; Mcconnaughey, Robert A.; Hilborn, Ray; Collie, Jeremy S.; Pitcher, C.R.; Amoroso, Ricardo O.; Parma, Ana M.; Suuronen, Petri; Kaiser, Michel J.

2018-01-01

Bottom-contact fishing gears are globally the most widespread anthropogenic sources of direct disturbance to the seabed and associated biota. Managing these fishing disturbances requires quantification of gear impacts on biota and the rate of recovery following disturbance. We undertook a systematic
Assessing Fish and Motile Fauna around Offshore Windfarms Using Stereo Baited Video.

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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
On the distribution of decapod crustaceans from the Magellan Biogeographic Province and the Antarctic region

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Enrique E. Boschi

2005-12-01

Full Text Available The distribution of decapod crustaceans in the southernmost areas of South America and the Antarctic is assessed considering the Magellan Biogeographic Province instead of the antiboreal region. Possible associations between decapod crustaceans from the Magellan Biogeographic Province and those from the Antarctic region are analysed. Species records were assigned to seven geographic regions that were clustered using multivariate analyses based on species presence/absence and Bray-Curtis similarity. The results showed two well-established clusters, one of which included the Pacific and Atlantic areas of the Magellan Province, the southern tip of South America and the Kerguelen Arc islands, with the highest similarity between the southern tip and the Atlantic area. Another cluster was well separated and included the Antarctic and South Georgia with the highest similarity index. Earlier studies and results obtained here suggest that the faunas of southern Chile and southern Argentina are biogeographically related. There is a low level of association among decapod species from the circum-Antarctic region and the Magellan Province.
A study of the influence of noise from offshore wind power plants on the marine bottom fauna; En studie om hur bottenlevande fauna paaverkas av ljud fraan vindkraftverk till havs

Energy Technology Data Exchange (ETDEWEB)

Wikstroem, Andreas; Granmo, Aake

2009-09-15

The aim of this study was to examine changes of behaviour and activity patterns in marine soft bottom fauna under the influence of low frequent noise. Controlled experiments were performed at Kristineberg Marine Research Station in Fiskebaeckskil. The experiments were performed utilizing generator and vibrator techniques producing frequencies of 61, 178 and 721 Hz with an average sound pressure around 99 dB re 1 muPa. The selection of frequencies was based upon the sound profile measured at Utgrunden offshore wind farm in Kalmarsund (Ingemansson Technology, 2003) with the aim of recreating natural conditions. In order to quantify the sound exposure, measurements on both sound pressure and water particle acceleration in the test tanks were performed. In total four different marine soft bottom species were studied: a common little white mussel (Abra nitida), brittle star (Amphiura filiformis), brown shrimp (Crangon crangon) and juvenile plaice (Pleuronectes platessa). For the white mussel its burrowing ability was studied. First the speeds of burrowing down into the sediment and thereafter, the burrowing activity in the surface layer of the sediment for the duration of 96 hours were registered. During the experiments with the brittle star Amphiura filiformis the number of arms active in gathering food were observed shortly after the sound had started and for a period of 72 hours. When the brown shrimp was exposed for sound the number of prey items consumed during one day and after 4 days were observed. The study on juvenile plaice was only a shorter pilot study where the fish were exposed for sound during 15 minutes. During this restricted time swimming activity and burrowing activity were observed and after the initial 15 minutes also the respiration frequency during measurement for one minute were documented. The study showed that the burrowing activity increased for the white mussel compared to the controls during exposure of frequencies around 178 Hz after 24
Effect of mining activities on the clam fisheries and bottom fauna of Goa estuaries

Digital Repository Service at National Institute of Oceanography (India)

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

Comparison of two clam beds and associated benthic fauna, in Mandovi and Cumbarjua canal estuarine system of Goa, India, severely affected by massive inputs of mining rejects, revealed that, in less than 10 years (1972-73 to 1982-83), high biotic...

Early cenozoic differentiation of polar marine faunas.

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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.
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.
Water masses transform at mid-depths over the Antarctic Continental Slope

Science.gov (United States)

Mead Silvester, Jess; Lenn, Yueng-Djern; Polton, Jeffrey; Phillips, Helen E.; Morales Maqueda, Miguel

2017-04-01

The Meridional Overturning Circulation (MOC) controls the oceans' latitudinal heat distribution, helping to regulate the Earth's climate. The Southern Ocean is the primary place where cool, deep waters return to the surface to complete this global circulation. While water mass transformations intrinsic to this process predominantly take place at the surface following upwelling, recent studies implicate vertical mixing in allowing transformation at mid-depths over the Antarctic continental slope. We deployed an EM-Apex float near Elephant Island, north of the Antarctic Peninsula's tip, to profile along the slope and use potential vorticity to diagnose observed instabilities. The float captures direct heat exchange between a lens of Upper Circumpolar Deep Water (UCDW) and surrounding Lower Circumpolar Deep Waters (LCDW) at mid-depths and over the course of several days. Heat fluxes peak across the top and bottom boundaries of the UCDW lens and peak diffusivities across the bottom boundary are associated with shear instability. Estimates of diffusivity from shear-strain finestructure parameterisation and heat fluxes are found to be in reasonable agreement. The two-dimensional Ertel potential vorticity is elevated both inside the UCDW lens and along its bottom boundary, with a strong contribution from the shear term in these regions and instabilities are associated with gravitational and symmetric forcing. Thus, shear instabilities are driving turbulent mixing across the lower boundary between these two water masses, leading to the observed heat exchange and transformation at mid-depths over the Antarctic continental slope. This has implications for our understanding of the rates of upwelling and ocean-atmosphere exchanges of heat and carbon at this critical location.
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.
Report on field research of the Spanish Antarctic Campaign 2014/15: a cooperative international research project with the 56th Japanese Antarctic Research Expedition

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Sakae Kudoh

2015-07-01

Full Text Available A study on the limnological and ecological characteristics of maritime Antarctic lakes on Byers Peninsula, Livingstone Island, South Shetland Islands, West Antarctica, was conducted by the Spanish Antarctic Research Campaign during the 2014/15 season, in cooperation with the research program of the 56th Japanese Antarctic Research Expedition. Limnological surveys of three hillside lakes and three lagoons near beaches were conducted under conditions of heavy snow cover. Soils and biological samples in the catchment areas of the lakes and lagoons were also collected and analyzed. The hillside lakes were covered by thick ice and snow, which maintained winter water conditions in the lakes, such as irreversible stratification, oxygen depletion of bottom water, very weak underwater light conditions, etc., even in mid-January, although swimming zooplankton were abundant. Water samples were also collected in coastal lagoons and streams, an environment in which birds and marine mammals transport materials through the aquatic system.
Marine fauna of hard substrata of the Cleaver bank and Dogger bank

NARCIS (Netherlands)

Schrieken, N.; Gittenberger, A.; Coolen, J.W.P.; Lengkeek, W.

2013-01-01

As most of the sea bottom in the Dutch part of the North Sea consists of sand, marine fauna that live in association with hard substrates are rarely monitored. We report here on the results of a species inventory in June 2011 done by scuba-diving while focusing on a wreck on the Dogger Bank and on
Marine fauna of hard substrata of the Cleaver Bank and Dogger Bank

NARCIS (Netherlands)

Schrieken, N.; Gittenberger, A.; Coolen, J.W.P.; Lengkeek, W.

2013-01-01

As most of the sea bottom in the Dutch part of the North Sea consists of sand, marine fauna that live in association with hard substrates are rarely monitored. We report here on the results of a species inventory in June 2011 done by scuba-diving while focusing on a wreck on the Dogger Bank and on
Strong Flows of Bottom Water in Abyssal Channels of the Atlantic

Science.gov (United States)

Morozov, E. G.

Analysis of bottom water transport through the abyssal channels of the Atlantic Ocean is presented. The study is based on recent observations in the Russian expeditions and historical data. A strong flow of Antarctic Bottom Water from the Argentine Basin to the Brazil Basin through the Vema Channel is observed on the basis of lowered profilers and anchored buoys with current meters. The further flow of bottom water in the Brazil Basin splits in the northern part of the basin. Part of the bottom water flows to the East Atlantic through the Romanche and Chain fracture zones. The other part follows the bottom topography and flows to the northwester into the North American Basin. Part of the northwesterly flow propagates through the Vema Fracture Zone into the Northeastern Atlantic. This flow generally fills the bottom layer in the Northeastern Atlantic basins. The flows of bottom waters through the Romanche and Chain fracture zones do not spread to the Northeast Atlantic due to strong mixing in the equatorial zone and enhanced transformation of bottom water properties.
RELIEF JENIS-JENIS FAUNA DAN SETTING LINGKUNGANNYA PADA PAHATAN DINDING CANDI BOROBUDUR (Fauna and Environmental Setting Reliefs on Sculptured Wall of the Borobudur Temple

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Bambang Agus Suripto

2001-04-01

cavewalls inhabited by human, temples, pyramids, and sphinxes. Sculptures on the wall of Borobudur Temple, show fauna reliefs, but the originof the fauna are still obscure, whether or not they came from India or part of them were from Java. The objectives of this research were to determine the species of group names of the fauna picture in the reliefs on the sculptured wall of the Borobudur Temple, Their origin, and to assess whether of not Java environment settings were depicted in the wall. Pictures of fauna reliefs in sculpture wall of langkan, the main wall from top to bottom in each Rupadhatu levels were taken, the name of each fauna species or group was identified using identification books, and their origins were determined through a literature study. Data were interpreted descriptively in order to understand whether of not Java environment settings were portrayed in the sculptured wall of the Borobudur Temple. There are at least 25 species of Osteighthyes, Reptilia, aves and Mammalia classess pictured naturally in the reliefs of the wall, and at least 5 species are pictured setilirly. These entire fauna naturally found in south Asia. Some of them have never lived in Java Island, such as lion, Pantera leo. Environment settings of seventh centure India were illustrated very well in the reliefs however, those of Java until the Dutch colonial era were not pictured at all.
Dating Antarctic ice sheet collapse: Proposing a molecular genetic approach

Science.gov (United States)

Strugnell, Jan M.; Pedro, Joel B.; Wilson, Nerida G.

2018-01-01

Sea levels at the end of this century are projected to be 0.26-0.98 m higher than today. The upper end of this range, and even higher estimates, cannot be ruled out because of major uncertainties in the dynamic response of polar ice sheets to a warming climate. Here, we propose an ecological genetics approach that can provide insight into the past stability and configuration of the West Antarctic Ice Sheet (WAIS). We propose independent testing of the hypothesis that a trans-Antarctic seaway occurred at the last interglacial. Examination of the genomic signatures of bottom-dwelling marine species using the latest methods can provide an independent window into the integrity of the WAIS more than 100,000 years ago. Periods of connectivity facilitated by trans-Antarctic seaways could be revealed by dating coalescent events recorded in DNA. These methods allow alternative scenarios to be tested against a fit to genomic data. Ideal candidate taxa for this work would need to possess a circumpolar distribution, a benthic habitat, and some level of genetic structure indicated by phylogeographical investigation. The purpose of this perspective piece is to set out an ecological genetics method to help resolve when the West Antarctic Ice Shelf last collapsed.
The alien terrestrial invertebrate fauna of the High Arctic archipelago of Svalbard: potential implications for the native flora and fauna

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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.
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.
Benthic foraminiferal response to the emergence of the Isthmus of Panama and coincident paleoceanographic changes

Science.gov (United States)

McDougall, K.

1996-01-01

Late Cenozoic benthic foraminiferal faunas from the Caribbean Deep Sea Drilling Project (DSDP) Site 502 (3052 m) and East Pacific DSDP Site 503 (3572 m) were analyzed to interpret bottom-water masses and paleoceanographic changes occurring as the Isthmus of Panama emerged. Major changes during the past 7 Myr occur at 6.7-6.2, 3.4, 2.0, and 1.1 Ma in the Caribbean and 6.7-6.4, 4.0-3.2, 2.1, 1.4, and 0.7 Ma in the Pacific. Prior to 6.7 Ma, benthic foraminiferal faunas at both sites indicate the presence of Antarctic Bottom Water (AABW). After 6.7 Ma benthic foraminiferal faunas indicate a shift to warmer water masses: North Atlantic Deep Water (NADW) in the Caribbean and Pacific Deep Water (PDW) in the Pacific. Flow of NADW may have continued across the rising sill between the Caribbean and Pacific until 5.6 Ma when the Pacific benthic foraminiferal faunas suggest a decrease in bottom-water temperatures. After 5.6 Ma deep-water to intermediate-water flow across the sill appears to have stopped as the bottom-water masses on either side of the sill diverge. The second change recorded by benthic foraminiferal faunas occurs at 3.4 Ma in the Caribbean and 4.0-3.2 Ma in the Pacific. At this time the Caribbean is flooded with cold AABW, which is either gradually warmed or is replaced by Glacial Bottom Water (GBW) at 2.0 Ma and by NADW at 1.1 Ma. These changes are related to global climatic events and to the depth of the sill between the Caribbean and Atlantic rather than the rising Isthmus of Panama. Benthic foraminiferal faunas at East Pacific Site 503 indicate a gradual change from cold PDW to warmer PDW between 4.0 and 3.2 Ma. The PDW is replaced by the warmer, poorly oxygenated PIW at 2.1 Ma. Although the PDW affects the faunas during colder intervals between 1.4 and 0.7 Ma, the PIW remains the principal bottom- water mass in the Guatemala Basin of the East Pacific.
Impacts of marine instability across the East Antarctic Ice Sheet on Southern Ocean dynamics

Directory of Open Access Journals (Sweden)

S. J. Phipps

2016-09-01

Full Text Available 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.
Response of deep-sea benthic foraminifera to Miocene paleoclimatic events, DSDP site 289

International Nuclear Information System (INIS)

Woodruff, F.; Douglas, R.G.

1981-01-01

Changes in the Miocene deep-sea benthic foraminifera at DSDP Site 289 closely correlate to the climatically induced variations in deep and bottom waters in the Pacific Ocean. In early Miocene time, oxygen and carbon isotopes indicate that bottom waters were relatively warm and poorly oxygenated. Benthic foraminiferal assemblages are characterized by various species inherited from the Oligocene. Expansion of the Antarctic icecap in the early middle Miocene, 14-16 m.y. ago, increased oxygen isotope values, produced cold, more oxygenated bottom waters and lead to a turnover in the benthic foraminifera. An Oligocene-early Miocene assemblage was replaced by a cibicidoid-dominated assemblage. Some species became extinct and benthic faunas became more bathymetrically restricted with the increased stratification of deep waters in the ocean. In mid-Miocene time, Epistominella exigua and E. umbonifera, indicative of young, oxygenated bottom waters, are relatively common at DSDP Site 289. Further glacial expansion 5-9 m.y. ago lowered sealevel, increased oceanic upwelling and associated biological productivity and intensified the oxygen minima. Abundant hispid and costate uvigerines become a dominant faunal element at shallow depths above 2500 m as E. umbonifera becomes common to abundant below 2500 m. By late Miocene time, benthic faunas similar in species composition and proportion to modern faunas on the Ontong-Java plateau, had become established. (Auth.)
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.
Cold-Water Coral Distributions in the Drake Passage Area from Towed Camera Observations – Initial Interpretations

Science.gov (United States)

Waller, Rhian G.; Scanlon, Kathryn M.; Robinson, Laura F.

2011-01-01

Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the Drake Passage (Southern Ocean), yet high winds, frequent storms and strong currents make seafloor sampling particularly difficult. As a result, few attempts to collect biological data have been made, leading to a paucity of information on benthic habitats or fauna in this area, particularly those on primarily hard-bottom seamounts and ridges. During a research cruise in 2008 six locations were examined (two on the Antarctic margin, one on the Shackleton Fracture Zone, and three on seamounts within the Drake Passage), using a towed camera with onboard instruments to measure conductivity, temperature, depth and turbidity. Dominant fauna and bottom type were categorized from 200 randomized photos from each location. Cold-water corals were present in high numbers in habitats both on the Antarctic margin and on the current swept seamounts of the Drake Passage, though the diversity of orders varied. Though the Scleractinia (hard corals) were abundant on the sedimented margin, they were poorly represented in the primarily hard-bottom areas of the central Drake Passage. The two seamount sites and the Shackleton Fracture Zone showed high numbers of stylasterid (lace) and alcyonacean (soft) corals, as well as large numbers of sponges. Though data are preliminary, the geological and environmental variability (particularly in temperature) between sample sites may be influencing cold-water coral biogeography in this region. Each area observed also showed little similarity in faunal diversity with other sites examined for this study within all phyla counted. This manuscript highlights how little is understood of these isolated
Cold-water coral distributions in the drake passage area from towed camera observations--initial interpretations.

Directory of Open Access Journals (Sweden)

Rhian G Waller

Full Text Available Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the Drake Passage (Southern Ocean, yet high winds, frequent storms and strong currents make seafloor sampling particularly difficult. As a result, few attempts to collect biological data have been made, leading to a paucity of information on benthic habitats or fauna in this area, particularly those on primarily hard-bottom seamounts and ridges. During a research cruise in 2008 six locations were examined (two on the Antarctic margin, one on the Shackleton Fracture Zone, and three on seamounts within the Drake Passage, using a towed camera with onboard instruments to measure conductivity, temperature, depth and turbidity. Dominant fauna and bottom type were categorized from 200 randomized photos from each location. Cold-water corals were present in high numbers in habitats both on the Antarctic margin and on the current swept seamounts of the Drake Passage, though the diversity of orders varied. Though the Scleractinia (hard corals were abundant on the sedimented margin, they were poorly represented in the primarily hard-bottom areas of the central Drake Passage. The two seamount sites and the Shackleton Fracture Zone showed high numbers of stylasterid (lace and alcyonacean (soft corals, as well as large numbers of sponges. Though data are preliminary, the geological and environmental variability (particularly in temperature between sample sites may be influencing cold-water coral biogeography in this region. Each area observed also showed little similarity in faunal diversity with other sites examined for this study within all phyla counted. This manuscript highlights how little is understood of these
A regional benthic fauna assessment method for the Southern North Sea using Margalef diversity and reference value modelling

NARCIS (Netherlands)

Loon, van Willem M.G.M.; Walvoort, Dennis J.J.; Hoey, van Gert; Vina-Herbon, Christina; Blandon, Abigayil; Pesch, Roland; Schmitt, Petra; Scholle, Jörg; Heyer, Karin; Lavaleye, Marc; Phillips, Graham; Duineveld, Gerard C.A.; Blomqvist, Mats

2018-01-01

The aims of this study are to develop an optimized method for regional benthic fauna assessment of the Southern North Sea which (a) is sensitive and precise (quantified as the slope and the R2 value of the pressure-impact relationships, respectively) for the anthropogenic pressures bottom fishing
New Carcharhiniform Sharks (Chondrichthyes, Elasmobranchii) from the Early to Middle Eocene of Seymour Island, Antarctic Peninsula

Science.gov (United States)

Engelbrecht, Andrea; Mörs, Thomas; Reguero, Marcelo A.; Kriwet, Jürgen

2018-01-01

Seymour Island, Antarctic Peninsula, is known for its wealth of fossil remains. This island provides one of the richest fossiliferous Paleogene sequences in the world. Chondrichthyans seemingly dominate this Eocene marine fauna and offer a rare insight into high-latitude faunas during the Palaeogene. So far, only a few isolated teeth of carcharhinid sharks have been reported from Seymour Island. Bulk sampling in the well-exposed La Meseta and Submeseta formations yielded new and abundant chondrichthyan material, including numerous teeth of carcharhinid and triakid sharks. Here, we present a reevaluation of the previously described carcharhinid remains and a description of new taxa: Meridiogaleus cristatus, gen. et sp. nov., Kallodentis rythistemma, gen. et sp. nov., Abdounia richteri, sp. nov., and Abdounia mesetae, sp. nov. The carcharhiniforms Mustelus sp. and Galeorhinus sp. are reported based on rare material, whereas teeth previously assigned to Scoliodon represent a nomen dubium. PMID:29551850

Faunal diversity of the benthic amphipods (Crustacea of the Magellan region as compared to the Antarctic (preliminary results

Directory of Open Access Journals (Sweden)

Claude de Broyer

1999-12-01

Full Text Available To investigate the marine benthic ecosystems of the Magellan region and to compare them with the better known Antarctic systems, three campaigns were recently carried out in this area: the Joint Magellan Victor Hensen Campaign 1994, the Polarstern ANT XIII/4 cruise 1996, and the Vidal Gormaz CIMAR FIORDO II cruise 1996. Numerous and diverse zoobenthos samples were collected mostly with an Agassiz trawl and with a small dredge, an epibenthic sledge, with baited traps or by diving. All gears together gathered more than 132,000 specimens of gammaridean and caprellidean amphipods. 137 species of gammaridean amphipods have been identified from the material to date. About 20% of these species appear to be new for science. This taxonomic work takes place in the framework of a general revision of the Southern Ocean amphipod fauna undertaken by theAntarctic Amphipodologists Network. A complete list of the benthic species of gammaridean and caprellidean amphipods is presented, including the zoogeographical distribution and the new records. The new abundant material collected, still under study, will allow a comparison of faunal diversity, zoogeographical and ecological traits of the Magellan benthic amphipod taxocoenoses with those of the West and East Antarctic benthos.
Antarctic research today

International Nuclear Information System (INIS)

Hempel, G.

1982-01-01

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.)
Bottom-water observations in the Vema fracture zone

Science.gov (United States)

Eittreim, Stephen L.; Biscaye, Pierre E.; Jacobs, Stanley S.

1983-03-01

The Vema fracture zone trough, at 11°N between 41° and 45°E, is open to the west at the 5000-m level but is silled at the 4650-m level on the east where it intersects the axis of the Mid-Atlantic Ridge. The trough is filled with Antarctic Bottom Water (AABW) with a potential temperature of 1.32°C and salinity of 34.82 ppt. The bottom water is thermally well mixed in a nearly homogeneous layer about 700 m thick. The great thickness of this bottom layer, as compared with the bottom-water structure of the western Atlantic basin, may result from enhanced mixing induced by topographic constriction at the west end of the fracture zone trough. A benthic thermocline, with potential temperature gradients of about 1.2 mdeg m-1, is associated with an abrupt increase in turbidity with depth at about 1200 m above bottom. A transitional layer of more moderate temperature gradients, about 0.4 mdeg m-1, lies between the benthic thermocline above and the AABW below. The AABW layer whose depth-averaged suspended paniculate concentrations range from 8 to 19 μg L-1, is consistently higher in turbidity than the overlying waters. At the eastern end of the trough, 140 m below sill depth, very low northeastward current velocities, with maximums of 3 cm s-1, were recorded for an 11-day period.
Observed trends of soil fauna in the Antarctic Dry Valleys: early signs of shifts predicted under climate change.

Science.gov (United States)

Andriuzzi, W S; Adams, B J; Barrett, J E; Virginia, R A; Wall, D H

2018-02-01

Long-term observations of ecological communities are necessary for generating and testing predictions of ecosystem responses to climate change. We investigated temporal trends and spatial patterns of soil fauna along similar environmental gradients in three sites of the McMurdo Dry Valleys, Antarctica, spanning two distinct climatic phases: a decadal cooling trend from the early 1990s through the austral summer of February 2001, followed by a shift to the current trend of warming summers and more frequent discrete warming events. After February 2001, we observed a decline in the dominant species (the nematode Scottnema lindsayae) and increased abundance and expanded distribution of less common taxa (rotifers, tardigrades, and other nematode species). Such diverging responses have resulted in slightly greater evenness and spatial homogeneity of taxa. However, total abundance of soil fauna appears to be declining, as positive trends of the less common species so far have not compensated for the declining numbers of the dominant species. Interannual variation in the proportion of juveniles in the dominant species was consistent across sites, whereas trends in abundance varied more. Structural equation modeling supports the hypothesis that the observed biological trends arose from dissimilar responses by dominant and less common species to pulses of water availability resulting from enhanced ice melt. No direct effects of mean summer temperature were found, but there is evidence of indirect effects via its weak but significant positive relationship with soil moisture. Our findings show that combining an understanding of species responses to environmental change with long-term observations in the field can provide a context for validating and refining predictions of ecological trends in the abundance and diversity of soil fauna. © 2018 by the Ecological Society of America.
Direct observations of the Antarctic Slope Current transport at 113°E

Science.gov (United States)

Peña-Molino, B.; McCartney, M. S.; Rintoul, S. R.

2016-10-01

The Antarctic Slope Current (ASC), defined here as the region of westward flow along the continental slope off Antarctica, forms the southern limb of the subpolar gyres. It regulates the exchange of water across the shelf break and provides a path for interbasin westward transport. Despite its significance, the ASC remains largely unobserved around most of the Antarctic continent. Here we present direct velocity observations from a 17 month current meter moored array deployed across the continental slope between the 1000 and the 4200 m isobaths, in the southeastern Indian Ocean near 113°E. The observed time-mean flow consists of a surface-intensified jet associated with the Antarctic Slope Front (ASF) and a broader bottom-intensified westward flow that extends out to approximately the 4000 m isobath and is strongest along the upper slope. The time-mean transport of the ASC is -29.2 Sv. Fluctuations in the transport are large, typically exceeding the mean by a factor of 2. They are mainly due to changes in the northward extent of the current over the lower slope. However, seasonal changes in the wind also drive variations in the transport of the ASF and the flow in the upper slope. Both mean and variability are largely barotropic, thus invisible to traditional geostrophic methods.
Climate change and the marine ecosystem of the western Antarctic Peninsula

Science.gov (United States)

Clarke, Andrew; Murphy, Eugene J; Meredith, Michael P; King, John C; Peck, Lloyd S; Barnes, David K.A; Smith, Raymond C

2006-01-01

The Antarctic Peninsula is experiencing one of the fastest rates of regional climate change on Earth, resulting in the collapse of ice shelves, the retreat of glaciers and the exposure of new terrestrial habitat. In the nearby oceanic system, winter sea ice in the Bellingshausen and Amundsen seas has decreased in extent by 10% per decade, and shortened in seasonal duration. Surface waters have warmed by more than 1 K since the 1950s, and the Circumpolar Deep Water (CDW) of the Antarctic Circumpolar Current has also warmed. Of the changes observed in the marine ecosystem of the western Antarctic Peninsula (WAP) region to date, alterations in winter sea ice dynamics are the most likely to have had a direct impact on the marine fauna, principally through shifts in the extent and timing of habitat for ice-associated biota. Warming of seawater at depths below ca 100 m has yet to reach the levels that are biologically significant. Continued warming, or a change in the frequency of the flooding of CDW onto the WAP continental shelf may, however, induce sublethal effects that influence ecological interactions and hence food-web operation. The best evidence for recent changes in the ecosystem may come from organisms which record aspects of their population dynamics in their skeleton (such as molluscs or brachiopods) or where ecological interactions are preserved (such as in encrusting biota of hard substrata). In addition, a southwards shift of marine isotherms may induce a parallel migration of some taxa similar to that observed on land. The complexity of the Southern Ocean food web and the nonlinear nature of many interactions mean that predictions based on short-term studies of a small number of species are likely to be misleading. PMID:17405211
Climate change and the marine ecosystem of the western Antarctic Peninsula.

Science.gov (United States)

Clarke, Andrew; Murphy, Eugene J; Meredith, Michael P; King, John C; Peck, Lloyd S; Barnes, David K A; Smith, Raymond C

2007-01-29

The Antarctic Peninsula is experiencing one of the fastest rates of regional climate change on Earth, resulting in the collapse of ice shelves, the retreat of glaciers and the exposure of new terrestrial habitat. In the nearby oceanic system, winter sea ice in the Bellingshausen and Amundsen seas has decreased in extent by 10% per decade, and shortened in seasonal duration. Surface waters have warmed by more than 1 K since the 1950s, and the Circumpolar Deep Water (CDW) of the Antarctic Circumpolar Current has also warmed. Of the changes observed in the marine ecosystem of the western Antarctic Peninsula (WAP) region to date, alterations in winter sea ice dynamics are the most likely to have had a direct impact on the marine fauna, principally through shifts in the extent and timing of habitat for ice-associated biota. Warming of seawater at depths below ca 100 m has yet to reach the levels that are biologically significant. Continued warming, or a change in the frequency of the flooding of CDW onto the WAP continental shelf may, however, induce sublethal effects that influence ecological interactions and hence food-web operation. The best evidence for recent changes in the ecosystem may come from organisms which record aspects of their population dynamics in their skeleton (such as molluscs or brachiopods) or where ecological interactions are preserved (such as in encrusting biota of hard substrata). In addition, a southwards shift of marine isotherms may induce a parallel migration of some taxa similar to that observed on land. The complexity of the Southern Ocean food web and the nonlinear nature of many interactions mean that predictions based on short-term studies of a small number of species are likely to be misleading.
Variations of the Antarctic Circumpolar Current (ACC) in the Kerguelen Sector during the Last Deglaciation : sedimentological and geochemical evidences

Science.gov (United States)

Bout-Roumazeilles, V.; Beny, F.; Mazaud, A.; Michel, E.; Crosta, X.; Davies, G. R.; Bory, A. J. M.

2017-12-01

High-resolution sedimentological and geochemical records were obtained from two sediment cores recovered by the French R/V Marion Dufresne during the INDIEN-SUD-ACC cruises near the sub-Antarctic Kerguelen Islands (49°S). This area is ideal to record past oceanic and atmospheric changes in the Southern Ocean because they are currently located in the northern branch of the Antarctic Circumpolar Current and under the direct influence of Southern Hemisphere Westerly wind belt. This study focuses on the last termination, with specific emphasis on the impact of severe climatic events (Heinrich Stadial 1, Antarctic Cold Reversal, Younger Dryas) onto the ocean-atmospheric exchange. Results indicates that most of the sediment is derived from the Kerguelen Plateau, characterized by high smectite content. Periodically, a minor contribution of Antarctica is noticeable. In particular, illite variations suggest fast and short northward incursions of Antarctic Bottom Water, probably formed in the Prydz Bay during the last glaciation. Grainsize repartition combined to magnetic parameters show a southward migration of the ACC and the fronts associated from the beginning of the deglaciation, which is consistent with Southern Hemisphere climate variations. On the opposite, it highlights an asynchronous decrease of the ACC strength, with a large drop during the Antarctic Cold Reversal when atmospheric CO2 increase was slowed down. Thus, at least in the studied area, the ACC strength and the Antarctic Climate were not synchronous during the last deglaciation.
The Antarctic Master Directory -- the Electronic Card Catalog of Antarctic Data

Science.gov (United States)

Scharfen, G.; Bauer, R.

2003-12-01

The Antarctic Master Directory (AMD) is a Web-based, searchable record of thousands of Antarctic data descriptions. These data descriptions contain information about what data were collected, where they were collected, when they were collected, who the scientists are, who the point of contact is, how to get the data, and information about the format of the data and what documentation and bibliographic information exists. With this basic descriptive information about content and access for thousands of Antarctic scientific data sets, the AMD is a resource for scientists to advertise the data they have collected and to search for data they need. The AMD has been created by more than twenty nations which conduct research in the Antarctic under the auspices of the Antarctic Treaty. It is a part of the International Directory Network/Global Change Master Directory (IDN/GCMD). Using the AMD is easy. Users can search on subject matter key words, data types, geographic place-names, temporal or spatial ranges, or conduct free-text searches. To search the AMD go to: http://gcmd.nasa.gov/Data/portals/amd/. Contributing your own data descriptions for Antarctic data that you have collected is also easy. Scientists can start by submitting a short data description first (as a placeholder in the AMD, and to satisfy National Science Foundation (NSF) reporting requirements), and then add to, modify or update their record whenever it is appropriate. An easy to use on-line tool and a simple tutorial are available at: http://nsidc.org/usadcc. With NSF Office of Polar Programs (OPP) funding, the National Snow and Ice Data Center (NSIDC) operates the U.S. Antarctic Data Coordination Center (USADCC), partly to assist scientists in using and contributing to the AMD. The USADCC website is at http://nsidc.org/usadcc.
Antarctic station life: The first 15 years of mixed expeditions to the Antarctic

Science.gov (United States)

Sarris, Aspa

2017-02-01

This study examined the experiences of women who lived and worked on remote and isolated Antarctic stations for up to 15 months at a time. The study employed purposeful sampling and a longitudinal - processual approach to study women's experiences over the first 15 years of mixed gender Antarctic expeditions. The retrospective analysis was based on a semi-structured interview administered to 14 women upon their return to Australia. The results showed that women referred to the natural physical Antarctic environment as one of the best aspects of their experience and the reason they would recommend the Antarctic to their friends as a good place to work. In describing the worst aspect of their experience, women referred to aspects of Antarctic station life, including: (i) the male dominated nature of station culture; (ii) the impact of interpersonal conflict, including gender based conflict and friction between scientists and trades workers; and (iii) the lack of anonymity associated with living and working with the same group of individuals, mainly men, for up to 12 months or more. The results are discussed within the context of the evolution of Antarctic station culture and recommendations are made in terms of the demography of expeditions, expeditioner selection and recruitment and the ongoing monitoring of Antarctic station culture. The study presents a framework that can be applied to groups and teams living and working in analogous isolated, confined and extreme work environments, including outer space missions.
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.
Productivity and linkages of the food web of the southern region of the western Antarctic Peninsula continental shelf

Science.gov (United States)

Ballerini, Tosca; Hofmann, Eileen E.; Ainley, David G.; Daly, Kendra; Marrari, Marina; Ribic, Christine A.; Smith, Walker O.; Steele, John H.

2014-03-01

The productivity and linkages in the food web of the southern region of the west Antarctic Peninsula continental shelf were investigated using a multi-trophic level mass balance model. Data collected during the Southern Ocean Global Ocean Ecosystem Dynamics field program were combined with data from the literature on the abundance and diet composition of zooplankton, fish, seabirds and marine mammals to calculate energy flows in the food web and to infer the overall food web structure at the annual level. Sensitivity analyses investigated the effects of variability in growth and biomass of Antarctic krill (Euphausia superba) and in the biomass of Antarctic krill predators on the structure and energy fluxes in the food web. Scenario simulations provided insights into the potential responses of the food web to a reduced contribution of large phytoplankton (diatom) production to total primary production, and to reduced consumption of primary production by Antarctic krill and mesozooplankton coincident with increased consumption by microzooplankton and salps. Model-derived estimates of primary production were 187-207 g C m-2 y-1, which are consistent with observed values (47-351 g C m-2 y-1). Simulations showed that Antarctic krill provide the majority of energy needed to sustain seabird and marine mammal production, thereby exerting a bottom-up control on higher trophic level predators. Energy transfer to top predators via mesozooplanton was a less efficient pathway, and salps were a production loss pathway because little of the primary production they consumed was passed to higher trophic levels. Increased predominance of small phytoplankton (nanoflagellates and cryptophytes) reduced the production of Antarctic krill and of its predators, including seabirds and seals.
Climate-dependent evolution of Antarctic ectotherms: An integrative analysis

Science.gov (United States)

Pörtner, Hans O.

2006-04-01

The paper explores the climate-dependent evolution of marine Antarctic fauna and tries to identify key mechanisms involved as well as the driving forces that have caused the physiological and life history characteristics observed today. In an integrative approach it uses the recent concept of oxygen and capacity limited thermal tolerance to identify potential links between molecular, cellular, whole-organism, and ecological characteristics of marine animal life in the Antarctic. As a generalized pattern, minimization of baseline energy costs, for the sake of maximized growth in the cold, appears as one over-arching principle shaping the evolution and functioning of Antarctic marine ectotherms. This conclusion is supported by recent comparisons with (sub-) Arctic ectotherms, where elevated levels of energy turnover result at unstable, including cold temperatures, and are related to wide windows of thermal tolerance and associated metabolic features. At biochemical levels, metabolic regulation at low temperatures in general, is supported by the cold compensation of enzyme kinetic parameters like substrate affinities and turnover numbers, through minute structural modifications of the enzyme molecule. These involve a shift in protein folding, sometimes supported by the replacement of individual amino acids. The hypothesis is developed that efficient metabolic regulation at low rates in Antarctic marine stenotherms occurs through high mitochondrial densities at low capacities and possibly enhanced levels of Arrhenius activation energies or activation enthalpies. This contrasts the more costly patterns of metabolic regulation at elevated rates in cold-adapted eurytherms. Energy savings in Antarctic ectotherms, largely exemplified in fish, typically involve low-cost, diffusive oxygen distribution due to high density of lipid membranes, loss of haemoglobin, myoglobin and the heat shock response, reduced anaerobic capacity, large myocytes with low ion exchange activities
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...
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
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
Ecology and living conditions of groundwater fauna

International Nuclear Information System (INIS)

Thulin, Barbara; Hahn, Hans Juergen

2008-09-01

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
FRASNIAN AND VISEAN-NAMURIAN CONODONT FAUNAS AT PRAPROTNO, SLOVENIA

OpenAIRE

KOLAR-JURKOVSEK, TEA; JURKOVSEK, BOGDAN

2017-01-01

Conodont faunas from the limestone pebbles of the Upper Paleozoic Conglomerate at Praprotno, Slovenia demonstrate the presence of two faunas. The older fauna, marked by Palmatolepis surecta and Polygnathus decorosus is indicative of the Frasnian stage (Upper Devonian). The younger fauna is dominated by Gnathodus bilineatus and contains Lochriea commutata and L. nodosa. This fauna is characteristic of the Late Visean-Namurian (Lower Carboniferous).
Pakistan and Antarctic research - an overview

International Nuclear Information System (INIS)

Rizvi, S.H.

1993-01-01

The paper describes the significance of Antarctica and the necessity of conducting scientific research for the understanding of the global environment and through various environmental processes operative in Antarctica. The paper presents a review of the Pakistan's activities and research interests in Antarctica focussing on the salient features of the Pakistan's Antarctic Research Programme and objectives. It summarises the significance of Antarctica, Antarctic Research and the interests of the world in Antarctica and international co-operation for Antarctic Research. The paper also highlights the philosophy of Antarctic Science and provides some guidelines for the development of Antarctic Research programmes for Pakistan and for the newcomers in Antarctica particularly for the developing countries. (author)
Dynamics of the Antarctic Circumpolar Current as seen by GRACE (Invited)

Science.gov (United States)

Thomas, M.; Dobslaw, H.; Bergmann, I.

2010-12-01

The Antarctic Circumpolar Current, being the strongest and longest ocean current on Earth, connects the three great ocean basins and contributes substantially to the global re-distribution of water masses, with a significant impact on global climate. Observational coverage from in-situ measurements is sparse due to the harsh environmental conditions, and satellite altimetry does not capture the full extent of the current due to seasonal sea-ice coverage. Ocean bottom pressure variations as sensed with the satellite gravity mission GRACE provide a promising way to broaden our observational basis. Besides monthly mean gravity fields that provide ocean bottom pressure variations averaged over 30 days, several alternative GRACE products with higher temporal resolution have been developed during the most recent years. These include 10-day solutions from GRGS Toulouse, weekly solutions from the GFZ Potsdam as well as constrained daily solutions from the University of Bonn which have been obtained by means of a Kalman filtering approach. In this presentation, ocean bottom pressure derived from these alternative GRACE releases will be contrasted against both in-situ observations and output from a numerical ocean model, highlighting the additional information contained in these GRACE solutions with respect to the standard monthly fields. By means of statistical analyses of ocean bottom pressure variations and barotropic transports it will be demonstrated how these new GRACE releases are contributing to our understanding of this highly dynamic great ocean conveyor.

Estimation of Antarctic Land-Fast Sea Ice Algal Biomass and Snow Thickness From Under-Ice Radiance Spectra in Two Contrasting Areas

Science.gov (United States)

Wongpan, P.; Meiners, K. M.; Langhorne, P. J.; Heil, P.; Smith, I. J.; Leonard, G. H.; Massom, R. A.; Clementson, L. A.; Haskell, T. G.

2018-03-01

Fast ice is an important component of Antarctic coastal marine ecosystems, providing a prolific habitat for ice algal communities. This work examines the relationships between normalized difference indices (NDI) calculated from under-ice radiance measurements and sea ice algal biomass and snow thickness for Antarctic fast ice. While this technique has been calibrated to assess biomass in Arctic fast ice and pack ice, as well as Antarctic pack ice, relationships are currently lacking for Antarctic fast ice characterized by bottom ice algae communities with high algal biomass. We analyze measurements along transects at two contrasting Antarctic fast ice sites in terms of platelet ice presence: near and distant from an ice shelf, i.e., in McMurdo Sound and off Davis Station, respectively. Snow and ice thickness, and ice salinity and temperature measurements support our paired in situ optical and biological measurements. Analyses show that NDI wavelength pairs near the first chlorophyll a (chl a) absorption peak (≈440 nm) explain up to 70% of the total variability in algal biomass. Eighty-eight percent of snow thickness variability is explained using an NDI with a wavelength pair of 648 and 567 nm. Accounting for pigment packaging effects by including the ratio of chl a-specific absorption coefficients improved the NDI-based algal biomass estimation only slightly. Our new observation-based algorithms can be used to estimate Antarctic fast ice algal biomass and snow thickness noninvasively, for example, by using moored sensors (time series) or mapping their spatial distributions using underwater vehicles.
Chemical and visual sensory systems in feeding behaviour of the Antarctic fish Ophthalmolycus amberensis (Zoarcidae

Directory of Open Access Journals (Sweden)

Edith Fanta

2001-03-01

Full Text Available The Antarctic eelpout Ophthalmolycus amberensis occurs in Admiralty Bay (King George Island, South Shetlands, at 140-200m depth, where light intensity is low. To assess behavioural and sensory adaptations for feeding under these conditions, laboratory tests were undertaken. Dead krill, fish fillet, and live amphipods were the preferred food items. Feeding responses were mainly induced by chemical stimuli. Visual stimuli were weak elicitors, leading to a long delay in the initiation of feeding behaviour. These fishes present a large olfactory epithelium, a high density of taste buds on the snout and close to the nostrils, and a retina that contained long rods, but no cones. Food selection was observed. Varied types of taste buds were present on the lips and in the oro-pharyngeal cavity. The capacity to use a chemo-sensory system as first elicitor for food detection, either in the absence or presence of light, allows O. amberensis to efficiently exploit different habitats at the sea bottom, in all Antarctic seasons.
Coherency Between Volume Transport in the Antarctic Circumpolar Current and Southern Hemisphere Winds

Science.gov (United States)

Makowski, Jessica; Chambers, Don; Bonin, Jennifer

2013-04-01

Previous studies have suggested that ocean bottom pressure (OBP) can be used to measure the transport variability of the Antarctic Circumpolar Current (ACC). The OBP observations from the Gravity Recovery and Climate Experiment (GRACE) will be used to calculate transport along the 150°E longitude choke point, between Antarctica and Australia. We will examine whether zonally averaged wind stress, wind stress curl, or local zonal winds are more coherent with zonal mass transport variability. Preliminary studies suggest that seasonal variation in transport across 150°E is more correlated with winds along and north of the northern front of the ACC: the Sub Tropical front (STF). It also appears that interannual variations in transport along 150°E are related to wind variations south of the STF and centered south of the Sub Antarctic Front (SAF). We have observed a strong anti-correlation across the SAF, in the Indian Ocean, which suggests wind stress curl may also be responsible for transport variations. Preliminary results will be presented.
Productivity and linkages of the food web of the southern region of the western Antarctic Peninsula continental shelf

Science.gov (United States)

Ballerini, Tosca; Hofmann, Eileen E.; Ainley, David G.; Daly, Kendra L.; Marrari, Marina; Ribic, Christine A.; Smith, Walker O.; Steele, John H.

2014-01-01

The productivity and linkages in the food web of the southern region of the west Antarctic Peninsula continental shelf were investigated using a multi-trophic level mass balance model. Data collected during the Southern Ocean Global Ocean Ecosystem Dynamics field program were combined with data from the literature on the abundance and diet composition of zooplankton, fish, seabirds and marine mammals to calculate energy flows in the food web and to infer the overall food web structure at the annual level. Sensitivity analyses investigated the effects of variability in growth and biomass of Antarctic krill (Euphausia superba) and in the biomass of Antarctic krill predators on the structure and energy fluxes in the food web. Scenario simulations provided insights into the potential responses of the food web to a reduced contribution of large phytoplankton (diatom) production to total primary production, and to reduced consumption of primary production by Antarctic krill and mesozooplankton coincident with increased consumption by microzooplankton and salps. Model-derived estimates of primary production were 187–207 g C m−2 y−1, which are consistent with observed values (47–351 g C m−2 y−1). Simulations showed that Antarctic krill provide the majority of energy needed to sustain seabird and marine mammal production, thereby exerting a bottom-up control on higher trophic level predators. Energy transfer to top predators via mesozooplanton was a less efficient pathway, and salps were a production loss pathway because little of the primary production they consumed was passed to higher trophic levels. Increased predominance of small phytoplankton (nanoflagellates and cryptophytes) reduced the production of Antarctic krill and of its predators, including seabirds and seals.
Lithuanian mammal fauna review

Directory of Open Access Journals (Sweden)

Linas Balciauskas

1996-12-01

Full Text Available Abstract Data on Lithuania mammal fauna are presented. From 78 mammal species recorded in Lithuania, 7 were seen only in the 17-18th centuries, two species are extinct. Recent Lithuanian mammal fauna contains 68 species. Five of them are observed occasionally. 63 mammal species are permant inhabitants, 18 included in the Red Data Book, mostly bats and dormice. 8 mammal species were introduced or reintroduced. Population tendencies of game animals are also considered.
Macrozoobenthic recolonization of the littoral and the soft bottom after an oil spill

International Nuclear Information System (INIS)

Lax, H.J.; Vainio, T.

1988-01-01

Two years after the Eira oil spill the oil concentration in the water had returned to its background level (0.5 ug/l) in the open sea areas. On the polluted shores (depth 0.1- 0.5 m) higher concentrations (2.3 ug/l) occurred occasionaly. No clear effects related to the oil spill were noticed on the dominating soft bottom species (Macoma baltica, Pontoporeia affinis). Among the other soft bottom species the crustacean Corophium volutator showed its lowest density immediately after the spill, becoming more and more abundant during the following two years. The effect of the oil spill on the littoral fauna could still be noticed two years after the spill. The crustacean Gammarus duebeni avoided its natural habitat (uppermost littoral zone). Lymnaea palustris showed and increased mortality immediately after the oil spill but recolonized the polluted shores a normal distribution
Increased Ice-age Influence of Antarctic Intermediate Water.

Science.gov (United States)

Muratli, J.; McManus, J.; Mix, A.; Chase, Z.

2008-12-01

A depth transect of three ODP sites collected along the central Chile Margin constrain Antarctic Intermediate Water (AAIW) distributions and regional export production over the last 30 ka. Reduced Re and Cd, and increased Mn are proxies for higher bottom water oxygenation; 230Th-normalized burial of opal is a proxy for productivity. Mn/Al is high during the glacial interval at all three sites, suggesting high oxygenation and the retreat of the oxygen minimum zone during this period. At Site 1233, within the core of modern AAIW, Re and Cd are unchanged from detrital values throughout the last 30 ky, implying continuously oxic conditions. In contrast, at the northern sites 1234 and 1235, which reside below and above AAIW respectively, Re and Cd rise rapidly from low glacial values at ~15ka, signifying lower oxygen concentrations at the sea floor during Holocene time relative to ice-age conditions. Local productivity, recorded in Th-normalized opal burial, is highest during the glacial interval at both sites 1233 and 1234, and varies independently from the redox proxies. We conclude that local productivity does not drive bottom water oxygenation here, and that ventilation of the shallow subsurface southeast Pacific increased during the last ice age, with an expanded depth range of AAIW relative to the present.
A recent case of Antarctic bioprospecting from Japan

Directory of Open Access Journals (Sweden)

Akiho Shibata

2010-03-01

Full Text Available Antarctic bioprospecting, namely the search for valuable genetic or chemical compounds in Antarctic nature, has been the subject of intense discussion within Antarctic Treaty Consultative Meetings. In this discussion, based on the so-called "end-users view point," utilizing the patent database to see how much Antarctic biological material has been used in patents, Antarctic bioprospecting has been depicted as a lucrative commercial activity operated by big multinational companies. This paper, instead, proposes an "access view point" for Antarctic bioprospecting, by examining a recent Japanese case in which scientists participating in the Japanese Antarctic Research Expedition in 2007 collected some sediment from Antarctic lakes near Syowa Station, isolated and cultured a particular fungus, and found the first evidence of the presence of antifreezing activity in oomycetes. In 2009, the scientists' affiliate institutions, including the National Institute of Advanced Industrial Science and Technology, applied for a patent on Antarctomyces psychrotrophicus Syw-1 and the antifreeze protein obtained from it. A detailed examination of this case demonstrates that the dichotomy of Antarctic bioprospecting into "commercial" and "scientific" does not reflect the reality of bioprospecting activities and, therefore, does not provide an appropriate ground for legal and policy discussion on Antarctic bioprospecting.
Marine litter in the upper São Vicente submarine canyon (SW Portugal): Abundance, distribution, composition and fauna interactions.

Science.gov (United States)

Oliveira, Frederico; Monteiro, Pedro; Bentes, Luis; Henriques, Nuno Sales; Aguilar, Ricardo; Gonçalves, Jorge M S

2015-08-15

Marine litter has become a worldwide environmental problem, tainting all ocean habitats. The abundance, distribution and composition of litter and its interactions with fauna were evaluated in the upper S. Vicente canyon using video images from 3 remote operated vehicle exploratory dives. Litter was present in all dives and the abundance was as high as 3.31 items100m(-1). Mean abundance of litter over rock bottom was higher than on soft substrate. Mean litter abundance was slightly higher than reported for other canyons on the Portuguese margin, but lower in comparison to more urbanized coastal areas of the world. Lost fishing gear was the prevalent type of litter, indicating that the majority of litter originates from maritime sources, mainly fishing activity. Physical contact with sessile fauna and entanglement of specimens were the major impacts of lost fishing gear. Based on the importance of this region for the local fishermen, litter abundance is expected to increase. Copyright © 2015 Elsevier Ltd. All rights reserved.
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
Distribution and abundance of Antarctic krill (Euphausia superba) along the Antarctic Peninsula

Science.gov (United States)

Siegel, Volker; Reiss, Christian S.; Dietrich, Kimberly S.; Haraldsson, Matilda; Rohardt, Gerhard

2013-07-01

Net-based data on the abundance, distribution, and demographic patterns of Antarctic krill are quantified from a contemporaneous two ship survey of the Antarctic Peninsula during austral summer 2011. Two survey areas were sampled focussed on Marguerite Bay in the south, and the tip of the Antarctic Peninsula in the north. Data from 177 stations showed that the highest concentrations of krill were found in the southern sampling area. Differences between areas were associated with a few large catches of one year old krill found in anomalously warm and productive waters in Marguerite Bay, and small krill catches in the less-productive, offshore waters in the north. Estimated krill density across the survey area was 3.4 krill m-2, and was low compared to the long-term average of 45 krill m-2 for the Elephant Island area. Overall recruitment between the two survey regions was similar, but per capita recruitment was about 60% lower than historical mean recruitment levels measured at Elephant Island since the late 1970s. Demographic patterns showed small krill concentrated near the coast, and large krill concentrated offshore on the shelf and slope all along the survey area. The offshore distribution of adult krill was delineated by the warm (˜1 °C), low salinity (33.8) water at 30 m, suggesting that most krill were present shoreward of the southern boundary of Antarctic Circumpolar Current Front. Distributions of larvae indicated that three hotspot areas were important for the production of krill: slope areas outside Marguerite Bay and north of the South Shetland Islands, and near the coast around Antarctic Sound. Successful spawning, as inferred from larval abundance, was roughly coincident with the shelf break and not with inshore waters. Given the rapid changes in climate along the Antarctic Peninsula and the lower per capita recruitment observed in recent years, studies comparing and contrasting production, growth, and recruitment across the Peninsula will be
Development of a Regional Glycerol Dialkyl Glycerol Tetraether (GDGT) - Temperature Calibration for Antarctic and sub-Antarctic Lakes

Science.gov (United States)

Roberts, S. J.; Foster, L. C.; Pearson, E. J.; Steve, J.; Hodgson, D.; Saunders, K. M.; Verleyen, E.

2016-12-01

Temperature calibration models based on the relative abundances of sedimentary glycerol dialkyl glycerol tetraethers (GDGTs) have been used to reconstruct past temperatures in both marine and terrestrial environments, but have not been widely applied in high latitude environments. This is mainly because the performance of GDGT-temperature calibrations at lower temperatures and GDGT provenance in many lacustrine settings remains uncertain. To address these issues, we examined surface sediments from 32 Antarctic, sub-Antarctic and Southern Chilean lakes. First, we quantified GDGT compositions present and then investigated modern-day environmental controls on GDGT composition. GDGTs were found in all 32 lakes studied. Branched GDGTs (brGDGTs) were dominant in 31 lakes and statistical analyses showed that their composition was strongly correlated with mean summer air temperature (MSAT) rather than pH, conductivity or water depth. Second, we developed the first regional brGDGT-temperature calibration for Antarctic and sub-Antarctic lakes based on four brGDGT compounds (GDGT-Ib, GDGT-II, GDGT-III and GDGT-IIIb). Of these, GDGT-IIIb proved particularly important in cold lacustrine environments. Our brGDGT-Antarctic temperature calibration dataset has an improved statistical performance at low temperatures compared to previous global calibrations (r2=0.83, RMSE=1.45°C, RMSEP-LOO=1.68°C, n=36 samples), highlighting the importance of basing palaeotemperature reconstructions on regional GDGT-temperature calibrations, especially if specific compounds lead to improved model performance. Finally, we applied the new Antarctic brGDGT-temperature calibration to two key lake records from the Antarctic Peninsula and South Georgia. In both, downcore temperature reconstructions show similarities to known Holocene warm periods, providing proof of concept for the new Antarctic calibration model.
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
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.
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
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
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
Draft genome of the Antarctic dragonfish, Parachaenichthys charcoti.

Science.gov (United States)

Ahn, Do-Hwan; Shin, Seung Chul; Kim, Bo-Mi; Kang, Seunghyun; Kim, Jin-Hyoung; Ahn, Inhye; Park, Joonho; Park, Hyun

2017-08-01

The Antarctic bathydraconid dragonfish, Parachaenichthys charcoti, is an Antarctic notothenioid teleost endemic to the Southern Ocean. The Southern Ocean has cooled to -1.8ºC over the past 30 million years, and the seawater had retained this cold temperature and isolated oceanic environment because of the Antarctic Circumpolar Current. Notothenioids dominate Antarctic fish, making up 90% of the biomass, and all notothenioids have undergone molecular and ecological diversification to survive in this cold environment. Therefore, they are considered an attractive Antarctic fish model for evolutionary and ancestral genomic studies. Bathydraconidae is a speciose family of the Notothenioidei, the dominant taxonomic component of Antarctic teleosts. To understand the process of evolution of Antarctic fish, we select a typical Antarctic bathydraconid dragonfish, P. charcoti. Here, we have sequenced, de novo assembled, and annotated a comprehensive genome from P. charcoti. The draft genome of P. charcoti is 709 Mb in size. The N50 contig length is 6145 bp, and its N50 scaffold length 178 362 kb. The genome of P. charcoti is predicted to contain 32 712 genes, 18 455 of which have been assigned preliminary functions. A total of 8951 orthologous groups common to 7 species of fish were identified, while 333 genes were identified in P. charcoti only; 2519 orthologous groups were also identified in both P. charcoti and N. coriiceps, another Antarctic fish. Four gene ontology terms were statistically overrepresented among the 333 genes unique to P. charcoti, according to gene ontology enrichment analysis. The draft P. charcoti genome will broaden our understanding of the evolution of Antarctic fish in their extreme environment. It will provide a basis for further investigating the unusual characteristics of Antarctic fishes. © The Author 2017. Published by Oxford University Press.
[Effects of global change on soil fauna diversity: A review].

Science.gov (United States)

Wu, Ting-Juan

2013-02-01

Terrestrial ecosystem consists of aboveground and belowground components, whose interaction affects the ecosystem processes and functions. Soil fauna plays an important role in biogeochemical cycles. With the recognizing of the significance of soil fauna in ecosystem processes, increasing evidences demonstrated that global change has profound effects on soil faunima diversity. The alternation of land use type, the increasing temperature, and the changes in precipitation pattern can directly affect soil fauna diversity, while the increase of atmospheric CO2 concentration and nitrogen deposition can indirectly affect the soil fauna diversity by altering plant community composition, diversity, and nutrient contents. The interactions of different environmental factors can co-affect the soil fauna diversity. To understand the effects of different driving factors on soil fauna diversity under the background of climate change would facilitate us better predicting how the soil fauna diversity and related ecological processes changed in the future.
Life style and biochemical adaptation in Antarctic fishes

Science.gov (United States)

di Prisco, Guido

2000-12-01

Respiration and metabolism are under investigation in Antarctic fish, in an effort to understand the interplay between ecology and biochemical and physiological processes. Fish of the dominant suborder Notothenioidei are red-blooded, except Channichthyidae (the most phyletically derived family), whose genomes retain transcriptionally inactive DNA sequences closely related to the α-globin gene of red-blooded notothenioids and have lost the β-globin locus. Our structure/function studies on 38 of the 80 red-blooded species are aimed at correlating sequence, multiplicity and oxygen binding with ecological constraints and at obtaining phylogenetic information on evolution. For comparative purposes, this work has been extended to non-Antarctic notothenioids. All sluggish bottom dwellers have a single major hemoglobin (Hb) and often a minor, functionally similar one. Three species of the family Nototheniidae have different life styles. They have uniquely specialised oxygen-transport systems, adjusted to the mode of life of each species. Artedidraconidae have a single Hb, lacking oxygen-binding cooperativity, similar to the ancestral hemoproteins of primitive organisms. The amino acid sequences are currently used in the molecular modelling approach. The study of several enzymes with key roles in metabolism (e.g. glucose-6-phosphate dehydrogenase, L-glutamate dehydrogenase, phosphorylase b, carbonic anhydrase) indicate that some aspects of the molecular structure (e.g. molecular mass, number of subunits, amino acid sequence, temperature of irreversible heat inactivation) have been conserved during development of cold adaptation. However, high catalytic efficiency, possibly due to subtle molecular changes, is observed at low temperature.

Air-sea interaction regimes in the sub-Antarctic Southern Ocean and Antarctic marginal ice zone revealed by icebreaker measurements

Science.gov (United States)

Yu, Lisan; Jin, Xiangze; Schulz, Eric W.; Josey, Simon A.

2017-08-01

This study analyzed shipboard air-sea measurements acquired by the icebreaker Aurora Australis during its off-winter operation in December 2010 to May 2012. Mean conditions over 7 months (October-April) were compiled from a total of 22 ship tracks. The icebreaker traversed the water between Hobart, Tasmania, and the Antarctic continent, providing valuable in situ insight into two dynamically important, yet poorly sampled, regimes: the sub-Antarctic Southern Ocean and the Antarctic marginal ice zone (MIZ) in the Indian Ocean sector. The transition from the open water to the ice-covered surface creates sharp changes in albedo, surface roughness, and air temperature, leading to consequential effects on air-sea variables and fluxes. Major effort was made to estimate the air-sea fluxes in the MIZ using the bulk flux algorithms that are tuned specifically for the sea-ice effects, while computing the fluxes over the sub-Antarctic section using the COARE3.0 algorithm. The study evidenced strong sea-ice modulations on winds, with the southerly airflow showing deceleration (convergence) in the MIZ and acceleration (divergence) when moving away from the MIZ. Marked seasonal variations in heat exchanges between the atmosphere and the ice margin were noted. The monotonic increase in turbulent latent and sensible heat fluxes after summer turned the MIZ quickly into a heat loss regime, while at the same time the sub-Antarctic surface water continued to receive heat from the atmosphere. The drastic increase in turbulent heat loss in the MIZ contrasted sharply to the nonsignificant and seasonally invariant turbulent heat loss over the sub-Antarctic open water.Plain Language SummaryThe icebreaker Aurora Australis is a research and supply vessel that is regularly chartered by the Australian Antarctic Division during the southern summer to operate in waters between Hobart, Tasmania, and Antarctica. The vessel serves as the main lifeline to three permanent research stations on the
Modification of deep waters in Marguerite Bay, western Antarctic Peninsula, caused by topographic overflows

Science.gov (United States)

Venables, Hugh J.; Meredith, Michael P.; Brearley, J. Alexander

2017-05-01

Circumpolar Deep Water (CDW) intrudes from the mid-layers of the Antarctic Circumpolar Current onto the shelf of the western Antarctic Peninsula, providing a source of heat and nutrients to the regional ocean. It is well known that CDW is modified as it flows across the shelf, but the mechanisms responsible for this are not fully known. Here, data from underwater gliders with high spatial resolution are used to demonstrate the importance of detailed bathymetry in inducing multiple local mixing events. Clear evidence for overflows is observed in the glider data as water flows along a deep channel with multiple transverse ridges. The ridges block the densest waters, with overflowing water descending several hundred metres to fill subsequent basins. This vertical flow leads to entrainment of overlying colder and fresher water in localised mixing events. Initially this process leads to an increase in bottom temperatures due to the temperature maximum waters descending to greater depths. After several ridges, however, the mixing is sufficient to remove the temperature maximum completely and the entrainment of colder thermocline waters to depth reduces the bottom temperature, to approximately the same as in the source region of Marguerite Trough. Similarly, it is shown that deep waters of Palmer Deep are warmer than at the same depth at the shelf break. The exact details of the transformations observed are heavily dependent on the local bathymetry and water column structure, but glacially-carved troughs and shallow sills are a common feature of the bathymetry of polar shelves, and these types of processes may be a factor in determining the hydrographic conditions close to the coast across a wider area.
Lichen flora around the Korean Antarctic Scientific Station, King George Island, Antarctic.

Science.gov (United States)

Kim, Ji Hee; Ahn, In-Young; Hong, Soon Gyu; Andreev, Mikhail; Lim, Kwang-Mi; Oh, Mi Jin; Koh, Young Jin; Hur, Jae-Seoun

2006-10-01

As part of the long-term monitoring projects on Antarctic terrestrial vegetation in relation to global climate change, a lichen floristical survey was conducted around the Korean Antarctic Station (King Sejong Station), which is located on Barton Peninsula, King George Island, in January and February of 2006. Two hundred and twenty-five lichen specimens were collected and sixty-two lichen species in 38 genera were identified by morphological characteristics, chemical constituents, TLC analysis and ITS nucleotide sequence analysis.
RADARSAT: The Antarctic Mapping Project

Science.gov (United States)

Jezek, Kenneth C.; Lindstrom, E. (Technical Monitor)

2002-01-01

The first Antarctic Imaging Campaign (AIC) occurred during the period September 9, 1997 through October 20, 1997. The AIC utilized the unique attributes of the Canadian RADARSAT-1 to acquire the first, high-resolution, synthetic aperture imagery covering the entire Antarctic Continent. Although the primary goal of the mission was the acquisition of image data, the nearly flawless execution of the mission enabled additional collections of exact repeat orbit data. These data, covering an extensive portion of the interior Antarctic, potentially are suitable for interferometric analysis of topography and surface velocity. This document summarizes the Project through completion with delivery of products to the NASA DAACs.
Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation

Science.gov (United States)

Coxall, Helen K.; Huck, Claire E.; Huber, Matthew; Lear, Caroline H.; Legarda-Lisarri, Alba; O'Regan, Matt; Sliwinska, Kasia K.; van de Flierdt, Tina; de Boer, Agatha M.; Zachos, James C.; Backman, Jan

2018-03-01

The onset of the North Atlantic Deep Water formation is thought to have coincided with Antarctic ice-sheet growth about 34 million years ago (Ma). However, this timing is debated, in part due to questions over the geochemical signature of the ancient Northern Component Water (NCW) formed in the deep North Atlantic. Here we present detailed geochemical records from North Atlantic sediment cores located close to sites of deep-water formation. We find that prior to 36 Ma, the northwestern Atlantic was stratified, with nutrient-rich, low-salinity bottom waters. This restricted basin transitioned into a conduit for NCW that began flowing southwards approximately one million years before the initial Antarctic glaciation. The probable trigger was tectonic adjustments in subarctic seas that enabled an increased exchange across the Greenland-Scotland Ridge. The increasing surface salinity and density strengthened the production of NCW. The late Eocene deep-water mass differed in its carbon isotopic signature from modern values as a result of the leakage of fossil carbon from the Arctic Ocean. Export of this nutrient-laden water provided a transient pulse of CO2 to the Earth system, which perhaps caused short-term warming, whereas the long-term effect of enhanced NCW formation was a greater northward heat transport that cooled Antarctica.
Environmental constraints on West Antarctic ice-sheet formation

Energy Technology Data Exchange (ETDEWEB)

Lindstrom, D R; MacAyeal, D R

1987-01-01

Small perturbations in Antarctic environmental conditions can culminate in the demise of the Antarctic ice sheet's western sector. This may have happened during the last interglacial period, and could recur within the next millennium due to atmospheric warming from trace gas and CO/sub 2/ increases. In this study, we investigate the importance of sea-level, accumulation rate, and ice influx from the East Antarctic ice sheet in the re-establishment of the West Antarctic ice sheet from a thin cover using a time-dependent numerical ice-shelf model. Our results show that a precursor to the West Antarctic ice sheet can form within 3000 years. Sea-level lowering caused by ice-sheet development in the Northern Hemisphere has the greatest environmental influence. Under favorable conditions, ice grounding occurs over all parts of the West Antarctic ice sheet except up-stream of Thwaites Glacier and in the Ross Sea region.
Development of fauna of water beetles (Coleoptera in waters bodies of a river valley – habitat factors, landscape and geomorphology

Directory of Open Access Journals (Sweden)

Pakulnicka Joanna

2016-01-01

Full Text Available The goal of the study was to identify the beetle fauna of a small lowland river valley against its spatial arrangement and the directions of beetle migrations between habitats, as well as to determine which environmental factors affect the characteristics of water beetle populations in a river valley's lentic water bodies. The field studies were carried out in various types of water bodies. 112 species of beetles with various ecological characteristics were identified. It was demonstrated that the diversity of water bodies in the valley is conducive to high local species richness. At the same time, the observed high degree of faunistic individualism may be regarded as a sign of poor symmetry in the directions of fauna propagation, particularly that of stagnobionts. The authors argue that high individualism is the consequence of poor hydrological contact between the water bodies due to topography and rare instances of high tide in the river, which, in turn, is the reason for active overflights remaining the main mean of migration between those water bodies. The factors restricting migration of fauna between the water bodies include certain landscape characteristics of the catchment which form topographical obstacles, mainly numerous and dense forest areas. The character of fauna in the respective types of water bodies is affected also by internal environmental factors, particularly the degree to which they are overgrown with macrophytes, type of bottom, type of mineral and organic matter as well as physical parameters of water, such as saturation, pH, temperature and biological oxygen demand.
Airspace: Antarctic Sound Transmission

OpenAIRE

Polli, Andrea

2009-01-01

This paper investigates how sound transmission can contribute to the public understanding of climate change within the context of the Poles. How have such transmission-based projects developed specifically in the Arctic and Antarctic, and how do these works create alternative pathways in order to help audiences better understand climate change? The author has created the media project Sonic Antarctica from a personal experience of the Antarctic. The work combines soundscape recordings and son...
Soil invertebrate fauna enhances grassland succession and diversity.

Science.gov (United States)

De Deyn, Gerlinde B; Raaijmakers, Ciska E; Zoomer, H Rik; Berg, Matty P; de Ruiter, Peter C; Verhoef, Herman A; Bezemer, T Martijn; van der Putten, Wim H

2003-04-17

One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation. Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores. More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein. However, the influence of invertebrate soil fauna on succession has so far received little attention. Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity. Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages. Soil fauna from the mid-succession stage had the strongest effect. Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity.
Antarctic climate change and the environment

Science.gov (United States)

2009-11-01

This volume provides a comprehensive, up-to-date account of how the physical and biological : environment of the Antarctic continent and Southern Ocean has changed from Deep Time until : the present day. It also considers how the Antarctic environmen...
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.
South African antarctic biological research programme

CSIR Research Space (South Africa)

SASCAR

1981-07-01

Full Text Available This document provides a description of the past, current and planned South African biological research activities in the sub-Antarctic and Antarctic regions. Future activities will fall under one of the five components of the research programme...
Neoglacial Antarctic sea-ice expansion driven by mid-Holocene retreat of the Ross Ice Shelf.

Science.gov (United States)

Bendle, J. A.; Newton, K.; Mckay, R. M.; Crosta, X.; Etourneau, J.; Anya, A. B.; Seki, O.; Golledge, N. R.; Bertler, N. A. N.; Willmott, V.; Schouten, S.; Riesselman, C. R.; Masse, G.; Dunbar, R. B.

2017-12-01

Recent decades have seen expanding Antarctic sea-ice coverage, coeval with thinning West Antarctic Ice Sheet (WAIS) ice shelves and the rapid freshening of surface and bottom waters along the Antarctic margin. The mid-Holocene Neoglacial transition represents the last comparable baseline shift in sea-ice behaviour. The drivers and feedbacks involved in both the recent and Holocene events are poorly understood and characterised by large proxy-model mismatches. We present new records of compound specific fatty acid isotope analyses (δ2H-FA), highly-branched isoprenoid alkenes (HBIs) TEX86L temperatures, grain-size, mass accumulations rates (MARs) and image analyses from a 171m Holocene sediment sequence from Site U1357 (IODP leg 318). In combination with published records we reconstruct Holocene changes in glacial meltwater, sedimentary inputs and sea-ice. The early Holocene (11 to 10 ka) is characterised by large fluctuations in inputs of deglacial meltwater and sediments and seismic evidence of downlapping material from the south, suggesting a dominating influence from glacial retreat of the local outlet glaciers. From 10 to 8 ka there is decreasing meltwater inputs, an onlapping drift and advection of material from the east. After ca. 8 ka positively correlated δ2H-FA and MARs infer that pulses of glacial melt correlate to stronger easterly currents, driving erosion of material from upstream banks and that the Ross Ice Shelf (RIS) becomes a major influence. A large mid-Holocene meltwater pulse (preceded by warming TEX86L temperatures) is evident between ca. 6 to 4.5 ka, culminating in a rapid and permanent increase in sea-ice from 4.5 ka. This is coeval with cosmogenic nuclide evidence for a rapid thinning of the Antarctic ice sheet during the mid-Holocene (Hein et al., 2016). We suggest this represents a final major pulse of deglaciation from the Ross Ice Shelf, which initiates the Neoglacial, driving cool surface waters along the coast and greater sea
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.
Persistent organohalogen contaminant burdens in Antarctic krill (Euphausia superba) from the eastern Antarctic sector: A baseline study

International Nuclear Information System (INIS)

Bengtson Nash, S.M.; Poulsen, A.H.; Kawaguchi, S.; Vetter, W.; Schlabach, M.

2008-01-01

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
The changing form of Antarctic biodiversity.

Science.gov (United States)

Chown, Steven L; Clarke, Andrew; Fraser, Ceridwen I; Cary, S Craig; Moon, Katherine L; McGeoch, Melodie A

2015-06-25

Antarctic biodiversity is much more extensive, ecologically diverse and biogeographically structured than previously thought. Understanding of how this diversity is distributed in marine and terrestrial systems, the mechanisms underlying its spatial variation, and the significance of the microbiota is growing rapidly. Broadly recognizable drivers of diversity variation include energy availability and historical refugia. The impacts of local human activities and global environmental change nonetheless pose challenges to the current and future understanding of Antarctic biodiversity. Life in the Antarctic and the Southern Ocean is surprisingly rich, and as much at risk from environmental change as it is elsewhere.
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
Implications for Crustal Structures and Heat Fluxes from Depth-to-the-Bottom of the Magnetic Source Estimates in West Antarctica, Amundsen Sea Sector

Science.gov (United States)

Dziadek, R.; Ferraccioli, F.; Gohl, K.; Spiegel, C.; Kaul, N. E.

2017-12-01

The West Antarctic Rift System is one of the least understood rift systems on earth, but displays a unique coupled relationship between tectonic processes and ice sheet dynamics. Geothermal heat flux (GHF) is a poorly constrained parameter in Antarctica and suspected to affect basal conditions of ice sheets, i.e., basal melting and subglacial hydrology. Thermomechanical models demonstrate the influential boundary condition of geothermal heat flux for (paleo) ice sheet stability. Young, continental rift systems are regions with significantly elevated geothermal heat flux (GHF), because the transient thermal perturbation to the lithosphere caused by rifting requires 100 Ma to reach long-term thermal equilibrium. We discuss airborne, high-resolution magnetic anomaly data from the Amundsen Sea Sector, to provide additional insight into deeper crustal structures related to the West Antarctic Rift System in the Amundsen/Bellingshausen sector. With the depth-to-the-bottom of the magnetic source (DBMS) estimates we reveal spatial changes at the bottom of the igneous crust and the thickness of the magnetic layer, which can be further incorporated into tectonic interpretations. The DBMS also marks an important temperature transition zone of approximately 580°C and therefore serves as a boundary condition for our numerical FEM thermal models in 2D and 3D.
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.
[Community structure of soil fauna in Eucalyptus grandis plantations at different slope locations].

Science.gov (United States)

Zhao, Yu; Zhong, Yu; Zhang, Jian; Yang, Wan-qin

2010-09-01

To understand the effects of slope location on the community structure of soil fauna in Eucalyptus grandis plantation, an investigation was made on the soil fauna in 3 E. grandis plantations at different slope locations in the hilly area of Sichuan Province from January to October 2009. A total of 39,2762 individuals were observed, belonging to 146 groups, 7 phyla, 16 classes, and 31 orders. The community composition, trophic group, diversity, and seasonal dynamics of soil fauna in the plantations all varied with slope. The abundance of macro-fauna, xeric meso- and micro-fauna, saprophagous macro-fauna, and omnivorous xeric meso- and micro-fauna increased with the decrease of slope, indicating that soil fauna had sensitive responses to the soil environmental factors affected by slope. Significant differences in the diversity of soil saprophagous macro-fauna and hygrophilous meso- and micro-fauna were observed at different slope locations, suggesting that these two faunal groups could be used as the indicators of the habitat heterogeneity of E. grandis plantations at different slope. Overall, slope location had definite effects on the community structure and distribution of soil fauna in the E. grandis plantations, but the effects were not statistically significant.

Carbon dioxide emissions of Antarctic tourism

NARCIS (Netherlands)

Farreny, R.; Oliver-Solà, J.; Lamers, M.A.J.; Amelung, B.; Gabarrell, X.; Rieradevall, J.; Boada, M.; Benayas, J.

2011-01-01

The increase of tourism to the Antarctic continent may entail not only local but also global environmental impacts. These latter impacts, which are mainly caused by transport, have been generally ignored. As a result, there is a lack of data on the global impacts of Antarctic tourism in terms of
Recent progress in ecological studies of soil fauna

NARCIS (Netherlands)

Hasegawa, Motohiro; Fujii, Saori; Kaneda, Satoshi; Ikeda, Hiroshi; Hishi, Takuo; Hyodo, Fujio; Kobayashi, Makoto

2017-01-01

Progress in ecological studies of soil fauna includes studies of the role and effects of soil fauna on decomposition and soil carbon dynamics in relation to global environmental changes, the introduction of molecular biology approaches to such studies, feeding habit analysis using stable isotopes,
Topography of Spoil Heaps and Its Role in Plant Succession and Soil Fauna Presence

Directory of Open Access Journals (Sweden)

Walmsley A.

2017-03-01

Full Text Available The spoil heaps from brown coal mining without technical reclamation are interesting specific sites for ecological relationships observation. This research was aimed at investigating whether topographic features, which determine soil nutrient and moisture distribution, in combination with soil fauna (wireworm and earthworm presence, affect plant community composition at a spontaneously revegetated post mining area with an undulating surface. Two sites of different age with three types of topographic features were selected, soil moisture and nutrient contents were measured, and plant community composition and soil macrofauna community were sampled at each position. Wireworms were present at all positions and were most abundant at the bottoms of waves at the younger site; their presence was correlated with the presence of several plant species with high palatability for wireworms, but the direction of the interaction is not clear. Earthworms were only present at the older site and had the highest abundance at flat sections. Earthworm presence affected the amount of nitrogen in soil - the highest nitrogen content was at the site with the highest earthworm density and was followed by a higher diversity of plant community. The plant community composition was generally correlated with plant available nutrient content - especially P and N. We infer that topographic features affect nutrient and soil fauna distribution, which consequently influences the plant community composition.
Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years

Science.gov (United States)

Gardner, Alex S.; Moholdt, Geir; Scambos, Ted; Fahnstock, Mark; Ligtenberg, Stefan; van den Broeke, Michiel; Nilsson, Johan

2018-02-01

Ice discharge from large ice sheets plays a direct role in determining rates of sea-level rise. We map present-day Antarctic-wide surface velocities using Landsat 7 and 8 imagery spanning 2013-2015 and compare to earlier estimates derived from synthetic aperture radar, revealing heterogeneous changes in ice flow since ˜ 2008. The new mapping provides complete coastal and inland coverage of ice velocity north of 82.4° S with a mean error of image pairs acquired during the daylight period. Using an optimized flux gate, ice discharge from Antarctica is 1929 ± 40 Gigatons per year (Gt yr-1) in 2015, an increase of 36 ± 15 Gt yr-1 from the time of the radar mapping. Flow accelerations across the grounding lines of West Antarctica's Amundsen Sea Embayment, Getz Ice Shelf and Marguerite Bay on the western Antarctic Peninsula, account for 88 % of this increase. In contrast, glaciers draining the East Antarctic Ice Sheet have been remarkably constant over the period of observation. Including modeled rates of snow accumulation and basal melt, the Antarctic ice sheet lost ice at an average rate of 183 ± 94 Gt yr-1 between 2008 and 2015. The modest increase in ice discharge over the past 7 years is contrasted by high rates of ice sheet mass loss and distinct spatial patters of elevation lowering. The West Antarctic Ice Sheet is experiencing high rates of mass loss and displays distinct patterns of elevation lowering that point to a dynamic imbalance. We find modest increase in ice discharge over the past 7 years, which suggests that the recent pattern of mass loss in Antarctica is part of a longer-term phase of enhanced glacier flow initiated in the decades leading up to the first continent-wide radar mapping of ice flow.
Chilean Antarctic Stations on King George Island

OpenAIRE

Katsutada Kaminuma

2000-01-01

The purpose of my visit to Chilean Antarctic Stations was to assess the present status of geophysical observations and research, as the South Shetland Island, West Antarctica, where the stations are located, are one of the most active tectonic regions on the Antarctic plate. The Instituto Antartico Chileno (INACH) kindly gave me a chance to stay in Frei/Escudero Bases as an exchange scientist under the Antarctic Treaty for two weeks in January 2000. I stayed in Frei Base as a member of a geol...
Reconsidering connectivity in the sub-Antarctic.

Science.gov (United States)

Moon, Katherine L; Chown, Steven L; Fraser, Ceridwen I

2017-11-01

Extreme and remote environments provide useful settings to test ideas about the ecological and evolutionary drivers of biological diversity. In the sub-Antarctic, isolation by geographic, geological and glaciological processes has long been thought to underpin patterns in the region's terrestrial and marine diversity. Molecular studies using increasingly high-resolution data are, however, challenging this perspective, demonstrating that many taxa disperse among distant sub-Antarctic landmasses. Here, we reconsider connectivity in the sub-Antarctic region, identifying which taxa are relatively isolated, which are well connected, and the scales across which this connectivity occurs in both terrestrial and marine systems. Although many organisms show evidence of occasional long-distance, trans-oceanic dispersal, these events are often insufficient to maintain gene flow across the region. Species that do show evidence of connectivity across large distances include both active dispersers and more sedentary species. Overall, connectivity patterns in the sub-Antarctic at intra- and inter-island scales are highly complex, influenced by life-history traits and local dynamics such as relative dispersal capacity and propagule pressure, natal philopatry, feeding associations, the extent of human exploitation, past climate cycles, contemporary climate, and physical barriers to movement. An increasing use of molecular data - particularly genomic data sets that can reveal fine-scale patterns - and more effective international collaboration and communication that facilitates integration of data from across the sub-Antarctic, are providing fresh insights into the processes driving patterns of diversity in the region. These insights offer a platform for assessing the ways in which changing dispersal mechanisms, such as through increasing human activity and changes to wind and ocean circulation, may alter sub-Antarctic biodiversity patterns in the future. © 2017 Cambridge
Environmental radioactivity in the antarctic station

International Nuclear Information System (INIS)

Gonzalez, S.; Osores, J.; Martinez, J.; Lopez, E.; Jara, R.

1998-01-01

Study about environmental radioactivity in the Peruvian antarctic station Machu Pichu they were carried out during the last three periods to the southern summer. The objective of the project it is to evaluate environmental component in order to elaborate a study it base on the levels background radioactivity and artificial in the antarctic region
FORMATION OF THE FOREST CENOSIS AT THE BOTTOM OF THE DRIED UP LAKES IN DRY STEPPE ZONE OF THE CHECHEN REPUBLIC

Directory of Open Access Journals (Sweden)

R. S. Erzhapova

2012-01-01

Full Text Available At the present time the lake Generalskiy completely went dry, water surface of the lake Maerskiy is a little more than 1 hectare. The bottom of the lake Generalskiy is completely overgrown by woody, shrubby and grassy vegetation. Was formed here biocenosis with their flora and fauna, which is a kind of «island of life» among the surrounding Sands. In the article the systematic list of the vegetation cover are given.
Lower Carboniferous Siderites: A Product of Bottom Seeps and Bacterial Metanogenesis (Subpolar Urals)

Science.gov (United States)

Antoshkina, A. I.; Ryabinkina, N. N.

2018-02-01

Complex modern micro- and spectroscopic methods for study of siderite concretions in the Lower Carboniferous terrigenous strata on the Kozhym River (Subpolar Urals) have shown that its formation was caused by destruction of clay minerals due to the activity of bacterial communities. The abundance of these bacteria was caused by gas-fluid seeps and bacterial methanogenesis processes in bottom deposits. In basins with normal marine fauna, this led to local desalination, hydrogen sulfide contamination, mass collapse of primary organisms, and the development of element-specific bacteria. The occurrence of these bacteria caused the formation of specific authigenic mineralization in the concretion of sideritic bacteriolites: the framboidal pyrite, sphalerite, galenite, barite, sulfoselenides, and tellurides.
Soil fauna: key to new carbon models

Science.gov (United States)

Filser, Juliane; Faber, Jack H.; Tiunov, Alexei V.; Brussaard, Lijbert; Frouz, Jan; De Deyn, Gerlinde; Uvarov, Alexei V.; Berg, Matty P.; Lavelle, Patrick; Loreau, Michel; Wall, Diana H.; Querner, Pascal; Eijsackers, Herman; José Jiménez, Juan

2016-11-01

Soil organic matter (SOM) is key to maintaining soil fertility, mitigating climate change, combatting land degradation, and conserving above- and below-ground biodiversity and associated soil processes and ecosystem services. In order to derive management options for maintaining these essential services provided by soils, policy makers depend on robust, predictive models identifying key drivers of SOM dynamics. Existing SOM models and suggested guidelines for future SOM modelling are defined mostly in terms of plant residue quality and input and microbial decomposition, overlooking the significant regulation provided by soil fauna. The fauna controls almost any aspect of organic matter turnover, foremost by regulating the activity and functional composition of soil microorganisms and their physical-chemical connectivity with soil organic matter. We demonstrate a very strong impact of soil animals on carbon turnover, increasing or decreasing it by several dozen percent, sometimes even turning C sinks into C sources or vice versa. This is demonstrated not only for earthworms and other larger invertebrates but also for smaller fauna such as Collembola. We suggest that inclusion of soil animal activities (plant residue consumption and bioturbation altering the formation, depth, hydraulic properties and physical heterogeneity of soils) can fundamentally affect the predictive outcome of SOM models. Understanding direct and indirect impacts of soil fauna on nutrient availability, carbon sequestration, greenhouse gas emissions and plant growth is key to the understanding of SOM dynamics in the context of global carbon cycling models. We argue that explicit consideration of soil fauna is essential to make realistic modelling predictions on SOM dynamics and to detect expected non-linear responses of SOM dynamics to global change. We present a decision framework, to be further developed through the activities of KEYSOM, a European COST Action, for when mechanistic SOM models
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.

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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
Activities of the training vessel Umitaka-maru (KARE16 ; UM-12-08 of the Tokyo University of Marine Science and Technology during the 54th Japanese Antarctic Research Expedition in 2012/2013

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Yujiro Kitade

2016-07-01

Full Text Available A marine science cruise was undertaken in the Indian sector of the Southern Ocean during the 2012/2013 austral summer on the training vessel Umitaka-maru (KARE16; UM-12-08 of the Tokyo University of Marine Science and Technology (TUMSAT. A primary aim of the cruise was to carry out a TUMSAT and National Institute of Polar Research (NIPR collaborative project commissioned by the Ministry of Education, Culture, Sports, Science and Technology (MEXT, entitled“Japanese Antarctic Research Expedition (JARE Routine Observation: Physical and Chemical Oceanography”. In addition to the MEXT-commissioned project, two TUMSAT-NIPR collaborative projects were conducted: 1“Studies on Plankton Community Structure and Environment Parameters in the Southern Ocean”, which is one of the original research projects of the JARE phase VIII (JAREs-52 to -57 projects; and 2“Environment and Ecosystem Changes in the Southern Ocean”. The Umitaka-maru departed from Fremantle, Australia, on 31 December 2012, sailed to the study area situated along 110°E in the marginal sea ice zone, and returned to Hobart, Australia, on 24 January 2013. Detailed properties of the Antarctic bottom water were revealed from physical and chemical oceanographic observations collected using a conductivity-temperature-depth profiler deployed to near the seafloor in the marginal ice zone. In addition, participants performed various net castings to qualitatively evaluate the vertical distribution of plankton communities, and deployed two year-round mooring arrays to assess the dynamics of Antarctic bottom water.
Ferromanganese nodule fauna in the Tropical North Pacific Ocean: Species richness, faunal cover and spatial distribution

Science.gov (United States)

Veillette, Julie; Sarrazin, Jozée; Gooday, Andrew J.; Galéron, Joëlle; Caprais, Jean-Claude; Vangriesheim, Annick; Étoubleau, Joël; Christian, James R.; Kim Juniper, S.

2007-11-01

The poorly known ferromanganese nodule fauna is a widespread hard substratum community in the deep sea that will be considerably impacted by large-scale nodule mining operations. The objective of this study was to analyze the spatial distribution of the fauna attached to nodules in the Clarion-Clipperton Fracture Zone at two scales; a regional scale that includes the east (14°N, 130°W) and the west (9°N, 150°W) zones and a local scale in which different geological facies (A, B, C and west) are recognizable. The fauna associated with 235 nodules was quantitatively described: 104 nodules from the east zone (15 of facies A, 50 of facies B and 39 of facies C) and 131 nodules from the west zone. Percent cover was used to quantify the extent of colonization at the time of sampling, for 42 species out of the 62 live species observed. Fauna covered up to 18% of exposed nodule surface with an average of about 3%. While species richness increased with exposed nodule surface, both at the regional and at the facies scales (except for facies A), total species density decreased (again except for facies A). When all nodules were included in the statistical analysis, there was no relation between faunal cover and exposed nodule surface. Nevertheless, faunal cover did decrease with exposed nodule surface for the east zone in general and for both facies B and C in particular. Species distributions among facies were significantly different but explained only a very small portion of the variance (˜5%). We identified two groups of associated species: a first group of two species and a second group of six species. The other species (34) were independently distributed, suggesting that species interactions play only a minor role in the spatial distribution of nodule fauna. The flux of particulate organic carbon to the bottom is the only major environmental factor considered to vary between the two zones within this study. We conclude that the higher species richness and higher
Antarctic fish in a changing world: metabolic, osmoregulatory and endocrine stress response

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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.
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...
Late Ordovician pelecypod faunas from the Cincinnati, Ohio area

Energy Technology Data Exchange (ETDEWEB)

Frey, R.C.

1985-01-01

The distribution of pelecypod faunas in the Late Ordovician strata exposed in the Cincinnati, Ohio area, points to a close relationship between lithofacies type and the life habits of these Ordovician bivalves. Muddy clastic shallow marine facies of Edenian, Maysvillian, and early Richmondian age support faunas dominated by endobyssate filter-feeding species, including a variety of modiomorphids and the genus Ambonychia, plus infaunal filter-feeding orthonotids, and in faunal deposit-feeding palaeotaxodonts. These pelecypod groups occur in claystones with a fauna of calymenid and asaphid trilobites, nautiloids, cyclomyan monoplacophorans, and occasionally crinoids and asterozoans. Younger Richmondian strata in the area are predominantly carbonate platform facies and support pelecypod faunas dominated by robust endobyssate and epibyssate ambonychiids, cyrtodontids, and colpomyids. These pelecypods are associated with diverse assemblage of articulate brachiopods, trepostome ectoprocts, solitary rugose corals, and mollusks in skeletal limestones representing storm-reworked thickets or ramos ectoprocts. This fundamental dichotomy in Late Ordovician pelecypod faunas is recognized not only in the Cincinnati area, but in Late Ordovician strata exposed on Manitoulin Island in Ontario and eastward into Quebec. Reconstructions of the life habits of these pelecypods demonstrates the dominance of the endobyssate mode of life in these Early Paleozoic pelecypods.
Investigation of the weathering effect on Rb-Sr systematics and trace element abundances in Antarctic and non-Antarctic meteorites

International Nuclear Information System (INIS)

Nishikawa, Yoshiyuki; Nakamura, Noboru; Misawa, Keiji; Okano, Osamu; Yamamoto, Koshi; Kagami, Hiroo.

1990-01-01

In order to examine weathering effects on chondritic meteorites in Antarctic and non-Antarctic environments, the Rb-Sr isotopic ratios and abundances of REE, Ba, Sr, Rb, and K were determined for 8H-group chondrites (Yamato-790986 [H3], Yamato-74492 [H3], Grady [H3], Brownfield [H3], Clovis (No.1) [H3], Yamato-74155 [H4], Allegan [H5] [one whole-rock and two chondrules], and Yamato-74371 [H5]), and partly for the Etter (L5) chondrite. The Allegan whole-rock shows a flat REE pattern with a large negative Eu anomaly and Sr depletion. Analyses of Rb-Sr systematics of one whole-rock and two chondrules show somewhat younger age 4.38±0.12 b.y. It is suggested that REE and Rb-Sr were redistributed during the early thermal metamorphism. Except for Allegan, most other H-chondrites (finds) show the perturbation of the Rb-Sr systematics, indicating recent loss of Rb. It was found that the weathering degree is related with the Rb-Sr disturbance in Antarctic H-chondrite. In spite of different degrees of weathering, all the Antarctic H-chondrites studied (including heavily weathered ones) show flat REE patterns normal as H-chondrite with occasional occurrence of minor Eu anomalies, indicating the tough resistance of REE in H-chondrites to the Antarctic weathering. On the other hand, non-Antarctic finds (particularly the weathered chondrites) indicate light-REE enriched patterns with a large negative Ce anomaly and extreme enrichment of Ba, suggestive of terrestrial contaminations. (author)
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
Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years

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A. S. Gardner

2018-02-01

Full Text Available Ice discharge from large ice sheets plays a direct role in determining rates of sea-level rise. We map present-day Antarctic-wide surface velocities using Landsat 7 and 8 imagery spanning 2013–2015 and compare to earlier estimates derived from synthetic aperture radar, revealing heterogeneous changes in ice flow since ∼ 2008. The new mapping provides complete coastal and inland coverage of ice velocity north of 82.4° S with a mean error of < 10 m yr−1, resulting from multiple overlapping image pairs acquired during the daylight period. Using an optimized flux gate, ice discharge from Antarctica is 1929 ± 40 Gigatons per year (Gt yr−1 in 2015, an increase of 36 ± 15 Gt yr−1 from the time of the radar mapping. Flow accelerations across the grounding lines of West Antarctica's Amundsen Sea Embayment, Getz Ice Shelf and Marguerite Bay on the western Antarctic Peninsula, account for 88 % of this increase. In contrast, glaciers draining the East Antarctic Ice Sheet have been remarkably constant over the period of observation. Including modeled rates of snow accumulation and basal melt, the Antarctic ice sheet lost ice at an average rate of 183 ± 94 Gt yr−1 between 2008 and 2015. The modest increase in ice discharge over the past 7 years is contrasted by high rates of ice sheet mass loss and distinct spatial patters of elevation lowering. The West Antarctic Ice Sheet is experiencing high rates of mass loss and displays distinct patterns of elevation lowering that point to a dynamic imbalance. We find modest increase in ice discharge over the past 7 years, which suggests that the recent pattern of mass loss in Antarctica is part of a longer-term phase of enhanced glacier flow initiated in the decades leading up to the first continent-wide radar mapping of ice flow.
Trace-element analysis of Antarctic H chondrites: Chemical weathering and comparisons with their non-Antarctic counterparts

International Nuclear Information System (INIS)

Kwok, J.E.

1986-01-01

Large numbers of meteorites have been discovered in Antarctica over the last decade (7000 fragments probably representing over 1200 separate events). They are important for their numbers and for their complement of unique or rare specimens; they also have long terrestrial ages (up to 1,000,000 years) compared to non-Antarctic falls (usually < 200 years). We report compositional data for mobile/volatile trace elements Ag, Au, Bi, Cd, Co, Cs, In, Rb, Sb, Se, Te, Ti, U, and Zn in a suite of Antarctic H chondrites. Our data show that heavily oxidized H chondrites are leached of a portion of their trace elements and, therefore, have been chemically compromised by their stay in Antarctica. The less oxidized specimens seem to have retained their chemical integrity. We suggest possibilities for using chemical data to measure the degree of a chondrite's chemical weathering. We compare our data to that obtained previously for non-Antarctic H chondrites (Linger et al., 1986), by petrologic type (H4, H5, H6, H4-6) and shock-loading (moderately shocked facies a-c, heavily shocked facies d-f). Many statistically significant differences are found between non-Antarctic and Victoria Land, Antarctica H chondrites of each petrologic type and of shock facies d-f

Fauna Europaea - Orthopteroid orders

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Heller, K.-G.; Bohn, H.; Haas, F.; Willemse, F.; de Jong, Y.

2016-01-01

Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region),
Meteorological observatory for Antarctic data collection

International Nuclear Information System (INIS)

Grigioni, P.; De Silvestri, L.

1996-01-01

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
Offshore Antarctic Peninsula Gas Hydrate Reservoir Characterization by Geophysical Data Analysis

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Michela Giustiniani

2010-12-01

Full Text Available A gas hydrate reservoir, identified by the presence of the bottom simulating reflector, is located offshore of the Antarctic Peninsula. The analysis of geophysical dataset acquired during three geophysical cruises allowed us to characterize this reservoir. 2D velocity fields were obtained by using the output of the pre-stack depth migration iteratively. Gas hydrate amount was estimated by seismic velocity, using the modified Biot-Geerstma-Smit theory. The total volume of gas hydrate estimated, in an area of about 600 km2, is in a range of 16 × 109–20 × 109 m3. Assuming that 1 m3 of gas hydrate corresponds to 140 m3 of free gas in standard conditions, the reservoir could contain a total volume that ranges from 1.68 to 2.8 × 1012 m3 of free gas. The interpretation of the pre-stack depth migrated sections and the high resolution morpho-bathymetry image allowed us to define a structural model of the area. Two main fault systems, characterized by left transtensive and compressive movement, are recognized, which interact with a minor transtensive fault system. The regional geothermal gradient (about 37.5 °C/km, increasing close to a mud volcano likely due to fluid-upwelling, was estimated through the depth of the bottom simulating reflector by seismic data.
Antarctic snow and global climate

International Nuclear Information System (INIS)

Granberg, H.B.

2001-01-01

Global circulation models (GCM) indicate that global warming will be most pronounced at polar regions and high latitudes, causing concern about the stability of the Antarctic ice cap. A project entitled the Seasonal Snow in Antarctica examined the properties of the near surface snow to determine the current conditions that influence snow cover development. The goal was to assess the response of the snow cover in Queen Maud Land (QML) to an increased atmospheric carbon dioxide content. The Antarctic snow cover in QML was examined as part of the FINNARP expeditions in 1999 and 2000 which examined the processes that influence the snow cover. Its energy and mass balance were also assessed by examining the near surface snow strata in shallow (1-2 m) pits and by taking measurements of environmental variables. This made it possible to determine if the glacier is in danger of melting at this northerly location in the Antarctic. The study also made it possible to determine which variables need to change and by how much, for significant melting to occur. It was shown that the Antarctic anticyclone creates particular conditions that protect the snow cover from melting. The anticyclone brings dry air from the stratosphere during most of the year and is exempt from the water vapour feedback. It was concluded that even a doubling of atmospheric carbon dioxide will not produce major snow melt runoff. 8 refs
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.
Psychrotrophic metal tolerant bacteria for mobilisation of metals in Antarctic waters

Digital Repository Service at National Institute of Oceanography (India)

Gonsalves, M.J.B.D.

Cold tolerant psychrotrophic bacteria abound in the Antarctic waters. While Antarctic krills are known to concentrate heavy metals at ppm levels, psychrotrophic bacteria from Antarctic fresh and marine waters have been reported to tolerate them...
Effects of human trampling on populations of soil fauna in the McMurdo Dry Valleys, Antarctica.

Science.gov (United States)

Ayres, Edward; Nkem, Johnson N; Wall, Diana H; Adams, Byron J; Barrett, J E; Broos, Emma J; Parsons, Andrew N; Powers, Laura E; Simmons, Breana L; Virginia, Ross A

2008-12-01

Antarctic ecosystems are often considered nearly pristine because levels of anthropogenic disturbance are extremely low there. Nevertheless, over recent decades there has been a rapid increase in the number of people, researchers and tourists, visiting Antarctica. We evaluated, over 10 years, the direct impact of foot traffic on the abundance of soil animals and soil properties in Taylor Valley within the McMurdo Dry Valleys region of Antarctica. We compared soils from minimally disturbed areas with soils from nearby paths that received intermediate and high levels of human foot traffic (i.e., up to approximately 80 passes per year). The nematodes Scottnema lindsayae and Eudorylaimus sp. were the most commonly found animal species, whereas rotifers and tardigrades were found only occasionally. On the highly trampled footpaths, abundance of S. lindsayae and Eudorylaimus sp. was up to 52 and 76% lower, respectively, than in untrampled areas. Moreover, reduction in S. lindsayae abundance was more pronounced after 10 years than 2 years and in the surface soil than in the deeper soil, presumably because of the longer period of disturbance and the greater level of physical disturbance experienced by the surface soil. The ratio of living to dead Eudorylaimus sp. also declined with increased trampling intensity, which is indicative of increased mortality or reduced fecundity. At one site there was evidence that high levels of trampling reduced soil CO(2) fluxes, which is related to total biological activity in the soil. Our results show that even low levels of human traffic can significantly affect soil biota in this ecosystem and may alter ecosystem processes, such as carbon cycling. Consequently, management and conservation plans for Antarctic soils should consider the high sensitivity of soil fauna to physical disturbance as human presence in this ecosystem increases.
Fauna Europaea

DEFF Research Database (Denmark)

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

2015-01-01

density, and the more fertile habitats are extensively cultivated. This has undoubtedly increased the extinction risk for numerous species of brachyceran flies, yet with the recent re-discovery of Thyreophoracynophila (Panzer), there are no known cases of extinction at a European level. However, few......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...
FAUNA SILVESTRE

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Luis Fernando Osorio, Director 5 Simp. For.

2012-10-01

Full Text Available Comité científico del simposio Director Luis Fernando Osorio Vélez, Ph.D. Universidad Nacional de Colombia, sede Medellín. Colombia. Fauna silvestre Brian C. Bock, Ph.D. Universidad de Antioquia. Colombia. Jaime Polanía Vorenberg, Ph.D. Universidad Nacional de Colombia. Colombia. Joan Gastón Zamora Abrego, Ph.D. Universidad Nacional de Colombia. Colombia. Néstor Javier Mancera Rodríguez, Ph.D. Universidad Nacional de Colombia. Colombia. Sergio Solari, Ph.D. Universidad de Antioquia. Colombia.
Bottom fish assemblages at the shelf and continental slope off East Greenland

DEFF Research Database (Denmark)

Jørgensen, Ole A; Hvingel, Carsten; Møller, P.R.

2015-01-01

During 2006 and 2008 two bottom trawl surveys were conducted at East Greenland to 72°N covering depths down to 1500 m. In the 149 trawl hauls in total 113 fish species were recorded of which 37 were considered pelagic and excluded from the analyses. As a first step the abundance data for the 76...... benthic species were used for analyses of the fish fauna diversity and fish assemblages. Nine assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each...... distribution, species composition, temperature and depth. Three of the assemblages were located in the cold Iceland Sea while six were found in the somewhat warmer Irminger Sea...
Spatial Distribution of Soil Fauna In Long Term No Tillage

Science.gov (United States)

Corbo, J. Z. F.; Vieira, S. R.; Siqueira, G. M.

2012-04-01

The soil is a complex system constituted by living beings, organic and mineral particles, whose components define their physical, chemical and biological properties. Soil fauna plays an important role in soil and may reflect and interfere in its functionality. These organisms' populations may be influenced by management practices, fertilization, liming and porosity, among others. Such changes may reduce the composition and distribution of soil fauna community. Thus, this study aimed to determine the spatial variability of soil fauna in consolidated no-tillage system. The experimental area is located at Instituto Agronômico in Campinas (São Paulo, Brazil). The sampling was conducted in a Rhodic Eutrudox, under no tillage system and 302 points distributed in a 3.2 hectare area in a regular grid of 10.00 m x 10.00 m were sampled. The soil fauna was sampled with "Pitfall Traps" method and traps remained in the area for seven days. Data were analyzed using descriptive statistics to determine the main statistical moments (mean variance, coefficient of variation, standard deviation, skewness and kurtosis). Geostatistical tools were used to determine the spatial variability of the attributes using the experimental semivariogram. For the biodiversity analysis, Shannon and Pielou indexes and richness were calculated for each sample. Geostatistics has proven to be a great tool for mapping the spatial variability of groups from the soil epigeal fauna. The family Formicidae proved to be the most abundant and dominant in the study area. The parameters of descriptive statistics showed that all attributes studied showed lognormal frequency distribution for groups from the epigeal soil fauna. The exponential model was the most suited for the obtained data, for both groups of epigeal soil fauna (Acari, Araneae, Coleoptera, Formicidae and Coleoptera larva), and the other biodiversity indexes. The sampling scheme (10.00 m x 10.00 m) was not sufficient to detect the spatial
Biological studies in the Antarctic waters: A review

Digital Repository Service at National Institute of Oceanography (India)

Dhargalkar, V.K.

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Chilean Antarctic Stations on King George Island

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Katsutada Kaminuma

2000-07-01

Full Text Available The purpose of my visit to Chilean Antarctic Stations was to assess the present status of geophysical observations and research, as the South Shetland Island, West Antarctica, where the stations are located, are one of the most active tectonic regions on the Antarctic plate. The Instituto Antartico Chileno (INACH kindly gave me a chance to stay in Frei/Escudero Bases as an exchange scientist under the Antarctic Treaty for two weeks in January 2000. I stayed in Frei Base as a member of a geological survey group named "Tectonic Evolution of the Antarctic Peninsula" which was organized by Prof. F. Herve, University of Chile, from January 05 to 19,2000. All my activity in the Antarctic was organized by INACH. During my stay in Frei Base, I also visited Bellingshausen (Russian, Great Wall (China and Artigas (Uruguay stations. All these stations are located within walking distance of Frei Base. King Sejong Station (Korea, located 10km east from Frei Base, and Jubany Base (Argentine, another 6km south-east from King Sejong Station, were also visited with the aid of a zodiac boat that was kindly operated for us by King Sejong Station. All stations except Escudero Base carry out meteorological observations. The seismological observations in Frei Base are operated by Washington State University of the U. S. monitoring of earthquake activity and three-component geomagnetic observations are done at King Sejong and Great Wall stations. Earth tide is monitored at Artigas Base. Continuous monitoring of GPS and gravity change are planned at King Sejong Station in the near future. Scientific research activities of each country in the area in the 1999/2000 Antarctic summer season were studied and the logistic ability of all stations was also assessed for our future international cooperation.
Zoogeography of the shorefish fauna of Clipperton Atoll

Science.gov (United States)

Robertson, D. R.; Allen, G. R.

1996-06-01

One hundred and fifteen species of fishes (14 oceanic, plus 101 shore and nearshore species) are known from Clipperton Island, a small, remote coral atoll in the tropical eastern Pacific (TEP). This fish fauna includes only ˜ 14% of the region's shallow-water species, and also is depauperate relative to the fish faunas of other isolated tropical islands. The island's isolation, small size, reduced habitat diversity, and oceanic environment contribute to this paucity of species. Fifty-two species at Clipperton can be identified as TEP; these include 37 widespread species, six species shared only with the Revillagigedo Islands [the nearest (950 km) offshore shoals], and eight endemic to Clipperton. Endemics species apparently have a mix of west and east Pacific origins. Sixty-three species are transpacific; they include three new records (of Naso surgeonfishes) that maybe vagrants recruited > 4,000 km from Oceania. Clipperton is situated at the juncture between the TEP and Oceania. Its fish fauna contains about equal numbers of TEP and transpacific species. This faunal structure reflects the relative influence of surface currents from Oceania and the TEP. Although most of Clipperton's transpacific shorefishes are widespread in eastern Oceania, the Clipperton fauna has specific affinities to the fauna of the Line Islands, which are located within the main eastbound current from Oceania. Clipperton may therefore be a major stepping stone for dispersal between Oceania and the remainder of the TEP. About 50% of the non-oceanic, tropical transpacific fishes occur there, and at least 75 % of those species apparently have resident populations at the island.
Tolerance of Antarctic soil fungi to hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Hughes, Kevin A.; Bridge, Paul; Clark, Melody S. [British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET (United Kingdom)

2007-01-01

Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research Station (Adelaide Island, Antarctic Peninsula) was assessed in the presence of ten separate aromatic and aliphatic hydrocarbons [marine gas oil (MGO), dodecane, hexadecane, benzoic acid, p-hydroxybenzoic acid, toluene, phenol, biphenyl, naphthalene and m- and p-xylenes with ethylbenzene]. Aromatic hydrocarbons inhibited soil microbial growth more than aliphatic hydrocarbons. Soil microorganisms from a moss patch, where little previous impact or hydrocarbon contamination had occurred, were less tolerant of hydrocarbons than those from high impact sites. Fungal growth rates of Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp. and Phoma herbarum were assessed in the presence of hydrocarbons. Generally, aromatic hydrocarbons inhibited or stopped hyphal extension, though growth rates increased with some aliphatic hydrocarbons. Hyphal dry weight measurements suggested that Mortierella sp. may be able to use dodecane as sole carbon and energy source. Hydrocarbon-degrading Antarctic fungi may have use in future hydrocarbon spill bioremediation. (author)
The genome of the Antarctic-endemic copepod, Tigriopus kingsejongensis.

Science.gov (United States)

Kang, Seunghyun; Ahn, Do-Hwan; Lee, Jun Hyuck; Lee, Sung Gu; Shin, Seung Chul; Lee, Jungeun; Min, Gi-Sik; Lee, Hyoungseok; Kim, Hyun-Woo; Kim, Sanghee; Park, Hyun

2017-01-01

The Antarctic intertidal zone is continuously subjected to extremely fluctuating biotic and abiotic stressors. The West Antarctic Peninsula is the most rapidly warming region on Earth. Organisms living in Antarctic intertidal pools are therefore interesting for research into evolutionary adaptation to extreme environments and the effects of climate change. We report the whole genome sequence of the Antarctic-endemic harpacticoid copepod Tigriopus kingsejongensi . The 37 Gb raw DNA sequence was generated using the Illumina Miseq platform. Libraries were prepared with 65-fold coverage and a total length of 295 Mb. The final assembly consists of 48 368 contigs with an N50 contig length of 17.5 kb, and 27 823 scaffolds with an N50 contig length of 159.2 kb. A total of 12 772 coding genes were inferred using the MAKER annotation pipeline. Comparative genome analysis revealed that T. kingsejongensis -specific genes are enriched in transport and metabolism processes. Furthermore, rapidly evolving genes related to energy metabolism showed positive selection signatures. The T. kingsejongensis genome provides an interesting example of an evolutionary strategy for Antarctic cold adaptation, and offers new genetic insights into Antarctic intertidal biota. © The Author 2017. Published by Oxford University Press.
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
Fauna Europaea: Helminths (Animal Parasitic)

Czech Academy of Sciences Publication Activity Database

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

-, č. 2 (2014), e1060 ISSN 1314-2828 Institutional support: RVO:60077344 Keywords : Acanthocephala * Biodiversity * Biodiversity Informatics * Cestoda * Fauna Europaea * Helminth * Monogenea * Nematoda * Parasite * Taxonomic indexing * Taxonomy * Trematoda * Zoology Subject RIV: EB - Genetics ; Molecular Biology
Composition and similarity of global anomodont-bearing tetrapod faunas

Science.gov (United States)

Fröbisch, Jörg

2009-08-01

Anomodont synapsids represent the dominant herbivores of Permian and Triassic terrestrial vertebrate ecosystems. Their taxonomic diversity and morphological disparity in combination with their cosmopolitan distribution makes them an ideal study object for macroevolutionary patterns across the most devastating extinction event in earth history. This study provides a thorough review of anomodont-bearing tetrapod faunas to form the basis for a faunal similarity analysis and future studies of anomodont diversity. The stratigraphic correlation and composition of all known anomodont assemblages is revisited, including a discussion of the validity of the globally distributed anomodont species. The similarity analysis of anomodont faunas is performed on the basis of presence-absence data of anomodont taxa, using explorative methods such as cluster analysis (UPGMA) and non-metric multidimensional scaling (NMDS). The recovered faunal groupings indicate a common biostratigraphic age and furthermore reflect biogeographic patterns. Even though endemism and faunal provinciality was a constant element in anomodont faunas of the Permian and Triassic, the available evidence indicates that the end-Permian extinction resulted in a distinct uniformity that was unique to Early Triassic anomodont faunas. This is in particular characterized by the global distribution and overwhelming abundance of the disaster taxon Lystrosaurus. In contrast, cosmopolitan anomodonts also existed in the Late Permian (e.g., Diictodon) and Middle Triassic (e.g., Shansiodon), but those taxa coexisted with endemic faunal elements rather than dominated the fauna as Lystrosaurus did.
Are Sediments a Source of Fukushima Radiocesium for Marine Fauna in Coastal Japan?

Science.gov (United States)

Wang, C.; Fisher, N. S.; Baumann, Z.

2016-02-01

The Fukushima nuclear power plant accident in 2011 resulted in the largest accidental release of artificial radionuclides into the world's oceans. Among the fission products released in large quantities, 137Cs has the greatest potential for long-term impacts on marine biota and human consumers of seafood. In particular, some species of bottom fish near Fukushima were very contaminated and had higher radiocesium (134Cs and 137Cs) levels than pelagic fish in the same area, sometimes exceeding Japanese safety limits >4 years after the accident. Benthic invertebrates, many being prey items for bottom fish, show the same slow decrease in radiocesium as sediments, suggesting that contaminated sediment could be a source of radiocesium for benthic fauna. We evaluated the binding of 137Cs to sediments (Kd found to be 44-60 ml g-1) and found that bioturbation by the polychaete Nereis succinea greatly increased the initial release rate of Cs to overlying seawater. We also assessed the bioavailability of dissolved and sediment-bound Cs for deposit-feeding polychaetes, and its subsequent transfer to crabs and fish, and measured the influence of water temperature on Cs accumulation in fish. Assimilation efficiency (AE) of ingested 137Cs ranged from 16% in polychaetes ingesting sediments to 79% in fish ingesting worms. Efflux rate constants ranged from 5% d-1 for killifish to 40% d-1 for polychaetes. Animal absorption and retention of dissolved 137Cs were also measured. These parameters are used to model radiocesium bioaccumulation and trophic transfer in benthic food chains. Our results are consistent with the idea that sediments can be an important source of Cs for benthic food chains and help explain why some species of bottom fish remained more contaminated than pelagic fish in Japanese coastal waters.

Benthic foraminifera and bottom water evolution in the middle-southern Okinawa Trough during the last 18 ka

Institute of Scientific and Technical Information of China (English)

LI Tiegang; XIANG Rong; SUN Rongtao; CAO Qiyuan

2005-01-01

A piston sediment core E017 from the middle-southern Okinawa Trough was investigated. A preliminary study of the deep-water evolution since 18 cal. ka BP was performed based on the quantitative census data of benthic foraminiferal fauna, together with planktonic foraminiferal oxygen and carbon isotope, AMS14C dating, and the previous results achieved in the southern Okinawa Trough. The result shows that the benthic fauna was dominated by Bulimina aculeata (d'Orbigny), Uvigerina peregrina (Cushman), Hispid Uvigerina and Uvigerina dirupta (Todd) during the glaciation-deglaciation before 9.2 cal. ka BP, while Epistominella exigua (Brady), Pullenia bulloides (d'Orbigny), Cibicidoides hyalina (Hofker), Sphaeroidina bulloides (d'Orbigny) and Globocassidulina subglobosa (Brady) predominated the fauna in the post-glacial period after 9.2 cal. ka BP. The benthic foraminifera accumulation rate (BFAR), paleoproductivity estimates and benthic foraminiferal assemblage conformably indicate that surface water paleoproductivity and organic matter flux during the glaciation-deglaciation were higher than those of the post-glacial period in the middle-southern Okinawa Trough, and gradually enhanced from the southern to the central Okinawa Trough during the glaciation-deglaciation, which could be caused by the discrepancy of the terrigenous nutrients supply. High abundances of E. exigua, an indicator of pulsed organic matter input, after 9.2 cal. ka BP may indicate that the intensity of seasonally riverine pulsed flux during the post-glacial period was stronger than that of the glaciation-deglaciation period, and the seasonal influx in the central trough might be stronger than in the south. The temporal distributions of the typical species indicating bottom water oxygen content and ventilation condition show that the ventilation of the bottom water during the post-glacial period is more active than the glaciation-deglaciation, which reflects that the evolution of the intermediate and
RESEARCH ON ARGES RIVER FISH FAUNA IN BUDEASA-GOLESTI AREA

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Alina-Mihaela Truţă

2015-12-01

Full Text Available Arges River was subject to periodic ichthyologic, hydrobiological and hydrological research. By its content and approach the present paper shows a series of research on fish fauna in Budeasa-Golesti area of Arges River, Pitesti. By research presented in the study we sought to evaluate the state and evolution of fish fauna in the city reservoirs, Pitesti area, over the last 30 years, trying to highlight the causes that led to the current situation and to propose measures for the conservation of natural fish fauna in the future. Fish fauna in Pitesti area currently consists of 14 species belonging to four families: Cyprinidae (9 species, Cobitidae (1 species, Esocidae (1 species and Percidae (3 species. Most species live naturally in lakes studied except for one species Pseudorasbora parva which was introduced accidentally. The research undertaken to reflect changes in the fish fauna in the last 30 years, indicates an increase in the number of species, either through deliberate stocking for sport fishing purposes or due to changes in biotope favouring the development of certain species which were accidental in the past.
Basin-scale heterogeneity in Antarctic precipitation and its impact on surface mass variability

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J. Fyke

2017-11-01

Full Text Available Annually averaged precipitation in the form of snow, the dominant term of the Antarctic Ice Sheet surface mass balance, displays large spatial and temporal variability. Here we present an analysis of spatial patterns of regional Antarctic precipitation variability and their impact on integrated Antarctic surface mass balance variability simulated as part of a preindustrial 1800-year global, fully coupled Community Earth System Model simulation. Correlation and composite analyses based on this output allow for a robust exploration of Antarctic precipitation variability. We identify statistically significant relationships between precipitation patterns across Antarctica that are corroborated by climate reanalyses, regional modeling and ice core records. These patterns are driven by variability in large-scale atmospheric moisture transport, which itself is characterized by decadal- to centennial-scale oscillations around the long-term mean. We suggest that this heterogeneity in Antarctic precipitation variability has a dampening effect on overall Antarctic surface mass balance variability, with implications for regulation of Antarctic-sourced sea level variability, detection of an emergent anthropogenic signal in Antarctic mass trends and identification of Antarctic mass loss accelerations.
Emerging spatial patterns in Antarctic prokaryotes.

Science.gov (United States)

Chong, Chun-Wie; Pearce, David A; Convey, Peter

2015-01-01

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 groups where appropriate
Toward a complete soil C and N cycle: incorporating the soil fauna.

Science.gov (United States)

Osler, Graham H R; Sommerkorn, Martin

2007-07-01

Increasing pressures on ecosystems through global climate and other land-use changes require predictive models of their consequences for vital processes such as soil carbon and nitrogen cycling. These environmental changes will undoubtedly affect soil fauna. There is sufficient evidence that soil fauna have significant effects on all of the pools and fluxes in these cycles, and soil fauna mineralize more N than microbes in some habitats. It is therefore essential that their role in the C and N cycle be understood. Here we introduce a new framework that attempts to reconcile our current understanding of the role of soil fauna within the C and N cycle with biogeochemical models and soil food web models. Using a simple stoichiometric approach to integrate our understanding of N mineralization and immobilization with the C:N ratio of substrates and faunal life history characteristics, as used in food web studies, we consider two mechanisms through which soil fauna can directly affect N cycling. First, fauna that are efficient assimilators of C and that have prey with similar C:N ratios as themselves, are likely to contribute directly to the mineral N pool. Second, fauna that are inefficient assimilators of C and that have prey with higher C:N ratios than themselves are likely to contribute most to the dissolved organic matter (DOM) pool. Different groups of fauna are likely to contribute to these two pathways. Protists and bacteria-feeding nematodes are more likely to be important for N mineralization through grazing on microbial biomass, while the effects of enchytraeids and fungal-feeding microarthropods are most likely to be important for DOM production. The model is consistent with experimental evidence and, despite its simplicity, provides a new framework in which the effects of soil fauna on pools and fluxes can be understood. Further, the model highlights our gaps in knowledge, not only for effects of soil fauna on processes, but also for understanding of the
Contrasting Arctic and Antarctic atmospheric responses to future sea-ice loss

Science.gov (United States)

England, M.; Polvani, L. M.; Sun, L.

2017-12-01

By the end of this century, the annual mean Antarctic sea ice area is projected to decline by over a third, an amount similar to that in the Arctic, but the effect of Antarctic sea ice loss on the atmosphere remains largely unexplored. Using the Community Earth Systems Model (CESM) Whole Atmosphere Coupled Climate Model (WACCM), we investigate the effect of future Antarctic sea ice loss, and contrast it with its Arctic counterpart. This is accomplished by analyzing integrations of the model with historic and future sea ice levels, using the RCP8.5 scenario. This allows us to disentangle the effect of future sea ice loss on the atmosphere from other aspects of the coupled system. We find that both Antarctic and Arctic sea ice loss act to shift the tropospheric jet equatorwards, counteracting the poleward shift due to increases in greenhouse gases. Although the total forcing to the atmosphere is similar in both hemispheres, the response to Arctic sea ice loss is larger in amplitude and but more seasonally varying, while the response in the Antarctic persists throughout the year but with a smaller amplitude. Furthermore, the atmospheric temperature response over the Antarctic is trapped closer to the surface than in the Arctic, and perhaps surprisingly, we find that the surface temperature response to Antarctic sea ice loss is unable to penetrate the Antarctic continent.
Ross Ice Shelf, Antarctic Ice and Clouds

Science.gov (United States)

1991-01-01

In this view of Antarctic ice and clouds, (56.5S, 152.0W), the Ross Ice Shelf of Antarctica is almost totally clear, showing stress cracks in the ice surface caused by wind and tidal drift. Clouds on the eastern edge of the picture are associated with an Antarctic cyclone. Winds stirred up these storms have been known to reach hurricane force.
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.
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.
Organochlorine residues in tissues of marine fauna along the coast ...

African Journals Online (AJOL)

These findings highlight evidence of pollution of marine fauna at the Kenyan coastal sites. It is necessary to have thorough waste management programs as a strategy to minimize marine pollution. KEY WORDS: Environmental samples; Marine samples; Kenya-Mombasa coastline; Marine fauna, Organochlorine, Pesticides.
HUBUNGAN KEDEKATAN EKOLOGIS ANTARA FAUNA TANAH DENGAN KARAKTERISTIK TANAH GAMBUT YANG DIDRAINASE UNTUK HTI Acacia crassicarpa (Ecological Proximity Relationship Between Soil Fauna and The Characteristics of Drained Peatland for Industrial Plantation

Directory of Open Access Journals (Sweden)

Yunita Lisnawati

2014-10-01

Full Text Available ABSTRAK Pengelolaan lahan gambut untuk pengembangan HTI Acacia crassicarpa diawali dengan pembuatan saluran drainase dan pembukaan lahan (land clearing yang kemudian dilanjutkan dengan penyiapan lahan untuk penanaman, sedangkan kegiatan pemeliharaan meliputi pemberantasan gulma dengan menggunakan herbisida dan pemupukan. Kegiatan pengelolaan dan pemeliharaan tentunya mempunyai dampak bagi kondisi ekologis lahan gambut. Perubahan kondisi ekologis terjadi karena perubahan lahan yang selanjutnya berpengaruh terhadap kelimpahan dan keragaman fauna tanah.Kelimpahan dan keragaman fauna tanah serta fungsi ekosistem menunjukkan hubungan yang sangat kompleks dan belum banyak diketahui dengan pasti. Kecenderungan fauna tanah untuk memilih suatu habitat dipengaruhi oleh beberapa faktor lingkungan baik biotik maupun abiotik. Tujuan dari penelitian ini adalah untuk mengkaji kedekatan ekologis antara karakteristik tanah gambut yang didrainase untuk HTI A. crassicarpa dengan kelimpahan fauna tanahnya. Penelitian dilakukan di HTI lahan gambut PT. Arara Abadi, Distrik Rasau Kuning, Kabupaten Siak, Riau. Pengambilan sampel fauna tanah dengan metode pencuplikan contoh tanah yang berukuran 25 x 25 x 25 cm3, pemisahan fauna tanah dengan tanah dilakukan dengan menggunakan modifikasi corong barlese. Parameter yang diamati adalah kelimpahan dan keragaman fauna tanah, kematangan gambut (C/N, kadar air gambut, dan kedalaman muka air tanah gambut. Untuk menilai kedekatan ekologis digunakan analisis hirarki. Hasil penelitian menunjukkan bahwa kelimpahan fauna tanah tertinggi terdapat pada tegakan A. crassicarpa umur 2 tahun. Keragaman jenis fauna tanah di lokasi penelitian termasuk melimpah sedang dengan nilai H’ 1,2. Formicidae berpotensi sebagai bioindikator kelembaban tanah gambut yang rendah yang dicirikan dengan kandungan kadar air yang rendah dan mempunyai tingkat kematangan gambut yang lebih tinggi. Entomobryidae berpotensi sebagai bioindikator kadar air
Summer diet of the Salvin's prion at sub-Antarctic Marion Island

African Journals Online (AJOL)

1988-02-14

Feb 14, 1988 ... Thirty-nine food samples were collected from Salvin's prions Pachyptila salvini at sub-Antarctic Marion Island,. Prince Edward Islands. ..... guide to foraging methods used by marine birds in. Antarctic and sub-Antarctic seas. BIOMASS Handbook. 24: 1-22. GRINDLEY, J.R. & LANE, S.B. 1979. Zooplankton.
Seabed images from Southern Ocean shelf regions off the northern Antarctic Peninsula and in the southeastern Weddell Sea

Science.gov (United States)

Piepenburg, Dieter; Buschmann, Alexander; Driemel, Amelie; Grobe, Hannes; Gutt, Julian; Schumacher, Stefanie; Segelken-Voigt, Alexandra; Sieger, Rainer

2017-07-01

Recent advances in underwater imaging technology allow for the gathering of invaluable scientific information on seafloor ecosystems, such as direct in situ views of seabed habitats and quantitative data on the composition, diversity, abundance, and distribution of epibenthic fauna. The imaging approach has been extensively used within the research project DynAMo (Dynamics of Antarctic Marine Shelf Ecosystems) at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven (AWI), which aimed to comparatively assess the pace and quality of the dynamics of Southern Ocean benthos. Within this framework, epibenthic spatial distribution patterns have been comparatively investigated in two regions in the Atlantic sector of the Southern Ocean: the shelf areas off the northern tip of the Antarctic Peninsula, representing a region with above-average warming of surface waters and sea-ice reduction, and the shelves of the eastern Weddell Sea as an example of a stable high-Antarctic marine environment that is not (yet) affected by climate change. The AWI Ocean Floor Observation System (OFOS) was used to collect seabed imagery during two cruises of the German research vessel Polarstern, ANT-XXIX/3 (PS81) to the Antarctic Peninsula from January to March 2013 and ANT-XXXI/2 (PS96) to the Weddell Sea from December 2015 to February 2016. Here, we report on the image and data collections gathered during these cruises. During PS81, OFOS was successfully deployed at a total of 31 stations at water depths between 29 and 784 m. At most stations, series of 500 to 530 pictures ( > 15 000 in total, each depicting a seabed area of approximately 3.45 m2 or 2.3 × 1.5 m) were taken along transects approximately 3.7 km in length. During PS96, OFOS was used at a total of 13 stations at water depths between 200 and 754 m, yielding series of 110 to 293 photos (2670 in total) along transects 0.9 to 2.6 km in length. All seabed images taken during the two cruises
El estudio de la Fauna Ibérica

Directory of Open Access Journals (Sweden)

Ramos Sánchez, María Ángeles

2007-10-01

Full Text Available Since the beginning in 1989, Fauna Ibérica has promoted coordinated research in Taxonomy bringing together more than 100 Spanish and non-Spanish experts. The programme supported by CSIC Presidency is lead by Museo Nacional de Ciencias Naturales. As a result, 30 Fauna Ibérica monographs has been published in addition to a year average of 50-60 scientific papers describing more than 50 new species per year. IBERFAUNA, the Data Bank of the Spanish Fauna, has been created including 38.000 out of the 61.000 species estimated to live in the Iberian Peninsula and Balearic Islands. This area is confirmed as one of the most biodiverse of the European Union with more than 50 % of the European species and more than 50 % of its endemics. Among future plans, a more stable organization is proposed in order to: maintaining dichotomy paper/digital publications, increasing interactivity among taxonomists and training, developing cyber-tools to facilitate public access to the information and increasing the strength of Fauna Ibérica through collaboration with other international initiatives and other areas of knowledge.Desde su inicio en 1989, Fauna Ibérica ha impulsado la investigación coordinada de más de 100 taxónomos españoles y extranjeros. El programa, apoyado por la Presidencia del CSIC, está dirigido por el Museo Nacional de Ciencias Naturales. Como resultado, se han publicado 30 monografías de la serie Fauna Ibérica, y un promedio anual de 50-60 artículos científicos que describen más de 50 nuevas especies por año. Se ha creado el Banco de Datos, IBERFAUNA, que cuenta ya con 38.000 de las aproximadamente 61.000 especies que habitan en la Península Ibérica y Baleares. Se confirma como una de las regiones más ricas en biodiversidad de la Unión Europea, con más del 50 % de las especies y más de un 50 % de sus endemismos. Entre los planes de futuro, se propone una estructura estable para Fauna Ibérica, que mantenga la dicotomía soporte
Invasive mammals and habitat modification interact to generate unforeseen outcomes for indigenous fauna.

Science.gov (United States)

Norbury, Grant; Byrom, Andrea; Pech, Roger; Smith, James; Clarke, Dean; Anderson, Dean; Forrester, Guy

2013-10-01

both suppression of invasive predators and retiring land from grazing can benefit indigenous species, but our results suggest that the ensuing vegetation changes and complex interactions among invasive species can block recovery of indigenous fauna vulnerable to mesopredators. Top-down and bottom-up ecological release of mesopredators and landscape supplementation of top predators are key processes to consider when managing invaded communities in complex landscapes.
Changes of benthic fauna in the Kattegat - An indication of climate change at mid-latitudes?

Science.gov (United States)

Göransson, Peter

2017-07-01

Several predictions point to changes in the marine benthic macrofauna associated with climate change, but so far only a few and minor changes have been reported. This study relates observed changes in the species composition to climate change by looking on the past decades in the Kattegat between Denmark and Sweden. A reduction of the total number species and a reduction of species with a northern range parallel to an increase of species with a southern range have been observed. The most likely explanation of the changes is the increase in temperature of the bottom water. Increased temperature could change the species distributions but also decrease primary production which impacts recruitment and growth. Hypoxia and bottom trawling could also act synergistic in this process. A sparse occurrence of previously encountered Arctic-Boreal species and critical foundation species, which gives the area its special character, suggests a change in biodiversity and might therefore be designated as early warning signals of a warmer climate. The northern fauna below the halocline with limited capacity of dispersal and low reproduction potential, can be considered as sensitive with low adaptive capacity to climate change. Therefore, not only tropical and high-latitude species, but also benthos on deep bottoms at mid-latitudes, could be vulnerable to warming. As many species live at the edge of their range in the Kattegat, and also are dependent of distant recruitment, large scale changes will probably be detected here at an early stage. It is important to protect relatively undisturbed reference areas in the Kattegat for future studies, but also for preserving a large number of ecosystem services, biotopes, habitats, and fish species.
POTENSI FAUNA AKUATIK EKOSISTEM HUTAN MANGROVE DI KAWASAN TELUK PANGPANG KABUPATEN BANYUWANGI

Directory of Open Access Journals (Sweden)

Yanuar Rustrianto Buwono

2016-01-01

Full Text Available Mangrove ecosystem located between terrestrial and marine coastal areas are changing constantly due to human activities that affect the aquatic fauna several species of fish and non-fish. The aim of research to determine the level of importance and biodiversity index value of mangrove, analyze abundance, biomass, diversity and equity, as well as the spread of aquatic fauna mangrove forest ecosystem. Results of the study showed an index of biodiversity of mangrove flora in the medium category with a relative importance value index Rhizophoraceae and Sonneratiaceae dominate in all phases. Economically valuable aquatic fauna found amounted to 21 species of 15 families. Groups of fish fauna found bedul fish (A. caninus have abundance and biomass as much as 975 ind at 18,299.56 gr, meanwhile the non fish fauna found werus shrimp (Metapenaeus sp. has an abundance of as much as 1,936 ind and biomass crabs (P. pelagicus have amounted to 13,609.38 gr associated in mangrove areas Pangpang Bay. Fauna biodiversity index included in the medium category, meanwhile the index of evenness fauna belonging in the high category. Dispersal patterns at the mouth of the bay with the mouth of the river flow Wagut fauna found in the form of pelagic and demersal fish such as family Mugilidae, Clupediae, Leiognatidae, Psettodidae. At the center of the edge of the bay in the form of aquaculture ponds found that pelagic fish group Centropomidae, Polynemidae, Sillagidae family. Meanwhile, at the end of the bay with the river flow Setail found the group that demersal fish Platycephalidae and Gobidae family.
Modelling the Antarctic Ice Sheet

DEFF Research Database (Denmark)

Pedersen, Jens Olaf Pepke; Holm, A.

2015-01-01

to sea level high stands during past interglacial periods. A number of AIS models have been developed and applied to try to understand the workings of the AIS and to form a robust basis for future projections of the AIS contribution to sea level change. The recent DCESS (Danish Center for Earth System......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...
Fauna Europaea: Helminths (Animal Parasitic)

NARCIS (Netherlands)

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

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
ORTHOPTERA FAUNA OF SĂLAJ COUNTY, ROMANIA

Directory of Open Access Journals (Sweden)

Gellért Puskás

2017-07-01

Full Text Available : Orthoptera fauna of Sălaj County, NW Romania is reviewed based on new and literature data. 63 species were collected during field investigations in 2014-2015, thus the known Orthoptera species in the region are 74 (30 Acridoidea, 3 Tetrigoidea, 1 Tridactyloidea, 7 Grylloidea, 33 Tettigonioidea. 9 species are recorded in the county for the first time (Chorthippus mollis, Ch. montanus, Ch. vagans, Euchorthippus pulvinatus, Stenobothrus stigmaticus, Tetrix tuerki, Isophya kraussii, Metrioptera brachyptera, Pholidoptera frivaldszkyi. Isophya kraussii kraussii is a new subspecies for the fauna of Romania. Correct original spelling of the name of Ph. frivaldszkyi (Herman, 1871 is fixed.

Antarctic aerosols - A review

Science.gov (United States)

Shaw, Glenn E.

1988-02-01

Tropospheric aerosols with the diameter range of half a micron reside in the atmosphere for tens of days and teleconnect Antarctica with other regions by transport that reaches planetary scales of distances; thus, the aerosol on the Antarctic ice represents 'memory modules' of events that took place at regions separated from Antarctica by tens of thousands of kilometers. In terms of aerosol mass, the aerosol species include insoluble crustal products (less than 5 percent), transported sea-salt residues (highly variable but averaging about 10 percent), Ni-rich meteoric material, and anomalously enriched material with an unknown origin. Most (70-90 percent by mass) of the aerosol over the Antarctic ice shield, however, is the 'natural acid sulfate aerosol', apparently deriving from biological processes taking place in the surrounding oceans.
Bottom head assembly

International Nuclear Information System (INIS)

Fife, A.B.

1998-01-01

A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs
The Fauna Biodiversity of Ikot Ondo Community Forest in Essien ...

African Journals Online (AJOL)

Osondu

2012-05-24

May 24, 2012 ... Abstract. Prolonged deforestation, poaching and wildlife habitat loss has been a serious threat to wildlife conservation in Nigeria, thereby endangering fauna diversity resources in the country. This study was carried out to determine the population estimate of wild fauna in the communal land of Ikot.
MECHANISMS FOR THE SEASONAL CYCLE IN THE ANTARCTIC COASTAL OCEANS

OpenAIRE

オオシマ; Kay I., OHSHIMA

1996-01-01

Seasonal variations of the Antarctic coastal oceans has not been well understood owing to logistical difficulties in observations, especially during the ice-covered season. Recently, 'Weddell Gyre Study' and 'Japanese Antarctic Climate Research program' have revealed the following seasonal variations in the Antarctic coastal ocean. First, the thickness of the Winter Water (WW) layer, characterized by cold, fresh, oxygen-rich water, exhibits its maximum in the austral fall and its minimum in t...
Impact of Global Warming on Flora and Fauna

OpenAIRE

, A. Srivastava; , S. Srivastav

2011-01-01

The paper, illustrated with graphs, discusses the impact of global warming on şora & fauna, its underlying causes, and attempts to trim down it with the collaboration of all individuals. The paper relates that, as an outcome of global warming, climate changes have reached anomalous levels with rainfall and hurricanes of unusual intensity. Everyday gases such as carbon dioxide are released to warm the earth, allowing it to be a place that can be inhabited by şora & fauna. Howev...
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.
Fauna Europaea: Hymenoptera: Symphyta & Ichneumonoidea

NARCIS (Netherlands)

Achterberg, van K.; Taeger, A.; Blank, S.M.; Zwakhals, K.; Viitasaari, M.; Sick Ki Yu, D.; Jong, de Y.

2017-01-01

Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region),
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...
Mysterious iodine-overabundance in Antarctic meteorites

Science.gov (United States)

Dreibus, G.; Waenke, H.; Schultz, L.

1986-01-01

Halogen as well as other trace element concentrations in meteorite finds can be influenced by alteration processes on the Earth's surface. The discovery of Antarctic meteorites offered the opportunity to study meteorites which were kept in one of the most sterile environment of the Earth. Halogen determination in Antartic meteorites was compared with non-Antarctic meteorites. No correlation was found between iodine concentration and the weathering index, or terrestrial age. The halogen measurements indicate a contaminating phase rich in iodine and also containing chlorine. Possible sources for this contamination are discussed.
Mysterious iodine-overabundance in Antarctic meteorites

International Nuclear Information System (INIS)

Dreibus, G.; Waenke, H.; Schultz, L.

1986-01-01

Halogen as well as other trace element concentrations in meteorite finds can be influenced by alteration processes on the Earth's surface. The discovery of Antarctic meteorites offered the opportunity to study meteorites which were kept in one of the most sterile environment of the Earth. Halogen determination in Antartic meteorites was compared with non-Antarctic meteorites. No correlation was found between iodine concentration and the weathering index, or terrestrial age. The halogen measurements indicate a contaminating phase rich in iodine and also containing chlorine. Possible sources for this contamination are discussed
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.
The vertebrate fauna of Ichauway, Baker County, GA

Science.gov (United States)

Smith, L.L.; Steen, D.A.; Stober, J.M.; Freeman, Mary C.; Golladay, S.W.; Conner, L.M.; Cochrane, J.

2006-01-01

Less than 4% of the once extensive Pinus palustris (longleaf pine) ecosystem remains today. Although longleaf pine habitats are recognized for their high species diversity, few published accounts document the vertebrate faunas of remaining tracts. Here we report on the vertebrate species richness of lchauway, an 11,300-ha property in Baker County, GA. The property includes ca. 7300 ha of longleaf pine with native ground cover, along with more than 30 seasonal wetlands and ca. 45 km of riparian habitat associated with Ichawaynochaway Creek, Big Cypress Creek, and the Flint River. The fauna includes 61 species of fish, 31 amphibians, 53 reptiles, 191 birds, and 41 mammals. Despite the relative isolation of the property from other natural ecosystems, the vertebrate fauna of lchauway is remarkably diverse and may offer an example of reference conditions to guide restoration of longleaf pine forests, associated seasonal wetlands, and riparian areas elsewhere in the southeastern U S.
The evolution of Greek fauna since classical times

Directory of Open Access Journals (Sweden)

Konstantinos Sidiropoulos

2017-02-01

Full Text Available This article concerns the Greek fauna of classical and late antiquity and changes up to the present day. The main sources for the fauna of antiquity are historical, geographical and zoological texts, as well as descriptions from travellers who visited Greece. The study of the texts of classical and late antiquity was based on the following classical authors: Xenophon, Aristotle, Aristophanes Byzantios, Pliny, Dio Chrysostom, Plutarch, Pausanias and Aelian. Some species that were present in the Greek fauna of classical and late antiquity, such as the lion and the leopard, are today extinct in Greece, whereas some other species that are now common, such as the cat, the chicken and the peacock, were introduced about that time or a little earlier from other regions. Some other species that are also common today, such as the wild rabbit and the pheasant, were unknown at that time, as they appeared later in Greece from other areas.
77 FR 5403 - Conservation of Antarctic Animals and Plants

Science.gov (United States)

2012-02-03

... NATIONAL SCIENCE FOUNDATION 45 CFR Part 670 Conservation of Antarctic Animals and Plants AGENCY: National Science Foundation. ACTION: Final rule. SUMMARY: Pursuant to the Antarctic Conservation Act of 1978, The National Science Foundation (NSF) is amending its regulations to reflect newly designated...
[Distribution pattern of meso-micro soil fauna in Eucalyptus grandis plantation].

Science.gov (United States)

Huang, Yumei; Zhang, Jian; Yang, Wanqin

2006-12-01

In this paper, meso-micro soil fauna were extracted and collected by Baermann's and Tullgren' s method, and their distribution pattern in the Eucalyptus grandis plantation of Hongya County, Sichuan Province was studied. A total of 13 550 specimens were collected, belonging to 6 phyla, 13 classes, and 26 orders. Acarina, Nematoda, Collembola were the dominant groups, and Enchytraeidae was the frequent one. The group and individual numbers of meso-micro soil fauna varied with seasons, being the maximum in autumn or winter, fewer in summer, and the minimum in spring. The density of meso-micro soil fauna in soil profile decreased rapidly with increasing soil depth, but a converse distribution was observed from time to time in 5 - 10 cm and 10 - 15 cm soil layers. The meso-micro soil fauna collected by Baermann's and Tullgren's method had a density of 3. 333 x 10(3) - 2. 533 x 10(5) ind x m(-2) and 1.670 x 10(2) - 2.393 x 10(5) ind x m(-2), respectively, and the decreasing rate of the density with the increase of soil depth was higher for those collected by Tullgren's method. The density-group index of meso-micro soil fauna in the E. grandis plantation was the lowest in spring, but the highest in autumn or summer. There were no significant differences in the density of meso-micro soil fauna and in the density-group index between E. grandis plantation and Quercus acutissima secondary forest.
In vitro immunobiological activity of an Antarctic streptomyces polysaccharide

International Nuclear Information System (INIS)

Toshkova, R.; Yossifova, L.; Gardeva, E.; Zvetkova, E.; Ivanova, V.

2010-01-01

Antarctic Streptomyces sp. 1010, were obtained from sea water samples (Livingston Island, Antarctica), during the Third Bulgarian Antarctic Scientific Expedition (1994-1995). The ecophysiological methods for isolation and characterization of these active, cold-adapted, Gram-positive microorganisms (psychrophiles) in morphological, phenotypic, genetic and taxonomic aspects, have been earlier reported. In this study, a new extracellular polysaccharide (heteropolysaccharide) has been isolated and purified from cultured broth of the Antarctic Streptomyces sp. 1010. The monosaccharide content of the Antarctic streptomyces heteropolysaccharide has been examined by TLC and GC/MS. The mitogenic and immuno potential properties of the purified Antarctic Streptomyces polysaccharide (ASMP) have been studied in vitro - in the short-term cultures of human peripheral blood mononuclear cells (hPBMCs - lymphocytes and monocytes) and mouse spleen lymphocytes (mouse splenocytes - mSps). The results obtained show that ASMP has a double lectin-like effect on the proliferative activity of hPBMCs: similar to this of Con A on the lymphoid cells (preliminary T-lymphocytes) and to the effect of LPS on the mononuclear from monocyte-macrophage lineage. Expressed as proliferative index (PI), the mitogenic response of mSps to the in vitro influence of ASMP was also higher than PI in the negative, as well as in the positive controls (mSps, cultured in the presence of PHA, Con A and LPS). The new Antarctic Streptomyces' heteropolysaccharide examined could be useful in the future as an immunomodulative biologically active substance and its extracellular production may contribute to the development of thermobiochemistry, immunomodulative drug therapy and immunopharmaceutical industry. (authors)
AGU honored for Antarctic book

Science.gov (United States)

AGU has won an honorable mention award at the Fifteenth Annual Awards Program for Excellence in Professional and Scholarly Publishing sponsored by the Association of American Publishers for the book Volcanoes of the Antarctic Plate and Southern Oceans. The book is part of AGU's Antarctic Research Series, an outgrowth of research done during the International Geophysical Year that was begun in 1963 with a grant from the National Science Foundation. The award was presented at the AAP Annual Awards Dinner on February 6 at the Ritz-Carlton Hotel in Washington, D.C. The award consists of a medallion and a plate on which the names of the publisher, title, and authors are engraved.
Introduction. Antarctic ecology: from genes to ecosystems. Part 2. Evolution, diversity and functional ecology.

Science.gov (United States)

Rogers, Alex D; Murphy, Eugene J; Johnston, Nadine M; Clarke, Andrew

2007-12-29

The Antarctic biota has evolved over the last 100 million years in increasingly isolated and cold conditions. As a result, Antarctic species, from micro-organisms to vertebrates, have adapted to life at extremely low temperatures, including changes in the genome, physiology and ecological traits such as life history. Coupled with cycles of glaciation that have promoted speciation in the Antarctic, this has led to a unique biota in terms of biogeography, patterns of species distribution and endemism. Specialization in the Antarctic biota has led to trade-offs in many ecologically important functions and Antarctic species may have a limited capacity to adapt to present climate change. These include the direct effects of changes in environmental parameters and indirect effects of increased competition and predation resulting from altered life histories of Antarctic species and the impacts of invasive species. Ultimately, climate change may alter the responses of Antarctic ecosystems to harvesting from humans. The unique adaptations of Antarctic species mean that they provide unique models of molecular evolution in natural populations. The simplicity of Antarctic communities, especially from terrestrial systems, makes them ideal to investigate the ecological implications of climate change, which are difficult to identify in more complex systems.
Antarctic isolation: immune and viral studies

Science.gov (United States)

Tingate, T. R.; Lugg, D. J.; Muller, H. K.; Stowe, R. P.; Pierson, D. L.

1997-01-01

Stressful environmental conditions are a major determinant of immune reactivity. This effect is pronounced in Australian National Antarctic Research Expedition populations exposed to prolonged periods of isolation in the Antarctic. Alterations of T cell function, including depression of cutaneous delayed-type hypersensitivity responses and a peak 48.9% reduction of T cell proliferation to the mitogen phytohaemagglutinin, were documented during a 9-month period of isolation. T cell dysfunction was mediated by changes within the peripheral blood mononuclear cell compartment, including a paradoxical atypical monocytosis associated with altered production of inflammatory cytokines. There was a striking reduction in the production by peripheral blood mononuclear cells of the predominant pro-inflammatory monokine TNF-alpha and changes were also detected in the production of IL-1, IL-2, IL-6, IL-1ra and IL-10. Prolonged Antarctic isolation is also associated with altered latent herpesvirus homeostasis, including increased herpesvirus shedding and expansion of the polyclonal latent Epstein-Barr virus-infected B cell population. These findings have important long-term health implications.
The nepheloid bottom layer and water masses at the shelf break of the western Ross Sea

Science.gov (United States)

Capello, Marco; Budillon, Giorgio; Cutroneo, Laura; Tucci, Sergio

2009-06-01

In the austral summers of 2000/2001 and 2002/2003 the Italian CLIMA Project carried out two oceanographic cruises along the northwestern margin of the Ross Sea, where the Antarctic Bottom Water forms. Here there is an interaction between the water masses on the sea floor of the outer shelf and slope with a consequent evolution of benthic nepheloid layers and an increase in total particulate matter. We observed three different situations: (a) the presence of triads (bottom structures characterized by a concomitant jump in turbidity, temperature, and salinity data) and high re-suspension phenomena related to the presence of the Circumpolar Deep Water and its mixing with cold, salty shelf waters associated with gravity currents; (b) the absence of triads with high re-suspension, implying that when the gravity currents are no longer active the benthic nepheloid layer may persist until the suspended particles settle to the sea floor, suggesting that the turbidity data can be used to study recent gravity current events; and (c) the absence of turbidity and sediment re-suspension phenomena supports the theory that a steady situation had been re-established and the current interaction no longer occurred or had finished sometime before.

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.
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.
Ecuadorian antarctic act

International Nuclear Information System (INIS)

1998-02-01

To develop research in this continent involves to take communion with earth where the cold pole of the planet is located, the stormiest sea of the world surround it and where the capricious continental and geographical distribution permits the pass of meteorological violent and continuous systems. The Ecuador, in execution of the acquired commitments like Full Member of the System of the Antarctic Treaty, carried out the VII Expedition to the White Continent with an extensive program of scientific investigation in the field of: Sciences of Life, Sciences of the Earth and Atmospheric Sciences, so much in the environment of the Pacific Southeast, the Drake Pass, Bransfield Strait and the nearby ecosystems antarctic to Point Fort William in the Greenwich Island, site where the Ecuadorian station Pedro Vicente Maldonado is located. The scientific articles, result of the fruitful work of national investigator is consigned in this fourth edition. This publication constitutes our contribution to the world in the knowledge, understanding and handling of the marvelous White Continent from the middle of our planet, Ecuador
Biostratigraphic implications of the first Eocene land-mammal fauna from the North American coastal plain

Science.gov (United States)

Westgate, James W.

1988-11-01

A newly discovered vertebrate fossil assemblage, the Casa Blanca local fauna, comes from the Laredo Formation, Claiborne Group, of Webb County, Texas, and is the first reported Eocene land-mammal fauna from the coastal plain of North America. The mammalian fauna is correlated with the Serendipity and Candelaria local faunas of west Texas, the Uinta C faunas of the Rocky Mountains, the Santiago Formation local fauna of southern California, and the Swift Current Creek local fauna of Saskatchewan. The vertebrate-bearing deposit lies about 32 m above a horizon containing the marine gastropod Turritella cortezi, which ranges from east Texas to northeast Mexico in the lower half of the Cook Mountain and Laredo Formations and is a guide fossil to the Hurricane Lentil in the Cook Mountain Formation. Nannoplankton found in these middle Eocene formations belong to the upper half of Nannoplankton Zone I6 and allow correlation with European beds of late Lutetian to early Bartonian age.
Spatial pattern in Antarctica: what can we learn from Antarctic bacterial isolates?

Science.gov (United States)

Chong, Chun Wie; Goh, Yuh Shan; Convey, Peter; Pearce, David; Tan, Irene Kit Ping

2013-09-01

A range of small- to moderate-scale studies of patterns in bacterial biodiversity have been conducted in Antarctica over the last two decades, most suggesting strong correlations between the described bacterial communities and elements of local environmental heterogeneity. However, very few of these studies have advanced interpretations in terms of spatially associated patterns, despite increasing evidence of patterns in bacterial biogeography globally. This is likely to be a consequence of restricted sampling coverage, with most studies to date focusing only on a few localities within a specific Antarctic region. Clearly, there is now a need for synthesis over a much larger spatial to consolidate the available data. In this study, we collated Antarctic bacterial culture identities based on the 16S rRNA gene information available in the literature and the GenBank database (n > 2,000 sequences). In contrast to some recent evidence for a distinct Antarctic microbiome, our phylogenetic comparisons show that a majority (~75 %) of Antarctic bacterial isolates were highly similar (≥99 % sequence similarity) to those retrieved from tropical and temperate regions, suggesting widespread distribution of eurythermal mesophiles in Antarctic environments. However, across different Antarctic regions, the dominant bacterial genera exhibit some spatially distinct diversity patterns analogous to those recently proposed for Antarctic terrestrial macroorganisms. Taken together, our results highlight the threat of cross-regional homogenisation in Antarctic biodiversity, and the imperative to include microbiota within the framework of biosecurity measures for Antarctica.
Are Antarctic minke whales unusually abundant because of 20th century whaling?

Science.gov (United States)

Ruegg, Kristen C; Anderson, Eric C; Scott Baker, C; Vant, Murdoch; Jackson, Jennifer A; Palumbi, Stephen R

2010-01-01

Severe declines in megafauna worldwide illuminate the role of top predators in ecosystem structure. In the Antarctic, the Krill Surplus Hypothesis posits that the killing of more than 2 million large whales led to competitive release for smaller krill-eating species like the Antarctic minke whale. If true, the current size of the Antarctic minke whale population may be unusually high as an indirect result of whaling. Here, we estimate the long-term population size of the Antarctic minke whale prior to whaling by sequencing 11 nuclear genetic markers from 52 modern samples purchased in Japanese meat markets. We use coalescent simulations to explore the potential influence of population substructure and find that even though our samples are drawn from a limited geographic area, our estimate reflects ocean-wide genetic diversity. Using Bayesian estimates of the mutation rate and coalescent-based analyses of genetic diversity across loci, we calculate the long-term population size of the Antarctic minke whale to be 670,000 individuals (95% confidence interval: 374,000-1,150,000). Our estimate of long-term abundance is similar to, or greater than, contemporary abundance estimates, suggesting that managing Antarctic ecosystems under the assumption that Antarctic minke whales are unusually abundant is not warranted.
Effect of progressive inoculation of fauna-free sheep with holotrich protozoa and total-fauna on rumen fermentation, microbial diversity and methane emissions.

Science.gov (United States)

Belanche, Alejandro; de la Fuente, Gabriel; Newbold, Charles J

2015-03-01

Rumen methanogenesis represents an energy waste for the ruminant and an important source of greenhouse gas; thus, integrated studies are needed to fully understand this process. Eight fauna-free sheep were used to investigate the effect of successive inoculation with holotrich protozoa then with total fauna on rumen methanogenesis. Holotrichs inoculation neither altered rumen fermentation rate nor diet digestibility, but increased concentrations of acetate (+15%), butyrate (+57%), anaerobic fungi (+0.82 log), methanogens (+0.41 log) and methanogenesis (+54%). Further inoculation with total fauna increased rumen concentrations of protozoa (+1.0 log), bacteria (+0.29 log), anaerobic fungi (+0.78 log), VFA (+8%), ammonia and fibre digestibility (+17%) without affecting levels of methanogens or methanogenesis. Rumen methanogens population was fairly stable in terms of structure and diversity, while the bacterial community was highly affected by the treatments. Inoculation with holotrich protozoa increased bacterial diversity. Further inoculation with total fauna lowered bacterial diversity but increased concentrations of certain propionate and lactate-producing bacteria, suggesting that alternative H2 sinks could be relevant. This experiment suggests that holotrich protozoa have a greater impact on rumen methanogenesis than entodiniomorphids. Thus, further research is warranted to understand the effect of holotrich protozoa on methane formation and evaluate their elimination from the rumen as a potential methane mitigation strategy. © Federation of European Microbiological Society 2014.
Fauna-associated changes in chemical and biochemical properties of soil.

Science.gov (United States)

Tripathi, G; Sharma, B M

2006-12-01

To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both sites. The soil samples were sent to laboratory, their chemical and biochemical properties were analyzed. Woodlice showed 25% decrease in organic carbon and organic matter as compared to control site. Whereas termites and mites showed 58% and 16% decrease in organic carbon and organic matter. In contrast, available nitrogen (nitrate and ammonical both) and phosphorus exhibited 2-fold and 1.2-fold increase, respectively. Soil respiration and dehydrogenase activity at the sites rich in woodlice, termites and mites produced 2.5-, 3.5- and 2-fold increases, respectively as compared to their control values. Fauna-associated increase in these biological parameters clearly reflected fauna-induced microbial activity in soil. Maximum decrease in organic carbon and increase in nitrate-nitrogen and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were produced by termites and minimum by mites reflecting termite as an efficient soil improver in desert environment. The soil fauna-associated changes in chemical (organic carbon, nitrate-nitrogen, ammonical-nitrogen, phosphorus) and biochemical (soil respiration, dehydrogenase activity) properties of soil improve soil health and help in conservation of desert pedoecosystem.
Feasibility of Using Alternate Fuels in the U.S. Antarctic Program: Initial Assessment

Science.gov (United States)

2017-09-01

Polar Programs. Morris, A. 2015a. Email communication. 21 April. Centennial , CO: Antarctic Support Contractor. ———. 2015b. Personal...communication. 19 May. Centennial , CO: Antarctic Support Contractor. ———. 2014. Email communication. 24 November. Centennial , CO: Antarctic Support
The use of drilling by the U.S. Antarctic program

Energy Technology Data Exchange (ETDEWEB)

Wade, M.C.; Webb, J.W.; Hedberg, W.H.

1994-08-01

This report on drilling in the Antarctic has been prepared by the U.S. National Science Foundation (NSF) to assist principal investigators and others in complying with the National Environmental Policy Act (NEPA) and the Antarctic Treaty of 1961. Implementing regulations for NEPA are spelled out in 40 CFR 1500-1508. Environmental protection under the Antarctic Treaty is addressed in the Protocol on Environmental Protection to the Antarctic Treaty (hereafter referred to as the Protocol), which was adopted by 26 countries in 1991. In the United States, responsibility for compliance with these requirements rests with the NSF Office of Polar Programs (OPP), which manages the U.S. Antarctic Program (USAP). The USAP recognizes the potentially profound impacts that its presence and activities can have on the antarctic environment. In its extensive support of operations and research in Antarctica, the USAP uses all practical means to foster and maintain natural conditions while supporting scientific endeavors in a safe and healthful manner. Reducing human impacts on the antarctic environment is a major goal of the USAP. The USAP`s operating philosophy is based on broad yet reasonable and practical assumptions concerning environmental protection. The USAP maintains three year-round stations on the continent to support scientific research. Research and associated support operations at these stations and camps sometimes involve drilling into ice, soil, or ocean sediments. In order to comply with NEPA and the Protocol, it is necessary for principal investigators and others to assess the environmental effects of drilling. This report has been prepared to assist in this process by describing various drilling technologies currently available for use in Antarctica, generally characterizing the potential environmental impacts associated with these drilling techniques, and identifying possible mitigation measures to reduce impacts.
The effects of sub-ice-shelf melting on dense shelf water formation and export in idealized simulations of Antarctic margins

Science.gov (United States)

Marques, Gustavo; Stern, Alon; Harrison, Matthew; Sergienko, Olga; Hallberg, Robert

2017-04-01

Dense shelf water (DSW) is formed in coastal polynyas around Antarctica as a result of intense cooling and brine rejection. A fraction of this water reaches ice shelves cavities and is modified due to interactions with sub-ice-shelf melt water. This modified water mass contributes to the formation of Antarctic Bottom Water, and consequently, influences the large-scale ocean circulation. Here, we investigate the role of sub-ice-shelf melting in the formation and export of DSW using idealized simulations with an isopycnal ocean model (MOM6) coupled with a sea ice model (SIS2) and a thermodynamic active ice shelf. A set of experiments is conducted with variable horizontal grid resolutions (0.5, 1.0 and 2.0 km), ice shelf geometries and atmospheric forcing. In all simulations DSW is spontaneously formed in coastal polynyas due to the combined effect of the imposed atmospheric forcing and the ocean state. Our results show that sub-ice-shelf melting can significantly change the rate of dense shelf water outflows, highlighting the importance of this process to correctly represent bottom water formation.
CHARLES DARWIN: INMORTALIZADO EN EPÓNIMOS DE GEA, FLORA Y FAUNA RECIENTES DE CHILE

OpenAIRE

Pérez, Vicente

2009-01-01

Se presentan epónimos de gea, flora y fauna de Chile, erigidos en honor de Charles Darwin, naturalista a bordo del H.M.S. Beagle (1831-1836), para denominar accidentes geográficos de territorio chileno y nuevas especies de flora y fauna descritas de ejemplares recolectados en Chile por él. Eponyms of gea, flora and fauna, erected in honour of Charles Darwin, naturalist on board of the H.M.S. Beagle (1831-1836), for desígnate geographic accidents and new species of flora and fauna described...
Isolation and Antifouling Activity of Azulene Derivatives from the Antarctic Gorgonian Acanthogorgia laxa.

Science.gov (United States)

Patiño Cano, Laura P; Quintana Manfredi, Rodrigo; Pérez, Miriam; García, Mónica; Blustein, Guillermo; Cordeiro, Ralf; Pérez, Carlos D; Schejter, Laura; Palermo, Jorge A

2018-01-01

Three azulenoid sesquiterpenes (1 - 3) were isolated from the Antarctic gorgonian Acanthogorgia laxa collected by bottom trawls at -343 m. Besides linderazulene (1), and the known ketolactone 2, a new brominated C 16 linderazulene derivative (3) was also identified. This compound has an extra carbon atom at C(7) of the linderazulene framework. The antifouling activity of compounds 1 and 2 was assayed in the laboratory with Artemia salina larvae, and also in field tests, by incorporation in soluble-matrix experimental antifouling paints. The results obtained after a 45 days field trial of the paints, showed that compounds 1 and 2 displayed good antifouling potencies against a wide array of organisms. Compound 3, a benzylic bromide, was unstable and for this reason was not submitted to bioassays. Two known cembranolides: pukalide and epoxypukalide, were also identified as minor components of the extract. © 2018 Wiley-VHCA AG, Zurich, Switzerland.
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.
The United States Antarctic Program Data Center (USAP-DC): Recent Developments

Science.gov (United States)

Nitsche, F. O.; Bauer, R.; Arko, R. A.; Shane, N.; Carbotte, S. M.; Scambos, T.

2017-12-01

Antarctic earth and environmental science data are highly valuable, often unique research assets. They are acquired with substantial and expensive logistical effort, frequently in areas that will not be re-visited for many years. The data acquired in support of Antarctic research span a wide range of disciplines. Historically, data management for the US Antarctic Program (USAP) has made use of existing disciplinary data centers, and the international Antarctic Master Directory (AMD) has served as a central metadata catalog linking to data files hosted in these external repositories. However, disciplinary repositories do not exist for all USAP-generated data types and often it is unclear what repositories are appropriate, leading to many datasets being served locally from scientist's websites or not available at all. The USAP Data Center (USAP-DC; www.usap-dc.org), operated as part of the Interdisciplinary Earth Data Alliance (IEDA), contributes to the broader preservation of research data acquired with funding from NSF's Office of Polar Programs by providing a repository for diverse data from the Antarctic region. USAP-DC hosts data that spans the range of Antarctic research from snow radar to volcano observatory imagery to penguin counts to meteorological model outputs. Data services include data documentation, long-term preservation, and web publication, as well as scientist support for registration of data descriptions into the AMD in fulfillment of US obligations under the International Antarctic Treaty. In Spring 2016, USAP-DC and the NSIDC began a new collaboration to consolidate data services for Antarctic investigators and to integrate the NSF-funded glaciology collection at NSIDC with the collection hosted by USAP-DC. Investigator submissions for NSF's Glaciology program now make use of USAP-DC's web submission tools, providing a uniform interface for Antarctic investigators. The tools have been redesigned to collect a broader range of metadata. Each data
[Interrelationships between soil fauna and soil environmental factors in China: research advance].

Science.gov (United States)

Wang, Yi; Wei, Wei; Yang, Xing-zhong; Chen, Li-ding; Yang, Lei

2010-09-01

Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna's bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e., more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multi-environmental factors and long-term monitoring should be conducted on large scale areas.
Antarctic science

Science.gov (United States)

Summerhayes, Colin

Once upon a time, dinosaurs roamed Antarctica and swam in its seas. Since then, life evolved as the climate cooled into the ice ages. Life will no doubt continue to evolve there as the globe now warms. But nowadays, humans are having a profound and direct effect on life in Antarctica, the sub-Antarctic islands, and the surrounding Southern Ocean, which are being invaded by a wide range of alien species including microbes, algae, fungi, bryophytes, land plants, invertebrates, fish, birds, and mammals.
The multi-millennial Antarctic commitment to future sea-level rise.

Science.gov (United States)

Golledge, N R; Kowalewski, D E; Naish, T R; Levy, R H; Fogwill, C J; Gasson, E G W

2015-10-15

Atmospheric warming is projected to increase global mean surface temperatures by 0.3 to 4.8 degrees Celsius above pre-industrial values by the end of this century. If anthropogenic emissions continue unchecked, the warming increase may reach 8-10 degrees Celsius by 2300 (ref. 2). The contribution that large ice sheets will make to sea-level rise under such warming scenarios is difficult to quantify because the equilibrium-response timescale of ice sheets is longer than those of the atmosphere or ocean. Here we use a coupled ice-sheet/ice-shelf model to show that if atmospheric warming exceeds 1.5 to 2 degrees Celsius above present, collapse of the major Antarctic ice shelves triggers a centennial- to millennial-scale response of the Antarctic ice sheet in which enhanced viscous flow produces a long-term commitment (an unstoppable contribution) to sea-level rise. Our simulations represent the response of the present-day Antarctic ice-sheet system to the oceanic and climatic changes of four representative concentration pathways (RCPs) from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We find that substantial Antarctic ice loss can be prevented only by limiting greenhouse gas emissions to RCP 2.6 levels. Higher-emissions scenarios lead to ice loss from Antarctic that will raise sea level by 0.6-3 metres by the year 2300. Our results imply that greenhouse gas emissions in the next few decades will strongly influence the long-term contribution of the Antarctic ice sheet to global sea level.
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. Copyright © 2015 Elsevier B.V. All rights reserved.
[Microelement contents of litter, soil fauna and soil in Pinus koraiensis and broad-leaved mixed forest].

Science.gov (United States)

Yin, Xiu-qin; Li, Jin-xia; Dong, Wei-hua

2007-02-01

The analysis on the Mn, Zn and Cu contents of litter, soil fauna and soil in Pinus korazenszis and broad-leaved mixed forest in Liangshui Natural Reserve of Xiaoxing' an Mountains showed that the test microelement contents in the litter, soil fauna and soil all followed the sequence of Mn > Zn > Cu, but varied with these environmental components, being in the sequence of soil > litter > soil fauna for Mn, soil fauna > litter and soil for Zn, and soil fauna > soil > litter for Cu. The change range of test microelement contents in litter was larger in broad-leaved forest than in coniferous forest. Different soil fauna differed in their microelement-enrichment capability, e. g. , earthworm, centipede, diplopod had the highest content of Mn, Zn and Cu, respectively. The contents of test microelements in soil fauna had significant correlations with their environmental background values, litter decomposition rate, food habit of soil fauna, and its absorbing selectivity and enrichment to microelements. The microelements contained in 5-20 cm soil layer were more than those in 0-5 cm soil layer, and their dynamics differed in various soil layers.

Quantarctica: A Unique, Open, Standalone GIS Package for Antarctic Research and Education

Science.gov (United States)

Roth, George; Matsuoka, Kenichi; Skoglund, Anders; Melvær, Yngve; Tronstad, Stein

2017-04-01

The Norwegian Polar Institute has developed Quantarctica (http://quantarctica.npolar.no), an open GIS package for use by the international Antarctic community. Quantarctica includes a wide range of cartographic basemap layers, geophysical and glaciological datasets, and satellite imagery in standardized open file formats with a consistent Antarctic map projection and customized layer and labeling styles for quick, effective cartography. Quantarctica's strengths as an open science platform lie in 1) The complete, ready-to-use data package which includes full-resolution, original-quality vector and raster data, 2) A policy for freely-redistributable and modifiable data including all metadata and citations, and 3) QGIS, a free, full-featured, modular, offline-capable open-source GIS suite with a rapid and active development and support community. The Quantarctica team is actively incorporating more up-to-date, peer-reviewed, freely distributable pan-Antarctic geospatial datasets for the next version release in 2017. As part of this ongoing development, we are investigating the best approaches for quickly and seamlessly distributing new and updated data to users, storing datasets in efficient, open file formats while maintaining full data integrity, and coexisting with numerous online data portals in a way that most actively benefits the Antarctic community. A recent survey of Quantarctica users showed broad geographical adoption among Antarctic Treaty countries, including those outside the large US and UK Antarctic programs. Maps and figures produced by Quantarctica have also appeared in open-access journals and outside of the formal scientific community on popular science and GIS blogs. Our experience with the Quantarctica project has shown the tremendous value of education and outreach, not only in promoting open software, data formats, and practices, but in empowering Antarctic science groups to more effectively use GIS and geospatial data. Open practices are
Stable isotopes and Antarctic moss banks: Plants and soil microbes respond to recent warming on the Antarctic Peninsula

Science.gov (United States)

Royles, Jessica; Amesbury, Matthew; Ogée, Jérôme; Wingate, Lisa; Convey, Peter; Hodgson, Dominic; Griffiths, Howard; Leng, Melanie; Charman, Dan

2014-05-01

The Antarctic Peninsula is one of the most rapidly warming regions on Earth, with air temperature increases of as much as 3°C recorded since the 1950s. However, the longer-term context of this change is limited and existing records, largely relying on ice core data, are not suitably located to be able to trace the spatial signature of change over time. We are working on a project exploiting stable isotope records preserved in moss peat banks spanning 10 degrees of latitude along the Antarctic Peninsula as an archive of late Holocene climate variability. Here we present a unique time series of past moss growth and soil microbial activity that has been produced from a 150 year old moss bank at Lazarev Bay, Alexander Island (69°S), a site at the southern limit of significant plant growth in the Antarctic Peninsula region. These moss banks are ideal archives for palaeoclimate research as they are well-preserved by freezing, generally monospecific, easily dated by radiocarbon techniques, and have sufficiently high accumulation rates to permit decadal resolution. We use accumulation rates, cellulose δ13C and fossil testate amoebae to show that growth rates, assimilation and microbial productivity rose rapidly in the 1960s, consistent with temperature change, although recently may have stalled, concurrent with other evidence. The increase in biological activity is unprecedented in the last 150 years. Along with work completed on Signy Island (60°S), in the South Orkney Islands, in which we used carbon isotope evidence to show recent climate-related enhancement of CO2 assimilation and peat accumulation rates in Antarctica, the observed relationships between moss growth, microbial activity and climate suggests that moss bank records have the potential to test the regional expression of temperature variability shown by instrumental data on the Antarctic Peninsula over centennial to millennial timescales, by providing long-term records of summer growth conditions
Fauna Europaea: Hymenoptera – Symphyta & Ichneumonoidea

NARCIS (Netherlands)

van Achterberg, K.; Taeger, A.; Blank, S.M.; Zwakhals, K.; Viitasaari, M.; Yu, D.S.K.; de Jong, Y.

2017-01-01

Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region),
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.
Fauna of four streams in the Black Mountain District of South Wales

Energy Technology Data Exchange (ETDEWEB)

Jones, J R.E.

1948-01-01

This paper is a general study of four torrential streams in the 'Black Mountain' district of South Wales. Fauna collections were made at seven collecting stations, between altitudes of 1550 and 400 ft. Observations were made on the chemical nature of the water, current speed and temperature. The fauna taken as a whole is rich, including about 151 species. Of the four streams, the one flowing north has the richest fauna, which includes about 130 species in which all the usual aquatic animal groups except the hirudinea are represented. This may be attributed to its equable temperature, abundant and uniform flow, variable gradient, adequate macroflora, and alkaline-neutral moderately calcareous water. The streams flowing south all have very soft, acid water; their stream-beds are more uniform in gradient, they are extremely variable in flow, have a more scanty macroflora, and on sunny summer days the water temperature is high, little below the shade temperature. All have a much poorer fauna than the north-flowing stream. One has a pH of 6.0-6.8, the fauna includes about 65 species, the usual insect groups are well represented but only 9 species other than insects occur. The second has a pH of 6.0 at low level to 4.4 in full flood; here 57 species were found, again mainly insects, and the ephemorophtera are very poorly represented. The third southern stream is generally even more acid, pH 5.8-4.2. Its fauna includes 55 species of which 24 are beetles, plecoptera are very poorly represented and ephemeroptera absent.
Characteristic Flora and Fauna of the Kachin State, Northern Myanmar

International Nuclear Information System (INIS)

Yi Yi Win; Cilia Linburt; Yin Yin May

2005-10-01

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.
Effects of simulated acid rain on soil fauna community composition and their ecological niches.

Science.gov (United States)

Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

2017-01-01

Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO 2 ], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions. Copyright Â© 2016 Elsevier Ltd. All rights reserved.
Can we observe the fronts of the Antarctic Circumpolar Current using GRACE OBP?

Science.gov (United States)

Makowski, J.; Chambers, D. P.; Bonin, J. A.

2014-12-01

The Antarctic Circumpolar Current (ACC) and the Southern Ocean remains one of the most undersampled regions of the world's oceans. The ACC is comprised of four major fronts: the Sub-Tropical Front (STF), the Polar Front (PF), the Sub-Antarctic Front (SAF), and the Southern ACC Front (SACCF). These were initially observed individually from repeat hydrographic sections and their approximate locations globally have been quantified using all available temperature data from the World Ocean and Climate Experiment (WOCE). More recent studies based on satellite altimetry have found that the front positions are more dynamic and have shifted south by up to 1° on average since 1993. Using ocean bottom pressure (OBP) data from the current Gravity Recovery and Climate Experiment (GRACE) we have measured integrated transport variability of the ACC south of Australia. However, differentiation of variability of specific fronts has been impossible due to the necessary smoothing required to reduce noise and correlated errors in the measurements. The future GRACE Follow-on (GFO) mission and the post 2020 GRACE-II mission are expected to produce higher resolution gravity fields with a monthly temporal resolution. Here, we study the resolution and error characteristics of GRACE gravity data that would be required to resolve variations in the front locations and transport. To do this, we utilize output from a high-resolution model of the Southern Ocean, hydrology models, and ice sheet surface mass balance models; add various amounts of random and correlated errors that may be expected from GFO and GRACE-II; and quantify requirements needed for future satellite gravity missions to resolve variations along the ACC fronts.
Metal and antibiotic-resistance in psychrotrophic bacteria from Antarctic marine waters

Digital Repository Service at National Institute of Oceanography (India)

De; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

In the wake of the findings that Antarctic krills concentrate heavy metals at ppm level, (Yamamoto et al., 1987), the Antarctic waters from the Indian side were examined for the incidence of metal and antibiotic-resistant bacteria during...
Characterizing the Seismic Ocean Bottom Environment of the Bransfield Strait

Science.gov (United States)

Washington, B.; Lekic, V.; Schmerr, N. C.

2017-12-01

Ocean bottom seismometers record ground motions that result from earthquakes, anthropogenic sound sources (e.g. propellers, air gun sources, etc.), ocean waves and currents, biological activity, as well as surface processes on the sea and coastal land. Over a two-week span in April, 2001 - the Austral late fall -ten stations arranged in eleven lines were deployed beneath the Bransfield Strait along the Antarctica Peninsula to passively record data before and after an active source seismic survey. The goal of this study is to understand ocean bottom seismicity, identify centers of seismic activity and characterize possible glaciological mechanisms of icequakes and tremors. The instruments were sampled at 200Hz, allowing signals of ice-quakes, small earthquakes, and other high frequency sources to be detected and located. By visualizing the data as spectrograms, we identify and document ground vibrations excited by local earthquakes, whale songs, and those potentially due to surface processes, such as the cracking and movement of icebergs or ice shelves, including possible harmonic tremors from the ice or the volcanic arc nearby. Using relative timing of P-wave arrivals, we locate the hypocenters of nearby earthquakes and icequakes, and present frequency-dependent polarization analysis of their waveforms. Marine mammal sounds were detected in a substantial part of the overall acoustic environment-late March and Early April are the best months to hear whales such as humpback, sperm and orca communicating amongst each other because they are drawn to the cold, nutrient-rich Antarctic waters. We detect whales communicating for several hours in the dataset. Other extensively recorded sources resemble harmonic tremors, and we also identify signals possibly associated with waves set up on the notoriously stormy seas.
Molluscan diversity along a Mediterranean soft bottom sublittoral ecotone

Directory of Open Access Journals (Sweden)

Panayota Koulouri

2006-12-01

Full Text Available Molluscan diversity associated with sublittoral soft-bottoms was studied in Heraklion Bay as part of a long-term multidisciplinary research programme in the coastal environment of northern Crete (eastern Mediterranean. Quantitative benthic samples were collected in a pilot survey from a grid of 28 stations, followed by a seasonal sampling carried out over a seven- station transect located from 10 to 40 m depth. Univariate and multivariate analyses indicated the presence of a clear zonation along the depth gradient for the molluscan fauna and three main associations were identified in bathymetric zones parallel to the coastline. The structure of the local molluscan communities revealed the existence of an extended transition zone (ecotone between a shallow sandy association and a deeper muddy one and a functional pattern, based on the feeding guilds, was evident along the environmental gradient. Application of graphical techniques, by using molluscan taxocoenosis, indicated a rather naturally disturbed habitat. Beta-diversity measures indicated different seasonal community adaptations to the prevailing environmental conditions. Results derived from this study revealed that beta-diversity may be a good descriptor for the assessment of the strength and breadth of sublittoral transition zones along environmental gradients.
Antarctic Meteorite Newsletter

Science.gov (United States)

Lindstrom, Marilyn

2000-01-01

This newsletter contains something for everyone! It lists classifications of about 440 meteorites mostly from the 1997 and 1998 ANSMET (Antarctic Search for Meteorites) seasons. It also gives descriptions of about 45 meteorites of special petrologic type. These include 1 iron, 17 chondrites (7 CC, 1 EC, 9 OC) and 27 achondrites (25 HED, UR). Most notable are an acapoloite (GRA98028) and an olivine diogenite (GRA98108).
Preliminary Compositional Comparisons of H-Chondrite Falls to Antarctic H-Chondrite Populations

Science.gov (United States)

Kallemeyn, G. W.; Krot, A. N.; Rubin, A. E.

1993-07-01

In a series of papers [e.g., 1,2], Lipschutz and co-workers compared trace- element RNAA data from Antarctic and non-Antarctic H4-6 chondrites and concluded that the two populations have significantly different concentrations of several trace elements including Co, Se, and Sb. They interpreted their data as indicating that these Antarctic H chondrites form different populations than observed H falls and may have originated in separate parent bodies. Recent work by Sears and co-workers [e.g., 3] has shown that there seem to be distinct populations of Antarctic H chondrites, distinguishable on the bases of induced thermoluminescence (TL) peak temperature, metallographic cooling rate, and cosmic ray exposure age. They showed that a group of Antarctic H chondrites having abnormally high induced TL peak temperatures (>=190 degrees C) also has cosmic ray exposure ages Ma (mostly ~8 Ma) and fast metallographic cooling rates (~100 K/Ma). Another group having induced TL peak temperatures 20 Ma and slower cooling rates (~10-20 K/Ma). We studied 24 H4-6 chondrites from Victoria Land (including 12 previously analyzed by the Lipschutz group) by optical microscopy and electron microprobe. Many of the Antarctic H chondrites studied by Lipschutz and co- workers are unsuitable for proper compositional comparisons with H chondrite falls: Four are very weathered, five are extensively shocked, and two are extensively brecciated. Furthermore, at least five of the samples contain solar-wind gas (and hence are regolith breccias) [4]. These samples were rejected because of possible compositional modification by secondary processes. For our INAA study we chose a suite of relatively unweathered and unbrecciated Antarctic H chondrites (including nine from the Lipschutz set): ALHA 77294 (H5, S3); ALHA 79026 (H5, S3); ALHA 79039 (H5, S3); ALHA 80131 (H5, S3); ALHA 80132 (H5, S4); ALHA 81037 (H6, S3); EETA 79007 (H5, S4); LEW 85320 (H6, S4); LEW 85329 (H6, S3); RKPA 78002 (H5, S2); and RKPA
Mariene flora en fauna te boek

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Hoeksema, B.W.; Gittenberger, A.

2006-01-01

Het aantal boeken over de Nederlandse flora en fauna neemt gestaag toe. En ook de afgelopen jaren zijn er weer aardig wat nieuwe titels uitgekomen over het Nederlandse zeeleven. Op deze pagina's vier van die boeken. Eerder, in de Onderwatersport van april 2005, is ook al een aantal titels
Distributional records of Antarctic fungi based on strains preserved in the Culture Collection of Fungi from Extreme Environments (CCFEE Mycological Section associated with the Italian National Antarctic Museum (MNA

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Laura Selbmann

2015-07-01

Full Text Available This dataset includes information regarding fungal strains collected during several Antarctic expeditions: the Italian National Antarctic Research program (PNRA expeditions “X” (1994/1995, “XII” (1996/1997, “XVII” (2001/2002, “XIX” (2003/2004, “XXVI” (2010/2011, the Czech “IPY Expedition” (2007–2009 and a number of strains donated by E. Imre Friedmann (Florida State University in 2001, isolated from samples collected during the U.S.A. Antarctic Expeditions of 1980-1982. Samples, consisting of colonized rocks, mosses, lichens, sediments and soils, were collected in Southern and Northern Victoria Land of the continental Antarctica and in the Antarctic Peninsula. A total of 259 different strains were isolated, belonging to 32 genera and 38 species, out of which 12 represented new taxa. These strains are preserved in the Antarctic section of the Culture Collection of Fungi from Extreme Environments (CCFEE, which represents one of the collections associated with the Italian National Antarctic Museum (MNA, Section of Genoa, Italy, located at the Laboratory of Systematic Botany and Mycology, Department of Ecological and Biological Sciences (DEB, Tuscia University (Viterbo, Italy. The CCFEE hosts a total of 486 Antarctic fungal strains from worldwide extreme environments. Distributional records are reported here for 259 of these strains. The holotypes of the 12 new species included in this dataset are maintained at CCFEE and in other international collections: CBS-KNAW Fungal Biodiversity Centre (Utrecht, Netherlands; DBVPG, Industrial Yeasts Collection (University of Perugia, Italy; DSMZ, German Collection of Microorganisms and Cell Cultures (Brunswick, Germany; IMI, International Mycological Institute (London, U.K..
Fauna of four streams in the Black Mountain District of South Wales

Energy Technology Data Exchange (ETDEWEB)

Jones, J.R.E.

1948-01-01

This paper is a general study of four torrential streams in the 'Black Mountain' district of South Wales. Fauna collections were made at seven collecting stations, between altitudes of 1550 and 400 ft. Observations were made on the chemical nature of the water, current speed and temperature. The fauna taken as a whole is rich, including about 151 species. Of the four streams, the one flowing north has the richest fauna, which includes about 130 species in which all the usual aquatic animal groups except the hirudinea are represented. This may be attributed to its equable temperature, abundant and uniform flow, variable gradient, adequate macroflora, and alkaline-neutral moderately calcareous water. The streams flowing south all have very soft, acid water; their stream-beds are more uniform in gradient, they are extremely variable in flow, have a more scanty macroflora, and on sunny summer days the water temperature is high, little below the shade temperature. All have a much poorer fauna than the north-flowing stream. One has a pH of 6.0-6.8, the fauna includes about 65 species, the usual insect groups are well represented but only 9 species other than insects occur. The second has a pH of 6.0 at low level to 4.4 in full flood; here 57 species were found, again mainly insects, and the ephemorophtera are very poorly represented. The third southern stream is generally even more acid, pH 5.8-4.2. Its fauna includes 55 species of which 24 are beetles, plecoptera are very poorly represented and ephemeroptera absent.
Diversity and distribution patterns in high southern latitude sponges.

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Rachel V Downey

Full Text Available Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ∼43%, with a higher level for the class Hexactinellida (68%. Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent
Why should we care about soil fauna? Por que devemos nos importar com a fauna do solo?

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Jonathan Michael Anderson

2009-08-01

Full Text Available The reasons why we care about soil fauna are related to their intrinsic, utilitarian and functional values. The intrinsic values embrace aesthetic or moral reasons for conserving below-ground biodiversity. Unfortunately, the protection of soil invertebrates has rarely been a criterion for avoiding changes in land use and management. Utilitarian, or direct use values, have been investigated more extensively for fungi, bacteria and marine invertebrates than for soil fauna. However, some traditional remedies, novel enzymes and pharmaceutical compounds have been derived from earthworms, termites and other groups, and gut symbionts may provide microbial strains with interesting properties for biotechnology. The functional importance of soil invertebrates in ecosystem processes has been a major focus of research in recent decades. It is suggested herein that it is rarely possible to identify the role of soil invertebrates as rate determinants of soil processes at plot and ecosystem scales of hectares and above because other biophysical controls override their effects. There are situations, however, where the activities of functional groups of soil animals, even of species, are synchronised in space or time by plant events, resource inputs, seasonality or other perturbations to the system, and their emergent effects are detectable as higher order controls.As razões porque nos importamos com a fauna do solo estão relacionadas com seus valores intrínsecos, utilitários e funcionais. Os valores intrínsecos abrangem razões morais ou estéticas para conservar a biodiversidade subterrânea. Infelizmente, a proteção dos invertebrados do solo raramente tem sido um critério para evitar mudanças no manejo e uso da terra. Valores utilitários, ou de uso direto, têm sido pesquisados mais extensamente para fungos, bactérias e invertebrados marinhos do que para a fauna do solo. Contudo, alguns remédios tradicionais, enzimas novas e produtos farmac
The Sponge Zygomycale parishii(Bowerbank) and its Endobiotic Fauna

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Duarte, Luiz; Nalesso, Rosebel

1996-02-01

The endobiotic fauna of the sponge Zygomycale parishii(Bowerbank) was studied for 2·5 years at two sites, Ubatuba and São Sebastião, on the northern coast of the State of São Paulo, Brazil. Ninety-two macrofaunal species (over 1 mm long) were identified among which Cnidaria, Turbellaria, Nemertinea, Sipuncula, Polychaeta, Mollusca, Crustacea, Pycnogonida, Echinodermata, Ascidiacea and Pisces were represented. The results obtained on the number of species (species richness), the abundances of different species and faunal composition were related to the physico-biotic characteristics of the study sites. The influence of sample volume and other methodological artifacts on sample characteristics were also examined. The ophiuroid Ophiactis savignyi(Müller & Troschell) was the dominant endobiotic species, comprising 64% of all individuals collected. The São Sebastião endobiotic fauna was more diversified than the Ubatuba endobiotic fauna, possibly due to higher larval recruitment, and to the closeness of Z. parishiito the sea-floor providing a greater possibility for inhabitants of this microhabitat to find and to live inside the sponge.
Spatial and temporal variability across life's hierarchies in the terrestrial Antarctic.

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Chown, Steven L; Convey, Peter

2007-12-29

Antarctica and its surrounding islands lie at one extreme of global variation in diversity. Typically, these regions are characterized as being species poor and having simple food webs. Here, we show that terrestrial systems in the region are nonetheless characterized by substantial spatial and temporal variations at virtually all of the levels of the genealogical and ecological hierarchies which have been thoroughly investigated. Spatial variation at the individual and population levels has been documented in a variety of genetic studies, and in mosses it appears that UV-B radiation might be responsible for within-clump mutagenesis. At the species level, modern molecular methods have revealed considerable endemism of the Antarctic biota, questioning ideas that small organisms are likely to be ubiquitous and the taxa to which they belong species poor. At the biogeographic level, much of the relatively small ice-free area of Antarctica remains unsurveyed making analyses difficult. Nonetheless, it is clear that a major biogeographic discontinuity separates the Antarctic Peninsula and continental Antarctica, here named the 'Gressitt Line'. Across the Southern Ocean islands, patterns are clearer, and energy availability is an important correlate of indigenous and exotic species richness, while human visitor numbers explain much of the variation in the latter too. Temporal variation at the individual level has much to do with phenotypic plasticity, and considerable life-history and physiological plasticity seems to be a characteristic of Antarctic terrestrial species. Environmental unpredictability is an important driver of this trait and has significantly influenced life histories across the region and probably throughout much of the temperate Southern Hemisphere. Rapid climate change-related alterations in the range and abundance of several Antarctic and sub-Antarctic populations have taken place over the past several decades. In many sub-Antarctic locations, these

Food choice of Antarctic soil arthropods clarified by stable isotope signatures

NARCIS (Netherlands)

Bokhorst, S.F.; Ronfort, C.; Huiskes, A.H.L.; Convey, P.; Aerts, R.A.M.

2007-01-01

Antarctic soil ecosystems are amongst the most simplified on Earth and include only few soil arthropod species, generally believed to be opportunistic omnivorous feeders. Using stable isotopic analyses, we investigated the food choice of two common and widely distributed Antarctic soil arthropod
Unexpectedly high ultrafine aerosol concentrations above East Antarctic sea ice

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R. S. Humphries

2016-02-01

Full Text Available Better characterisation of aerosol processes in pristine, natural environments, such as Antarctica, have recently been shown to lead to the largest reduction in uncertainties in our understanding of radiative forcing. Our understanding of aerosols in the Antarctic region is currently based on measurements that are often limited to boundary layer air masses at spatially sparse coastal and continental research stations, with only a handful of studies in the vast sea-ice region. In this paper, the first observational study of sub-micron aerosols in the East Antarctic sea ice region is presented. Measurements were conducted aboard the icebreaker Aurora Australis in spring 2012 and found that boundary layer condensation nuclei (CN3 concentrations exhibited a five-fold increase moving across the polar front, with mean polar cell concentrations of 1130 cm−3 – higher than any observed elsewhere in the Antarctic and Southern Ocean region. The absence of evidence for aerosol growth suggested that nucleation was unlikely to be local. Air parcel trajectories indicated significant influence from the free troposphere above the Antarctic continent, implicating this as the likely nucleation region for surface aerosol, a similar conclusion to previous Antarctic aerosol studies. The highest aerosol concentrations were found to correlate with low-pressure systems, suggesting that the passage of cyclones provided an accelerated pathway, delivering air masses quickly from the free troposphere to the surface. After descent from the Antarctic free troposphere, trajectories suggest that sea-ice boundary layer air masses travelled equatorward into the low-albedo Southern Ocean region, transporting with them emissions and these aerosol nuclei which, after growth, may potentially impact on the region's radiative balance. The high aerosol concentrations and their transport pathways described here, could help reduce the discrepancy currently present between
Unexpectedly high ultrafine aerosol concentrations above East Antarctic sea ice

Science.gov (United States)

Humphries, R. S.; Klekociuk, A. R.; Schofield, R.; Keywood, M.; Ward, J.; Wilson, S. R.

2016-02-01

Better characterisation of aerosol processes in pristine, natural environments, such as Antarctica, have recently been shown to lead to the largest reduction in uncertainties in our understanding of radiative forcing. Our understanding of aerosols in the Antarctic region is currently based on measurements that are often limited to boundary layer air masses at spatially sparse coastal and continental research stations, with only a handful of studies in the vast sea-ice region. In this paper, the first observational study of sub-micron aerosols in the East Antarctic sea ice region is presented. Measurements were conducted aboard the icebreaker Aurora Australis in spring 2012 and found that boundary layer condensation nuclei (CN3) concentrations exhibited a five-fold increase moving across the polar front, with mean polar cell concentrations of 1130 cm-3 - higher than any observed elsewhere in the Antarctic and Southern Ocean region. The absence of evidence for aerosol growth suggested that nucleation was unlikely to be local. Air parcel trajectories indicated significant influence from the free troposphere above the Antarctic continent, implicating this as the likely nucleation region for surface aerosol, a similar conclusion to previous Antarctic aerosol studies. The highest aerosol concentrations were found to correlate with low-pressure systems, suggesting that the passage of cyclones provided an accelerated pathway, delivering air masses quickly from the free troposphere to the surface. After descent from the Antarctic free troposphere, trajectories suggest that sea-ice boundary layer air masses travelled equatorward into the low-albedo Southern Ocean region, transporting with them emissions and these aerosol nuclei which, after growth, may potentially impact on the region's radiative balance. The high aerosol concentrations and their transport pathways described here, could help reduce the discrepancy currently present between simulations and observations of
Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years

NARCIS (Netherlands)

Gardner, Alex S.; Moholdt, Geir; Scambos, Ted; Fahnstock, Mark; Ligtenberg, Stefan; van den Broeke, Michiel; Nilsson, Johan

2018-01-01

Ice discharge from large ice sheets plays a direct role in determining rates of sea-level rise. We map present-day Antarctic-wide surface velocities using Landsat 7 and 8 imagery spanning 2013–2015 and compare to earlier estimates derived from synthetic aperture radar, revealing heterogeneous
Monitoring trace elements in Antarctic penguin chicks from South Shetland Islands, Antarctica.

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Jerez, Silvia; Motas, Miguel; Benzal, Jesús; Diaz, Julia; Barbosa, Andrés

2013-04-15

The concentration of human activities in the near-shore ecosystems from the northern Antarctic Peninsula area can cause an increasing bioavailability of pollutants for the vulnerable Antarctic biota. Penguin chicks can reflect this potential impact in the rookeries during the breeding season. They also can reflect biomagnification phenomena since they are on the top of the Antarctic food chain. The concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were measured by ICP-MS in samples of liver, kidney, muscle, bone, feather and stomach content of gentoo, chinstrap and Adélie penguin chicks (n=15 individuals) collected opportunistically in the Islands of King George and Deception (South Shetland Islands, Antarctica). The detected levels of some trace elements were not as low as it could be expected in the isolated Antarctic region. Penguin chicks can be useful indicators of trace elements abundance in the study areas. Carcasses of Antarctic penguin chicks were used to evaluate the bioavailability of trace elements in the Islands of King George and Deception. Copyright © 2013 Elsevier Ltd. All rights reserved.
Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle

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Kuhn, G.; Wu, S.; Hass, H. C.; Klages, J. P.; Zheng, X.; Arz, H. W.; Esper, O.; Hillenbrand, C. D.; Lange, C.; Lamy, F.; Lohmann, G.; Müller, J.; McCave, I. N. N.; Nürnberg, D.; Roberts, J.; Tiedemann, R.; Timmermann, A.; Titschack, J.; Zhang, X.

2017-12-01

The evolution of the Antarctic Ice Sheet during the last climate cycle and the interrelation to global atmospheric and ocean circulation remains controversial and plays an important role for our understanding of ice sheet response to modern global warming. The timing and sequence of deglacial warming is relevant for understanding the variability and sensitivity of the Antarctic Ice Sheet to climatic changes, and the continuing rise of atmospheric greenhouse gas concentrations. The Antarctic Ice Sheet is a pivotal component of the global water budget. Freshwater fluxes from the ice sheet may affect the Antarctic Circumpolar Current (ACC), which is strongly impacted by the westerly wind belt in the Southern Hemisphere (SHWW) and constricted to its narrowest extent in the Drake Passage. The flow of ACC water masses through Drake Passage is, therefore, crucial for advancing our understanding of the Southern Ocean's role in global meridional overturning circulation and global climate change. In order to address orbital and millennial-scale variability of the Antarctic ice sheet and the ACC, we applied a multi-proxy approach on a sediment core from the central Drake Passage including grain size, iceberg-rafted debris, mineral dust, bulk chemical and mineralogical composition, and physical properties. In combination with already published and new sediment records from the Drake Passage and Scotia Sea, as well as high-resolution data from Antarctic ice cores (WDC, EDML), we now have evidence that during glacial times a more northerly extent of the perennial sea-ice zone decreased ACC current velocities in the central Drake Passage. During deglaciation the SHWW shifted southwards due to a decreasing temperature gradient between subtropical and polar latitudes caused by sea ice and ice sheet decline. This in turn caused Southern Hemisphere warming, a more vigorous ACC, stronger Southern Ocean ventilation, and warm Circumpolar Deep Water (CDW) upwelling on Antarctic shelves
Water masses, ocean fronts, and the structure of Antarctic seabird communities: putting the eastern Bellingshausen Sea in perspective

Science.gov (United States)

Ribic, Christine A.; Ainley, David G.; Ford, R. Glenn; Fraser, William R.; Tynan, Cynthia T.; Woehler, Eric J.

2015-01-01

Waters off the western Antarctic Peninsula (i.e., the eastern Bellingshausen Sea) are unusually complex owing to the convergence of several major fronts. Determining the relative influence of fronts on occurrence patterns of top-trophic species in that area, therefore, has been challenging. In one of the few ocean-wide seabird data syntheses, in this case for the Southern Ocean, we analyzed ample, previously collected cruise data, Antarctic-wide, to determine seabird species assemblages and quantitative relationships to fronts as a way to provide context to the long-term Palmer LTER and the winter Southern Ocean GLOBEC studies in the eastern Bellingshausen Sea. Fronts investigated during both winter (April–September) and summer (October–March) were the southern boundary of the Antarctic Circumpolar Current (ACC), which separates the High Antarctic from the Low Antarctic water mass, and within which are embedded the marginal ice zone and Antarctic Shelf Break Front; and the Antarctic Polar Front, which separates the Low Antarctic and the Subantarctic water masses. We used clustering to determine species' groupings with water masses, and generalized additive models to relate species' densities, biomass and diversity to distance to respective fronts. Antarctic-wide, in both periods, highest seabird densities and lowest species diversity were found in the High Antarctic water mass. In the eastern Bellingshausen, seabird density in the High Antarctic water mass was lower (as low as half that of winter) than found in other Antarctic regions. During winter, Antarctic-wide, two significant species groups were evident: one dominated by Adélie penguins (Pygoscelis adeliae) (High Antarctic water mass) and the other by petrels and prions (no differentiation among water masses); in eastern Bellingshausen waters during winter, the one significant species group was composed of species from both Antarctic-wide groups. In summer, Antarctic-wide, a High Antarctic group
Impact of agricultural practices on selected soil decomposers fauna

International Nuclear Information System (INIS)

Abdalatif, M. A.; Alrayah, A.; Azar, W. Z.

2009-01-01

Soil decomposers fauna i.e. collembolan, mites and nematodes were studied and compared between and within sites in relation to site, treatment and time of collection in Shambat arable and El Rwakeeb dry land. Comparison of results between sites showed that population density/volume of decomposers fauna sampled from Shambat site exceeded their assemblages sampled from El Rawakeeb site. Treatment application in form of cattle manure and neem leaves powder were observed to induce insignificant changes in the three faunal groups between the two sites. Temporal variations showed significant annual variations and insignificant seasonal variations between the two sites. Within each site, population density/volume of each of collembolan, mites and nematodes increased in response to cattle manure application in both sites. Whereas, neem leaves powder application induced a significant decrease in population density/volume of collembola in both sites. These results are generally attributed to variability of soil properties which may add to the suitability of Shambat soil to El Rawakeeb one for the survival of decomposers fauna. Within each site, increase in population density/volume of these fauna upon cattle manure application was attributed to ability of cattle manure to improve soil properties and to provide food. The negative effect of neem leaves powder on mites and nematodes was attributed to neem toxicity, whereas, its positive effects on collembolan was attributed to the ability of collembolan to withstand neem toxicity, collembolan probably physiologically resistant and the neem powder provided food, thus increasing its numbers compared to the central treatment.(Author)
Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes.

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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. © 2013 John Wiley & Sons Ltd/CNRS.
THE GARGANO TERRE ROSSE INSULAR FAUNAS: AN OVERVIEW

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FEDERICO MASINI

2010-11-01

Full Text Available After forty years from its discovery, the history of the field surveys and of the researches on the fossiliferous deposits on Gargano is briefly reported. The Gargano fauna belongs to the Abruzzo-Apulian Palaeobioprovince (including also Scontrone and Palena, Abruzzo. The fossil assemblage comprehends all the classes of terrestrial vertebrates: Reptilia, Amphibia, Aves and Mammalia. The faunal composition is unbalanced and presents the features of a typical insular endemic fauna. The bulk of the assemblage is composed of small mammals and birds. Based on literature, we report the most characteristic features, phylogenetic relationships, and evolutionary remarks on a list of mammals, focusing particularly on the adaptations of the most endemic taxa. Moreover, a biochronological scheme of the major faunal events is proposed and illustrated. Although still imperfect, the scheme is the first synopsis of all the biochronological and taxonomical information on mammals so far available. Eventually, the hypotheses on the origin and modes of colonisation are summarized and shortly discussed. From this overview the Gargano fauna is indeed of great interest for studies of evolution and biogeography. Nonetheless, there are persistent uncertainties on its age and origin, as well as on the age of infilling of the karstic fissure system of this unique fossiliferous locality.
Trophodynamics of suprabenthic fauna on coastal muddy bottoms of the southern Tyrrhenian Sea (western Mediterranean)

Science.gov (United States)

Fanelli, E.; Cartes, J. E.; Badalamenti, F.; Rumolo, P.; Sprovieri, M.

2009-02-01

The trophodynamics of suprabenthic fauna were analyzed in the Gulf of Castellammare (North-western Sicily, Italy) at depths ranging between 40 and 80 m. Variations in species abundance and biomass together with changes in nitrogen and carbon stable isotope composition were explored at a seasonal scale, from November 2004 to June 2005. Suprabenthos showed maximum biomass and abundance from late winter to summer, while minimum values were found in autumn. The highest abundances of mysids and copepods occurred in March, 1 month after the peak of primary production. Amphipod abundance was higher in summer, likely due to a relative increase in organic matter in the sediments. Statistical analysis provided evidence for separation of sample abundances as a function of season. The best match between suprabenthos abundance and environmental variables was found with Chlorophyll a recorded 3 months before the sampling. Stable isotope analyses suggest a relatively complex food web in the Gulf of Castellammare with several potential food sources. Some suprabenthic species (i.e. mysids and copepods) exhibited depleted values of δ13C, indicating a planktonic source of nutrition. Cumaceans and amphipods displayed more enriched δ13C values, pointing to more detritivorous behaviour. A third group with intermediate δ13C values comprised species with a mixed diet (e.g. Ampelisca spp., Apherusa vexatrix and Harpinia spp.). Assuming a 15N-enrichment of ca. 2.54‰ between consumers and their diet, at least two trophic levels can be distinctly identified: (1) filter feeders/grazers (mysids, copepods), suspension/deposit feeders ( Ampelisca spp., A. vexatrix, small Goneplax rhomboides) and omnivores, alternatively feeding on detritus and small invertebrates such as meiobenthos (the cumacean Leucon mediterraneus or the amphipod Westwoodilla rectirostris); (2) carnivores on small crustaceans and zooplankton (the amphipod Harpinia spp., the gobiid fish Lesuerigobius suerii and the decapod
Physical reworking by near-bottom flow alters the metazoan meiofauna of Fieberling Guyot (northeast Pacific)

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Thistle, David; Levin, Lisa A.; Gooday, Andrew J.; Pfannkuche, Olaf; Lambshead, P. John D.

1999-12-01

Although much of the deep sea is physically tranquil, some regions experience near-bottom flows that rework the surficial sediment. During periods of physical reworking, animals in the reworked layer risk being suspended, which can have both positive and negative effects. Reworking can also change the sediment in ecologically important ways, so the fauna of reworked sites should differ from that of quiescent locations. We combined data from two reworked, bathyal sites on the summit of Fieberling Guyot (32°27.631'N, 127°49.489'W; 32°27.581'N, 127°47.839'W) and compared the results with those of more tranquil sites. We tested for differences in the following parameters, which seemed likely to be sensitive to the direct or indirect effects of reworking: (1) the vertical distribution of the meiofauna in the sea bed, (2) the relative abundance of surface-living harpacticoids, (3) the proportion of the fauna consisting of interstitial harpacticoids, (4) the ratio of harpacticoids to nematodes. We found that the vertical distributions of harpacticoid copepods, ostracods, and kinorhynchs were deeper on Fieberling. In addition, the relative abundance of surface-living harpacticoids was less, the proportion of interstitial harpacticoids was greater, and the ratio of harpacticoids to nematodes was greater on Fieberling. These differences between Fieberling and the comparison sites suggest that physical reworking affects deep-sea meiofauna and indicate the nature of some of the effects.
Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula

International Nuclear Information System (INIS)

Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

2015-01-01

Highlights: • We assessed mercury bioaccumulation in seabirds in the Antarctic Peninsula. • Levels of Hg were higher in gentoo penguins & brown skuas than chinstrap penguins. • Mercury BMF in the brown skua/penguins relationship was higher than 1. • Long-range environmental transport is the likely mercury route in Antarctic. - Abstract: In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2–7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula
The Guadalupian Fauna

Science.gov (United States)

Girty, George H.

1908-01-01

The first descriptions of the Guadalupian fauna were published nearly fifty years ago. This early account of Shumard's was meager enough, but gave promise of a facies interesting and novel among the known Carboniferous faunas of North America. The following pages add largely to our knowledge of Guadalupian life, and I believe more than make good any promise contained in the previous account. Nevertheless, even the collections of the Guadalupian fauna here described fail to do justice to its richness and diversity, and the present report is completed with the hope of returning to the subject after another visit to the Guadalupe Mountains. Although a description of this range and the adjacent region can be found elsewhere, a repetition of the more important facts will conduce to a better understanding of the geologic relations of the fauna described herein and will serve to illustrate the references to localities and horizons necessarily involved in the paleontologic discussion. The Guadalupe Mountains are situated chiefly in southeastern New Mexico, but extend across the border for a short distance into the trans-Pecos region of Texas. Save only for this southern extreme both their geology and their topography are practically unknown, and it should be understood that anything hereafter said of them relates only to that portion. These mountains form a north-south range of considerable height, which rises abruptly from an arid and treeless plain, stretching westward to more mountainous elevations, the Cornudas Mountains and the Sierra Tinaja Pinta. This plain is locally known as Crow Flats and forms a part of the Salt Basin (Pl. I). It is now used as cattle ranges, water being raised by windmills. The only permanent surface water consists of salt lakes - broad, shallow pools incrusted with saline deposits, which in the early days were extensively sought for domestic use. This water is of course unfit for consumption, but cattle seem as a rule not to mind the less
[History of Polish botanical and mycological researches on sheets of land of Antarctic and Sub-Antarctic in the years 1977-2009].

Science.gov (United States)

Köhler, Piotr; Olech, Maria

2011-01-01

The work includes a description of the period from the moment of setting up Polish Polar Station on King George Island (1977) to the end of International Polar Year IV in 2009. Researches on flower plants focused, among others, on plants' morphology, morphological composition of the pollen and anatomical ultra-structure of the leaves. There were also carried out biochemical and other searches for the internal mutability. Within physiological studies one concentrated on the problem of reaction to temperature stress. Biological researches focused mainly on solving taxonomic and bio-geographic problems. Finally, were published several monographs and, among others, the first in history complete description of moss' flora of the whole of Antarctic (2008). Research works over algae included also such issues as floristics, bio-geography, taxonomy and ecology (for instance, the rookery's impact on distribution of algae, or the influence of inanimate factors on dynamics of condensing the Diatoma in different water and soil-bound tanks). Up till now, within mycological investigations has been identified a variety of lichen fungi that for the most part of Antarctic are a novelty. There were scientifically described new for science genera and species of Western Antarctic. Lichenological studies were made in the field of taxonomy, geography, lichenometry, biochemistry of lichens, lichenoindication, ecophysiology and from the point of analysis of base metals' content. There were also described new for science species. Since 1991, were published the results of searches for the base metals' content and vestigial chemical elements in lichens' thallus. Ecophysiological researches concerned both micro-climatic conditions' impact on primary production and lichens' adaptation to a very cold climate. One discovered a mechanism of two-phase hydratization/dehydratization of lichens' thallus. On the ground of palaeobotanical analyzes was reconstructed a development of flora in Western
The origin of platyrrhines: An evaluation of the Antarctic scenario and the floating island model.

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Houle, A

1999-08-01

This paper evaluates whether 1) protoplatyrrhines could have migrated to South America via Antarctica, and 2) the floating island model is a plausible transoceanic mode of dispersal for land vertebrates like protoplatyrrhines. Results show that Eocene Antarctica and Australia supported large and dense forests, and that the Antarctic fauna was comprised of many species of vertebrates, including placental and marsupial land mammals. However, no primate remains have ever been reported from these continents. Antarctica and South America were connected until the Middle Eocene (i.e., after the oldest Asian anthropoids), but two major water barriers existed between Antarctica and Asia since the Early Eocene. The Eocene and Oligocene water gap separating Africa and Antarctica was excessively large. Thus, all scenarios involving an Antarctic route have been rejected. The African scenario is difficult to falsify because only one water barrier existed, both paleowinds and paleocurrents were favorable, and Paleogene African anthropoids show phylogenetic affinities to platyrrhines. I tested whether a journey on a hypothetical floating island over the Paleogene Atlantic Ocean exceeds the survival limit of a genetically viable group of animals such as protoplatyrrhines. Studies of water deprivation suggest that they could have been able, with a body weight averaging 1 kg, to survive without water for at least 13 days. I have used the present Atlantic Ocean as a model for the velocity of Paleogene paleowinds and paleocurrents. Considering winds as the key accelerating force of floating islands, the Paleogene Atlantic water barrier could have been crossed, in the most conservative scenario, in 8 days at 50 Mya, 11 days at 40 Mya, and 15 days at 30 Mya. In order to survive a transoceanic journey, however, protoplatyrrhines had to be preadapted to strong seasonal variations in water availability in their original (African) environment. Once on the sea, their brains would have
Synchronous turnover of flora, fauna, and climate at the Eocene–Oligocene Boundary in Asia

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Sun, Jimin; Ni, Xijun; Bi, Shundong; Wu, Wenyu; Ye, Jie; Meng, Jin; Windley, Brian F.

2014-01-01

The Eocene–Oligocene Boundary (~34 million years ago) marks one of the largest extinctions of marine invertebrates in the world oceans and of mammalian fauna in Europe and Asia in the Cenozoic era. A shift to a cooler climate across this boundary has been suggested as the cause of this extinction in the marine environment, but there is no manifold evidence for a synchronous turnover of flora, fauna and climate at the Eocene–Oligocene Boundary in a single terrestrial site in Asia to support this hypothesis. Here we report new data of magnetostratigraphy, pollen and climatic proxies in the Asian interior across the Eocene–Oligocene Boundary; our results show that climate change forced a turnover of flora and fauna, suggesting there was a change from large-size perissodactyl-dominant fauna in forests under a warm-temperate climate to small rodent/lagomorph-dominant fauna in forest-steppe in a dry-temperate climate across the Eocene–Oligocene Boundary. These data provide a new terrestrial record for this significant Cenozoic environmental event. PMID:25501388
[Community structure of soil meso- and micro-fauna in different habitats of urbanized region].

Science.gov (United States)

Qin, Zhong; Zhang, Jia-en; Li, Qing-fang

2009-12-01

Investigations were made in May, June, and November 2007 and January 2008 to study the structural characteristics and their seasonal variations of soil meso- and micro-fauna communities in six habitats of three land use types (forest land, constructed grassland and farmland) in Tianhe District of Guangzhou City. The horizontal spatial distribution of soil fauna differed with habitat. During the investigation periods, the Botanical Garden of South China Agricultural University had the highest individual number (1286) of soil mesa- and micro-fauna, while the farmland, especially in the Fenghuang Street area, had the lowest number of individuals and groups. The seasonal variation of the individual number was in order of autumn (1815) > spring (1623) > winter (1365) > summer (1276). Hierarchical clustering and detrended correspondence analysis also showed that the community composition of soil meso- and micro-fauna in different habitats exhibited distinct seasonal variation. In the same seasons, the community structure and composition of soil meso- and micro-fauna in different habitats were correlated to the degrees of human interferences and the properties of soil environment.
Synchronous turnover of flora, fauna, and climate at the Eocene-Oligocene Boundary in Asia.

Science.gov (United States)

Sun, Jimin; Ni, Xijun; Bi, Shundong; Wu, Wenyu; Ye, Jie; Meng, Jin; Windley, Brian F

2014-12-12

The Eocene-Oligocene Boundary (~34 million years ago) marks one of the largest extinctions of marine invertebrates in the world oceans and of mammalian fauna in Europe and Asia in the Cenozoic era. A shift to a cooler climate across this boundary has been suggested as the cause of this extinction in the marine environment, but there is no manifold evidence for a synchronous turnover of flora, fauna and climate at the Eocene-Oligocene Boundary in a single terrestrial site in Asia to support this hypothesis. Here we report new data of magnetostratigraphy, pollen and climatic proxies in the Asian interior across the Eocene-Oligocene Boundary; our results show that climate change forced a turnover of flora and fauna, suggesting there was a change from large-size perissodactyl-dominant fauna in forests under a warm-temperate climate to small rodent/lagomorph-dominant fauna in forest-steppe in a dry-temperate climate across the Eocene-Oligocene Boundary. These data provide a new terrestrial record for this significant Cenozoic environmental event.
[Responses of soil fauna to environment degeneration in the process of wind erosion desertification of Hulunbeir steppe].

Science.gov (United States)

Lü, Shi-Hai; Lu, Xin-Shi; Gao, Ji-Xi

2007-09-01

To reveal the relationships between soil fauna and soil environmental factors in the process of steppe desertification, field survey combined with laboratory analysis was made to study the community structure, population density and biodiversity of soil fauna, and their relationships with the changes of soil organic matter, hydrolysable nitrogen, available phosphorus and moisture contents and soil pH at different stages of desertification of Hulunbeir steppe. The soil faunal specimens collected belonged to 4 phyla, 6 classes and 12 orders. Nematoda was the only dominant group of medium- and small-sized soil fauna, occupying 94.3% of the total, while Coleoptera and Hemiptera were the dominant groups of large-sized soil fauna, with the amount of 79.7%. The group amount, population density, diversity, and evenness of soil fauna had an obvious decreasing trend with the aggravation of steppe desertification. At serious stage of desertification, soil fauna vanished completely. The population density of soil fauna in 0-20 cm soil layer had significant linear correlations with soil nutrients and moisture contents, soil pH, and litter mass, indicating that soil fauna had stronger sensibility to the changes of soil environmental factors in the process of wind erosion desertification of Hulunbeir steppe.

Tabulate Corals after the Frasnian/Famennian Crisis: A Unique Fauna from the Holy Cross Mountains, Poland.

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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.
Tabulate Corals after the Frasnian/Famennian Crisis: A Unique Fauna from the Holy Cross Mountains, Poland.

Directory of Open Access Journals (Sweden)

Mikołaj K Zapalski

Full Text Available 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.
Guía para restricción física de fauna silvestre

OpenAIRE

Torres-Chaparro, María Yanneth; Quintero-Sánchez, Vladimir

2016-01-01

Esta guía presenta los protocolos y actividades que deben realizarse durante la manipulación de fauna silvestre en los Centros de Atención y Valoración (CAV). Como bien es sabido, el tráfico de fauna silvestre es una actividad ilícita que trae consigo unos problemas profundos de pérdida de biodiversidad. Dentro de las estrategias de control de tráfico de fauna se realizan actividades de control y monitoreo, presentándose situaciones en las cuales un gran número de animales son rescatados, dec...
Climate Change Impacts in the sub-Antarctic Islands Technical Report N.2 of ONERC

International Nuclear Information System (INIS)

2009-01-01

Difficult to apprehend as a whole, the polar regions constitute the Arctic to the North, an ocean surrounded by emerged lands, and the Antarctic to the South, a continent bordered by the Austral Ocean where a belt of sub Antarctic islands lies. Climate change impacts on sub Antarctic islands are varied, direct and indirect: glacier retreat, more favourable conditions for introduced species, marine biodiversity modification, etc. This report discusses the French, British, Australian, South African and New Zealand sub Antarctic islands, the climatic evolutions and the resulting impacts, focused especially on biodiversity. The Observatoire National sur les Effets du Rechauffement Climatique and the International Polar Foundation have been joined in this endeavour by the French polar institute Paul-Emile Victor, the administration of the French Southern and Antarctic Lands (TAAF in French) and the International Union for the Conservation of Nature. (authors)
Persistent Organic Pollutants in Biotic and Abiotic Components of Antarctic Pristine Environment

Science.gov (United States)

Bhardwaj, Laxmikant; Chauhan, Abhishek; Ranjan, Anuj; Jindal, Tanu

2018-05-01

Over the past decades, research in Antarctica has built a new understanding of Antarctica, its past, present and future. Human activities and long-range pollutants are increasing on the Antarctic continent. Research on persistent organic pollutants (POPs) has been carried out internationally by several countries having their permanent research stations to explain the impact of an ever increasing range of POPs in Antarctic ecosystem. POPs have been detected in Antarctica despite its geographical isolation and almost complete absence of human settlements. The presence of POPs in different abiotic (atmosphere, water bodies, sediments, soil, sea ice) and biotic components (mosses, lichens, krill, penguins, skua, etc.) in Antarctica has been studied and documented around for decades and has either been banned or strictly regulated but is still found in the environment. This review focuses on recent research pertaining to sources and occurrence of POPs in Antarctic lake water, soil, sediment, lichen, mosses and other Antarctic marine community. This review also proposes to summarize the current state of research on POPs in Antarctica environment and draw the earliest conclusions on possible significance of POPs in Antarctica based on presently available information from related Antarctic environment.
A 25-year Record of Antarctic Ice Sheet Elevation and Mass Change

Science.gov (United States)

Shepherd, A.; Muir, A. S.; Sundal, A.; McMillan, M.; Briggs, K.; Hogg, A.; Engdahl, M.; Gilbert, L.

2017-12-01

Since 1992, the European Remote-Sensing (ERS-1 and ERS-2), ENVISAT, and CryoSat-2 satellite radar altimeters have measured the Antarctic ice sheet surface elevation, repeatedly, at approximately monthly intervals. These data constitute the longest continuous record of ice sheet wide change. In this paper, we use these observations to determine changes in the elevation, volume and mass of the East Antarctic and West Antarctic ice sheets, and of parts of the Antarctic Peninsula ice sheet, over a 25-year period. The root mean square difference between elevation rates computed from our survey and 257,296 estimates determined from airborne laser measurements is 54 cm/yr. The longevity of the satellite altimeter data record allows to identify and chart the evolution of changes associated with meteorology and ice flow, and we estimate that 3.6 % of the continental ice sheet, and 21.7 % of West Antarctica, is in a state of dynamical imbalance. Based on this partitioning, we estimate the mass balance of the East and West Antarctic ice sheet drainage basins and the root mean square difference between these and independent estimates derived from satellite gravimetry is less than 5 Gt yr-1.
Fauna do solo em áreas com Eucalyptus spp. e Pinus elliottii, Santa Maria, RS.

Directory of Open Access Journals (Sweden)

Maria Izabel Jacques Soares

2009-10-01

Full Text Available Normal 0 21 MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} Este trabalho, com início na primavera de 1996 e término no inverno de 1997, teve como objetivo realizar o levantamento populacional da fauna do solo em áreas com Eucalyptus spp. e Pinus elliottii, situadas no Campus da Universidade Federal de Santa Maria, Rio Grande do Sul, Brasil. Para a coleta do solo, utilizou-se um extrator, formando-se amostras em dez pontos, nas profundidades de 0-5, 5-10, 10-15 e de 15-20 cm, em cada estação do ano. Por meio deste estudo, pôde-se identificar alguns representantes dos Phylum Annelida e Arthropoda que participam do contexto fauna-solo-vegetação. O total de indivíduos, seu respectivo percentual e número de indivíduos por metro quadrado foram obtidos. Observou-se o predomínio do Phylum Arthropoda e, mais especificamente, da classe Insecta na área com Eucalyptus spp. e do Phylum Annelida na área com Pinus elliottii. A variável profundidade originou modelos matemáticos que explicam a distribuição populacional dentre as áreas estudadas. A variável estação do ano não apresentou uma diferença significativa. Não foi possível, portanto, estabelecer um modelo de distribuição populacional.
Genetic signature of Last Glacial Maximum regional refugia in a circum-Antarctic sea spider

Science.gov (United States)

Soler-Membrives, Anna; Linse, Katrin; Miller, Karen J.; Arango, Claudia P.

2017-10-01

The evolutionary history of Antarctic organisms is becoming increasingly important to understand and manage population trajectories under rapid environmental change. The Antarctic sea spider Nymphon australe, with an apparently large population size compared with other sea spider species, is an ideal target to look for molecular signatures of past climatic events. We analysed mitochondrial DNA of specimens collected from the Antarctic continent and two Antarctic islands (AI) to infer past population processes and understand current genetic structure. Demographic history analyses suggest populations survived in refugia during the Last Glacial Maximum. The high genetic diversity found in the Antarctic Peninsula and East Antarctic (EA) seems related to multiple demographic contraction-expansion events associated with deep-sea refugia, while the low genetic diversity in the Weddell Sea points to a more recent expansion from a shelf refugium. We suggest the genetic structure of N. australe from AI reflects recent colonization from the continent. At a local level, EA populations reveal generally low genetic differentiation, geographically and bathymetrically, suggesting limited restrictions to dispersal. Results highlight regional differences in demographic histories and how these relate to the variation in intensity of glaciation-deglaciation events around Antarctica, critical for the study of local evolutionary processes. These are valuable data for understanding the remarkable success of Antarctic pycnogonids, and how environmental changes have shaped the evolution and diversification of Southern Ocean benthic biodiversity.
The Effect of Crop Residue Application to Soil Fauna Community and Mungbean Growth (Vigna radata

Directory of Open Access Journals (Sweden)

SUGIYARTO

2000-01-01

Full Text Available Litterbag experiment was carried out to determine the effect of crop residue application to soil fauna community and mungbean growth. The experiment arranged in randomized complete design with triplicate. The four treatment application of crotalarian, rice straw and banana’s aerial stem residues as well as without residue application as control. Soil fauna community and mungbean growth measured at 8 weeks after mungbean sown. Soil fauna extracted by modified Barless-Tullgren extractor apparatus. Height and dry weight of mungbean measured as crop growth parameters. The results indicated that the soil fauna densities and diversities as well as the growth of mungbean tended to increase by the application of crop residues. The effect of the treatment decreasing in the following order: banana’s aerial stem residue > crotalarian residue > rice straw > without residue application. There were high correlation between mungbean growth and soil fauna diversities.© 2001 Jurusan Biologi FMIPA UNS SurakartaKey words:
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
Microbial populations in Antarctic permafrost: biodiversity, state, age, and implication for astrobiology.

Science.gov (United States)

Gilichinsky, D A; Wilson, G S; Friedmann, E I; McKay, C P; Sletten, R S; Rivkina, E M; Vishnivetskaya, T A; Erokhina, L G; Ivanushkina, N E; Kochkina, G A; Shcherbakova, V A; Soina, V S; Spirina, E V; Vorobyova, E A; Fyodorov-Davydov, D G; Hallet, B; Ozerskaya, S M; Sorokovikov, V A; Laurinavichyus, K S; Shatilovich, A V; Chanton, J P; Ostroumov, V E; Tiedje, J M

2007-04-01

Antarctic permafrost soils have not received as much geocryological and biological study as has been devoted to the ice sheet, though the permafrost is more stable and older and inhabited by more microbes. This makes these soils potentially more informative and a more significant microbial repository than ice sheets. Due to the stability of the subsurface physicochemical regime, Antarctic permafrost is not an extreme environment but a balanced natural one. Up to 10(4) viable cells/g, whose age presumably corresponds to the longevity of the permanently frozen state of the sediments, have been isolated from Antarctic permafrost. Along with the microbes, metabolic by-products are preserved. This presumed natural cryopreservation makes it possible to observe what may be the oldest microbial communities on Earth. Here, we describe the Antarctic permafrost habitat and biodiversity and provide a model for martian ecosystems.
Epigeal Fauna and Soil Chemical Attributes in Grazing and Regeneration Areas

Directory of Open Access Journals (Sweden)

Leandro Ribeiro Nogueira

2017-05-01

Full Text Available ABSTRACT The objective of this study was to evaluate the influence of natural pasture and spontaneous regeneration on soil chemical properties and epigeal fauna community using a secondary Atlantic Forest as reference. The study areas were located in Passa Vinte, Minas Gerais, Brazil. In each study area, pitfall traps were used to sample epigeal fauna in the dry and rainy seasons. Earth samples were collected at a depth of 0-5 cm in the dry and rainy seasons for analysis of chemical attributes. The pasture and regeneration areas showed an overall activity of epigeal fauna and functional groups similar to the forest area. However, the diversity evaluated by the Shannon and Pielou evenness indices and the total richness were lower than the observed in the forest. The best fertility attributes were observed in the forest and pasture areas.
Water bird fauna in the Carpathian Basin from the beginnings through historical times

OpenAIRE

Kessler Jenő (Eugen)

2017-01-01

This study aims to summarize the knowledge about the evolution and fossil remains of avian fauna near waterbodies, since ornithologists, who rarely come across or research the paleontology of birds, do not possess significantly detailed knowledge about the evolution and evidence of the current avian fauna.
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
IPAB Antarctic Drifting Buoy Data, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — The World Climate Research Programme (WCRP) International Programme for Antarctic Buoys (IPAB), through participating research organizations in various countries,...
Wind profile radar for study of Antarctic air circulation

International Nuclear Information System (INIS)

Ragaini, E.; Sarango, M.F.; Vasquez, E.H.

1992-01-01

After a brief discussion of meteorological methods used in the Antarctic, the paper gives an outline of a coordinated international research project whose objective is to set up a wind profiler radar station that would give meteorologists information regarding Antarctic atmospheric dynamics useful in their investigation of the causes and effects of the hole in the ozone layer. The radar instrumentation is to provide continuous readings of wind velocity at varying altitudes above the polar continent
Evaluating Wind Power Potential in the Spanish Antarctic Base (BAE)

International Nuclear Information System (INIS)

Arribas, L.M.; Garcia Barquero, C; Navarro, J.; Cuerva, A.; Cruz, I.; Roque, V.; Marti, I.

2000-01-01

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
77 FR 41809 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2012-07-16

..., Lockheed Martin IS&GS, Antarctic Support Contract, 7400 S. Tucson Way, Centennial, CO 80112-3938. Activity..., Antarctic Support Contract, 7400 S. Tucson Way, Centennial, CO 80112-3938. Activity for Which Permit Is.... Applicant: Celia Lang, Lockheed Martin IS&GS, Antarctic Support Contract, 7400 S. Tucson Way, Centennial, CO...
Regional Antarctic snow accumulation over the past 1000 years

Directory of Open Access Journals (Sweden)

E. R. Thomas

2017-11-01

Full Text Available Here we present Antarctic snow accumulation variability at the regional scale over the past 1000 years. A total of 79 ice core snow accumulation records were gathered and assigned to seven geographical regions, separating the high-accumulation coastal zones below 2000 m of elevation from the dry central Antarctic Plateau. The regional composites of annual snow accumulation were evaluated against modelled surface mass balance (SMB from RACMO2.3p2 and precipitation from ERA-Interim reanalysis. With the exception of the Weddell Sea coast, the low-elevation composites capture the regional precipitation and SMB variability as defined by the models. The central Antarctic sites lack coherency and either do not represent regional precipitation or indicate the model inability to capture relevant precipitation processes in the cold, dry central plateau. Our results show that SMB for the total Antarctic Ice Sheet (including ice shelves has increased at a rate of 7 ± 0.13 Gt decade−1 since 1800 AD, representing a net reduction in sea level of ∼ 0.02 mm decade−1 since 1800 and ∼ 0.04 mm decade−1 since 1900 AD. The largest contribution is from the Antarctic Peninsula (∼ 75 % where the annual average SMB during the most recent decade (2001–2010 is 123 ± 44 Gt yr−1 higher than the annual average during the first decade of the 19th century. Only four ice core records cover the full 1000 years, and they suggest a decrease in snow accumulation during this period. However, our study emphasizes the importance of low-elevation coastal zones, which have been under-represented in previous investigations of temporal snow accumulation.
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.

[Co-occurrence of soil fauna communities with changes in altitude on the northern slope of Changbai Mountain].

Science.gov (United States)

Tong, Fuchun; Jin, Zhedong; Wang, Qingli; Xiao, Yihua

2003-10-01

The co-occurrence of soil fauna communities at different altitudes may reflect at some extent the relationships among communities, their coexistence, and the replacement of species along the altitude gradient. The continuous or disjunctive distribution of different species along altitude gradient not only reflected the environment variation at altitude gradient, but also the biological and ecological spatiality as well as the adaptability of species. The northern slope of Changbai Moutain has not only a high diversity in soil fauna types and species, but also a high variation of diversity pattern along the altitude gradient, which is a perfect transect for the research of biodiversity and gradient patterns. From 550 m to 2,560 m on the northern slope of Changbai Mountain, twenty-two plots were investigated with an interval of 100 m in altitude. By using Jaccard index, the co-occurrence of soil fauna communities at different altitudes was analyzed. For the species of different life forms or for all the species as a whole, the co-occurrence of soil faunae between neighboring communities was the highest, except for that between different soil fauna types. The peak and valley values of the co-occurrence of soil fauna communities along altitude gradient were matched with their gradient patterns, and the co-occurrence of soil faunae at different layers or all of the soil fauna communities were decreased with increasing altitude difference.
Personality Testing in Antarctic Expeditioners: Cross Cultural Comparisons and Evidence for Generalizability

Science.gov (United States)

Musson, D. M.; Sandal, G. M.; Harper, M. L.; Helmreich, R. L.

Antarctica provides an ideal environment in which to study human behaviour under conditions of isolation and confinement. Such research is currently being conducted through several national Antarctic research programs, with the subject pool for these investigations necessarily consisting of individuals from multiple nationalities. Cross-cultural research has shown, however, that psychological traits and individual values may vary significantly between national and ethnic groups. Until now, there has been an implicit assumption that Antarctic personnel are essentially similar from one national program to another and that therefore findings from any one nation's Antarctic program should generalize to another, as well as to other domains such as spaceflight. We believe that it is necessary to validate this assumption through empirical research. This objective of this analysis was to determine the degree of similarity between the psychological testing profiles of Antarctic research personnel from different national Antarctic programs, and to determine the degrees of similarity or difference of these personnel to a normative population. METHODS In separate studies, Antarctic personnel from Australia (n=57), Norway (=37), and Great Britain (n=145) were administered the Personal Characteristics Inventory (PCI) before departing to Antarctica. The PCI is a battery consisting of 11 psychological scales designed to assess specific traits related to achievement and interpersonal competence that have been shown to be particularly salient to human performance under stressful and complex conditions. For comparative normative data, a group of 441 U.S. undergraduate students were also administered the PCI. Due to historical reasons, researchers in this study used 2 versions of the PCI, and only 9 of the 11 scales were directly equivalent. RESULTS For the three national Antarctic groups (Australia, Norway, and Great Britain), no significant variation was found between group mean
The fauna of brackish ponds at Port Canning, Lower Bengal Part 1 - Introduction and Preliminary Account of the Fauna

Digital Repository Service at National Institute of Oceanography (India)

Annandale, N.

A general survey the fauna of brackishwater ponds at Port Canning, Lower Bengal, India, was carried out The Port Canning is situated on the Matla river having numerous creeks which runup into the delta of the Ganges about sixty miles from the open...
Water bird fauna in the Carpathian Basin from the beginnings through historical times

Directory of Open Access Journals (Sweden)

Kessler Jenő (Eugen

2017-06-01

Full Text Available This study aims to summarize the knowledge about the evolution and fossil remains of avian fauna near waterbodies, since ornithologists, who rarely come across or research the paleontology of birds, do not possess significantly detailed knowledge about the evolution and evidence of the current avian fauna.
Treatment and prevention of infection following bites of the Antarctic fur seal (Arctocephalus gazella

Directory of Open Access Journals (Sweden)

Kouliev T

2015-04-01

Full Text Available Timur Kouliev,1 Victoria Cui2 1Beijing United Family Hospital, Beijing, People's Republic of China; 2Department of Biological Sciences, Columbia University, New York, NY, USA Abstract: In recent decades, an increasing number of people have traveled to sub-Antarctic and Antarctic regions each year for research, tourism, and resource exploitation. Hunting of Antarctic fur seals (Arctocephalus gazella almost pushed the species to extinction in the early 1900s, but populations have since shown rapid and substantial recovery. The species' range has re-expanded to include several islands south of the Antarctic Convergence, most notably South Georgia, and now overlaps with many popular Antarctic travel destinations. Both male and female fur seals can become extremely aggressive when provoked, and their bites, if not properly treated, pose a significant risk of infection by microorganisms not usually encountered in cases of animal bites. In this report, we present the case of a patient treated for a fur seal bite during an Antarctic expedition cruise, review the literature concerning seal bites, and suggest the use of antibiotic prophylaxis to prevent complications. Keywords: zoonotic, polar tourism, prophylaxis, seal finger, expedition medicine
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.)
Effects of nitrogen addition on soil fauna communities in Larix gmelinii and Fraxinus mandshurica plantations

OpenAIRE

Haifeng Zhuang; Yue Sun; Jiacun Gu; Yang Xu; Zhengquan Wang

2010-01-01

Soil fauna play a key role in regulating carbon allocation and nutrient cycling in terrestrial ecosystems. As soil fauna are sensitive to environmental changes, increases in soil nitrogen (N) availability resulting from global changes may profoundly influence the structure and function of soil faunal communities. However, the response of soil fauna in forest ecosystems to increases in soil N availability is still poorly understood. In order to explore the relationship between soil N availabil...
Antarctic climate variability on regional and continental scales over the last 2000 years

Directory of Open Access Journals (Sweden)

B. Stenni

2017-11-01

Full Text Available Climate trends in the Antarctic region remain poorly characterized, owing to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. Here, within the framework of the PAGES Antarctica2k working group, we build an enlarged database of ice core water stable isotope records from Antarctica, consisting of 112 records. We produce both unweighted and weighted isotopic (δ18O composites and temperature reconstructions since 0 CE, binned at 5- and 10-year resolution, for seven climatically distinct regions covering the Antarctic continent. Following earlier work of the Antarctica2k working group, we also produce composites and reconstructions for the broader regions of East Antarctica, West Antarctica and the whole continent. We use three methods for our temperature reconstructions: (i a temperature scaling based on the δ18O–temperature relationship output from an ECHAM5-wiso model simulation nudged to ERA-Interim atmospheric reanalyses from 1979 to 2013, and adjusted for the West Antarctic Ice Sheet region to borehole temperature data, (ii a temperature scaling of the isotopic normalized anomalies to the variance of the regional reanalysis temperature and (iii a composite-plus-scaling approach used in a previous continent-scale reconstruction of Antarctic temperature since 1 CE but applied to the new Antarctic ice core database. Our new reconstructions confirm a significant cooling trend from 0 to 1900 CE across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions. Within this long-term cooling trend from 0 to 1900 CE, we find that the warmest period occurs between 300 and 1000 CE, and the coldest interval occurs from 1200 to 1900 CE. Since 1900 CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the
Leadership in politics and science within the Antarctic Treaty

OpenAIRE

John R. Dudeney; David W.H. Walton

2012-01-01

For over 50 years the Antarctic has been governed through the Antarctic Treaty, an international agreement now between 49 nations of whom 28 Consultative Parties (CPs) undertake the management role. Ostensibly, these Parties have qualified for their position on scientific grounds, though diplomacy also plays a major role. This paper uses counts of policy papers and science publications to assess the political and scientific outputs of all CPs over the last 18 years. We show that a subset of t...
Iceberg killing fields limit huge potential for benthic blue carbon in Antarctic shallows.

Science.gov (United States)

Barnes, David K A

2017-07-01

Climate-forced ice losses are increasing potential for iceberg-seabed collisions, termed ice scour. At Ryder Bay, West Antarctic Peninsula (WAP) sea ice, oceanography, phytoplankton and encrusting zoobenthos have been monitored since 1998. In 2003, grids of seabed markers, covering 225 m 2 , were established, surveyed and replaced annually to measure ice scour frequency. Disturbance history has been recorded for each m 2 of seabed monitored at 5-25 m for ~13 years. Encrusting fauna, collected from impacted and nonimpacted metres each year, show coincident benthos responses in growth, mortality and mass of benthic immobilized carbon. Encrusting benthic growth was mainly determined by microalgal bloom duration; each day, nanophytoplankton exceeded 200 μg L -1 produced ~0.05 mm radial growth of bryozoans, and sea temperature >0 °C added 0.002 mm day -1 . Mortality and persistence of growth, as benthic carbon immobilization, were mainly influenced by ice scour. Nearly 30% of monitored seabed was hit each year, and just 7% of shallows were not hit. Hits in deeper water were more deadly, but less frequent, so mortality decreased with depth. Five-year recovery time doubled benthic carbon stocks. Scour-driven mortality varied annually, with two-thirds of all monitored fauna killed in a single year (2009). Reduced fast ice after 2006 ramped iceberg scouring, killing half the encrusting benthos each year in following years. Ice scour coupled with low phytoplankton biomass drove a phase shift to high mortality and depressed zoobenthic immobilized carbon stocks, which has persevered for 10 years since. Stocks of immobilized benthic carbon averaged nearly 15 g m -2 . WAP ice scouring may be recycling 80 000 tonnes of carbon yr -1 . Without scouring, such carbon would remain immobilized and the 2.3% of shelf which are shallows could be as productive as all the remaining continental shelf. The region's future, when glaciers reach grounding lines and iceberg
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
THE ORIGINS OF THE SOUTHERN AFRICAN MAMMAL FAUNA ...

African Journals Online (AJOL)

Southern Africa can be geographically subdivided into different biotic zones, differing from .... The greater part of the southern African mammal fauna consists of savanna .... spread into southern Africa by way of the Savanna biotic zone.
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.
Characteristics of Soil Fauna Communities and Habitat in Small- Holder Cocoa Plantation in South Konawe

OpenAIRE

Laode Muhammad Harjoni Kilowasid; Tati Suryati Syamsudin; Franciscus Xaverius Susilo; Endah Sulistyawati; Hasbullah Syaf

2013-01-01

The composition of the soil fauna community have played an important role in regulating decomposition and nutrient cycling in agro-ecosystems (include cocoa plantation). Changes in food availability and conditions in the soil habitat can affected the abundance and diversity of soil fauna. This study aimed: (i) to analyze the pattern of changes in soil fauna community composition and characteristic of soil habitat based on the age increasing of cocoa plantation, and (ii) to identify taxa of so...
Cylinder-type bottom reflector

International Nuclear Information System (INIS)

Elter, C.; Fritz, R.; Kissel, K.F.; Schoening, J.

1982-01-01

Proposal of a bottom reflector for gas-cooled nuclear reactor plants with a pebble bed of spherical fuel elements, where the horizontal forces acting from the core and the bottom reflector upon the side reflector are equally distributed. This is attained by the upper edge of the bottom reflector being placed levelly and by the angle of inclination of the recesses varying. (orig.) [de
The Research on Elevation Change of Antarctic Ice Sheet Based on CRYOSAT-2 Alimeter

Science.gov (United States)

Sun, Q.; Wan, J.; Liu, S.; Li, Y.

2018-04-01

In this paper, the Cryosat-2 altimeter data distributed by the ESA, and these data are processed to extract the information of the elevation change of the Antarctic ice sheet from 2010 to 2017. Firstly, the main pretreatment preprocessing for Cryosat-2 altimetry data is crossover adjustment and elimination of rough difference. Then the grid DEM of the Antarctic ice sheet was constructed by using the kriging interpolation method,and analyzed the spatial characteristic time characteristics of the Antarctic ice sheet. The latitude-weighted elevation can be obtained by using the elevation data of each cycle, and then the general trend of the Antarctic ice sheet elevation variation can be seen roughly.
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.
A long term strategy for Antarctic tourism : The key to decision making within the Antarctic Treaty System?

NARCIS (Netherlands)

Bastmeijer, C.J.; Maher, P.; Stewart, E.; Lück, M.

2011-01-01

The fast increase of Antarctic tourism raises various management questions. Questions relating to the safety of tourists, questions regarding the interaction between science and tourism and questions relating to direct, indirect or cumulative affects on Antarctica's environment and wilderness
Historical Arctic and Antarctic Surface Observational Data

Data.gov (United States)

National Aeronautics and Space Administration — This product consists of meteorological data from 105 Arctic weather stations and 137 Antarctic stations, extracted from the National Climatic Data Center (NCDC)'s...
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.

The effect of lindane on non-target fauna in a maize agro-ecosystem in Zambia

International Nuclear Information System (INIS)

Deedat, Y.D.; Chanda, S.; Chivundu, A.M.; Kalembe, G.; Mecha, C.D.

1997-01-01

The effect of lindane on non-target fauna in a maize agro-ecosystem was studied in Zambia in 1992 and 1993. While lindane was effective against the stalk borers, a target pest, it also affected other non-target fauna. Ants, spiders and springtails were significantly reduced. However the effect was only transient and lasted for approximately two months. Lindane appeared to have no real effect on aerial non-target fauna or on soil inhabiting microorganisms. (author). 8 refs, 6 tabs
Ecological Diversity of Soil Fauna as Ecosystem Engineers in Small-Holder Cocoa Plantation in South Konawe

Directory of Open Access Journals (Sweden)

Laode Muhammad Harjoni Kilowasid

2012-05-01

Full Text Available Taxa diversity within soil fauna functional groups can affected ecosystem functioning such as ecosystem engineers,which influence decomposition and nutrient cycling. The objective of this study is to describe ecological diversityvariation within soil fauna as ecosystem engineers in soil ecosystem of cocoa (Theobroma cacao L. plantation.Sampling was conducted during one year period from five different ages of plantation. Soil fauna removed from soilcore using hand sorting methods. A total of 39 genera of soil fauna as ecosystem engineers were found during thesestudies. Thirty five genera belong to the group of Formicidae (ants, three genera of Isoptera (termites, and onegenera of Oligochaeta (earthworms. Ecological diversity variation within ecosystem engineers was detected withSimpson indices for dominance and evenness. The highest diversity of ecosystem engineers was in the young ageof plantation. This study reinforces the importance biotic interaction which contributed to the distribution andabundance within soil fauna community as ecosystem engineers in small-holder cocoa plantation.
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.
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. Copyright © 2016 Elsevier GmbH. All rights reserved.
Spatial structures in the heat budget of the Antarctic Atmospheric Boundary Layer

NARCIS (Netherlands)

van der Berg, W.J.; van den Broeke, M.R.; van Meijgaard, E.

2008-01-01

Output from the regional climate model RACMO2/ANT is used to calculate the heat budget of the Antarctic atmospheric boundary layer (ABL). The main feature of the wintertime Antarctic ABL is a persistent temperature deficit compared to the free atmosphere. The magnitude of this deficit is controlled
Ecological Diversity of Soil Fauna as Ecosystem Engineers in Small-Holder Cocoa Plantation in South Konawe

OpenAIRE

Laode Muhammad Harjoni Kilowasid; Tati Suryati Syamsudin; Franciscus Xaverius Susilo; Endah Sulistyawati

2012-01-01

Taxa diversity within soil fauna functional groups can affected ecosystem functioning such as ecosystem engineers,which influence decomposition and nutrient cycling. The objective of this study is to describe ecological diversityvariation within soil fauna as ecosystem engineers in soil ecosystem of cocoa (Theobroma cacao L.) plantation.Sampling was conducted during one year period from five different ages of plantation. Soil fauna removed from soilcore using hand sorting methods. A total of ...
Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow.

Science.gov (United States)

Liao, Shu; Yang, Wanqin; Tan, Yu; Peng, Yan; Li, Jun; Tan, Bo; Wu, Fuzhong

2015-01-01

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.
Testing oils in antarctic soils

International Nuclear Information System (INIS)

Leufkens, D.

2001-01-01

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
Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf.

Science.gov (United States)

Garabato, Alberto C Naveira; Forryan, Alexander; Dutrieux, Pierre; Brannigan, Liam; Biddle, Louise C; Heywood, Karen J; Jenkins, Adrian; Firing, Yvonne L; Kimura, Satoshi

2017-02-09

The instability and accelerated melting of the Antarctic Ice Sheet are among the foremost elements of contemporary global climate change. The increased freshwater output from Antarctica is important in determining sea level rise, the fate of Antarctic sea ice and its effect on the Earth's albedo, ongoing changes in global deep-ocean ventilation, and the evolution of Southern Ocean ecosystems and carbon cycling. A key uncertainty in assessing and predicting the impacts of Antarctic Ice Sheet melting concerns the vertical distribution of the exported meltwater. This is usually represented by climate-scale models as a near-surface freshwater input to the ocean, yet measurements around Antarctica reveal the meltwater to be concentrated at deeper levels. Here we use observations of the turbulent properties of the meltwater outflows from beneath a rapidly melting Antarctic ice shelf to identify the mechanism responsible for the depth of the meltwater. We show that the initial ascent of the meltwater outflow from the ice shelf cavity triggers a centrifugal overturning instability that grows by extracting kinetic energy from the lateral shear of the background oceanic flow. The instability promotes vigorous lateral export, rapid dilution by turbulent mixing, and finally settling of meltwater at depth. We use an idealized ocean circulation model to show that this mechanism is relevant to a broad spectrum of Antarctic ice shelves. Our findings demonstrate that the mechanism producing meltwater at depth is a dynamically robust feature of Antarctic melting that should be incorporated into climate-scale models.
Zoogeography of the southern African echinoderm fauna

African Journals Online (AJOL)

1988-04-17

Apr 17, 1988 ... Pertinent features of the oceanography of southern Africa are reviewed and an analysis of the echinoderm fauna in relation to the genera] ..... five extant echinoderm classes (all species). Crinoids. Asteroids Ophiuroids .... Australia and New Zealand, which are included with. R eprod u ced by Sabin et G.
A Fauna de Morcegos Fósseis como Ferramenta na Caracterização de Paleoambientes Quaternários.

Directory of Open Access Journals (Sweden)

Leonardo Santos Avilla

2007-07-01

Full Text Available This study proposes to reconstruct the paleoenvironment from Quaternary sites of the caves in the sertão baiano and Lagoa Santa region during the Pleistocene. The paleofauna of bats from these sites were compared to the extant fauna of 25 localities, representing most important Neotropical biome. This study was possible because all bat fossil species from both sites were elements of the extant Neotropical fauna, excepting Desmodus draculae. Because bats are considered goodenvironmental definers, the association of extant and fossil fauna permits the recognition of similar environments. The similarity between faunas was analyzed by Jaccard index with a posterior grouping analysis by UPGMA. The paleofauna of Lagoa Santa matched to Caatinga fauna, suggesting a dry and open environment adjacent to the Lagoa Santa cavesduring the Pleistocene. The paleofauna of sertão baiano caves matched to neither of the analyzed faunas. Most authorssuggest that fossil record of the sertão baiano caves represents a faunal mixture. The dissimilarity between the paleofaunaof bats from the sertão baiano caves and the other analyzed faunas resulted of this study is in agreement to the argumentof a faunal mixture represented by the former.
222Rn in the Antarctic Peninsula during 1986

International Nuclear Information System (INIS)

Pereira, E.B.; Setzer, A.W.; Cavalcanti, I.F.A.

1988-01-01

222 Rn was continuously measured at the Brazilian Antarctic Station (62 0 S, 58 0 W) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m -3 with surges peaking 0.4 Bq.m -3 . The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variations of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone. (author)
Standing crop and growth rates of net phytoplankton and nanoplankton in Antarctic waters

Digital Repository Service at National Institute of Oceanography (India)

Goes, J.I.; Fondekar, S.P.; Parulekar, A.H.

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Living resources of Antarctic India's contribution to exploration and future plans for exploration

Digital Repository Service at National Institute of Oceanography (India)

Parulekar, A.H.

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Balance of the West Antarctic Ice Sheet

Science.gov (United States)

2002-01-01

For several decades, measurements of the West Antarctic Ice Sheet showed it to be retreating rapidly. But new data derived from satellite-borne radar sensors show the ice sheet to be growing. Changing Antarctic ice sheets remains an area of high scientific interest, particularly in light of recent global warming concerns. These new findings are significant because scientists estimate that sea level would rise 5-6 meters (16-20 feet) if the ice sheet collapsed into the sea. Do these new measurements signal the end of the ice sheet's 10,000-year retreat? Or, are these new satellite data simply much more accurate than the sparse ice core and surface measurements that produced the previous estimates? Another possibility is that the ice accumulation may simply indicate that the ice sheet naturally expands and retreats in regular cycles. Cryologists will grapple with these questions, and many others, as they examine the new data. The image above depicts the region of West Antarctica where scientists measured ice speed. The fast-moving central ice streams are shown in red. Slower tributaries feeding the ice streams are shown in blue. Green areas depict slow-moving, stable areas. Thick black lines depict the areas that collect snowfall to feed their respective ice streams. Reference: Ian Joughin and Slawek Tulaczyk Science Jan 18 2002: 476-480. Image courtesy RADARSAT Antarctic Mapping Project
Isolation and characterization of Campylobacter spp. from Antarctic fur seals (Arctocephalus gazella) at Deception Island, Antarctica.

Science.gov (United States)

García-Peña, F J; Pérez-Boto, D; Jiménez, C; San Miguel, E; Echeita, A; Rengifo-Herrera, C; García-Párraga, D; Ortega-Mora, L M; Pedraza-Díaz, S

2010-09-01

The presence of Campylobacter spp. was investigated in 41 Antarctic fur seals (Arctocephalus gazella) and 9 Weddell seals (Leptonychotes weddellii) at Deception Island, Antarctica. Infections were encountered in six Antarctic fur seals. The isolates, the first reported from marine mammals in the Antarctic region, were identified as Campylobacter insulaenigrae and Campylobacter lari.
Effects of Formica ants on soil fauna-results from a short-term exclusion and a long-term natural experiment.

Science.gov (United States)

Lenoir, Lisette; Bengtsson, Jan; Persson, Tryggve

2003-02-01

Wood ants (Formica spp.) were hypothesised to affect the composition and greatly reduce the abundance of large-sized soil fauna by predation. This was tested in two ways. Firstly, a 4-year-long experimental study was carried out in a mixed forest. Five ant-free 1.3-m(2) plots were created by fenced exclosures within an ant territory. Five nearby plots had fences with entrances for the ants. In addition, five non-fenced control plots were selected. Soil fauna (e.g. Coleoptera, Diptera larvae, Collembola and Araneae) was sampled during the summers of 1997-2000. The soil fauna was affected by the exclosures but there was no detectable effect of ants on the soil fauna. Secondly, soil fauna was studied within a large-scale natural experiment in which the long-term (30 years) effects of red wood ants could be assessed inside and outside ant territories. This long-term natural experiment revealed no significant effects of ants on the abundance or composition of soil fauna. The results from the two studies indicate that the effects of wood ants on soil fauna are fairly small. The hypothesis that wood ants are key-stone predators on soil fauna could, thus, not be supported.
Glacial morphology and depositional sequences of the Antarctic Continental Shelf

Science.gov (United States)

ten Brink, Uri S.; Schneider, Christopher

1995-01-01

Proposes a simple model for the unusual depositional sequences and morphology of the Antarctic continental shelf. It considers the regional stratal geometry and the reversed morphology to be principally the results of time-integrated effects of glacial erosion and sedimentation related to the location of the ice grounding line. The model offers several guidelines for stratigraphic interpretation of the Antarctic shelf and a Northern Hemisphere shelf, both of which were subject to many glacial advances and retreats. -Authors
Structural Uncertainty in Antarctic sea ice simulations

Science.gov (United States)

Schneider, D. P.

2016-12-01

The inability of the vast majority of historical climate model simulations to reproduce the observed increase in Antarctic sea ice has motivated many studies about the quality of the observational record, the role of natural variability versus forced changes, and the possibility of missing or inadequate forcings in the models (such as freshwater discharge from thinning ice shelves or an inadequate magnitude of stratospheric ozone depletion). In this presentation I will highlight another source of uncertainty that has received comparatively little attention: Structural uncertainty, that is, the systematic uncertainty in simulated sea ice trends that arises from model physics and mean-state biases. Using two large ensembles of experiments from the Community Earth System Model (CESM), I will show that the model is predisposed towards producing negative Antarctic sea ice trends during 1979-present, and that this outcome is not simply because the model's decadal variability is out-of-synch with that in nature. In the "Tropical Pacific Pacemaker" ensemble, in which observed tropical Pacific SST anomalies are prescribed, the model produces very realistic atmospheric circulation trends over the Southern Ocean, yet the sea ice trend is negative in every ensemble member. However, if the ensemble-mean trend (commonly interpreted as the forced response) is removed, some ensemble members show a sea ice increase that is very similar to the observed. While this results does confirm the important role of natural variability, it also suggests a strong bias in the forced response. I will discuss the reasons for this systematic bias and explore possible remedies. This an important problem to solve because projections of 21st -Century changes in the Antarctic climate system (including ice sheet surface mass balance changes and related changes in the sea level budget) have a strong dependence on the mean state of and changes in the Antarctic sea ice cover. This problem is not unique to
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

Extreme late chronotypes and social jetlag challenged by Antarctic conditions in a population of university students from Uruguay.

Science.gov (United States)

Tassino, Bettina; Horta, Stefany; Santana, Noelia; Levandovski, Rosa; Silva, Ana

2016-01-01

In humans, a person's chronotype depends on environmental cues and on individual characteristics, with late chronotypes prevailing in youth. Social jetlag (SJL), the misalignment between an individual׳s biological clock and social time, is higher in late chronotypes. Strong SJL is expected in Uruguayan university students with morning class schedules and very late entertainment activities. Sleep disorders have been reported in Antarctic inhabitants, that might be a response to the extreme environment or to the strictness of Antarctic life. We evaluated, for the first time in Uruguay, the chronotypes and SJL of 17 undergraduate students of the First Uruguayan Summer School on Antarctic Research, using Munich Chronotype Questionnaire (MCTQ) and sleep logs (SL) recorded during 3 phases: pre-Antarctic, Antarctic, and post-Antarctic. The midsleep point of free days corrected for sleep debt on work days (MSFsc,) was used as proxy of individuals' chronotype, whose values (around 6 a.m.) are the latest ever reported. We found a SJL of around 2 h in average, which correlated positively with MSFsc, confirming that late chronotypes generate a higher sleep debt during weekdays. Midsleep point and sleep duration significantly decreased between pre-Antarctic and Antarctic phases, and sleep duration rebounded to significant higher values in the post-Antarctic phase. Waking time, but not sleep onset time, significantly varied among phases. This evidence suggests that sleep schedules more likely depended on the social agenda than on the environmental light-dark shifts. High motivation of students towards Antarctic activities likely induced a subjective perception of welfare non-dependent on sleep duration.
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...
Soils of Sub-Antarctic tundras: diversity and basic chemical characteristics

Science.gov (United States)

Abakumov, Evgeny; Vlasov, Dmitry; Mukhametova, Nadezhda

2014-05-01

Antarctic peninsula is known as specific part of Antarctica, which is characterizes by humid and relatively warm climate of so-called sub Antarctic (maritime) zone. Annual precipitation and long above zero period provides the possibility of sustainable tundra's ecosystem formation. Therefore, the soil diversity of these tundra landscapes is maximal in the whole Antarctic. Moreover, the thickness of parent material debris's is also highest and achieves a 1 or 2 meters as highest. The presence of higher vascular plants Deshampsia antarctica which is considered as one of the main edificators provides the development of humus accumulation in upper solum. Penguins activity provides an intensive soil fertilization and development of plant communities with increased density. All these factors leads to formation of specific and quite diverse soil cover in sub Antarctic tundra's. These ecosystems are presented by following permafrost affected soils: Leptosols, Lithoosols, Crysols, Gleysols, Peats and Ornhitosols. Also the post Ornhitosols are widely spreaded in subantarcic ecosystems, they forms on the penguin rockeries during the plant succession development, leaching of nutrients and organic matter mineralization. "Amphibious" soils are specific for seasonal lakes, which evaporates in the end if Australian summer. These soils have specific features of bio sediments and soils as well. Soil chemical characteristic as well as organic matter features discussed in comparison with Antacrtic continental soil in presentation.
Modeling the Thermal Interactions of Meteorites Below the Antarctic Ice

Science.gov (United States)

Oldroyd, William Jared; Radebaugh, Jani; Stephens, Denise C.; Lorenz, Ralph; Harvey, Ralph; Karner, James

2017-10-01

Meteorites with high specific gravities, such as irons, appear to be underrepresented in Antarctic collections over the last 40 years. This underrepresentation is in comparison with observed meteorite falls, which are believed to represent the actual population of meteorites striking Earth. Meteorites on the Antarctic ice sheet absorb solar flux, possibly leading to downward tunneling into the ice, though observations of this in action are very limited. This descent is counteracted by ice sheet flow supporting the meteorites coupled with ablation near mountain margins, which helps to force meteorites towards the surface. Meteorites that both absorb adequate thermal energy and are sufficiently dense may instead reach a shallow equilibrium depth as downward melting overcomes upward forces during the Antarctic summer. Using a pyronometer, we have measured the incoming solar flux at multiple depths in two deep field sites in Antarctica, the Miller Range and Elephant Moraine. We compare these data with laboratory analogues and model the thermal and physical interactions between a variety of meteorites and their surroundings. Our Matlab code model will account for a wide range of parameters used to characterize meteorites in an Antarctic environment. We will present the results of our model along with depth estimates for several types of meteorites. The recovery of an additional population of heavy meteorites would increase our knowledge of the formation and composition of the solar system.
Low genetic diversity in Antarctic populations of the lichen-forming ascomycete Cetraria aculeata and its photobiont

Directory of Open Access Journals (Sweden)

Stephanie Domaschke

2012-03-01

Full Text Available Lichens, symbiotic associations of fungi (mycobionts and green algae or cyanobacteria (photobionts, are poikilohydric organisms that are particularly well adapted to withstand adverse environmental conditions. Terrestrial ecosystems of the Antarctic are therefore largely dominated by lichens. The effects of global climate change are especially pronounced in the maritime Antarctic and it may be assumed that the lichen vegetation will profoundly change in the future. The genetic diversity of populations is closely correlated to their ability to adapt to changing environmental conditions and to their future evolutionary potential. In this study, we present evidence for low genetic diversity in Antarctic mycobiont and photobiont populations of the widespread lichen Cetraria aculeata. We compared between 110 and 219 DNA sequences from each of three gene loci for each symbiont. A total of 222 individuals from three Antarctic and nine antiboreal, temperate and Arctic populations were investigated. The mycobiont diversity is highest in Arctic populations, while the photobionts are most diverse in temperate regions. Photobiont diversity decreases significantly towards the Antarctic but less markedly towards the Arctic, indicating that ecological factors play a minor role in determining the diversity of Antarctic photobiont populations. Richness estimators calculated for the four geographical regions suggest that the low genetic diversity of Antarctic populations is not a sampling artefact. Cetraria aculeata appears to have diversified in the Arctic and subsequently expanded its range into the Southern Hemisphere. The reduced genetic diversity in the Antarctic is most likely due to founder effects during long-distance colonization.
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.
Antarctic Glaciological Data at NSIDC: field data, temperature, and ice velocity

Science.gov (United States)

Bauer, R.; Bohlander, J.; Scambos, T.; Berthier, E.; Raup, B.; Scharfen, G.

2003-12-01

An extensive collection of many Antarctic glaciological parameters is available for the polar science community upon request. The National Science Foundation's Office of Polar Programs funds the Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) to archive and distribute Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program. AGDC facilitates data exchange among Principal Investigators, preserves recently collected data useful to future research, gathers data sets from past research, and compiles continent-wide information useful for modeling and field work planning. Data sets are available via our web site, http://nsidc.org/agdc/. From here, users can access extensive documentation, citation information, locator maps, derived images and references, and the numerical data. More than 50 Antarctic scientists have contributed data to the archive. Among the compiled products distributed by AGDC are VELMAP and THERMAP. THERMAP is a compilation of over 600 shallow firn temperature measurements ('10-meter temperatures') collected since 1950. These data provide a record of mean annual temperature, and potentially hold a record of climate change on the continent. The data are represented with maps showing the traverse route, and include data sources, measurement technique, and additional measurements made at each site, i.e., snow density and accumulation. VELMAP is an archive of surface ice velocity measurements for the Antarctic Ice Sheet. The primary objective of VELMAP is to assemble a historic record of outlet glaciers and ice shelf ice motion over the Antarctic. The collection includes both PI-contributed measurements and data generated at NSIDC using Landsat and SPOT satellite imagery. Tabular data contain position, speed, bearing, and data quality information, and related references. Two new VELMAP data sets are highlighted: the Mertz Glacier and the Institute Ice Stream. Mertz Glacier ice
Can Antarctic lichens acclimatize to changes in temperature?

Science.gov (United States)

Colesie, Claudia; Büdel, Burkhard; Hurry, Vaughan; Green, Thomas George Allan

2018-03-01

The Antarctic Peninsula, a tundra biome dominated by lichens and bryophytes, is an ecozone undergoing rapid temperature shifts. Such changes may demand a high physiological plasticity of the local lichen species to maintain their role as key drivers in this pristine habitat. This study examines the response of net photosynthesis and respiration to increasing temperatures for three Antarctic lichen species with different ecological response amplitudes. We hypothesize that negative effects caused by increased temperatures can be mitigated by thermal acclimation of respiration and/or photosynthesis. The fully controlled growth chamber experiment simulated intermediate and extreme temperature increases over the time course of 6 weeks. Results showed that, in contrast to our hypothesis, none of the species was able to down-regulate temperature-driven respiratory losses through thermal acclimation of respiration. Instead, severe effects on photobiont vitality demonstrated that temperatures around 15°C mark the upper limit for the two species restricted to the Antarctic, and when mycobiont demands exceeded the photobiont capacity they could not survive within the lichen thallus. In contrast, the widespread lichen species was able to recover its homoeostasis by rapidly increasing net photosynthesis. We conclude that to understand the complete lichen response, acclimation processes of both symbionts, the photo- and the mycobiont, have to be evaluated separately. As a result, we postulate that any acclimation processes in lichen are species-specific. This, together with the high degree of response variability and sensitivity to temperature in different species that co-occur spatially close, complicates any predictions regarding future community composition in the Antarctic. Nevertheless, our results suggest that species with a broad ecological amplitude may be favoured with on-going changes in temperature. © 2017 John Wiley & Sons Ltd.
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.
A latest Permian non-reef calcisponge fauna from Laibin, Guangxi, southern China and its significance

Directory of Open Access Journals (Sweden)

Ya-Sheng Wu

2017-01-01

Full Text Available A calcisponge fauna occurs in uppermost Permian Conodont Clarkina meishanensis yini zone of the sequence exposed in the vicinity of Laibin, Guangxi Zhuang Autonomous Region, southern China. The fauna is dominated by one thalamid species, Amblysiphonella vesiculosa de Koninck, 1863, and one new sclerosponge genus and species, Radiofibrosclera laibinensis gen. et sp. nov. They are associated with a few other accessory species, including the thalamid sponges Amblysiphonella laibinensis Deng, 1981, Colospongia sp., Polycystocoelia sp., and the inozoan sponge Acoelia discontinua sp. nov. Though the individuals are abundant, the species diversity is very low. Without common calcisponge components of Changhsingian reefal faunas, the assemblage is interpreted as not a reefal fauna. The water depth at which they dwelled was less than 105 m, and more probably less than 40 m. Its occurrence indicates a significant sea-level drop at the end of Late Permian Changhsingian Age.
Bottom friction models for shallow water equations: Manning’s roughness coefficient and small-scale bottom heterogeneity

Science.gov (United States)

Dyakonova, Tatyana; Khoperskov, Alexander

2018-03-01

The correct description of the surface water dynamics in the model of shallow water requires accounting for friction. To simulate a channel flow in the Chezy model the constant Manning roughness coefficient is frequently used. The Manning coefficient nM is an integral parameter which accounts for a large number of physical factors determining the flow braking. We used computational simulations in a shallow water model to determine the relationship between the Manning coefficient and the parameters of small-scale perturbations of a bottom in a long channel. Comparing the transverse water velocity profiles in the channel obtained in the models with a perturbed bottom without bottom friction and with bottom friction on a smooth bottom, we constructed the dependence of nM on the amplitude and spatial scale of perturbation of the bottom relief.
The George V Land Continental Margin (East Antarctica): new Insights Into Bottom Water Production and Quaternary Glacial Processes from the WEGA project

Science.gov (United States)

Caburlotto, A.; de Santis, L.; Lucchi, R. G.; Giorgetti, G.; Damiani, D.; Macri', P.; Tolotti, R.; Presti, M.; Armand, L.; Harris, P.

2004-12-01

The George Vth Land represents the ending of one of the largest subglacial basin (Wilkes Basin) of the East Antarctic Ice Sheet (EAIS). Furthermore, its coastal areas are zone of significant production of High Salinity Shelf Water (HSSW). Piston and gravity cores and high resolution echo-sounding (3.5 kHz) and Chirp profiles collected in the frame of the joint Australian and Italian WEGA (WilkEs Basin GlAcial History) project provide new insights into the Quaternary history of the EAIS and the HSSW across this margin: from the sediment record filling and draping valleys and banks along the continental shelf, to the continuous sedimentary section of the mound-channel system on the continental rise. The discovery of a current-lain sediment drift (Mertz Drift, MD) provides clues to understanding the age of the last glacial erosive events, as well as to infer flow-pathways of bottom-water masses changes. The MD shows disrupted, fluted reflectors due to glacial advance during the LGM (Last Glacial Maximum) in shallow water, while undisturbed sediment drift deposited at greater water depth, indicates that during the LGM the ice shelf was floating over the deep sector of the basin. The main sedimentary environment characterising the modern conditions of the continental rise is dominated by the turbiditic processes with a minor contribution of contour currents action. Nevertheless, some areas (WEGA Channel) are currently characterised by transport and settling of sediment through HSSW, originating in the shelf area. This particular environment likely persisted since pre-LGM times. It could indicate a continuous supply of sedimentary material from HSSW during the most recent both glacial and interglacial cycles. This would be consistent with the results obtained in the continental shelf suggesting that the Ice Sheet was not grounding over some parts of the continental shelf. Furthermore, the comparison of the studied area with other Antarctic margins indicate that, contrary
[Contributions of soil fauna to litter decomposition in alpine/subalpine forests].

Science.gov (United States)

Liu, Rui-Long; Li, Wei-Min; Yang, Wan-Qin; Tan, Bo; Wang, Wen-Jun; Xu, Zhen-Feng; Wu, Fu-Zhong

2013-12-01

A field experiment was conducted using the litterbag method to quantify the contribution of soil fauna to litter mass loss of Salix paraplesia, Sabina saltuaria, Betula albosinensis and Abies faxoniana during different key periods of the decomposition process of the first year (from November 2011 to October 2012). The results showed that the mass loss rate showed S. paraplesia > B. albosinensis > A. faxoniana > S. saltuaria, and the rate in the growing season was greater than in the freeze-thaw season. The contribution rate of soil fauna to the mass decomposition displayed as S. saltuaria (26.7%) > A. faxoniana (18.8%) > B. albosinensis (15.7%) > S. paraplesia (13.2%), which was higher in the freeze-thaw season than in the growing season for litter of B. albo-sinensis and A. faxoniana while vice versa for litter of B. albosinensis and A. faxoniana. The contribution of soil fauna was mainly related to organic C, P and N/P in the freeze-thaw season, while N, C/N, lignin and lignin/cellulose in the growing season.
An assessment of Environmental Conditions and the Benthic Fauna

African Journals Online (AJOL)

user

Increased population growth puts intense ... stations suggesting good adaptation of prevailing species to small changes in water quality. .... level with the help of taxonomic keys ... The spatial relationships ..... for the structure of macro-fauna.
Antarctic Ice Sheet Slope and Aspect Based on Icesat's Repeat Orbit Measurement

Science.gov (United States)

Yuan, L.; Li, F.; Zhang, S.; Xie, S.; Xiao, F.; Zhu, T.; Zhang, Y.

2017-09-01

Accurate information of ice sheet surface slope is essential for estimating elevation change by satellite altimetry measurement. A study is carried out to recover surface slope of Antarctic ice sheet from Ice, Cloud and land Elevation Satellite (ICESat) elevation measurements based on repeat orbits. ICESat provides repeat ground tracks within 200 meters in cross-track direction and 170 meters in along-track direction for most areas of Antarctic ice sheet. Both cross-track and along-track surface slopes could be obtained by adjacent repeat ground tracks. Combining those measurements yields a surface slope model with resolution of approximately 200 meters. An algorithm considering elevation change is developed to estimate the surface slope of Antarctic ice sheet. Three Antarctic Digital Elevation Models (DEMs) were used to calculate surface slopes. The surface slopes from DEMs are compared with estimates by using in situ GPS data in Dome A, the summit of Antarctic ice sheet. Our results reveal an average surface slope difference of 0.02 degree in Dome A. High resolution remote sensing images are also used in comparing the results derived from other DEMs and this paper. The comparison implies that our results have a slightly better coherence with GPS observation than results from DEMs, but our results provide more details and perform higher accuracy in coastal areas because of the higher resolution for ICESat measurements. Ice divides are estimated based on the aspect, and are weakly consistent with ice divides from other method in coastal regions.
Fuel oil and dispersant toxicity to the Antarctic sea urchin (Sterechinus neumayeri).

Science.gov (United States)

Alexander, Frances J; King, Catherine K; Reichelt-Brushett, Amanda J; Harrison, Peter L

2017-06-01

The risk of a major marine fuel spill in Antarctic waters is increasing, yet there are currently no standard or suitable response methods under extreme Antarctic conditions. Fuel dispersants may present a possible solution; however, little data exist on the toxicity of dispersants or fuels to Antarctic species, thereby preventing informed management decisions. Larval development toxicity tests using 3 life history stages of the Antarctic sea urchin (Sterechinus neumayeri) were completed to assess the toxicity of physically dispersed, chemically dispersed, and dispersant-only water-accommodated fractions (WAFs) of an intermediate fuel oil (IFO 180, BP) and the chemical dispersant Slickgone NS (Dasic International). Despite much lower total petroleum hydrocarbon concentrations, physically dispersed fuels contained higher proportions of low-to-intermediate weight carbon compounds and were generally at least an order of magnitude more toxic than chemically dispersed fuels. Based on concentrations that caused 50% abnormality (EC50) values, the embryonic unhatched blastula life stage was the least affected by fuels and dispersants, whereas the larval 4-armed pluteus stage was the most sensitive. The present study is the first to investigate the possible implications of the use of fuel dispersants for fuel spill response in Antarctica. The results indicate that the use of a fuel dispersant did not increase the hydrocarbon toxicity of IFO 180 to the early life stages of Antarctic sea urchins, relative to physical dispersal. Environ Toxicol Chem 2017;36:1563-1571. © 2016 SETAC. © 2016 SETAC.
South African Antarctic earth science research programme

CSIR Research Space (South Africa)

SASCAR

1984-02-01

Full Text Available This document describes the past, current and planned future South African earth science research programme in the Antarctic, Southern Ocean and subantarctic regions. The scientific programme comprises five components into which present and future...
On the Antarctic Slope Front and Current crossing of the South Scotia Ridge

Science.gov (United States)

Orsi, A. H.; Palmer, M.; Gomis, D.; Flexas, M. M.; Kim, Y.-S.; Jordà, G.; Wiederwohl, C.; Álvarez, M.

2012-04-01

To unveil the contorted path followed by the Antarctic Slope Current connecting the Weddell and Scotia Seas, hydrographic stations with unprecedented spatial resolution were occupied on a series of sections across the slope and multiple channels in the double-pronged western portion of the South Scotia Ridge. Fieldwork consisted of two cruises from the ESASSI (January 2008) and ACROSS (February 2009) programs, the Spanish and USA/Argentina components of the International Polar Year core project SASSI (Synoptic Antarctic Shelf-Slope Interaction study). In this region the Antarctic Slope Current can be located by the pronounced in-shore deepening of isopycnals over the continental slope, rendering the strong subsurface temperature and salinity gradients characteristic of the Antarctic Slope Front. Before reaching the gaps in the southern Ridge near 51°W and 50°W, the ASC carries about 3 Sv of upper layer waters, but it splits into shallow and deep branches upon turning north through these two gaps. The shallower branch enters the Hesperides Trough at 51°W, then shows a tight cyclonic loop back to that longitude roughly following the slope's 700-m isobath, and turns again westward through a similar gap in the northern Ridge. In the Scotia Sea the westward-flowing Antarctic Slope Current is found as far west as the Elephant Island along slightly deeper levels of slope (1100 m) before it is blocked by the Antarctic Circumpolar Current south of the Shackleton Fracture Zone (56°W). The deeper branch of the ASC in the Powell Basin crosses the southern Ridge near 50°W and roughly follows the 1600-m isobath before entering the Scotia Sea through the Hesperides Gap farther to the east (49°W). Thereafter the deeper waters carried westward by this branch become undistinguishable from those circulating farther offshore. Repeat cross-slope sections at both southern and northern flanks of the South Scotia Ridge showed significant temporal variability in the characteristics
CITES aplicació en fauna salvatge i clínica d'animals exótics /

OpenAIRE

Ticó Gil, Gemma.

2011-01-01

CITES: Convention on International Trade in Endangered Species of Wild Fauna and Flora = Conveni sobre el Comerç Internacional d’Espècies Amenaçades de Fauna i Flora Silvestre. Treball presentat a l'assignatura de Deontologia i Veterinària Legal (21223)
Checklist of the earthworm fauna of Croatia (Oligochaeta: Lumbricidae).

Science.gov (United States)

Kutuzović, Davorka Hackenberger; Kutuzović, Branimir Hackenberger

2013-01-01

A checklist of the Croatian earthworm fauna (Oligochaeta: Lumbricidae) is presented, including published records and authors' personal data. This is the first checklist for Croatia only, with comprehensive information for each earthworm species regarding ecological category, habitat, distribution type and distribution in Croatia. The currently known earthworm fauna of Croatia comprises 68 species belonging to 17 genera, with Octodrilus being the species-richest genus (15 species). Chorologically these species can be allocated to 13 different types of distribution. Nineteen species are endemic of which 10 species are endemic to Croatia and 9 species are endemic to Croatia and neighbouring countries (Italy, Slovenia, Hungary, and Montenegro). The endemic earthworms are distributed in the areas of higher altitudes in the Continental and Alpine biogeographic region, mostly covered with forest or autochtonous vegetation.

Changes in glacier dynamics in the northern Antarctic Peninsula since 1985

Science.gov (United States)

Seehaus, Thorsten; Cook, Alison J.; Silva, Aline B.; Braun, Matthias

2018-02-01

The climatic conditions along the northern Antarctic Peninsula have shown significant changes within the last 50 years. Here we present a comprehensive analysis of temporally and spatially detailed observations of the changes in ice dynamics along both the east and west coastlines of the northern Antarctic Peninsula. Temporal evolutions of glacier area (1985-2015) and ice surface velocity (1992-2014) are derived from a broad multi-mission remote sensing database for 74 glacier basins on the northern Antarctic Peninsula ( disintegration showed the largest retreat by 208.59 km2. Glaciers on the east coast north of the former Prince Gustav Ice Shelf extent in 1986 receded by only 21.07 km2 (1985-2015) and decelerated by about 58 % on average (1992-2014). A dramatic acceleration after ice shelf disintegration with a subsequent deceleration is observed at most former ice shelf tributaries on the east coast, combined with a significant frontal retreat. In 2014, the flow speed of the former ice shelf tributaries was 26 % higher than before 1996. Along the west coast the average flow speeds of the glaciers increased by 41 %. However, the glaciers on the western Antarctic Peninsula revealed a strong spatial variability of the changes in ice dynamics. By applying a hierarchical cluster analysis, we show that this is associated with the geometric parameters of the individual glacier basins (hypsometric indexes, maximum surface elevation of the basin, flux gate to catchment size ratio). The heterogeneous spatial pattern of ice dynamic evolutions at the northern Antarctic Peninsula shows that temporally and spatially detailed observations as well as further monitoring are necessary to fully understand glacier change in regions with such strong topographic and climatic variances.
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 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. © 2013 John Wiley & Sons Ltd.
Bottom-linked innovation

DEFF Research Database (Denmark)

Kristensen, Catharina Juul

2018-01-01

hitherto been paid little explicit attention, namely collaboration between middle managers and employees in innovation processes. In contrast to most studies, middle managers and employees are here both subjects of explicit investigation. The collaboration processes explored in this article are termed...... ‘bottom-linked innovation’. The empirical analysis is based on an in-depth qualitative study of bottom-linked innovation in a public frontline institution in Denmark. By combining research on employee-driven innovation and middle management, the article offers new insights into such collaborative......Employee-driven innovation is gaining ground as a strategy for developing sustainable organisations in the public and private sector. This type of innovation is characterised by active employee participation, and the bottom-up perspective is often emphasised. This article explores an issue that has...
EVA: Evryscopes for the Arctic and Antarctic

Science.gov (United States)

Richichi, A.; Law, N.; Tasuya, O.; Fors, O.; Dennihy, E.; Carlberg, R.; Tuthill, P.; Ashley, M.; Soonthornthum, B.

2017-06-01

We are planning to build Evryscopes for the Arctic and Antarctic (EVA), which will enable the first ultra-wide-field, high-cadence sky survey to be conducted from both Poles. The system is based on the successful Evryscope concept, already installed and operating since 2015 at Cerro Tololo in Chile with the following characteristics: robotic operation, 8,000 square degrees simultaneous sky coverage, 2-minute cadence, milli-mag level photometric accuracy, pipelined data processing for real-time analysis and full data storage for off-line analysis. The initial location proposed for EVA is the PEARL station on Ellesmere island; later also an antarctic location shall be selected. The science goals enabled by this unique combination of almost full-sky coverage and high temporal cadence are numerous, and include among others ground-breaking forays in the fields of exoplanets, stellar variability, asteroseismology, supernovae and other transient events. The EVA polar locations will enable uninterrupted observations lasting in principle over weeks and months. EVA will be fully robotic. We discuss the EVA science drivers and expected results, and present the logistics and the outline of the project which is expected to have first light in the winter of 2018. The cost envelope can be kept very competitive thanks to R&D already employed for the CTIO Evryscope, to our experience with both Arctic and Antarctic locations, and to the use of off-the-shelf components.
Stochastic modelling of basal temperatures in divide regions of the Antarctic ice sheet over the last 1.5 million years

Science.gov (United States)

Van Liefferinge, Brice; Pattyn, Frank; Cavitte, Marie G. P.; Young, Duncan A.; Roberts, Jason L.

2017-04-01

The quest for oldest ice in Antarctica has recently been launched through an EU H2020 project (Beyond EPICA - Oldest Ice) and aims at identifying suitable areas for a potential future drilling. Retrieving an ice core of such age is essential to understand the relation between orbital changes and atmospheric composition during the mid-Pliocene transition. However, sites for a potential undisturbed record of 1.5 million-year old ice in Antarctica are difficult to find and require slow-moving ice (preferably an ice divide) and basal conditions that are not disturbed by large topographic variations. Furthermore, ice should be sufficiently thick but cold basal conditions should still prevail, since basal melting would destroy the bottom layers. Therefore, ice-flow conditions and thermodynamic characteristics are crucial for identifying potential locations of undisturbed ice. Van Liefferinge and Pattyn (2013) identified suitable areas based on a pan-Antarctic simplified thermodynamic ice sheet model and demonstrated that uncertainty in geothermal conditions remain a major unknown. In order to refine these estimates, and provide uncertainties, we employ a full thermo-mechanically coupled higher-order ice sheet model (Pattyn, 2003; Pattyn et al., 2004). Initial conditions for the calculations are based on an inversion of basal slipperiness, based on observed surface topography (Pollard and DeConto, 2012; Pattyn, in prep.). Uncertainties in geothermal conditions are introduced using the convolution of two Gaussian probability density functions: (a) the reconstruction of the Antarctic ice sheet geometry and testing ice thickness variability over the last 2 million years (Pollard and DeConto, 2009) and (b) the surface temperature reconstruction over the same period (Snyder et al., 2016). The standard deviation, the skewness and the kurtosis of the whole Antarctic ice sheet are analyzed to observe likely probable melt conditions. Finally, we focus on model results in the
Impact and distribution of bottom trawl fishing on mud-bottom communities in the Kattegat

DEFF Research Database (Denmark)

Pommer, Christina Dahl; Olesen, Michael; Hansen, Jorgen L. S.

2016-01-01

The Kattegat in the inner Danish waters has been trawled for at least 80 yr, but so far only few attempts have been made to quantify the trawl effort, its spatial distribution and its potential ecological impact on the benthic fauna. GIS-analyses of VMS-data from trawling in the Kattegat by both ...
A comparison of the grasshopper fauna ( Orthoptera: Acridoidea ...

African Journals Online (AJOL)

The grasshopper fauna of the Uluguru Mountains and the East Usambara Mountains is compared. There is a marked relationship between habitat and similarity in species composition. The faunal similarity between sites rises with distance from the forest, evidently because the savannah species are widespread species ...
A Ludlow conodont fauna from Irian Jaya (Indonesia)

NARCIS (Netherlands)

Boogaard, van den M.

1990-01-01

The conodont fauna extracted from a boulder in the Lorentz River (southern Irian Jaya) is described. Arguments are put forward that the elements of Distomodus dubius (Rhodes, 1953) sensu Jeppsson, 1972 are part of the apparatus of species of Coryssognathus Link & Druce, 1972, a genus that
Revisiting Antarctic Ozone Depletion

Science.gov (United States)

Grooß, Jens-Uwe; Tritscher, Ines; Müller, Rolf

2015-04-01

Antarctic ozone depletion is known for almost three decades and it has been well settled that it is caused by chlorine catalysed ozone depletion inside the polar vortex. However, there are still some details, which need to be clarified. In particular, there is a current debate on the relative importance of liquid aerosol and crystalline NAT and ice particles for chlorine activation. Particles have a threefold impact on polar chlorine chemistry, temporary removal of HNO3 from the gas-phase (uptake), permanent removal of HNO3 from the atmosphere (denitrification), and chlorine activation through heterogeneous reactions. We have performed simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) employing a recently developed algorithm for saturation-dependent NAT nucleation for the Antarctic winters 2011 and 2012. The simulation results are compared with different satellite observations. With the help of these simulations, we investigate the role of the different processes responsible for chlorine activation and ozone depletion. Especially the sensitivity with respect to the particle type has been investigated. If temperatures are artificially forced to only allow cold binary liquid aerosol, the simulation still shows significant chlorine activation and ozone depletion. The results of the 3-D Chemical Transport Model CLaMS simulations differ from purely Lagrangian longtime trajectory box model simulations which indicates the importance of mixing processes.
A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond

OpenAIRE

Kennicutt, M.C.; Chown, S.L.; Cassano, J.J.; Liggett, D.; Peck, L.S.; Massom, R.; Rintoul, S.R.; Storey, J.; Vaughan, D.G.; Wilson, T.J.; Allison, I.; Ayton, J.; Badhe, R.; Baeseman, J.; Barrett, P.J.

2015-01-01

Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consu...
Origin of spherule samples recovered from antarctic ice sheet-Terrestrial or extraterrestrial?

Energy Technology Data Exchange (ETDEWEB)

Sekimoto, Shun; Takamiya, Koichi; Shibata, Seiichi [Research Reactor Institute, Kyoto University, Osaka (Japan); Kobayashi, Takayuki [College of Humanities and Sciences, Nihon University, Tokyo (Japan); Ebihara, Mitsuru [Dept. of Chemistry, Tokyo Metropolitan University, Tokyo (Japan)

2016-04-15

Thirty-eight spherules from the Antarctic ice sheet were analyzed using neutron activation analysis under two different conditions to investigate their origin. In almost all of these spherules, the contents of iron, cobalt, and manganese were determined to be 31% to 88%, 17 mg/kg to 810 mg/kg, and 0.017% to 7%, respectively. A detectable iridium content of 0.84 mg/kg was found in only one spherule, which was judged to be extraterrestrial in origin. A comparison of elemental compositions of the Antarctic spherules analyzed in this study with those of deep-sea sediment spherules and those of terrestrial materials revealed that most of the Antarctic spherules except for the sample in which iridium was detected could not be identified as extraterrestrial in origin.
Subsurface imaging reveals a confined aquifer beneath an ice-sealed Antarctic lake

DEFF Research Database (Denmark)

Dugan, H. A.; Doran, P. T.; Tulaczyk, S.

2015-01-01

Liquid water oases are rare under extreme cold desert conditions found in the Antarctic McMurdo Dry Valleys. Here we report geophysical results that indicate that Lake Vida, one of the largest lakes in the region, is nearly frozen and underlain by widespread cryoconcentrated brine. A ground...... this zone to be a confined aquifer situated in sediments with a porosity of 23-42%. Discovery of this aquifer suggests that subsurface liquid water may be more pervasive in regions of continuous permafrost than previously thought and may represent an extensive habitat for microbial populations. Key Points...... Geophysical survey finds low resistivities beneath a lake in Antarctic Dry Valleys Liquid brine abundant beneath Antarctic lake Aquifer provides microbial refugium in cold desert environment...
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.
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.
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...
Effects of of habitats and pesticides on aerobic capacity and survival of soil fauna.

Science.gov (United States)

Tripathi, G; Sharma, B M

2005-06-01

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. 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 gamma-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. 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 gamma-BHC, quinalphos, carbaryl and cypermethrin significantly reduced the CS activity of these animals. Gamma-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 gamma-BHC and quinalphos reduced the population of Acari, Coleoptera, Collembola, other arthropods as well as
Meltwater produced by wind–albedo interaction stored in an East Antarctic ice shelf

NARCIS (Netherlands)

Lenaerts, JTM; Lhermitte, S.L.M.; Drews, R.; Ligtenberg, SRM; Berger, S.; Helm, V.; Smeets, C.J.P.P.; van den Broeke, MR; van de Berg, W.J.; van Meijgaard, E; Eijkelboom, M.; Eisen, O.; Pattyn, F.

2017-01-01

Surface melt and subsequent firn air depletion can ultimately lead to disintegration of Antarctic ice shelves1, 2 causing grounded glaciers to accelerate3 and sea level to rise. In the Antarctic Peninsula, foehn winds enhance melting near the grounding line4, which in the recent past has led to the
Antarctic macrobenthic communities: A compilation of circumpolar information

Directory of Open Access Journals (Sweden)

Julian Gutt

2013-02-01

Full Text Available Comprehensive information on Antarctic macrobenthic community structure has been publicly available since the 1960s. It stems from trawl, dredge, grab, and corer samples as well as from direct and camera observations (Table 1–2. The quality of this information varies considerably; it consists of pure descriptions, figures for presence (absence and abundance of some key taxa or proxies for such parameters, e.g. sea-floor cover. Some data sets even cover a defined and complete proportion of the macrobenthos with further analyses on diversity and zoogeography. As a consequence the acquisition of data from approximately 90 different campaigns assembled here was not standardised. Nevertheless, it was possible to classify this broad variety of known macrobenthic assemblages to the best of expert knowledge (Gutt 2007; Fig. 1. This overview does not replace statistically sound community and diversity analyses. However, it shows from where which kind of information is available and it acts as an example of the feasibility and power of such data collections. The data set provides unique georeferenced biological basic information for the planning of future coordinated research activities, e.g. under the umbrella of the biology program “Antarctic Thresholds - Ecosystem Resilience and Adaptation” (AnT-ERA of the Scientific Committee on Antarctic Research (SCAR and especially for actual conservation issues, e.g. the planning of Marine Protected Areas (MPAs by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR.
[Influence of different types of surface on the diversity of soil fauna in Beijing Olympic Park].

Science.gov (United States)

Song, Ying-shi; Li, Xiao-wen; Li, Feng; Li, Hai-mei

2015-04-01

Soil fauna are impacted by urbanization. In order to explore the stress of different surface covers on diversity and community structure of soil fauna, we conducted this experiment in Beijing Olympic Park. In autumn of 2013, we used Baermann and Tullgren methods to study the diversity of soil fauna in the depth of 0-5 cm, 5-10 cm, 10-15 cm under four different land covers i.e. bared field (BF), totally impervious surface (TIS), partly impervious surface (PIS) and grassland (GL). The results showed that the total number of soil fauna in 100 cm3 was in order of GL (210) > PIS (193) > TIS (183) > BF (90), and the number of nematodes accounted for 72.0%-92.8% of the total number. On the vertical level, except for the TIS, the other three types of surface soil fauna had the surface gathered phenomenon. The Shannon diversity index and the Pielou evenness index of BF were lower, but the Simpson dominance index was higher than in the other land covers. The Shannon index and Margalef richness indes of GL were higher than those of the other land covers. The Shannon indexes of TIS and PIS were between the BF and GL. Except for the TIS and GL, the similarity indexes were between 0.4-0.5, indicating moderate non-similar characteristics. The diversity of soil fauna was significantly correlated with temperature, pH and available potassium.
78 FR 28000 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2013-05-13

... 1978 (Pub. L. 95-541), as amended by the Antarctic Science, Tourism and Conservation Act of 1996, has... facilities and equipment. Location Antarctic Peninsula region, ASPA 117-Avian Island, ASPA 128 Cape...

South African Antarctic research programme 1978-1982

CSIR Research Space (South Africa)

SASCAR

1978-12-01

Full Text Available This document provides a comprehensive review of the planned South African scientific activities in Antarctica and on the sub-Antarctic islands in the five year period starting in 1978. The scientific programmes are classified under five headings...
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
On the Atmospheric Correction of Antarctic Airborne Hyperspectral Data

Directory of Open Access Journals (Sweden)

Martin Black

2014-05-01

Full Text Available The first airborne hyperspectral campaign in the Antarctic Peninsula region was carried out by the British Antarctic Survey and partners in February 2011. This paper presents an insight into the applicability of currently available radiative transfer modelling and atmospheric correction techniques for processing airborne hyperspectral data in this unique coastal Antarctic environment. Results from the Atmospheric and Topographic Correction version 4 (ATCOR-4 package reveal absolute reflectance values somewhat in line with laboratory measured spectra, with Root Mean Square Error (RMSE values of 5% in the visible near infrared (0.4–1 µm and 8% in the shortwave infrared (1–2.5 µm. Residual noise remains present due to the absorption by atmospheric gases and aerosols, but certain parts of the spectrum match laboratory measured features very well. This study demonstrates that commercially available packages for carrying out atmospheric correction are capable of correcting airborne hyperspectral data in the challenging environment present in Antarctica. However, it is anticipated that future results from atmospheric correction could be improved by measuring in situ atmospheric data to generate atmospheric profiles and aerosol models, or with the use of multiple ground targets for calibration and validation.
Fertilizer regime impacts on abundance and diversity of soil fauna across a poplar plantation chronosequence in coastal Eastern China.

Science.gov (United States)

Wang, Shaojun; Chen, Han Y H; Tan, Yan; Fan, Huan; Ruan, Honghua

2016-02-09

Soil fauna are critical for ecosystem function and sensitive to the changes of soil fertility. The effects of fertilization on soil fauna communities, however, remain poorly understood. We examined the effects of fertilization form and quantity on the abundance, diversity and composition of soil fauna across an age-sequence of poplar plantations (i.e., 4-, 9- and 20-yr-old) in the coastal region of eastern China. We found that the effects of fertilization on faunal abundance, diversity, and composition differed among stand ages. Organic fertilizers increased the total abundance of soil fauna, whereas low level inorganic fertilizers imparted increases only in the 4- and 9-yr-old stands. The number of faunal groups did not change with fertilization, but Shannon's and Margalef diversity indices increased under low level organic fertilization, and decreased under inorganic fertilization in the 9- and 20-yr-old stands. Community composition of soil fauna differed strongly with fertilization and stand age. The changes in soil fauna were strongly associated with the changes in microbial biomass carbon, dissolved organic carbon and nitrogen, and available phosphorus and potassium. Our findings suggest that the responses of soil fauna to fertilization may be mediated through the fertilization effects on soil nutrient availability.
Edafic fauna under different straw levels in sugarcane crop

Directory of Open Access Journals (Sweden)

Rossiana Ribeiro Lino de Abreu

2014-09-01

Full Text Available The organisms that constitute the soil fauna are highly relevant to the litter-soil compartments, because they act in important processes, such as fragmentation of the plant material, decomposition and nutrients cycling. This study aimed to evaluate the invertebrate fauna community in soil cultivated with sugarcane harvested without burning, considering the maintenance of different straw levels on the soil surface. Treatments consisted of different amounts of sugarcane straw: T0% (0 Mg ha-1; T25% (2.2 Mg ha-1; T50% (5.1 Mg ha-1; T75% (7.8 Mg ha-1; and T100% (12.0 Mg ha-1. Samples were collected in the dry season and late wet season, with "Pitfall" traps. The number of individuals per trap per day during the dry period ranged from 11.1 (T0% to 14.7 (T25% and, in the rainy season, from 15.11 (T0% to 33.15 (T75%. The highest Shannon values were observed during the rainy season, and the lowest values for diversity and equitability resulted in a higher incidence of Araneae and Formicidae groups. The amount of straw on soil showed no significant influence on ecological indices and total and average wealth. The harvest time affected the number of individuals, species wealth and Shannon and Pielou's indices. The maintenance of straw on the soil surface benefitted the soil fauna, concerning the conventional crop management.
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...
Climate Prediction Center(CPC)Monthly 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...
IMPACTOS DE LAS CARRETERAS SOBRE LA FAUNA SILVESTRE Y SUS PRINCIPALES MEDIDAS DE MANEJO

Directory of Open Access Journals (Sweden)

María del Pilar Arroyave

Full Text Available El objetivo de este artículo es presentar el impacto de los proyectos viales sobre la fauna silvestre y evaluar las medidas de manejo de estos efectos. Se revisó y analizó la información de diversos estudios realizados en el mundo, al igual que algunos estudios de impacto ambiental de carreteras que se han desarrollado en Antioquia. Se encontró que los principales impactos son el atropellamiento, el aislamiento de poblaciones y el cambio en los patrones reproductivos de la fauna; esto trae como consecuencia la disminución de las poblaciones de especies de fauna silvestre. También se plantean las estrategias comúnmente implementadas para el manejo de los impactos.
Unexpectedly high ultrafine aerosol concentrations above East Antarctic sea-ice

Science.gov (United States)

Humphries, R. S.; Klekociuk, A. R.; Schofield, R.; Keywood, M.; Ward, J.; Wilson, S. R.

2015-10-01

The effect of aerosols on clouds and their radiative properties is one of the largest uncertainties in our understanding of radiative forcing. A recent study has concluded that better characterisation of pristine, natural aerosol processes leads to the largest reduction in these uncertainties. Antarctica, being far from anthropogenic activities, is an ideal location for the study of natural aerosol processes. Aerosol measurements in Antarctica are often limited to boundary layer air-masses at spatially sparse coastal and continental research stations, with only a handful of studies in the sea ice region. In this paper, the first observational study of sub-micron aerosols in the East Antarctic sea ice region is presented. Measurements were conducted aboard the ice-breaker Aurora Australis in spring 2012 and found that boundary layer condensation nuclei (CN3) concentrations exhibited a five-fold increase moving across the Polar Front, with mean Polar Cell concentrations of 1130 cm-3 - higher than any observed elsewhere in the Antarctic and Southern Ocean region. The absence of evidence for aerosol growth suggested that nucleation was unlikely to be local. Air parcel trajectories indicated significant influence from the free troposphere above the Antarctic continent, implicating this as the likely nucleation region for surface aerosol, a similar conclusion to previous Antarctic aerosol studies. The highest aerosol concentrations were found to correlate with low pressure systems, suggesting that the passage of cyclones provided an accelerated pathway, delivering air-masses quickly from the free-troposphere to the surface. After descent from the Antarctic free troposphere, trajectories suggest that sea ice boundary layer air-masses travelled equator-ward into the low albedo Southern Ocean region, transporting with them emissions and these aerosol nuclei where, after growth, may potentially impact on the region's radiative balance. The high aerosol concentrations and
78 FR 54686 - Notice of Permit Applications Received under the Antarctic Conservation Act of 1978

Science.gov (United States)

2013-09-05

... the Antarctic Conservation Act of 1978 (Pub. L. 95-541), as amended by the Antarctic Science, Tourism... of the ongoing effort to monitor the spatial scale of human impacts in Antarctica. Samples taken near...
The Bottom Boundary Layer.

Science.gov (United States)

Trowbridge, John H; Lentz, Steven J

2018-01-03

The oceanic bottom boundary layer extracts energy and momentum from the overlying flow, mediates the fate of near-bottom substances, and generates bedforms that retard the flow and affect benthic processes. The bottom boundary layer is forced by winds, waves, tides, and buoyancy and is influenced by surface waves, internal waves, and stratification by heat, salt, and suspended sediments. This review focuses on the coastal ocean. The main points are that (a) classical turbulence concepts and modern turbulence parameterizations provide accurate representations of the structure and turbulent fluxes under conditions in which the underlying assumptions hold, (b) modern sensors and analyses enable high-quality direct or near-direct measurements of the turbulent fluxes and dissipation rates, and (c) the remaining challenges include the interaction of waves and currents with the erodible seabed, the impact of layer-scale two- and three-dimensional instabilities, and the role of the bottom boundary layer in shelf-slope exchange.
The Bottom Boundary Layer

Science.gov (United States)

Trowbridge, John H.; Lentz, Steven J.

2018-01-01

The oceanic bottom boundary layer extracts energy and momentum from the overlying flow, mediates the fate of near-bottom substances, and generates bedforms that retard the flow and affect benthic processes. The bottom boundary layer is forced by winds, waves, tides, and buoyancy and is influenced by surface waves, internal waves, and stratification by heat, salt, and suspended sediments. This review focuses on the coastal ocean. The main points are that (a) classical turbulence concepts and modern turbulence parameterizations provide accurate representations of the structure and turbulent fluxes under conditions in which the underlying assumptions hold, (b) modern sensors and analyses enable high-quality direct or near-direct measurements of the turbulent fluxes and dissipation rates, and (c) the remaining challenges include the interaction of waves and currents with the erodible seabed, the impact of layer-scale two- and three-dimensional instabilities, and the role of the bottom boundary layer in shelf-slope exchange.
The late Cainozoic East Antarctic ice sheet

International Nuclear Information System (INIS)

Colhoun, E.A.

1999-01-01

A review, mainly of East Antarctic late Cainozoic (post 40 Ma) geological and geomorphological evidence, supports the hypothesis of the continuous presence of an ice sheet, of about the present size, since the late Miocene. Evidence is presented and the view advanced that, during the late Wisconsin maximum of isotope stage 2, ice was not nearly as thick or extensive over the continental shelf as required by the model of 'maximum' Antarctic glaciation. Some of the factors influencing the contribution of Antarctica to post-glacial sea-level rise are discussed. It is considered that Antarctica's contribution was probably considerably less than previously estimated. The dating of marine and freshwater sequences in the Vestfold and Bunger Hills is consistent with deglaciation around the Pleistocene Holocene boundary, after the Late Wisconsin maximum. A date of ∼25 ka BP from permafrost in the Larsemann Hills means that either the Larsemann Hills were not glaciated during the Late Wisconsin or the ice failed to erode much of the permafrost surface. The degree of weathering of rock and glacial drifts in the Vestfold, Larsemann and Bunger Hills suggests a long time for formation, perhaps considerably longer than indicated by the dated marine and freshwater sediment sequences. Cosmogenic isotope dating in the Vestfold Hills has provided equivocal ages for deglaciation. While the results could indicate deglaciation before 80 ka BP, they do not confirm such early deglaciation. If the ice cover was thin and failed to remove the previous rock exposure profile, then the assays could predate the last ice advance. Weathered iron crust fragments in the till suggest little erosion. The raised beaches of the oases are Holocene. Assuming they have been produced by post Late Wisconsin isostatic uplift and by the Holocene transgression, calculations show that the Antarctic continental ice sheet could not have been more than ∼500 m thicker in the inner shelf-coastal zone. The
Antarctic Lithosphere Studies: Progress, Problems and Promise

Science.gov (United States)

Dalziel, I. W. D.; Wilson, T. J.

2017-12-01

In the sixty years since the International Geophysical Year, studies of the Antarctic lithosphere have progressed from basic geological observations and sparse geophysical measurements to continental-scale datasets of radiometric dates, ice thickness, bedrock topography and characteristics, seismic imaging and potential fields. These have been augmented by data from increasingly dense broadband seismic and geodetic networks. The Antarctic lithosphere is known to have been an integral part, indeed a "keystone" of the Pangea ( 250-185Ma) and Gondwanaland ( 540-180 Ma) supercontinents. It is widely believed to have been part of hypothetical earlier supercontinents Rodinia ( 1.0-0.75 Ga) and Columbia (Nuna) ( 2.0-1.5 Ga). Despite the paucity of exposure in East Antarctica, the new potential field datasets have emboldened workers to extrapolate Precambrian geological provinces and structures from neighboring continents into Antarctica. Hence models of the configuration of Columbia and its evolution into Rodinia and Gondwana have been proposed, and rift-flank uplift superimposed on a Proterozoic orogenic root has been hypothesized to explain the Gamburtsev Subglacial Mountains. Mesozoic-Cenozoic rifting has imparted a strong imprint on the West Antarctic lithosphere. Seismic tomographic evidence reveals lateral variation in lithospheric thickness, with the thinnest zones within the West Antarctic rift system and underlying the Amundsen Sea Embayment. Upper mantle low velocity zones are extensive, with a deeper mantle velocity anomaly underlying Marie Byrd Land marking a possible mantle plume. Misfits between crustal motions measured by GPS and GIA model predictions can, in part, be linked with the changes in lithosphere thickness and mantle rheology. Unusually high uplift rates measured by GPS in the Amundsen region can be interpreted as the response of regions with thin lithosphere and weak mantle to late Holocene ice mass loss. Horizontal displacements across the TAM
Antarctic Ice-Sheet Mass Balance from Satellite Altimetry 1992 to 2001

Science.gov (United States)

Zwally, H. Jay; Brenner, Anita C.; Cornejo, Helen; Giovinetto, Mario; Saba, Jack L.; Yi, Donghui

2003-01-01

A major uncertainty in understanding the causes of the current rate of sea level rise is the potential contributions from mass imbalances of the Greenland and Antarctic ice sheets. Estimates of the current mass balance of the Antarctic ice sheet are derived from surface- elevation changes obtained from 9 years of ERS - 1 & 2 radar altimeter data. Elevation time-series are created from altimeter crossovers among 90-day data periods on a 50 km grid to 81.5 S. The time series are fit with a multivariate linear/sinusoidal function to give the average rate of elevation change (dH/dt). On the major Rome-Filchner, Ross, and Amery ice shelves, the W d t are small or near zero. In contrast, the ice shelves of the Antarctic Peninsula and along the West Antarctic coast appear to be thinning significantly, with a 23 +/- 3 cm per year surface elevation decrease on the Larsen ice shelf and a 65 +/- 4 cm per year decrease on the Dotson ice shelf. On the grounded ice, significant elevation decreases are obtained over most of the drainage basins of the Pine Island and Thwaites glaciers in West Antarctica and inland of Law Dome in East Antarctica. Significant elevation increases are observed within about 200 km of the coast around much of the rest of the ice sheet. Farther inland, the changes are a mixed pattern of increases and decreases with increases of a few centimeters per year at the highest elevations of the East Antarctic plateau. The derived elevation changes are combined with estimates of the bedrock uplift from several models to provide maps of ice thickness change. The ice thickness changes enable estimates of the ice mass balances for the major drainage basins, the overall mass balance, and the current contribution of the ice sheet to global sea level change.
77 FR 50720 - Notice of Permit Modification Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2012-08-22

... Antarctic Conservation Act of 1978 (Pub. L. 95-541), as amended by the Antarctic Science, Tourism and..., bill and flipper dimensions taken, 3-5 feathers removed to confirm gender of the penguin, and have GPS...
78 FR 56743 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2013-09-13

... by the Antarctic Conservation Act of 1978 (Pub. L. 95-541), as amended by the Antarctic Science... measure ablation and GPS units to monitor the motion of the glacier. The GPR system will be moved...
Regional Changes in the Sea Ice Cover and Ice Production in the Antarctic

Science.gov (United States)

Comiso, Josefino C.

2011-01-01

Coastal polynyas around the Antarctic continent have been regarded as sea ice factories because of high ice production rates in these regions. The observation of a positive trend in the extent of Antarctic sea ice during the satellite era has been intriguing in light of the observed rapid decline of the ice extent in the Arctic. The results of analysis of the time series of passive microwave data indicate large regional variability with the trends being strongly positive in the Ross Sea, strongly negative in the Bellingshausen/Amundsen Seas and close to zero in the other regions. The atmospheric circulation in the Antarctic is controlled mainly by the Southern Annular Mode (SAM) and the marginal ice zone around the continent shows an alternating pattern of advance and retreat suggesting the presence of a propagating wave (called Antarctic Circumpolar Wave) around the circumpolar region. The results of analysis of the passive microwave data suggest that the positive trend in the Antarctic sea ice cover could be caused primarily by enhanced ice production in the Ross Sea that may be associated with more persistent and larger coastal polynyas in the region. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate-of-increase in the net ice export of about 30,000 km2 per year. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 km3/year, which is almost identical, within error bars, to our estimate of the trend in ice production. In addition to the possibility of changes in SAM, modeling studies have also indicated that the ozone hole may have a role in that it causes the deepening of the lows in the western Antarctic region thereby causing strong winds to occur offthe Ross-ice shelf.
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
Expanding Antarctic Sea Ice: Anthropogenic or Natural Variability?

Science.gov (United States)

Bitz, C. M.

2016-12-01

Antarctic sea ice extent has increased over the last 36 years according to the satellite record. Concurrent with Antarctic sea-ice expansion has been broad cooling of the Southern Ocean sea-surface temperature. Not only are Southern Ocean sea ice and SST trends at odds with expectations from greenhouse gas-induced warming, the trend patterns are not reproduced in historical simulations with comprehensive global climate models. While a variety of different factors may have contributed to the observed trends in recent decades, we propose that it is atmospheric circulation changes - and the changes in ocean circulation they induce - that have emerged as the most likely cause of the observed Southern Ocean sea ice and SST trends. I will discuss deficiencies in models that could explain their incorrect response. In addition, I will present results from a series of experiments where the Antarctic sea ice and ocean are forced by atmospheric perturbations imposed within a coupled climate model. Figure caption: Linear trends of annual-mean SST (left) and annual-mean sea-ice concentration (right) over 1980-2014. SST is from NOAA's Optimum Interpolation SST dataset (version 2; Reynolds et al. 2002). Sea-ice concentration is from passive microwave observations using the NASA Team algorithm. Only the annual means are shown here for brevity and because the signal to noise is greater than in the seasonal means. Figure from Armour and Bitz (2015).

Sabellaria spinulosa (Polychaeta, Annelida) reefs in the Mediterranean Sea: Habitat mapping, dynamics and associated fauna for conservation management

Science.gov (United States)

Gravina, Maria Flavia; Cardone, Frine; Bonifazi, Andrea; Bertrandino, Marta Simona; Chimienti, Giovanni; Longo, Caterina; Marzano, Carlotta Nonnis; Moretti, Massimo; Lisco, Stefania; Moretti, Vincenzo; Corriero, Giuseppe; Giangrande, Adriana

2018-01-01

Bio-constructions by Sabellaria worms play a key functional role in the coastal ecosystems being an engineer organism and for this reason are the object of protection. The most widespread reef building species along Atlantic and Mediterranean coasts is S. alveolata (L.), while the aggregations of S. spinulosa are typically limited to the North Sea coasts. This paper constitutes the first detailed description of unusual large S. spinulosa reefs in the Mediterranean Sea. Defining current health status and evaluating the most important threats and impacts is essential to address conservation needs and design management plans for these large biogenic structures. Present knowledge on Mediterranean reefs of S. alveolata is fragmentary compared to Northeast Atlantic reefs, and concerning S. spinulosa, this paper represents a focal point in the knowledge on Mediterranean reefs of this species. A one-year study on temporal changes in reef structure and associated fauna is reported. The annual cycle of S. spinulosa reef shows a spawning event in winter-early spring, a period of growth and tubes aggregation from spring-early summer to autumn and a degeneration phase in winter. The variations exhibited in density of the worm aggregation and the changes in the reef elevation highlight a decline and regeneration of the structure over a year. The many ecological roles of the S. spinulosa reef were mainly in providing a diversity of microhabitats hosting hard and sandy bottom species, sheltering rare species, and producing biogenic structures able to provide coastal protection. The Mediterranean S. spinulosa reef does not shelter a distinctive associated fauna; however the richness in species composition underscores the importance of the reef as a biodiversity hot-spot. Finally, the roles of the biogenic formations and their important biotic and physical dynamics support the adoption of strategies for conservation of Mediterranean S.spinulosa reefs, according to the aims of the
Radiometric dating of the extinction of the large Pleistocene fauna in Peru

International Nuclear Information System (INIS)

Falgueres, C.; Fontugne, M.

1994-01-01

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 ( 230 Th/ 234 U) 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
Estimation of radiobiological effects on fauna in the Chernobyl NPP accident zone

International Nuclear Information System (INIS)

Sushchenya, L.M.; Pikulik, M.M.; Plenin, A.E.

1990-01-01

The tendency towards decreasing the level of radioactive contamination for analyzed fauna (birds, mammals, amphibians, reptiles, insects) on the Belarus territory in 1987 is revealed. The dynamics of decreasing radionuclide buildup in fauna is sufficiently slowed-down nowadays, and radionuclide content increase is noted for groups of animals living on the most highly contaminated territories as compared with 1986 (according to geochemical, hematological, immunological and genetic characteristics. Analysis of population state in contaminated zones shows that direct radiation effects do not cause noticeable disturbances in ecology of animal populations and zoocenoses
75 FR 62891 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2010-10-13

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
76 FR 52354 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2011-08-22

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
77 FR 56237 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2012-09-12

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
75 FR 61520 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2010-10-05

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
75 FR 60830 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2010-10-01

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
76 FR 58049 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2011-09-19

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
75 FR 75501 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2010-12-03

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... applications received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
75 FR 25300 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2010-05-07

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
77 FR 31044 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2012-05-24

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received Under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
75 FR 6222 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2010-02-08

... protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received Under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
76 FR 58843 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2011-09-22

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Applications Received under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National...
Influence of radioactive environment pollution upon soil fauna at the region of Chernobylsk Atomic Power Station

International Nuclear Information System (INIS)

Krivolutskij, D.A.; Pokarzhevskij, A.D.; Usachev, V.L.; Shein, G.N.; Nadvornyj, V.G.; Viktorov, A.G.

1991-01-01

Populations of soil fauna in the region of 30-km zone of Chernobylsk NPP accident were investigated. in July, September and October of 1986, in April of 1987 and in October of 1988. It is shown that number of soecies of soil microarthropods and their populations in soils of pine forests around the NPP reduced sharply during the first year after the accident, as compared to the standard. Decrease of number and biomass of earthworm populations was observed in soils of agroecosystems. Decrease of share young specimen was especially noticeable. Populations of settled specimens of soil fauna regenerated slowly during the second year after the accident, the second year after the accident, and regeneration of the total population of soil fauna in 30-km zone proceeded due to poupylations of migrating specimens. 2-2.5 years later the population and biomass of soil fauna in contaminated regions regerated completely
Marine fauna of Malvan, Central west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Parulekar, A.H.

oysters, were identified. Rock pool environment was most interesting, as it not only had the maximum number of species but also a high order of faunal diversity. Eight zones indicating the vertical distribution of fauna in relation to tidal range were...
Hydrothermal and Chemosynthetic Ecosystems in the Southern Ocean: Current Knowledge on their Biology Paper 217790

Science.gov (United States)

Linse, K.; Rogers, A. D.; Bohrmann, G.; Copley, J.; Tyler, P. A.

2017-12-01

The existence of hydrothermal and other chemosynthetic ecosystems is not surprising in the Antarctic, with its active volcanoes, mid-ocean ridges and back-arc basins, and abundance of marine mammals. In the last two decades a variety of active chemosynthetic ecosystems have been discovered in the Southern Ocean, including low- and high-temperature hydrothermal vents, methane seeps, and whalefalls. Here a summary of the data from the known chemosynthetic communites will be presented, comparing the faunas of vent sites in the Bransfield Strait with those of the East Scotia Ridge (ESR) and the South Sandwich Arc, assessing the fauna at the South Georgia methane seep sites, and discussing the fauna on Antarctic whale falls. As the faunal assemblages of the ESR vents are the most studied in detail to date, this talk therefore focusses on the diversity and composition of the ESR macrofaunal assemblages, their foodweb structure and microdistributions in relation to fluid chemistry and microbiology, and their phylogenetic and biogeographic relationships. The Southern Ocean drives the global ocean conveyor belt, and is suggested to be the centre of origin for global deep-sea fauna, as well as a region of high deep-sea species diversity. In the context of chemosynthetic environments, it may provide a gateway connecting the global vent and seep systems. The mostly endemic species of Southern Ocean vent macrofauna show links to either one or more oceans (Atlantic, Indian, and Pacific), with some evidence for circum-Antarctic connection. The ESR species Gigantopelta chessoia, Kiwa tyleri and Vulcanolepas scotiaensis have their closest known relatives at the Longqi Vent Field on the Southwest Indian Ridge (SWIR), and one species of polynoid polychaete is known from ESR and SWIR vents. Meanwhile, Lepetdrilus sp. and a vesiocomyid clam are linked with species in the Atlantic vent fields. The stichasterid Paulasterias tyleri, the polychaete Rarricirrus jennae and the anthozoan
RARE COMPONENT OF THE FISH FAUNA OF THE SULINSKY NATIONAL LANDSCAPE RESERVE

Directory of Open Access Journals (Sweden)

Rudik-Leuska Natalia Jaroslavivna

2014-08-01

Full Text Available Maintenance of biological diversity is the main task of modern biology. At the legislative level, Ukraine has pledged its support in ratifying the Convention on the conservation of biological diversity. As part of the implementation of environmental policy in Ukraine preservation of rare fish fauna component is the most problematic aspect. The basic conservation lists acting in Ukraine are: Red List of threatened animals of the International Union for Conservation of Nature, Ukrainian Red Book, Annex III of the Convention on the Protection of wildlife and natural habitats, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, CITES, Washington, 1973. On the territory of Sula Bay located two objects of nature reserve fund - a landscape national reserve Sulinsky and National Park Nizhnesulsky that emphasizes the importance of this area for fish fauna reproduction. Its territory are spawning areas for almost all lower and middle parts of the Kremenchuk reservoir, ensuring more than half of total commercial catch of the Dnieper cascade. The article describes the species composition of the fish fauna, introduced in protected lists of different levels. The existence of seven such species was established. They belong to four families: four species - for cyprinids and one each - to sturgeon, loaches and catfishes. But we must remember that the priority activities should concern species with the highest conservation status. At the same time, four of them are only protected by Annex III of the Convention on the Protection of wildlife and natural habitats as poorly studied. These species require a more thorough study and not necessarily threatened with extinction. Remaining three species are under a real danger of extinction and are protected by the IUCN Red List and Ukrainian Red Book. Starlet also protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, CITES. Environmental
Temporal variability of live (stained benthic foraminiferal faunas in a river-dominated shelf – Faunal response to rapid changes of the river influence (Rhône prodelta, NW Mediterranean

Directory of Open Access Journals (Sweden)

E. Legrand

2012-04-01

.g. Clavulina cylindrica, Hopkinsina atlantica, Nonionella iridea and Nonionella turgida benefited from eutrophic conditions of the spring bloom (April 2007, May 2008. Conversely, the occurrence of Nouria polymorphinoides under oligotrophic conditions (September 2007, December 2008 was indicative of a benthic environment potentially disturbed by bottom currents. This study put into evidence the extremely rapid response of benthic foraminiferal faunas to strong variations in environmental conditions mostly induced by the Rhône dynamics.
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,...

[Soil meso- and micro-fauna community structures in different urban forest types in Shanghai, China.

Science.gov (United States)

Jin, Shi Ke; Wang, Juan Juan; Zhu, Sha; Zhang, Qi; Li, Xiang; Zheng, Wen Jing; You, Wen Hui

2016-07-01

Soil meso- and micro-fauna of four urban forest types in Shanghai were investigated in four months which include April 2014, July 2014, October 2014 and January 2015. A total of 2190 soil fauna individuals which belong to 6 phyla, 15 classes and 22 groups were collected. The dominant groups were Nematoda and Arcari, accounting for 56.0% and 21.8% of the total in terms of individual numbers respectively. The common groups were Enchytraeidae, Rotatoria, Collembola and Hymenoptera and they accounted for 18.7% of the total in terms of individual numbers. There was a significant difference (PMetasequoia glyptostroboides forest, the smallest in Cinnamomum camphora forest. The largest groupe number was found in near-nature forest, the smallest was found in M. glyptostroboides forest. There was obvious seasonal dynamics in each urban forest type and green space which had larger density in autumn and larger groupe number in summer and autumn. In soil profiles, the degree of surface accumulation of soil meso- and micro-fauna in C. camphora forest was higher than in other forests and the vertical distribution of soil meso- and micro-fauna in near-nature forest was relatively homogeneous in four layers. Density-group index was ranked as: near-nature forest (6.953)> C. camphora forest (6.351)> Platanus forest (6.313)>M. glyptostroboides forest (5.910). The community diversity of soil fauna in each vegetation type could be displayed preferably by this index. It could be inferred through redundancy analysis (RDA) that the soil bulk density, organic matter and total nitrogen were the main environmental factors influencing soil meso- and micro-fauna community structure in urban forest. The positive correlations occurred between the individual number of Arcari, Enchytraeidae and soil organic matter and total nitrogen, as well as between the individual number of Diptera larvae, Rotatoria and soil water content.
Data on the scale insect (Hemiptera: Coccomorpha) fauna of Greece, with description of two new species.

Science.gov (United States)

Szita, Éva; Fetykó, Kinga Gabriela; Benedicty, Zsuzsanna Konczné; Kozár, Ferenc; Partsinevelos, Georgios; Milonas, Panagiotis; Kaydan, Mehmet Bora

2017-10-09

Surveys of the scale insect (Hemiptera: Coccomorpha) fauna of Greece were carried out in 2013 and 2014. Altogether 93 scale insect species were collected, belonging to 11 families. Thirty-eight species (41%) proved to be new to the Greek fauna, including two species new to science (Anophococcus hellenicus Kaydan & Szita sp. n. (Acanthococcidae) and Iberococcus attikus Szita & Fetykó sp. n. (Pseudococcidae)), and two introduced invasive species (Phenacoccus graminicola Leonardi and Pseudococcus comstocki (Kuwana), both Pseudococcidae). The rest of the species seem to be native to the Greek fauna. The total number of scale insect species recorded from Greece is increased to 253.
New potassium-argon basalt data in relation to the Pliocene Bluff Downs Local Fauna, northern Australia

International Nuclear Information System (INIS)

Mackness, B.S.

2000-01-01

A new radiometric date of 3.6 Ma for the basalt overlying fossiliferous units of the Allingham Formation, provides a minimum age for the Bluff Downs Local Fauna. Ground studies and interpretation of aerial photography has clarified the volcanic history of the area and a new basalt flow has been identified and named. Although the age of the capping basalt permits a younger age for the Bluff Downs Local Fauna than originally described, the stratigraphy, combined with the interpreted stage of evolution of the fauna, still supports an Early Pliocene age for the site. Copyright (2000) Geological Society of Australia
78 FR 56744 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2013-09-13

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of Permit Applications Received...
77 FR 38834 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2012-06-29

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of permit applications received...
Dynamic Antarctic ice sheet during the early to mid-Miocene

Science.gov (United States)

Gasson, Edward; DeConto, Robert M.; Pollard, David; Levy, Richard H.

2016-03-01

Geological data indicate that there were major variations in Antarctic ice sheet volume and extent during the early to mid-Miocene. Simulating such large-scale changes is problematic because of a strong hysteresis effect, which results in stability once the ice sheets have reached continental size. A relatively narrow range of atmospheric CO2 concentrations indicated by proxy records exacerbates this problem. Here, we are able to simulate large-scale variability of the early to mid-Miocene Antarctic ice sheet because of three developments in our modeling approach. (i) We use a climate-ice sheet coupling method utilizing a high-resolution atmospheric component to account for ice sheet-climate feedbacks. (ii) The ice sheet model includes recently proposed mechanisms for retreat into deep subglacial basins caused by ice-cliff failure and ice-shelf hydrofracture. (iii) We account for changes in the oxygen isotopic composition of the ice sheet by using isotope-enabled climate and ice sheet models. We compare our modeling results with ice-proximal records emerging from a sedimentological drill core from the Ross Sea (Andrill-2A) that is presented in a companion article. The variability in Antarctic ice volume that we simulate is equivalent to a seawater oxygen isotope signal of 0.52-0.66‰, or a sea level equivalent change of 30-36 m, for a range of atmospheric CO2 between 280 and 500 ppm and a changing astronomical configuration. This result represents a substantial advance in resolving the long-standing model data conflict of Miocene Antarctic ice sheet and sea level variability.
Atmospheric Influences on the Anomalous 2016 Antarctic Sea Ice Decay

Science.gov (United States)

Raphael, M. N.; Schlosser, E.; Haumann, A.

2017-12-01

Over the past three decades, a small but significant increase in sea ice extent (SIE) has been observed in the Antarctic. However, in 2016 there was a surprisingly early onset of the melt season. The maximum Antarctic SIE was reached in August rather than end of September, and was followed by a rapid decrease. The decline of the sea ice area (SIA) started even earlier, in July. The retreat of the ice was particularly large in November where Antarctic SIE exhibited a negative anomaly (compared to the 1981-2010 average) of almost 2 Mio. km2, which, combined with reduced Arctic SIE, led to a distinct minimum in global SIE. And, satellite observations show that from November 2016 to February 2017, the daily Antarctic SIE has been at record low levels. We use sea level pressure and geopotential height data from the ECMWF- Interim reanalysis, in conjunction with sea ice data obtained from the National Snow and Ice Data Centre (NSIDC), to investigate possible atmospheric influences on the observed phenomena. Indications are that both the onset of the melt in July and the rapid decrease in SIA and SIE in November were triggered by atmospheric flow patterns related to a positive Zonal Wave 3 index, i.e. synoptic situations leading to strong meridional flow. Additionally the Southern Annular Mode (SAM) index reached its second lowest November value since the beginning of the satellite observations. It is likely that the SIE decrease was preconditioned by SIA decrease. Positive feedback effects led to accelerated melt and consequently to the extraordinary low November SIE.
The Signature of Southern Hemisphere Atmospheric Circulation Patterns in Antarctic Precipitation.

Science.gov (United States)

Marshall, Gareth J; Thompson, David W J; van den Broeke, Michiel R

2017-11-28

We provide the first comprehensive analysis of the relationships between large-scale patterns of Southern Hemisphere climate variability and the detailed structure of Antarctic precipitation. We examine linkages between the high spatial resolution precipitation from a regional atmospheric model and four patterns of large-scale Southern Hemisphere climate variability: the southern baroclinic annular mode, the southern annular mode, and the two Pacific-South American teleconnection patterns. Variations in all four patterns influence the spatial configuration of precipitation over Antarctica, consistent with their signatures in high-latitude meridional moisture fluxes. They impact not only the mean but also the incidence of extreme precipitation events. Current coupled-climate models are able to reproduce all four patterns of atmospheric variability but struggle to correctly replicate their regional impacts on Antarctic climate. Thus, linking these patterns directly to Antarctic precipitation variability may allow a better estimate of future changes in precipitation than using model output alone.
Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula.

Science.gov (United States)

Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

2015-02-28

In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2-7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula. Copyright © 2014 Elsevier Ltd. All rights reserved.
77 FR 67407 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2012-11-09

... designation of certain animals and certain geographic areas a requiring special protection. The regulations establish such a permit system to designate Antarctic Specially Protected Areas. The applications received... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic...
78 FR 59728 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978

Science.gov (United States)

2013-09-27

... requiring special protection. The regulations establish such a permit system to designate Antarctic... NATIONAL SCIENCE FOUNDATION Notice of Permit Applications Received Under the Antarctic... Foundation (NSF) is required to publish a notice of permit applications received to conduct activities...
The Earliest Colubroid-Dominated Snake Fauna from Africa: Perspectives from the Late Oligocene Nsungwe Formation of Southwestern Tanzania

Science.gov (United States)

McCartney, Jacob A.; Stevens, Nancy J.; O’Connor, Patrick M.

2014-01-01

The extant snake fauna has its roots in faunal upheaval occurring across the Paleogene - Neogene transition. On northern continents, this turnover is well established by the late early Miocene. However, this transition is poorly documented on southern landmasses, particularly on continental Africa, where no late Paleogene terrestrial snake assemblages are documented south of the equator. Here we describe a newly discovered snake fauna from the Late Oligocene Nsungwe Formation in the Rukwa Rift Basin of Tanzania. The fauna is small but diverse with eight identifiable morphotypes, comprised of three booids and five colubroids. This fauna includes Rukwanyoka holmani gen. et sp. nov., the oldest boid known from mainland Africa. It also provides the oldest fossil evidence for the African colubroid clade Elapidae. Colubroids dominate the fauna, comprising more than 75% of the recovered material. This is likely tied to local aridification and/or seasonality and mirrors the pattern of overturn in later snake faunas inhabiting the emerging grassland environments of Europe and North America. The early emergence of colubroid dominance in the Rukwa Rift Basin relative to northern continents suggests that the pattern of overturn that resulted in extant faunas happened in a more complex fashion on continental Africa than was previously realized, with African colubroids becoming at least locally important in the late Paleogene, either ahead of or as a consequence of the invasion of colubrids. The early occurrence of elapid snakes in the latest Oligocene of Africa suggests the clade rapidly spread from Asia to Africa, or arose in Africa, before invading Europe. PMID:24646522
The earliest colubroid-dominated snake fauna from Africa: perspectives from the Late Oligocene Nsungwe Formation of southwestern Tanzania.

Directory of Open Access Journals (Sweden)

Jacob A McCartney

Full Text Available The extant snake fauna has its roots in faunal upheaval occurring across the Paleogene-Neogene transition. On northern continents, this turnover is well established by the late early Miocene. However, this transition is poorly documented on southern landmasses, particularly on continental Africa, where no late Paleogene terrestrial snake assemblages are documented south of the equator. Here we describe a newly discovered snake fauna from the Late Oligocene Nsungwe Formation in the Rukwa Rift Basin of Tanzania. The fauna is small but diverse with eight identifiable morphotypes, comprised of three booids and five colubroids. This fauna includes Rukwanyoka holmani gen. et sp. nov., the oldest boid known from mainland Africa. It also provides the oldest fossil evidence for the African colubroid clade Elapidae. Colubroids dominate the fauna, comprising more than 75% of the recovered material. This is likely tied to local aridification and/or seasonality and mirrors the pattern of overturn in later snake faunas inhabiting the emerging grassland environments of Europe and North America. The early emergence of colubroid dominance in the Rukwa Rift Basin relative to northern continents suggests that the pattern of overturn that resulted in extant faunas happened in a more complex fashion on continental Africa than was previously realized, with African colubroids becoming at least locally important in the late Paleogene, either ahead of or as a consequence of the invasion of colubrids. The early occurrence of elapid snakes in the latest Oligocene of Africa suggests the clade rapidly spread from Asia to Africa, or arose in Africa, before invading Europe.
On the use of high-throughput sequencing for the study of cyanobacterial diversity in Antarctic aquatic mats.

Science.gov (United States)

Pessi, Igor Stelmach; Maalouf, Pedro De Carvalho; Laughinghouse, Haywood Dail; Baurain, Denis; Wilmotte, Annick

2016-06-01

The study of Antarctic cyanobacterial diversity has been mostly limited to morphological identification and traditional molecular techniques. High-throughput sequencing (HTS) allows a much better understanding of microbial distribution in the environment, but its application is hampered by several methodological and analytical challenges. In this work, we explored the use of HTS as a tool for the study of cyanobacterial diversity in Antarctic aquatic mats. Our results highlight the importance of using artificial communities to validate the parameters of the bioinformatics procedure used to analyze natural communities, since pipeline-dependent biases had a strong effect on the observed community structures. Analysis of microbial mats from five Antarctic lakes and an aquatic biofilm from the Sub-Antarctic showed that HTS is a valuable tool for the assessment of cyanobacterial diversity. The majority of the operational taxonomic units retrieved were related to filamentous taxa such as Leptolyngbya and Phormidium, which are common genera in Antarctic lacustrine microbial mats. However, other phylotypes related to different taxa such as Geitlerinema, Pseudanabaena, Synechococcus, Chamaesiphon, Calothrix, and Coleodesmium were also found. Results revealed a much higher diversity than what had been reported using traditional methods and also highlighted remarkable differences between the cyanobacterial communities of the studied lakes. The aquatic biofilm from the Sub-Antarctic had a distinct cyanobacterial community from the Antarctic lakes, which in turn displayed a salinity-dependent community structure at the phylotype level. © 2016 Phycological Society of America.
Homogenization patterns of the world's freshwater fish faunas.

Science.gov (United States)

Villéger, Sébastien; Blanchet, Simon; Beauchard, Olivier; Oberdorff, Thierry; Brosse, Sébastien

2011-11-01

The world is currently undergoing an unprecedented decline in biodiversity, which is mainly attributable to human activities. For instance, nonnative species introduction, combined with the extirpation of native species, affects biodiversity patterns, notably by increasing the similarity among species assemblages. This biodiversity change, called taxonomic homogenization, has rarely been assessed at the world scale. Here, we fill this gap by assessing the current homogenization status of one of the most diverse vertebrate groups (i.e., freshwater fishes) at global and regional scales. We demonstrate that current homogenization of the freshwater fish faunas is still low at the world scale (0.5%) but reaches substantial levels (up to 10%) in some highly invaded river basins from the Nearctic and Palearctic realms. In these realms experiencing high changes, nonnative species introductions rather than native species extirpations drive taxonomic homogenization. Our results suggest that the "Homogocene era" is not yet the case for freshwater fish fauna at the worldwide scale. However, the distressingly high level of homogenization noted for some biogeographical realms stresses the need for further understanding of the ecological consequences of homogenization processes.
76 FR 39905 - Notice of Permit Applications Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Science.gov (United States)

2011-07-07

... Antarctic Conservation Act of 1978 (Pub. L. 95-541), as amended by the Antarctic Science, Tourism and... ASPA 134--Cierva Point and Offshore islands, Danco Coast, Antarctica, to install boreholes and a soil... occurrence and properties, and soil properties along a latitudinal gradient on the western Antarctic...
Glacial isostatic stress shadowing by the Antarctic ice sheet

Science.gov (United States)

Ivins, E. R.; James, T. S.; Klemann, V.

2005-01-01

Numerous examples of fault slip that offset late Quaternary glacial deposits and bedrock polish support the idea that the glacial loading cycle causes earthquakes in the upper crust. A semianalytical scheme is presented for quantifying glacial and postglacial lithospheric fault reactivation using contemporary rock fracture prediction methods. It extends previous studies by considering differential Mogi-von Mises stresses, in addition to those resulting from a Coulomb analysis. The approach utilizes gravitational viscoelastodynamic theory and explores the relationships between ice mass history and regional seismicity and faulting in a segment of East Antarctica containing the great Antarctic Plate (Balleny Island) earthquake of 25 March 1998 (Mw 8.1). Predictions of the failure stress fields within the seismogenic crust are generated for differing assumptions about background stress orientation, mantle viscosity, lithospheric thickness, and possible late Holocene deglaciation for the D91 Antarctic ice sheet history. Similar stress fracture fields are predicted by Mogi-von Mises and Coulomb theory, thus validating previous rebound Coulomb analysis. A thick lithosphere, of the order of 150-240 km, augments stress shadowing by a late melting (middle-late Holocene) coastal East Antarctic ice complex and could cause present-day earthquakes many hundreds of kilometers seaward of the former Last Glacial Maximum grounding line.
Task-dependent cold stress during expeditions in Antarctic environments.

Science.gov (United States)

Morris, Drew M; Pilcher, June J; Powell, Robert B

2017-01-01

This study seeks to understand the degree of body cooling, cold perception and physical discomfort during Antarctic tour excursions. Eight experienced expedition leaders across three Antarctic cruise voyages were monitored during occupational tasks: kayaking, snorkelling and zodiac outings. Subjective cold perception and discomfort were recorded using a thermal comfort assessment and skin temperature was recorded using a portable data logger. Indoor cabin temperature and outdoor temperature with wind velocity were used as measures of environmental stress. Physical activity level and clothing insulation were estimated using previous literature. Tour leaders experienced a 6°C (2°C wind chill) environment for an average of 6 hours each day. Leaders involved in kayaking reported feeling colder and more uncomfortable than other leaders, but zodiac leaders showed greater skin temperature cooling. Occupational experience did not predict body cooling or cold stress perception. These findings indicate that occupational cold stress varies by activity and measurement methodology. The current study effectively used objective and subjective measures of cold-stress to identify factors which can contribute to risk in the Antarctic tourism industry. Results suggest that the type of activity may moderate risk of hypothermia, but not discomfort, potentially putting individuals at risk for cognitive related mistakes and cold injuries.
Twenty-five years of Antarctic upper atmosphere research at Rhodes University

International Nuclear Information System (INIS)

Gledhill, J.A.

1987-01-01

South Africa, as one of the twelve signatories of the Antarctic Treaty is required to establish presence in Antarctica. In this article the past 25 years of upper atmosphere research in Antarctica, and the ionosphere programme at SANAE (South African National Antarctic Expedition) are described. The use of ionograms, Barry ionosondes, airglow photometers, oblique incidence ionograms and the digitized FM ionosonde are discussed as well as anomalous daily variations, the ionospheric effects of particle precipitation, Atmosphere Explorer-C and project ISAAC (International South Atlantic Anomaly Campaign)
Mass balance of the Antarctic ice sheet.

Science.gov (United States)

Wingham, D J; Shepherd, A; Muir, A; Marshall, G J

2006-07-15

The Antarctic contribution to sea-level rise has long been uncertain. While regional variability in ice dynamics has been revealed, a picture of mass changes throughout the continental ice sheet is lacking. Here, we use satellite radar altimetry to measure the elevation change of 72% of the grounded ice sheet during the period 1992-2003. Depending on the density of the snow giving rise to the observed elevation fluctuations, the ice sheet mass trend falls in the range -5-+85Gtyr-1. We find that data from climate model reanalyses are not able to characterise the contemporary snowfall fluctuation with useful accuracy and our best estimate of the overall mass trend-growth of 27+/-29Gtyr-1-is based on an assessment of the expected snowfall variability. Mass gains from accumulating snow, particularly on the Antarctic Peninsula and within East Antarctica, exceed the ice dynamic mass loss from West Antarctica. The result exacerbates the difficulty of explaining twentieth century sea-level rise.

Effect of radioactive pollution of the environment on soil fauna in the region of the Chernobyl atomic station

International Nuclear Information System (INIS)

Krivolutskii, D.A.; Pokarzhevskii, A.D.; Usachev, V.L.; Shein, G.N.; Nadvornyi, V.G.; Viktorov, A.G.

1991-01-01

Investigations of soil fauna populations within a 30-km zone around the Chernobyl Atomic Energy Station between July 1986 and October 1988 showed a marked decrease in the first year after the accident in the species composition of soil microarthropods and in the abundance of their populations in soils of the local pine [Pinus] forests. The soils of agroecosystems showed a decrease in young individuals. In the second year after the accident, the populations of settled species of soil fauna recovered slowly, and recovery of the total abundance of soil fauna in the 30-km zone occurred due to populations of migrating species. After 2-2.5 years, the abundance and biomass of soil fauna populations in polluted areas had recovered
Isolation of Campylobacter spp. from Three Species of Antarctic Penguins in Different Geographic Locations.

Science.gov (United States)

García-Peña, F J; Llorente, M T; Serrano, T; Ruano, M J; Belliure, J; Benzal, J; Herrera-León, S; Vidal, V; D'Amico, V; Pérez-Boto, D; Barbosa, A

2017-03-01

The presence of Campylobacter species was studied in three Antarctic penguin species, Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua). A total of 390 penguins were captured in 12 different rookeries along the Antarctic Peninsula with differences in the amount of human visitation: six colonies were highly visited [Stranger Point, King George Island (P. papua and P. adeliae); Hannah Point, Livingston Island (P. papua and P. antarctica); Deception Island (P. antarctica); and Paradise Bay, Antarctic Peninsula (P. papua)], and six colonies were rarely visited [Devil's Point, Byers Peninsula, Livingston Island (P. papua); Cierva Cove, Antarctic Peninsula (P. papua); Rongé Island (P. papua and P. antarctica); Yalour Island (P. adeliae); and Avian Island (P. adeliae)]. A total of 23 strains were isolated from penguins from nine different rookeries. Campylobacter lari subsp. lari was isolated from eight samples (seven from P. papua and one from P. adeliae); C. lari subsp. concheus from 13 (ten from P. adeliae and three from P. antarctica) and C. volucris from two samples (both from P. papua). We did not find any significant differences in the prevalence of Campylobacter spp. between the populations in highly and rarely visited areas. This is the first report of C. lari subsp. concheus and C. volucris isolation from penguins in the Antarctic region.
Spatially Extensive Standardized Surveys Reveal Widespread, Multi-Decadal Increase in East Antarctic Adélie Penguin Populations.

Science.gov (United States)

Southwell, Colin; Emmerson, Louise; McKinlay, John; Newbery, Kym; Takahashi, Akinori; Kato, Akiko; Barbraud, Christophe; DeLord, Karine; Weimerskirch, Henri

2015-01-01

Seabirds are considered to be useful and practical indicators of the state of marine ecosystems because they integrate across changes in the lower trophic levels and the physical environment. Signals from this key group of species can indicate broad scale impacts or response to environmental change. Recent studies of penguin populations, the most commonly abundant Antarctic seabirds in the west Antarctic Peninsula and western Ross Sea, have demonstrated that physical changes in Antarctic marine environments have profound effects on biota at high trophic levels. Large populations of the circumpolar-breeding Adélie penguin occur in East Antarctica, but direct, standardized population data across much of this vast coastline have been more limited than in other Antarctic regions. We combine extensive new population survey data, new population estimation methods, and re-interpreted historical survey data to assess decadal-scale change in East Antarctic Adélie penguin breeding populations. We show that, in contrast to the west Antarctic Peninsula and western Ross Sea where breeding populations have decreased or shown variable trends over the last 30 years, East Antarctic regional populations have almost doubled in abundance since the 1980's and have been increasing since the earliest counts in the 1960's. The population changes are associated with five-year lagged changes in the physical environment, suggesting that the changing environment impacts primarily on the pre-breeding age classes. East Antarctic marine ecosystems have been subject to a number of changes over the last 50 years which may have influenced Adélie penguin population growth, including decadal-scale climate variation, an inferred mid-20th century sea-ice contraction, and early-to-mid 20th century exploitation of fish and whale populations.
Spatially Extensive Standardized Surveys Reveal Widespread, Multi-Decadal Increase in East Antarctic Adélie Penguin Populations.

Directory of Open Access Journals (Sweden)

Colin Southwell

Full Text Available Seabirds are considered to be useful and practical indicators of the state of marine ecosystems because they integrate across changes in the lower trophic levels and the physical environment. Signals from this key group of species can indicate broad scale impacts or response to environmental change. Recent studies of penguin populations, the most commonly abundant Antarctic seabirds in the west Antarctic Peninsula and western Ross Sea, have demonstrated that physical changes in Antarctic marine environments have profound effects on biota at high trophic levels. Large populations of the circumpolar-breeding Adélie penguin occur in East Antarctica, but direct, standardized population data across much of this vast coastline have been more limited than in other Antarctic regions. We combine extensive new population survey data, new population estimation methods, and re-interpreted historical survey data to assess decadal-scale change in East Antarctic Adélie penguin breeding populations. We show that, in contrast to the west Antarctic Peninsula and western Ross Sea where breeding populations have decreased or shown variable trends over the last 30 years, East Antarctic regional populations have almost doubled in abundance since the 1980's and have been increasing since the earliest counts in the 1960's. The population changes are associated with five-year lagged changes in the physical environment, suggesting that the changing environment impacts primarily on the pre-breeding age classes. East Antarctic marine ecosystems have been subject to a number of changes over the last 50 years which may have influenced Adélie penguin population growth, including decadal-scale climate variation, an inferred mid-20th century sea-ice contraction, and early-to-mid 20th century exploitation of fish and whale populations.
Fire and explosion hazards to flora and fauna from explosives.

Science.gov (United States)

Merrifield, R

2000-06-30

Deliberate or accidental initiation of explosives can produce a range of potentially damaging fire and explosion effects. Quantification of the consequences of such effects upon the surroundings, particularly on people and structures, has always been of paramount importance. Information on the effects on flora and fauna, however, is limited, with probably the weakest area lying with fragmentation of buildings and their effects on different small mammals. Information has been used here to gain an appreciation of the likely magnitude of the potential fire and explosion effects on flora and fauna. This is based on a number of broad assumptions and a variety of data sources including World War II bomb damage, experiments performed with animals 30-40 years ago, and more recent field trials on building break-up under explosive loading.
Flora y fauna crónica

OpenAIRE

Susana Chávez-Silverman

2004-01-01

“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 so...
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
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

seasonal trend in concentrations when looking at individual species or groups of species. The number of species caught in ponds and lakes was more or less identical, which together with an only slightly elevated heavy metal content of the fauna supported that stormwater ponds can contribute positively...... in bioaccumulation. The results were compared with similar results from two natural shallow lakes of the same region. The study showed that there was some tendency for copper and also to some degree for other metals to be present in slightly higher concentrations in fauna of the ponds. There was, however, no clear...
Litter quality mediated nitrogen effect on plant litter decomposition regardless of soil fauna presence.

Science.gov (United States)

Zhang, Weidong; Chao, Lin; Yang, Qingpeng; Wang, Qingkui; Fang, Yunting; Wang, Silong

2016-10-01

Nitrogen addition has been shown to affect plant litter decomposition in terrestrial ecosystems. The way that nitrogen deposition impacts the relationship between plant litter decomposition and altered soil nitrogen availability is unclear, however. This study examined 18 co-occurring litter types in a subtropical forest in China in terms of their decomposition (1 yr of exposure in the field) with nitrogen addition treatment (0, 0.4, 1.6, and 4.0 mol·N·m -2 ·yr -1 ) and soil fauna exclusion (litter bags with 0.1 and 2 cm mesh size). Results showed that the plant litter decomposition rate is significantly reduced because of nitrogen addition; the strength of the nitrogen addition effect is closely related to the nitrogen addition levels. Plant litters with diverse quality responded to nitrogen addition differently. When soil fauna was present, the nitrogen addition effect on medium-quality or high-quality plant litter decomposition rate was -26% ± 5% and -29% ± 4%, respectively; these values are significantly higher than that of low-quality plant litter decomposition. The pattern is similar when soil fauna is absent. In general, the plant litter decomposition rate is decreased by soil fauna exclusion; an average inhibition of -17% ± 1.5% was exhibited across nitrogen addition treatment and litter quality groups. However, this effect is weakly related to nitrogen addition treatment and plant litter quality. We conclude that the variations in plant litter quality, nitrogen deposition, and soil fauna are important factors of decomposition and nutrient cycling in a subtropical forest ecosystem. © 2016 by the Ecological Society of America.
Fauna parasitária de Leporinus lacustris e Leporinus friderici (Characiformes, Anostomidae da planície de inundação do alto rio Paraná, Brasil = Parasite fauna of Leporinus lacustris and Leporinus friderici (Characiformes, Anostomidae from the upper Paraná river floodplain, Brazil

Directory of Open Access Journals (Sweden)

Gislaine Guidelli

2006-07-01

Full Text Available Foram investigadas as faunas parasitárias de Leporinus lacustris e Leporinus friderici da planície de inundação do Alto rio Paraná, Brasil, objetivando compará-las em composição e estrutura das comunidades seguindo-se metodologias usuais no estudo dos parasitas.Foram observados alguns padrões e as faunas podem ser consideradas semelhantes em estrutura. A principal diferença nas faunas parasitárias refere-se às taxas diferenciais de utilização das espécies hospedeiras por algumas espécies parasitas em comum, representadas pela abundância. Esse indicador diferiu entre as espécies de peixes mostrando que, apesar delas serem hospedeiras apropriadas, sua exploração ocorre de forma distinta.The parasite fauna of Leporinus lacustris and Leporinus friderici from the Upper Paraná River floodplain, Brazil, was investigated aiming to make a comparison in terms of composition and structure of the communities. Usual methodologies in the study of parasite fauna were applied. Some patterns were observed, and the faunas can be considered similar in structure. The main difference in the parasite fauna was the use rate of the host by some shared parasite species, represented by abundance. This indicator differed in the fish speciesshowing that, although all are appropriate hosts, their exploitation occurs in different ways.
Searching the soil: forensic importance of edaphic fauna after the removal of a corpse.

Science.gov (United States)

Saloña, Marta I; Moraza, M Lourdes; Carles-Tolrá, Miguel; Iraola, Victor; Bahillo, Pablo; Yélamos, Tomás; Outerelo, Raimundo; Alcaraz, Rafael

2010-11-01

Arthropods at different stages of development collected from human remains in an advanced stage of decomposition (following autopsy) and from the soil at the scene are reported. The corpse was found in a mixed deciduous forest of Biscay (northern Spain). Soil fauna was extracted by sieving the soil where the corpse lay and placing the remains in Berlese-Tullgren funnels. Necrophagous fauna on the human remains was dominated by the fly Piophilidae: Stearibia nigriceps (Meigen, 1826), mites Ascidae: Proctolaelaps epuraeae (Hirschmann, 1963), Laelapidae: Hypoaspis (Gaeolaelaps) aculeifer (Canestrini, 1884), and the beetle Cleridae: Necrobia rufipes (de Geer, 1775). We confirm the importance of edaphic fauna, especially if the deceased is discovered in natural environs. Related fauna may remain for days after corpse removal and reveal information related to the circumstances of death. The species Nitidulidae: Omosita depressa (Linnaeus, 1758), Acaridae: Sancassania berlesei (Michael, 1903), Ascidae: Zerconopsis remiger (Kramer, 1876) and P. epuraeae, Urodinychidae: Uroobovella pulchella (Berlese, 1904), and Macrochelidae: Glyptholaspis americana (Berlese, 1888) were recorded for the first time in the Iberian Peninsula. 2010 American Academy of Forensic Sciences. Published 2010. This article is a U.S. Government work and is in the public domain in the U.S.A.
Soil fauna in forest and coffee plantations from the Sierra Nevada de Santa Mar ta, Colombia

International Nuclear Information System (INIS)

Camero R, Edgar

2002-01-01

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
[Effects of rare earth elements on soil fauna community structure and their ecotoxicity to Holotrichia parallela].

Science.gov (United States)

Li, Guiting; Jiang, Junqi; Chen, Jie; Zou, Yunding; Zhang, Xincai

2006-01-01

By the method of OECD filter paper contact, this paper studied the effects of applied rare earth elements on soil fauna community structure and their ecological toxicity to Holotrichia parallela in bean field. The results showed that there were no significant differences between the treatments and the control in soil fauna species, quantity of main species, and diversity index. Urgent and chronic toxic test showed that the differences between the treatments and the control were not significant. It was suggested that within the range of test dosages, rare earth elements had little ecological toxicity to Holotrichia parallela, and did not change the soil fauna community structure.
Monitoring of Antarctic moss ecosystems using a high spatial resolution imaging spectroscopy

Science.gov (United States)

Malenovsky, Zbynek; Lucieer, Arko; Robinson, Sharon; Harwin, Stephen; Turner, Darren; Veness, Tony

2013-04-01

The most abundant photosynthetically active plants growing along the rocky Antarctic shore are mosses of three species: Schistidium antarctici, Ceratodon purpureus, and Bryum pseudotriquetrum. Even though mosses are well adapted to the extreme climate conditions, their existence in Antarctica depends strongly on availability of liquid water from snowmelt during the short summer season. Recent changes in temperature, wind speed and stratospheric ozone are stimulating faster evaporation, which in turn influences moss growing rate, health state and abundance. This makes them an ideal bio-indicator of the Antarctic climate change. Very short growing season, lasting only about three months, requires a time efficient, easily deployable and spatially resolved method for monitoring the Antarctic moss beds. Ground and/or low-altitude airborne imaging spectroscopy (called also hyperspectral remote sensing) offers a fast and spatially explicit approach to investigate an actual spatial extent and physiological state of moss turfs. A dataset of ground-based spectral images was acquired with a mini-Hyperspec imaging spectrometer (Headwall Inc., the USA) during the Antarctic summer 2012 in the surroundings of the Australian Antarctic station Casey (Windmill Islands). The collection of high spatial resolution spectral images, with pixels about 2 cm in size containing from 162 up to 324 narrow spectral bands of wavelengths between 399 and 998 nm, was accompanied with point moss reflectance measurements recorded with the ASD HandHeld-2 spectroradiometer (Analytical Spectral Devices Inc., the USA). The first spectral analysis indicates significant differences in red-edge and near-infrared reflectance of differently watered moss patches. Contrary to high plants, where the Normalized Difference Vegetation Index (NDVI) represents an estimate of green biomass, NDVI of mosses indicates mainly the actual water content. Similarly to high plants, reflectance of visible wavelengths is
Radarsat Antarctic Mapping Project Digital Elevation Model, Version 2

Data.gov (United States)

National Aeronautics and Space Administration — The high-resolution Radarsat Antarctic Mapping Project (RAMP) Digital Elevation Model (DEM) combines topographic data from a variety of sources to provide consistent...
A tutela da fauna silvestre como efetivação do direito fundamental ao meio ambiente

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Emerson Bortolozi

2018-03-01

Full Text Available Esta pesquisa tem por objeto a análise da efetivação do direito fundamental ao meio ambiente sob a ótica da tutela à fauna silvestre, com base na Constituição Federal e em normas infraconstitucionais. Como se sabe, a Constituição de 1988 é um marco importantíssimo na evolução da defesa jurídica do meio ambiente, tendo desencadeado o surgimento de uma ampla legislação voltada à defesa de valores ambientais e, particularmente, da fauna silvestre. A partir da ótica constitucional e da legislação de proteção à fauna silvestre, como a Lei que cria Política Nacional do Meio Ambiente, a Lei que cria o Sistema Nacional de Unidades de Conservação – SNUC, a Lei de Uso Científico de Animais, a Lei de Rodeios e, em especial, a Lei de Proteção à Fauna, que foi recepcionada pela Constituição, é que se compõe o arsenal de ferramentas jurídicas que realizam a efetivação do direito fundamental ao meio ambiente animal. Por meio desse exame, identifica-se que a tutela da fauna silvestre acaba significando forma de efetivação do direito fundamental ao Meio Ambiente
Antarctic ozone loss in 1989-2010: evidence for ozone recovery?

Science.gov (United States)

Kuttippurath, J.; Lefèvre, F.; Pommereau, J.-P.; Roscoe, H. K.; Goutail, F.; Pazmiño, A.; Shanklin, J. D.

2012-04-01

We present a detailed estimation of chemical ozone loss in the Antarctic polar vortex from 1989 to 2010. The analyses include ozone loss estimates for 12 Antarctic ground-based (GB) stations. All GB observations show minimum ozone in the late September-early October period. Among the stations, the lowest minimum ozone values are observed at South Pole and the highest at Dumont d'Urville. The ozone loss starts by mid-June at the vortex edge and then progresses towards the vortex core with time. The loss intensifies in August-September, peaks by the end of September-early October, and recovers thereafter. The average ozone loss in the Antarctic is revealed to be about 33-50% in 1989-1992 in agreement with the increase in halogens during this period, and then stayed at around 48% due to saturation of the loss. The ozone loss in the warmer winters (e.g. 2002, and 2004) is lower (37-46%) and in the colder winters (e.g. 2003, and 2006) is higher (52-55%). Because of small inter-annual variability, the correlation between ozone loss and the volume of polar stratospheric clouds yields ~0.51. The GB ozone and ozone loss values are in good agreement with those found from the space-based observations of the Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), the Global Ozone Monitoring Experiment (GOME), the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and the Aura Microwave Limb Sounder (MLS), where the differences are within ±5% and are mostly within the error bars of the measurements. The piece-wise linear trends computed from the September-November vortex average GB and TOMS/OMI ozone show about -4 to -5.6 DU (Dobson Unit) yr-1 in 1989-1996 and about +1 DU yr-1 in 1997-2010. The trend during the former period is significant at 95% confidence intervals, but the trend in 1997-2010 is significant only at 85% confidence intervals. Our analyses suggest a period of about 9-10 yr to get the first detectable ozone
Reconciling projections of the Antarctic contribution to sea level rise

Science.gov (United States)

Edwards, Tamsin; Holden, Philip; Edwards, Neil; Wernecke, Andreas

2017-04-01

Two recent studies of the Antarctic contribution to sea level rise this century had best estimates that differed by an order of magnitude (around 10 cm and 1 m by 2100). The first, Ritz et al. (2015), used a model calibrated with satellite data, giving a 5% probability of exceeding 30cm by 2100 for sea level rise due to Antarctic instability. The second, DeConto and Pollard (2016), used a model evaluated with reconstructions of palaeo-sea level. They did not estimate probabilities, but using a simple assumption here about the distribution shape gives up to a 5% chance of Antarctic contribution exceeding 2.3 m this century with total sea level rise approaching 3 m. If robust, this would have very substantial implications for global adaptation to climate change. How are we to make sense of this apparent inconsistency? How much is down to the data - does the past tell us we will face widespread and rapid Antarctic ice losses in the future? How much is due to the mechanism of rapid ice loss ('cliff failure') proposed in the latter paper, or other parameterisation choices in these low resolution models (GRISLI and PISM, respectively)? How much is due to choices made in the ensemble design and calibration? How do these projections compare with high resolution, grounding line resolving models such as BISICLES? Could we reduce the huge uncertainties in the palaeo-study? Emulation provides a powerful tool for understanding these questions and reconciling the projections. By describing the three numerical ice sheet models with statistical models, we can re-analyse the ensembles and re-do the calibrations under a common statistical framework. This reduces uncertainty in the PISM study because it allows massive sampling of the parameter space, which reduces the sensitivity to reconstructed palaeo-sea level values and also narrows the probability intervals because the simple assumption about distribution shape above is no longer needed. We present reconciled probabilistic
Impacts of the north and tropical Atlantic Ocean on the Antarctic Peninsula and sea ice.

Science.gov (United States)

Li, Xichen; Holland, David M; Gerber, Edwin P; Yoo, Changhyun

2014-01-23

In recent decades, Antarctica has experienced pronounced climate changes. The Antarctic Peninsula exhibited the strongest warming of any region on the planet, causing rapid changes in land ice. Additionally, in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not declined, but has instead undergone a perplexing redistribution. Antarctic climate is influenced by, among other factors, changes in radiative forcing and remote Pacific climate variability, but none explains the observed Antarctic Peninsula warming or the sea-ice redistribution in austral winter. However, in the north and tropical Atlantic Ocean, the Atlantic Multidecadal Oscillation (a leading mode of sea surface temperature variability) has been overlooked in this context. Here we show that sea surface warming related to the Atlantic Multidecadal Oscillation reduces the surface pressure in the Amundsen Sea and contributes to the observed dipole-like sea-ice redistribution between the Ross and Amundsen-Bellingshausen-Weddell seas and to the Antarctic Peninsula warming. Support for these findings comes from analysis of observational and reanalysis data, and independently from both comprehensive and idealized atmospheric model simulations. We suggest that the north and tropical Atlantic is important for projections of future climate change in Antarctica, and has the potential to affect the global thermohaline circulation and sea-level change.
Temperature effects on hemocyanin oxygen binding in an antarctic cephalopod.

Science.gov (United States)

Zielinski, S; Sartoris, F J; Pörtner, H O

2001-02-01

The functional relevance of oxygen transport by hemocyanin of the Antarctic octopod Megaleledone senoi and of the eurythermal cuttlefish Sepia officinalis was analyzed by continuous and simultaneous recordings of changes in pH and hemocyanin oxygen saturation in whole blood at various temperatures. These data were compared to literature data on other temperate and cold-water cephalopods (octopods and giant squid). In S. officinalis, the oxygen affinity of hemocyanin changed at deltaP50/degrees C = 0.12 kPa (pH 7.4) with increasing temperatures; this is similar to observations in temperate octopods. In M. senoi, thermal sensitivity was much smaller (delta log P50/delta pH) increased with increasing temperature in both the cuttlefish and the Antarctic octopod. At low PO2 (1.0 kPa) and pH (7.2), the presence of a large venous oxygen reserve (43% saturation) insensitive to pH reflects reduced pH sensitivity and high oxygen affinity in M. senoi hemocyanin at 0 degrees C. In S. officinalis, this reserve was 19% at pH 7.4, 20 degrees C, and 1.7 kPa O2, a level still higher than in squid. These findings suggest that the lower metabolic rate of octopods and cuttlefish compared to squid is reflected in less pH-dependent oxygen transport. Results of the hemocyanin analysis for the Antarctic octopod were similar to those reported for Vampyroteuthis--an extremely high oxygen affinity supporting a very low metabolic rate. In contrast to findings in cold-adapted giant squid, the minimized thermal sensitivity of oxygen transport in Antarctic octopods will reduce metabolic scope and thereby contribute to their stenothermality.

UV effects on bottom ice algae

International Nuclear Information System (INIS)

Ryan, K.; Buckley, B.

1993-01-01

Antarctic sea ice can be surprisingly transparent to UV radiation, particularly during spring when ozone depletion reaches a maximum. A 5% reduction in photosynthetic production was observed in laboratory experiments for UVB levels expected under the ice at this time. In situ studies modifying the UVB radiation falling onto algae were inconclusive. (author). 5 refs
Peatland Ecosystem Processes in the Maritime Antarctic During Warm Climates.

Science.gov (United States)

Loisel, Julie; Yu, Zicheng; Beilman, David W; Kaiser, Karl; Parnikoza, Ivan

2017-09-27

We discovered a 50-cm-thick peat deposit near Cape Rasmussen (65.2°S), in the maritime Antarctic. To our knowledge, while aerobic 'moss banks' have often been examined, waterlogged 'peatlands' have never been described in this region before. The waterlogged system is approximately 100 m 2 , with a shallow water table. Surface vegetation is dominated by Warnstorfia fontinaliopsis, a wet-adapted moss commonly found in the Antarctic Peninsula. Peat inception was dated at 2750 cal. BP and was followed by relatively rapid peat accumulation (~0.1 cm/year) until 2150 cal. BP. Our multi-proxy analysis then shows a 2000-year-long stratigraphic hiatus as well as the recent resurgence of peat accumulation, sometime after 1950 AD. The existence of a thriving peatland at 2700-2150 cal. BP implies regionally warm summer conditions extending beyond the mid-Holocene; this finding is corroborated by many regional records showing moss bank initiation and decreased sea ice extent during this time period. Recent peatland recovery at the study site (maritime Antarctic region may promote a more peatland-rich landscape in the future.
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...
Improved simulation of Antarctic sea ice due to the radiative effects of falling snow

Science.gov (United States)

Li, J.-L. F.; Richardson, Mark; Hong, Yulan; Lee, Wei-Liang; Wang, Yi-Hui; Yu, Jia-Yuh; Fetzer, Eric; Stephens, Graeme; Liu, Yinghui

2017-08-01

Southern Ocean sea-ice cover exerts critical control on local albedo and Antarctic precipitation, but simulated Antarctic sea-ice concentration commonly disagrees with observations. Here we show that the radiative effects of precipitating ice (falling snow) contribute substantially to this discrepancy. Many models exclude these radiative effects, so they underestimate both shortwave albedo and downward longwave radiation. Using two simulations with the climate model CESM1, we show that including falling-snow radiative effects improves the simulations relative to cloud properties from CloudSat-CALIPSO, radiation from CERES-EBAF and sea-ice concentration from passive microwave sensors. From 50-70°S, the simulated sea-ice-area bias is reduced by 2.12 × 106 km2 (55%) in winter and by 1.17 × 106 km2 (39%) in summer, mainly because increased wintertime longwave heating restricts sea-ice growth and so reduces summer albedo. Improved Antarctic sea-ice simulations will increase confidence in projected Antarctic sea level contributions and changes in global warming driven by long-term changes in Southern Ocean feedbacks.
Persistent organochlorines in high-Antarctic fish; Persistente chlororganische Verbindungen in hochantarktischen Fischen

Energy Technology Data Exchange (ETDEWEB)

Zimmermann, S.

1997-11-01

24 chlorinated hydrocarbons from different classes (PCB, HCH, DDT, Chlordane, Hexachlorobenzene and Octachlorostyrene) were analyzed in four species of high-Antarctic fish (Aethotaxis mitopteryx, Pleuragramma antarcticum, Trematomus lepidorhinus, and Chinodraco myersi). The concentrations were in the order of 1 {mu}g/kg wet weight or 10 {mu}g/kg lipid weight, respectively. Highest concentrations were measured for HCB in all species. The species showed different distribution patterns for the organochlorines studied. Compared with concentrations in fish from other regions the organochlorine levels measured in Antarctic fish are rather low. It is unlikely that the burden of organochlorines will cause any toxic effects in high-Antarctic fish yet. Nevertheless, with regard to the sensitive Antarctic ecosystem, even small concentrations carry a high risk of harm for Antarctic life. Environmental pollution in Antarctica should be observed with a monitoring program using standardized methods. For this purpose, the fish species studied are very useful as bioindicators for organochlorine contamination. (orig.) [Deutsch] 24 persistente Chlorkohlenwasserstoffe verschiedener Schadstoffgruppen (PCB, HCH, DDT, Chlordan, Hexachlorbenzol und Octachlorstyrol) wurden in vier hochantarktischen Fischarten (Aethotaxis mitopteryx, Pleuragramma antarcticum, Trematomus lepidorhinus und Chionodraco myersi). Die Konzentrationen der nachgewiesenen Schadstoffe im Ganzfisch liegen jeweils in der Groessenordnung von 1 {mu}g/kg Feuchtgewicht bzw. 10 {mu}g/kg Lipidgewicht mit erheblichen Schwankungen je nach Schadstoff und Art. Die Spezies zeigen artspezifische Schadstoffverteilungsmuster. Die Konzentrationen sind gegenueber denen in Fischen aus Gebieten mit staerkerem zivilisatorischem Einfluss eher niedrig. Die Fremstoffbelastungen der hochantarktischen Fische fuehren wahrscheinlich noch nicht zu messbaren toxischen Effekten bei den Fischen. Dennoch geht von den Schadstoffen in Hinblick auf das
Modeling Antarctic Ice Sheet retreat in warm climates: a historical perspective.

Science.gov (United States)

Pollard, D.; Deconto, R. M.; Gasson, E.

2016-12-01

Early modeling of Antarctic Ice Sheet size vs. climate focused on asymmetry between retreat and growth, with much greater warming needed to cause retreat from full ice cover, due to Height Mass Balance Feedback and albedo feedback. This led to a long-standing model-data conflict, with models needing 1000 to2000 ppmv atmospheric CO2 to produce retreat from full size, vs. proxy data of large ice fluctuations despite much lower CO2 since the Miocene.Subsequent modeling with marine ice physics found that the West Antarctic Ice Sheet could undergo repeated warm-period collapses with realistic past forcing. However, that yields only 3 to 7 m equivalent sea-level rise above modern, compared to 10 to 20 m or more suggested by some geologic data. Large subglacial basins in East Antarctica could be vulnerable to the same processes,but did not retreat in most models due to narrower and shallower sills.After recent modifications, some ice sheet models were able to produce warm-period collapse of major East Antarctic basins, with sea-level rise of up to 15 m. The modifications are (i) hydrofracturing by surface melt, and structural failure of ice cliffs, or (ii) numerical treatment at the grounding line. In these models, large retreat occurs both for past warmintervals, and also for future business-as-usual scenarios.Some interpretations of data in the late Oligocene and Miocene suggest yet larger fluctuations, between 50 to 100% of modern Antarctic size. That would require surface-melt driven retreat of some terrestrial East Antarctic ice, despite the hysteresis issue raised above. A recent study using a coupled climate-ice sheet model found that with a finer climate gridand more frequent coupling exchange, substantial retreat of terrestrial Antarctica can occur with 500 to 840 ppmv CO2, much lower than in earlier models. This will allow meaningful interactions between modeling and deeper-time geologic interpretations since the late Oligocene.
The effect of soil fauna on carbon sequestration in soil

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Pižl, Václav; Kaneda, Satoshi; Šimek, Miloslav

2008-01-01

Roč. 10, - (2008) ISSN 1029-7006. [EGU General Assembly 2008. 13.04.2008-18.04.2008, Vienna] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil fauna * carbon sequestration * soil Subject RIV: EH - Ecology, Behaviour
Modelling the effects of environmental conditions on the acoustic occurrence and behaviour of Antarctic blue whales.

Directory of Open Access Journals (Sweden)

Fannie W Shabangu

Full Text Available Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC, latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of
Modelling the effects of environmental conditions on the acoustic occurrence and behaviour of Antarctic blue whales.

Science.gov (United States)

Shabangu, Fannie W; Yemane, Dawit; Stafford, Kathleen M; Ensor, Paul; Findlay, Ken P

2017-01-01

Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC), latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a) were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of Antarctic blue whales is
The Effects of Interactive Stratospheric Chemistry on Antarctic and Southern Ocean Climate Change in an AOGCM

Science.gov (United States)

Li, Feng; Newman, Paul; Pawson, Steven; Waugh, Darryn

2014-01-01

Stratospheric ozone depletion has played a dominant role in driving Antarctic climate change in the last decades. In order to capture the stratospheric ozone forcing, many coupled atmosphere-ocean general circulation models (AOGCMs) prescribe the Antarctic ozone hole using monthly and zonally averaged ozone field. However, the prescribed ozone hole has a high ozone bias and lacks zonal asymmetry. The impacts of these biases on model simulations, particularly on Southern Ocean and the Antarctic sea ice, are not well understood. The purpose of this study is to determine the effects of using interactive stratospheric chemistry instead of prescribed ozone on Antarctic and Southern Ocean climate change in an AOGCM. We compare two sets of ensemble simulations for the 1960-2010 period using different versions of the Goddard Earth Observing System 5 - AOGCM: one with interactive stratospheric chemistry, and the other with prescribed monthly and zonally averaged ozone and 6 other stratospheric radiative species calculated from the interactive chemistry simulations. Consistent with previous studies using prescribed sea surface temperatures and sea ice concentrations, the interactive chemistry runs simulate a deeper Antarctic ozone hole and consistently larger changes in surface pressure and winds than the prescribed ozone runs. The use of a coupled atmosphere-ocean model in this study enables us to determine the impact of these surface changes on Southern Ocean circulation and Antarctic sea ice. The larger surface wind trends in the interactive chemistry case lead to larger Southern Ocean circulation trends with stronger changes in northerly and westerly surface flow near the Antarctica continent and stronger upwelling near 60S. Using interactive chemistry also simulates a larger decrease of sea ice concentrations. Our results highlight the importance of using interactive chemistry in order to correctly capture the influences of stratospheric ozone depletion on climate
Penguin eggshell membranes reflect homogeneity of mercury in the marine food web surrounding the Antarctic Peninsula

International Nuclear Information System (INIS)

Brasso, Rebecka L.; Polito, Michael J.; Lynch, Heather J.; Naveen, R.; Emslie, Steven D.

2012-01-01

Remote regions such as the Antarctic have become increasingly important for investigations into far-reaching anthropogenic impacts on the environment, most recently in regard to the global mercury cycle. Spatial patterns of mercury availability in four regions of the Antarctic Peninsula were investigated using three species of sympatrically breeding Pygoscelis penguins as biomonitors. Eggshells with intact membranes from Adélie, Gentoo, and Chinstrap penguins were collected at 24 breeding colonies in the South Orkney Islands, South Shetland Islands, eastern Antarctic Peninsula, and western Antarctic Peninsula during the 2006/2007 austral summer. In addition, we compared eggshell membrane mercury concentrations with eggshell stable isotope values (δ 15 N and δ 13 C) to determine if species-specific trophic or foraging habitat preferences influenced female mercury exposure prior to breeding. With few exceptions, mercury concentrations were found to be fairly homogeneous throughout the Antarctic Peninsula suggesting little spatial variation in the risk of exposure to dietary mercury in this food web. Mercury concentrations in Gentoo and Adélie penguins were similar while Chinstrap penguins tended to have higher eggshell membrane mercury concentrations than their congeners. However, inter and intra-specific differences in eggshell membrane mercury concentration were not related to eggshell δ 15 N or δ 13 C values, a likely result of all three species foraging at similar trophic positions. The lack of regional-scale differences in mercury availability in this marine ecosystem may be a reflection of generally uniform atmospheric deposition and upwelling of regionally homogeneous deep water rather than from geographically distinct point sources. -- Highlights: ► We examined regional patterns of mercury availability in the Antarctic Peninsula. ► Three species of Pygoscelis penguins were used as biomonitors. ► Chinstrap penguins tended to have higher mercury
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.
Tightened constraints on the time-lag between Antarctic temperature and CO2 during the last deglaciation

Directory of Open Access Journals (Sweden)

T. D. van Ommen

2012-07-01

Full Text Available Antarctic ice cores provide clear evidence of a close coupling between variations in Antarctic temperature and the atmospheric concentration of CO2 during the glacial/interglacial cycles of at least the past 800-thousand years. Precise information on the relative timing of the temperature and CO2 changes can assist in refining our understanding of the physical processes involved in this coupling. Here, we focus on the last deglaciation, 19 000 to 11 000 yr before present, during which CO2 concentrations increased by ~80 parts per million by volume and Antarctic temperature increased by ~10 °C. Utilising a recently developed proxy for regional Antarctic temperature, derived from five near-coastal ice cores and two ice core CO2 records with high dating precision, we show that the increase in CO2 likely lagged the increase in regional Antarctic temperature by less than 400 yr and that even a short lead of CO2 over temperature cannot be excluded. This result, consistent for both CO2 records, implies a faster coupling between temperature and CO2 than previous estimates, which had permitted up to millennial-scale lags.
RARE COMPONENT OF THE FISH FAUNA OF THE 'SULINSKY' NATIONAL LANDSCAPE RESERVE

Directory of Open Access Journals (Sweden)

N. Ja. Rudik-Leuska

2014-06-01

Full Text Available Maintenance of biological diversity is the main task of modern biology. At the legislative level, Ukraine has pledged its support in ratifying the "Convention on the conservation of biological diversity." As part of the implementation of environmental policy in Ukraine preservation of rare fish fauna component is the most problematic aspect. The basic conservation lists acting in Ukraine are: Red List of threatened animals of the International Union for Conservation of Nature, Ukrainian Red Book, Annex III of the "Convention on the Protection of wildlife and natural habitats", the Convention on International Trade in Endangered Species of Wild Fauna and Flora, CITES, Washington, 1973. On the territory of Sula Bay located two objects of nature reserve fund - a landscape national reserve "Sulinsky" and National Park "Nizhnesulsky" that emphasizes the importance of this area for fish fauna reproduction. Its territory are spawning areas for almost all lower and middle parts of the Kremenchuk reservoir, ensuring more than half of total commercial catch of the Dnieper cascade. The article describes the species composition of the fish fauna, introduced in protected lists of different levels. The existence of seven such species was established. They belong to four families: four species - for cyprinids and one each - to sturgeon, loaches and catfishes. But we must remember that the priority activities should concern species with the highest conservation status. At the same time, four of them are only protected by Annex III of the "Convention on the Protection of wildlife and natural habitats" as poorly studied. These species require a more thorough study and not necessarily threatened with extinction. Remaining three species are under a real danger of extinction and are protected by the IUCN Red List and Ukrainian Red Book. Starlet also protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, CITES. Environmental
In-situ aircraft observations of ice concentrations within clouds over the Antarctic Peninsula and Larsen Ice Shelf

OpenAIRE

Grosvenor, D. P.; Choularton, T. W.; Lachlan-Cope, T.; Gallagher, M. W.; Crosier, J.; Bower, K. N.; Ladkin, R. S.; Dorsey, J. R.

2012-01-01

In-situ aircraft observations of ice crystal concentrations in Antarctic clouds are presented for the first time. Orographic, layer and wave clouds around the Antarctic Peninsula and Larsen Ice shelf regions were penetrated by the British Antarctic Survey's Twin Otter aircraft, which was equipped with modern cloud physics probes. The clouds studied were mostly in the free troposphere and hence ice crystals blown from the surface are unlikely to have been a major source for the ice phas...
Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

Energy Technology Data Exchange (ETDEWEB)

Jerez, Silvia [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Motas, Miguel, E-mail: motas@um.es [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Palacios, Maria Jose; Valera, Francisco [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Cuervo, Jose Javier; Barbosa, Andres [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, C/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

2011-10-15

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 {mu}g g{sup -1} dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 {mu}g g{sup -1} dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: > We study levels of trace elements in feathers of Antarctic penguins. > Eight different rookeries throughout the Antarctic Peninsula were sampled. > Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. > Relatively high metal levels were found in areas with major human presence. > Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.
Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

International Nuclear Information System (INIS)

Jerez, Silvia; Motas, Miguel; Palacios, Maria Jose; Valera, Francisco; Cuervo, Jose Javier; Barbosa, Andres

2011-01-01

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g -1 dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g -1 dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: → We study levels of trace elements in feathers of Antarctic penguins. → Eight different rookeries throughout the Antarctic Peninsula were sampled. → Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. → Relatively high metal levels were found in areas with major human presence. → Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.
Contrasting patterns in lichen diversity in the continental and maritime Antarctic

Science.gov (United States)

Singh, Shiv Mohan; Olech, Maria; Cannone, Nicoletta; Convey, Peter

2015-09-01

Systematic surveys of the lichen floras of Schirmacher Oasis (Queen Maud Land, continental Antarctic), Victoria Land (Ross Sector, continental Antarctic) and Admiralty Bay (South Shetland Islands, maritime Antarctic) were compared to help infer the major factors influencing patterns of diversity and biogeography in the three areas. Biogeographic patterns were determined using a variety of multivariate statistical tools. A total of 54 lichen species were documented from Schirmacher Oasis (SO), 48 from Victoria Land (VL) and 244 from Admiralty Bay (AB). Of these, 21 species were common to all areas. Most lichens from the SO and VL areas were microlichens, the dominant genus being Buellia. In AB, in contrast, many macrolichens were also present and the dominant genus was Caloplaca. In SO and VL large areas lacked any visible lichen cover, even where the ground was snow-free in summer. Small-scale diversity patterns were present in AB, where the number of species and genera was greater close to the coast. Most species recorded were rare in the study areas in which they were present and endemic to Antarctica.
The changing form of Antarctic biodiversity

OpenAIRE

Chown, Steven L.; Clarke, Andrew; Fraser, Ceridwen I.; Cary, S. Craig; Moon, Katherine L.; McGeoch, Melodie A.

2015-01-01

Antarctic biodiversity is much more extensive, ecologically diverse and biogeographically structured than previously thought. Understanding of how this diversity is distributed in marine and terrestrial systems, the mechanisms underlying its spatial variation, and the significance of the microbiota is growing rapidly. Broadly recognizable drivers of diversity variation include energy availability and historical refugia. The impacts of local human activities and global environmental change non...
Evaluación del riesgo de las carreteras nacionales para la fauna silvestre y el uso de ciencia ciudadana como herramienta para el monitoreo de fauna silvestre atropellada en Costa Rica

OpenAIRE

Gutiérrez Sanabria, Diego R.

2017-01-01

Evalua el riesgo de las carreteras nacionales para la fauna silvestre y el uso de ciencia ciudadana como herramienta para el monitoreo de fauna silvestre atropellada en Costa Rica. A partir de ahí se desarrolló y evaluó el uso de una aplicación informática en una plataforma web ya existente, para ser usado por cualquier smartphone, lo cual, representa una propuesta innovadora y por último, se usaron datos provenientes de esta aplicación, con una de las especies que más registros de atropellos...

Effect of different temperature regimes on the chlorophyll a concentration in four species of Antarctic macroalgae

Digital Repository Service at National Institute of Oceanography (India)

Dhargalkar, V.K.

th Symp. on Polar Biology, Nat. Inst. Pf Polar Research. Tokyo. Mem. natn. lnst. polar Res. Tokyo(Spec.Issue).32: l12-116. Papenfuss, G. F. 1964. Catalogue and bibliography of Antarctic and sub- antarctic benthic marine algae. Am. Geophys. Union...
ARM West Antarctic Radiation Experiment (AWARE) Science Plan

Energy Technology Data Exchange (ETDEWEB)

Lubin, D [National Science Foundation; Bromwich, DH [Ohio State University; Russell, LM [Scripps Institution of Oceanography; Verlinde, J [The Pennsylvania State University; Vogelmann, AM [Brookhaven National Laboratory

2015-10-01

West Antarctica is one of the most rapidly warming regions on Earth, and this warming is closely connected with global sea level rise. The discovery of rapid climate change on the West Antarctic Ice Sheet (WAIS) has challenged previous explanations of Antarctic climate change that focused on strengthening of circumpolar westerlies in response to the positive polarity trend in the Southern Annular Mode. West Antarctic warming does not yet have a comprehensive explanation: dynamical mechanisms may vary from one season to the next, and these mechanisms very likely involve complex teleconnections with subtropical and tropical latitudes. The prime motivation for this proposal is that there has been no substantial atmospheric science or climatological field work on West Antarctica since the 1957 International Geophysical Year and that research continued for only a few years. Direct meteorological information on the WAIS has been limited to a few automatic weather stations for several decades, yet satellite imagery and meteorological reanalyses indicate that West Antarctica is highly susceptible to advection of warm and moist maritime air with related cloud cover, depending on the location and strength of low pressure cells in the Amundsen, Ross, and Bellingshausen Seas. There is a need to quantify the role of these changing air masses on the surface energy balance, including all surface energy components and cloud-radiative forcing. More generally, global climate model simulations are known to perform poorly over the Antarctic and Southern Oceans, and the marked scarcity of cloud information at southern high latitudes has so far inhibited significant progress. Fortunately, McMurdo Station, where the Atmospheric Radiation Measurement Facility’s (ARM’s) most advanced cloud and aerosol instrumentation is situated, has a meteorological relationship with the WAIS via circulation patterns in the Ross and Amundsen Seas. We can therefore gather sophisticated data with cloud
Efeito de restos da cultura do abacaxizeiro e de agrobio na fauna do solo Effect of residues of pineaplle plant and agrobio in the soil fauna

Directory of Open Access Journals (Sweden)

Alecsandra de Almeida

2010-12-01

Full Text Available Objetivou-se avaliar o efeito de restos culturais de abacaxizeiro (Ananas comosus L. 'Smooth Cayenne' na fauna de artrópodes,em cultivos em campo. As mudas, do tipo filhote, foram plantadas no mês de junho, em um Latossolo Vermelho Amarelo, que recebeu 0, 30 e 60t/ha de restos de abacaxizeiro, aplicados superficialmente e incorporados a 10cm de profundidade, com e sem a adição do biofertilizante-Agrobio10% (v/v. Foram coletadas amostras a 05 cm de profundidade aos 90, 210, 330 e 450 dias após a aplicação dos resíduos. Identificou-se, durante os 15 meses de avaliações, o predomínio de Acari e Collembola. A maior densidade de animais foi observada na primeira amostragem, aos 90 dias após a adição dos restos. No entanto, diferenças na abundância da fauna de solo só foram observadas, 330 dias após a adição dos resíduos.This study was conducted under field conditions, in order to determine the effect of pineapple crop (Ananas comosus L. residues on the edaphic arthropod fauna. Slips were planted in June, in Red-Yellow Latossol , with crop residues in amounts of 0, 30 and 60 t/ha, placed on the surface or tilled under 10cm, with and without 10% (v/v Agrobio biofertilizer applied along with the residues and sprayed monthly at 3% (v/v two months after planting. Soil samples were collected from the top 5.0 cm of soil at 90, 210, 330 and 450 days after the application of residues. Over 15 months, the predominance of Acari and Collembolan was observed. The highest density of animals was observed in the first sample, at 90 days after the addition of residues. Nevertheless, differences in soil fauna abundance between treatments were not detected until 330 days after soil management with crop residues.
Toxicity of fuel-contaminated soil to Antarctic moss and terrestrial algae.

Science.gov (United States)

Nydahl, Anna C; King, Catherine K; Wasley, Jane; Jolley, Dianne F; Robinson, Sharon A

2015-09-01

Fuel pollution is a significant problem in Antarctica, especially in areas where human activities occur, such as at scientific research stations. Despite this, there is little information on the effects of petroleum hydrocarbons on Antarctic terrestrial biota. The authors demonstrate that the Antarctic mosses Bryum pseudotriquetrum, Schistidium antarctici, and Ceratodon purpureus, and the Antarctic terrestrial alga Prasiola crispa are relatively tolerant to Special Antarctic Blend (SAB) fuel-contaminated soil (measured as total petroleum hydrocarbons). Freshly spiked soils were more toxic to all species than were aged soils containing degraded fuel, as measured by photosynthetic efficiency (variable fluorescence/maximum fluorescence [Fv/Fm]), pigment content, and visual observations. Concentrations that caused 20% inhibition ranged from 16,600 mg/kg to 53,200 mg/kg for freshly spiked soils and from 30,100 mg/kg to 56,200 mg/kg for aged soils. The photosynthetic efficiency of C. purpureus and S. antarctici was significantly inhibited by exposure to freshly spiked soils with lowest-observed-effect concentrations of 27,900 mg/kg and 40,400 mg/kg, respectively. Prasiola crispa was the most sensitive species to freshly spiked soils (Fv/Fm lowest-observed-effect concentration 6700 mg/kg), whereas the Fv/Fm of B. pseudotriquetrum was unaffected by exposure to SAB fuel even at the highest concentration tested (62,900 mg/kg). Standard toxicity test methods developed for nonvascular plants can be used in future risk assessments, and sensitivity data will contribute to the development of remediation targets for petroleum hydrocarbons to guide remediation activities in Antarctica. © 2015 SETAC.
Levels of essential and potentially toxic trace metals in Antarctic macro algae

International Nuclear Information System (INIS)

Farias, Silvia; Arisnabarreta, Sebastian Perez; Vodopivez, Cristian; Smichowski, Patricia

2002-01-01

Eleven species of Antarctic algae were examined for their accumulation ability in the uptake of different metals and metalloids from the Antarctic aquatic environment. Macro algae were collected during the 2000 austral summer season at Jubany Station (Argentinean base) around Potter Cove, King George Island. The elements quantified were: As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr, V, and Zn. An optimized microwave-assisted digestion procedure was used to digest the samples and the elements were determined by inductively coupled plasma optical emission spectrometry. A wide range of metal retention capacity among the different species was observed. The highest levels of trace elements were found in Monostroma hariotii and Phaeurus antarcticus, with concentrations up to 3095 μg g -1 for Fe. On the basis of the levels of trace elements observed in Monostroma hariotii and its wide distribution in the Antarctic Peninsula, this organism accomplishes a number of prerequisites to be considered as an adequate biomonitor for future studies
Movement of Trace Elements During Residence in the Antarctic Ice: a Laboratory Simulation

Science.gov (United States)

Strait, Melissa M.

1991-01-01

Recent work has determined that differences in the trace element distribution between Antarctic eucrites and non-Antarctic eucrites may be due to weathering during residence in the ice, and samples that demonstrate trace element disturbances do not necessarily correspond to eucrites that appear badly weathered to the naked eye. This study constitutes a preliminary test of the idea that long-term residence in the ice is the cause of the trace element disturbances observed in the eucrites. Samples of a non-Antarctic eucrite were leached in water at room temperature conditions. Liquid samples were analyzed for rare earth element abundances using ion chromatography. The results for the short-term study showed little or no evidence that leaching had occurred. However, there were tantalizing hints that something may be happening. The residual solid samples are currently being analyzed for the unleached trace metals using instrumental neutron activation analysis and should show evidence of disturbance if the chromatography clues were real. In addition, another set of samples continues to be intermittently sampled for later analysis. The results should give us information about the movement of trace elements under our conditions and allow us to make some tentative extrapolations to what we observe in actual Antarctic eucrite samples.
Brucella antibody seroprevalence in Antarctic seals (Arctocephalus gazella, Leptonychotes weddellii and Mirounga leonina).

Science.gov (United States)

Jensen, Silje-Kristin; Nymo, Ingebjørg Helena; Forcada, Jaume; Hall, Ailsa; Godfroid, Jacques

2013-09-03

Brucellosis is a worldwide infectious zoonotic disease caused by Gram-negative bacteria of the genus Brucella, and Brucella infections in marine mammals were first reported in 1994. A serosurvey investigating the presence of anti-Brucella antibodies in 3 Antarctic pinniped species was undertaken with a protein A/G indirect enzyme-linked immunosorbent assay (iELISA) and the Rose Bengal test (RBT). Serum samples from 33 Weddell seals Leptonychotes weddelli were analysed, and antibodies were detected in 8 individuals (24.2%) with the iELISA and in 21 (65.6%) with the RBT. We tested 48 southern elephant seal Mirounga leonina sera and detected antibodies in 2 animals (4.7%) with both the iELISA and the RBT. None of the 21 Antarctic fur seals Arctocephalus gazella was found positive. This is the first report of anti-Brucella antibodies in southern elephant seals. The potential impact of Brucella infection in pinnipeds in Antarctica is not known, but Brucella spp. are known to cause abortion in terrestrial species and cetaceans. Our findings suggest that Brucella infection in pinnipeds is present in the Antarctic, but to date B. pinnipedialis has not been isolated from any Antarctic pinniped species, leaving the confirmation of infection pending.
A Comparative Study of the Soil Fauna in forests and cultivated land on sandy soils in Suriname

NARCIS (Netherlands)

Drift, van der J.

1963-01-01

1. In the coastal area of Suriname the soil and surface fauna were studied in various types of agricultural land, and compared with the fauna in the adjacent forests. 2. In primeval forest the soil macroarthropods are less numerous than in secondary forest (Formicidae excluded). They range generally
Pressing technology for large bottoms

International Nuclear Information System (INIS)

Jilek, L.

1986-01-01

The technology has been selected of a circular plate bent into the shape of a trough, for pressing bottoms of pressure vessels from a circular plate of large diameter. The initial sheet is first bent in the middle by heating with the edges remaining straight. These are then welded longitudinally by electroslag welding and the circular shape is flame cut. The result will be a plate with a straight surface in the middle with raised edges which may be pressed into the desired shape. In this manner it is also possible to press pressure vessel bottoms with tube couplings from plates which are thickened in the middle and drilled; additional welding is then eliminated. Deformation from heat treatment may be avoided by the use of a fixture in the shape of a ring with a groove into which is fixed the edge of the bottom. During hardening of the bottom it will be necessary to care for the withdrawal of vapours and gases which would hamper uniform cooling. Bottom hardening with the grill and the cupola downwards has been proven. Deformation which occurs during treatment may to a certain extent be removed by calibration which cannot, however, be made without special fixtures and instruments. (J.B.)
Law 16.518 Antarctic Treaty: approve the protocols about Environment protection and annex s

International Nuclear Information System (INIS)

1994-01-01

The treaty Antarctic in their appendix C in its articles is about the elimination of residuals by means of its removal of the area of having Treated Antarctic among them radioactive materials, planning of the wastes, communication treatment and exam of the plans of treatment of wastes, treatment proceeding prevention of sea contamination ,discharge of hydrocarbons petroliferous, discharge of liquid noxious substances [es
The aquatic annelid fauna of the San Marcos River headsprings, Hays County, Texas

Directory of Open Access Journals (Sweden)

McLean L.D. Worsham

2016-09-01

Full Text Available The San Marcos River in Central Texas has been well studied and has been demonstrated to be remarkably specious. Prior to the present study, research on free-living invertebrates in the San Marcos River only dealt with hard bodied taxa with the exception of the report of one gastrotrich, and one subterranean platyhelminth that only incidentally occurs in the head spring outflows. The remainder of the soft-bodied metazoan fauna that inhabit the San Marcos River had never been studied. Our study surveyed the annelid fauna and some other soft-bodied invertebrates of the San Marcos River headsprings. At least four species of Hirudinida, two species of Aphanoneura, one species of Branchiobdellida, and 11 (possibly 13 species of oligochaetous clitellates were collected. Other vermiform taxa collected included at least three species of Turbellaria and one species of Nemertea. We provide the results of the first survey of the aquatic annelid fauna of the San Marcos Springs, along with a dichotomous key to these annelids that includes photos of some representative specimens, and line drawings to elucidate potentially confusing diagnostic structures.
The aquatic annelid fauna of the San Marcos River headsprings, Hays County, Texas

Science.gov (United States)

Worsham, McLean L. D.; Gibson, Randy; Huffman, David G.

2016-01-01

Abstract The San Marcos River in Central Texas has been well studied and has been demonstrated to be remarkably specious. Prior to the present study, research on free-living invertebrates in the San Marcos River only dealt with hard bodied taxa with the exception of the report of one gastrotrich, and one subterranean platyhelminth that only incidentally occurs in the head spring outflows. The remainder of the soft-bodied metazoan fauna that inhabit the San Marcos River had never been studied. Our study surveyed the annelid fauna and some other soft-bodied invertebrates of the San Marcos River headsprings. At least four species of Hirudinida, two species of Aphanoneura, one species of Branchiobdellida, and 11 (possibly 13) species of oligochaetous clitellates were collected. Other vermiform taxa collected included at least three species of Turbellaria and one species of Nemertea. We provide the results of the first survey of the aquatic annelid fauna of the San Marcos Springs, along with a dichotomous key to these annelids that includes photos of some representative specimens, and line drawings to elucidate potentially confusing diagnostic structures. PMID:27853397
Antarctic krill 454 pyrosequencing reveals chaperone and stress transcriptome.

Directory of Open Access Journals (Sweden)

Melody S Clark

Full Text Available BACKGROUND: The Antarctic krill Euphausia superba is a keystone species in the Antarctic food chain. Not only is it a significant grazer of phytoplankton, but it is also a major food item for charismatic megafauna such as whales and seals and an important Southern Ocean fisheries crop. Ecological data suggest that this species is being affected by climate change and this will have considerable consequences for the balance of the Southern Ocean ecosystem. Hence, understanding how this organism functions is a priority area and will provide fundamental data for life history studies, energy budget calculations and food web models. METHODOLOGY/PRINCIPAL FINDINGS: The assembly of the 454 transcriptome of E. superba resulted in 22,177 contigs with an average size of 492bp (ranging between 137 and 8515bp. In depth analysis of the data revealed an extensive catalogue of the cellular chaperone systems and the major antioxidant proteins. Full length sequences were characterised for the chaperones HSP70, HSP90 and the super-oxide dismutase antioxidants, with the discovery of potentially novel duplications of these genes. The sequence data contained 41,470 microsatellites and 17,776 Single Nucleotide Polymorphisms (SNPs/INDELS, providing a resource for population and also gene function studies. CONCLUSIONS: This paper details the first 454 generated data for a pelagic Antarctic species or any pelagic crustacean globally. The classical "stress proteins", such as HSP70, HSP90, ferritin and GST were all highly expressed. These genes were shown to be over expressed in the transcriptomes of Antarctic notothenioid fish and hypothesized as adaptations to living in the cold, with the associated problems of decreased protein folding efficiency and increased vulnerability to damage by reactive oxygen species. Hence, these data will provide a major resource for future physiological work on krill, but in particular a suite of "stress" genes for studies understanding
Constraining the Antarctic contribution to interglacial sea-level rise

Science.gov (United States)

Naish, T.; Mckay, R. M.; Barrett, P. J.; Levy, R. H.; Golledge, N. R.; Deconto, R. M.; Horgan, H. J.; Dunbar, G. B.

2015-12-01

Observations, models and paleoclimate reconstructions suggest that Antarctica's marine-based ice sheets behave in an unstable manner with episodes of rapid retreat in response to warming climate. Understanding the processes involved in this "marine ice sheet instability" is key for improving estimates of Antarctic ice sheet contribution to future sea-level rise. Another motivating factor is that far-field sea-level reconstructions and ice sheet models imply global mean sea level (GMSL) was up to 20m and 10m higher, respectively, compared with present day, during the interglacials of the warm Pliocene (~4-3Ma) and Late Pleistocene (at ~400ka and 125ka). This was when atmospheric CO2 was between 280 and 400ppm and global average surface temperatures were 1- 3°C warmer, suggesting polar ice sheets are highly sensitive to relatively modest increases in climate forcing. Such magnitudes of GMSL rise not only require near complete melt of the Greenland Ice Sheet and the West Antarctic Ice Sheet, but a substantial retreat of marine-based sectors of East Antarctic Ice Sheet. Recent geological drilling initiatives on the continental margin of Antarctica from both ship- (e.g. IODP; International Ocean Discovery Program) and ice-based (e.g. ANDRILL/Antarctic Geological Drilling) platforms have provided evidence supporting retreat of marine-based ice. However, without direct access through the ice sheet to archives preserved within sub-glacial sedimentary basins, the volume and extent of ice sheet retreat during past interglacials cannot be directly constrained. Sediment cores have been successfully recovered from beneath ice shelves by the ANDRILL Program and ice streams by the WISSARD (Whillans Ice Stream Sub-glacial Access Research Drilling) Project. Together with the potential of the new RAID (Rapid Access Ice Drill) initiative, these demonstrate the technological feasibility of accessing the subglacial bed and deeper sedimentary archives. In this talk I will outline the
Full Waveform Adjoint Seismic Tomography of the Antarctic Plate

Science.gov (United States)

Lloyd, A. J.; Wiens, D.; Zhu, H.; Tromp, J.; Nyblade, A.; Anandakrishnan, S.; Aster, R. C.; Huerta, A. D.; Winberry, J. P.; Wilson, T. J.; Dalziel, I. W. D.; Hansen, S. E.; Shore, P.

2017-12-01

Recent studies investigating the response and influence of the solid Earth on the evolution of the cryosphere demonstrate the need to account for 3D rheological structure to better predict ice sheet dynamics, stability, and future sea level impact, as well as to improve glacial isostatic adjustment models and more accurately measure ice mass loss. Critical rheological properties like mantle viscosity and lithospheric thickness may be estimated from shear wave velocity models that, for Antarctica, would ideally possess regional-scale resolution extending down to at least the base of the transition zone (i.e. 670 km depth). However, current global- and continental-scale seismic velocity models are unable to obtain both the resolution and spatial coverage necessary, do not take advantage of the full set of available Antarctic data, and, in most instance, employ traditional seismic imaging techniques that utilize limited seismogram information. We utilize 3-component earthquake waveforms from almost 300 Antarctic broadband seismic stations and 26 southern mid-latitude stations from 270 earthquakes (5.5 ≤ Mw ≤ 7.0) between 2001-2003 and 2007-2016 to conduct a full-waveform adjoint inversion for Antarctica and surrounding regions of the Antarctic plate. Necessary forward and adjoint wavefield simulations are performed utilizing SPECFEM3D_GLOBE with the aid of the Texas Advanced Computing Center. We utilize phase observations from seismogram segments containing P, S, Rayleigh, and Love waves, including reflections and overtones, which are autonomously identified using FLEXWIN. The FLEXWIN analysis is carried out over a short (15-50 s) and long (initially 50-150 s) period band that target body waves, or body and surface waves, respectively. As our model is iteratively refined, the short-period corner of the long period band is gradually reduced to 25 s as the model converges over 20 linearized inversion iterations. We will briefly present this new high
Satellite gravity gradient views help reveal the Antarctic lithosphere

Science.gov (United States)

Ferraccioli, F.; Ebbing, J.; Pappa, F.; Kern, M.; Forsberg, R.

2017-12-01

Here we present and analyse satellite gravity gradient signatures derived from GOCE and superimpose these on tectonic and bedrock topography elements, as well as seismically-derived estimates of crustal thickness for the Antarctic continent. The GIU satellite gravity component images the contrast between the thinner crust and lithosphere underlying the West Antarctic Rift System and the Weddell Sea Rift System and the thicker lithosphere of East Antarctica. The new images also suggest that more distributed wide-mode lithospheric and crustal extension affects both the Ross Sea Embayment and the less well known Ross Ice Shelf segment of the rift system. However, this pattern is less clear towards the Bellingshousen Embayment, indicating that the rift system narrows towards the southern edge of the Antarctic Peninsula. In East Antarctica, the satellite gravity data provides new views into the Archean to Mesoproterozoic Terre Adelie Craton, and clearly shows the contrast wrt to the crust and lithosphere underlying both the Wilkes Subglacial Basin to the east and the Sabrina Subglacial Basin to the west. This finding augments recent interpretations of aeromagnetic and airborne gravity data over the region, suggesting that the Mawson Continent is a composite lithospheric-scale entity, which was affected by several Paleoproterozoic and Mesoproterozoic orogenic events. Thick crust is imaged beneath the Transantarctic Mountains, the Terre Adelie Craton, the Gamburtsev Subglacial Mountains and also Eastern Dronning Maud Land, in particular beneath the recently proposed region of the Tonian Oceanic Arc Superterrane. The GIA and GIU components help delineate the edges of several of these lithospheric provinces. One of the most prominent lithospheric-scale features discovered in East Antarctica from satellite gravity gradient imaging is the Trans East Antarctic Shear Zone that separates the Gamburtsev Province from the Eastern Dronning Maud Land Province and appears to form the
Antarctic sea ice losses drive gains in benthic carbon drawdown.

Science.gov (United States)

Barnes, D K A

2015-09-21

Climate forcing of sea-ice losses from the Arctic and West Antarctic are blueing the poles. These losses are accelerating, reducing Earth's albedo and increasing heat absorption. Subarctic forest (area expansion and increased growth) and ice-shelf losses (resulting in new phytoplankton blooms which are eaten by benthos) are the only significant described negative feedbacks acting to counteract the effects of increasing CO2 on a warming planet, together accounting for uptake of ∼10(7) tonnes of carbon per year. Most sea-ice loss to date has occurred over polar continental shelves, which are richly, but patchily, colonised by benthic animals. Most polar benthos feeds on microscopic algae (phytoplankton), which has shown increased blooms coincident with sea-ice losses. Here, growth responses of Antarctic shelf benthos to sea-ice losses and phytoplankton increases were investigated. Analysis of two decades of benthic collections showed strong increases in annual production of shelf seabed carbon in West Antarctic bryozoans. These were calculated to have nearly doubled to >2x10(5) tonnes of carbon per year since the 1980s. Annual production of bryozoans is median within wider Antarctic benthos, so upscaling to include other benthos (combined study species typically constitute ∼3% benthic biomass) suggests an increased drawdown of ∼2.9x10(6) tonnes of carbon per year. This drawdown could become sequestration because polar continental shelves are typically deeper than most modern iceberg scouring, bacterial breakdown rates are slow, and benthos is easily buried. To date, most sea-ice losses have been Arctic, so, if hyperboreal benthos shows a similar increase in drawdown, polar continental shelves would represent Earth's largest negative feedback to climate change. Copyright © 2015 Elsevier Ltd. All rights reserved.
Thoughts on controls on evolution and dispersal of benthos in the Magellan-Scotia Sea region: a workshop proposal

Directory of Open Access Journals (Sweden)

Michael R.A. Thomson

2005-12-01

Full Text Available The Scotia Arc and the Scotia Sea comprise a geologically young feature of the Earth’s surface that evolved over the last 40 million years (Ma or so, between the southern tip of South America and the northern tip of the Antarctic Peninsula. With the notable exception of the much younger South Sandwich Islands, the islands, banks and seamounts of the arc represent dispersed fragments of a previous continental link between southern South America (Magellan region and the Antarctic Peninsula. The benthic marine shelf faunas of the region are the focus of the IBMANT (Investigación Biolólogica Marina en Magallanes relacionada con la Antártida programme, and those of the surrounding oceanic deeps are the focus of ANDEEP (Antarctic Benthic Deep-Sea Biodiversity. Elucidating the potential relationships between the faunas of the region and the profound geographical, oceanographic and climatic changes undergone by the region in later Cenozoic time is hampered by significant unknowns in the geological history, the expense of further geoscientific exploration to fill these, and a general lack of communication between the biological and geological science communities. It is suggested that the time is opportune for a truly multidisciplinary workshop at which all the involved science communities have much to gain from the others.
Description of Pseudingolfiella possessionis n. sp. (Crustacea, Amphipoda) from sub-Antarctic Île de La Possession, Crozet archipelago: the second freshwater amphipod known from the Antarctic biome, a human introduction of Gondwanan ancestry?

Science.gov (United States)

Smet, Willem H De

2015-03-31

A new species of freshwater amphipod, Pseudingolfiella possessionis n. sp. (Senticaudata, Pseudingolfiellidae), is described from the submerged moss vegetation of small brooklets at sub-Antarctic Île de La Possession, Crozet archipelago. It constitutes the second freshwater amphipod species known for the sub-Antarctic and Antarctic region, and the fourth member of the genus. The main characters distinguishing it from all congeners are: the spine on the posterior margin of the dactylus, incisor and lamina mobilis of mandible each with 5 teeth, the setation of the maxilliped, the vestigial second article of pleopod 3 in the female, the undulate and laterally notched posterolateral margin of the external ramus of uropods 1 and 2 in the male, the spinulate dorsomedian projection of the telson.
76 FR 60933 - Antarctic Conservation Act Permit Applications

Science.gov (United States)

2011-09-30

... NATIONAL SCIENCE FOUNDATION Antarctic Conservation Act Permit Applications AGENCY: National... Conservation Act of 1978. DATES: Interested parties are invited to submit written data, comments, or views with... Regulation for conduct of a flight from South America, over the South Pole, landing at Teniente Marsh Base...

Insignificant change in Antarctic snowmelt volume since 1979

NARCIS (Netherlands)

Kuipers Munneke, P.; Picard, G.; van den Broeke, M.R.; Lenaerts, J.T.M.; van Meijgaard, E.

2012-01-01

Surface snowmelt is widespread in coastal Antarctica. Satellite-based microwave sensors have been observing melt area and duration for over three decades. However, these observations do not reveal the total volume of meltwater produced on the ice sheet. Here we present an Antarctic melt volume
Water, Rather than Temperature, Dominantly Impacts How Soil Fauna Affect Dissolved Carbon and Nitrogen Release from Fresh Litter during Early Litter Decomposition

Directory of Open Access Journals (Sweden)

Shu Liao

2016-10-01

Full Text Available Longstanding observations suggest that dissolved materials are lost from fresh litter through leaching, but the role of soil fauna in controlling this process has been poorly documented. In this study, a litterbag experiment employing litterbags with different mesh sizes (3 mm to permit soil fauna access and 0.04 mm to exclude fauna access was conducted in three habitats (arid valley, ecotone and subalpine forest with changes in climate and vegetation types to evaluate the effects of soil fauna on the concentrations of dissolved organic carbon (DOC and total dissolved nitrogen (TDN during the first year of decomposition. The results showed that the individual density and community abundance of soil fauna greatly varied among these habitats, but Prostigmata, Isotomidae and Oribatida were the dominant soil invertebrates. At the end of the experiment, the mass remaining of foliar litter ranged from 58% for shrub litter to 77% for birch litter, and the DOC and TDN concentrations decreased to 54%–85% and increased to 34%–269%, respectively, when soil fauna were not present. The effects of soil fauna on the concentrations of both DOC and TDN in foliar litter were greater in the subalpine forest (wetter but colder during the winter and in the arid valley (warmer but drier during the growing season, and this effect was positively correlated with water content. Moreover, the effects of fauna on DOC and TDN concentrations were greater for high-quality litter and were related to the C/N ratio. These results suggest that water, rather than temperature, dominates how fauna affect the release of dissolved substances from fresh litter.
ADMAP-2: The next-generation Antarctic magnetic anomaly map

Science.gov (United States)

Golynsky, Alexander; Golynsky, Dmitry; Ferraccioli, Fausto; Jordan, Tom; Damaske, Detlef; Blankenship, Don; Holt, Jack; Young, Duncan; Ivanov, Sergey; Kiselev, Alexander; Jokat, Wilfried; Gohl, Karsten; Eagles, Graeme; Bell, Robin; Armadillo, Egidio; Bozzo, Emanuelle; Caneva, Giorgio; Finn, Carol; Forsberg, Rene; Aitken, Alan

2017-04-01

The Antarctic Digital Magnetic Anomaly Project compiled the first international magnetic anomaly map of the Antarctic region south of 60°S (ADMAP-1) some six years after its 1995 launch (Golynsky et al., 2001; Golynsky et al., 2007; von Frese et al., 2007). This magnetic anomaly compilation provided new insights into the structure and evolution of Antarctica, including its Proterozoic-Archaean cratons, Proterozoic-Palaeozoic orogens, Palaeozoic-Cenozoic magmatic arc systems, continental rift systems and rifted margins, large igneous provinces and the surrounding oceanic gateways. The international working group produced the ADMAP-1 database from more than 1.5 million line-kilometres of terrestrial, airborne, marine and satellite magnetic observations collected during the IGY 1957-58 through 1999. Since the publication of the first magnetic anomaly map, the international geomagnetic community has acquired more than 1.9 million line-km of new airborne and marine data. This implies that the amount of magnetic anomaly data over the Antarctic continent has more than doubled. These new data provide important constraints on the geology of the enigmatic Gamburtsev Subglacial Mountains and Prince Charles Mountains, Wilkes Land, Dronning Maud Land, and other largely unexplored Antarctic areas (Ferraccioli et al., 2011, Aitken et al., 2014¸ Mieth & Jokat, 2014, Golynsky et al., 2013). The processing of the recently acquired data involved quality assessments by careful statistical analysis of the crossover errors. All magnetic data used in the ADMAP-2 compilation were delivered as profiles, although several of them were in raw form. Some datasets were decimated or upward continued to altitudes of 4 km or higher with the higher frequency geological signals smoothed out. The line data used for the ADMAP-1 compilation were reprocessed for obvious errors and residual corrugations. The new near-surface magnetic data were corrected for the international geomagnetic reference field
Soil fauna and diversity of animals in mining landscape of Karvina region Czech Republic

International Nuclear Information System (INIS)

Pullmanova, M.

2006-01-01

To study development of edaphon, esp. animals living on the top of the soil-epigeon, in relation to natural succession, were utilized the extreme different habitats from devastated landscape of Karvina region, Czech republic. Using the method of ground traps was collected numerous biological material of epigeon fauna at the spoil heap of the Dukla and Lazy face working area, in Karvina region. During two years of the research 2002-2004 was collected about 20 thousand examples. The fauna of epigeon, top horizon of the soil, was recovered and determined 24 taxons. The samples were analyzed according to several ecological criteria like an abundance, dominance, diversity and frequency. Special interest was paid to the succession and biodiversity of flora and fauna of spoil heap the reclamation process. Plants and animals that are adapted to specific conditions of life. First results show that the succession of community of edaphon is faster then succession of community of plants. (author)
Benthic fauna of Ungwana Bay, Mombassa (Kenya) - A preliminary account

Digital Repository Service at National Institute of Oceanography (India)

Ingole, B.S.

Studies on the benthic fauna of African waters have largely been limited to that of South Africa coast [3,5;7,9,15,18]. Although, the Mombassa Coast is considered importanat for the exploitation of fishery resources. Very little is known about its...
Fertilizer regime impacts on abundance and diversity of soil fauna across a poplar plantation chronosequence in coastal Eastern China

OpenAIRE

Shaojun Wang; Han Y. H. Chen; Yan Tan; Huan Fan; Honghua Ruan

2016-01-01

Soil fauna are critical for ecosystem function and sensitive to the changes of soil fertility. The effects of fertilization on soil fauna communities, however, remain poorly understood. We examined the effects of fertilization form and quantity on the abundance, diversity and composition of soil fauna across an age-sequence of poplar plantations (i.e., 4-, 9- and 20-yr-old) in the coastal region of eastern China. We found that the effects of fertilization on faunal abundance, diversity, and c...
Rita Bottoms: Polyartist Librarian

OpenAIRE

Bottoms, Rita; Reti, Irene; Regional History Project, UCSC Library

2005-01-01

Project Director Irene Reti conducted fourteen hours of interviews with Rita Bottoms, Head of Special Collections at the University Library, UC Santa Cruz, shortly before her retirement in March 2003. This oral history provides a vivid and intimate look at thirty-seven years behind the scenes in the library's Special Collections. For thirty-seven years Bottoms dedicated herself to collecting work by some of the most eminent writers and photographers of the twentieth century, includin...
Changes in Arctic and Antarctic Sea Ice as a Microcosm of Global Climate Change

Science.gov (United States)

Parkinson, Claire L.

2014-01-01

Polar sea ice is a key element of the climate system and has now been monitored through satellite observations for over three and a half decades. The satellite observations reveal considerable information about polar ice and its changes since the late 1970s, including a prominent downward trend in Arctic sea ice coverage and a much lesser upward trend in Antarctic sea ice coverage, illustrative of the important fact that climate change entails spatial contrasts. The decreasing ice coverage in the Arctic corresponds well with contemporaneous Arctic warming and exhibits particularly large decreases in the summers of 2007 and 2012, influenced by both preconditioning and atmospheric conditions. The increasing ice coverage in the Antarctic is not as readily explained, but spatial differences in the Antarctic trends suggest a possible connection with atmospheric circulation changes that have perhaps been influenced by the Antarctic ozone hole. The changes in the polar ice covers and the issues surrounding those changes have many commonalities with broader climate changes and their surrounding issues, allowing the sea ice changes to be viewed in some important ways as a microcosm of global climate change.
Shallow flows with bottom topography

NARCIS (Netherlands)

Heijst, van G.J.F.; Kamp, L.P.J.; Theunissen, R.; Rodi, W.; Uhlmann, M.

2012-01-01

This paper discusses laboratory experiments and numerical simulations of dipolar vortex flows in a shallow fluid layer with bottom topography. Two cases are considered: a step topography and a linearly sloping bottom. It is found that viscous effects – i.e., no-slip conditions at the non-horizontal
Time to stop mucking around? Impacts of underwater photography on cryptobenthic fauna found in soft sediment habitats.

Science.gov (United States)

De Brauwer, Maarten; Saunders, Benjamin J; Ambo-Rappe, Rohani; Jompa, Jamaluddin; McIlwain, Jennifer L; Harvey, Euan S

2018-07-15

Scuba diving tourism is a sustainable source of income for many coastal communities, but can have negative environmental impacts if not managed effectively. Diving on soft sediment habitats, typically referred to as 'muck diving', is a growing multi-million dollar industry with a strong focus on photographing cryptobenthic fauna. We assessed how the environmental impacts of scuba divers are affected by the activity they are engaged in while diving and the habitat they dive in. To do this, we observed 66 divers on coral reefs and soft sediment habitats in Indonesia and the Philippines. We found diver activity, specifically interacting with and photographing fauna, causes greater environmental disturbances than effects caused by certification level, gender, dive experience or age. Divers touched the substrate more often while diving on soft sediment habitats than on coral reefs, but this did not result in greater environmental damage on soft sediment sites. Divers had a higher impact on the substrate and touch animals more frequently when observing or photographing cryptobenthic fauna. When using dSLR-cameras, divers spent up to five times longer interacting with fauna. With the unknown, long-term impacts on cryptobenthic fauna or soft sediment habitats, and the increasing popularity of underwater photography, we argue for the introduction of a muck diving code of conduct. Copyright © 2018 Elsevier Ltd. All rights reserved.
ADMAP-2: The second generation Antarctic crustal magnetic anomaly map.

Science.gov (United States)

Ferraccioli, F.; Golynsky, A.; Golynsky, D.; Young, D. A.; Eagles, G.; Damaske, D.; Finn, C.; Aitken, A.; von Frese, R. R. B.; Ghidella, M. E.; Kim, H. R.; Hong, J.

2017-12-01

ADMAP-2 is the second generation crustal magnetic anomaly compilation for the Antarctic region south of 60°S. It was produced from more than 3.5 million line-km of near-surface terrestrial, airborne and marine magnetic observations collected since the International Geophysical Year 1957/58 through 2013. The data were edited, IGRF corrected, profile levelled and gridded at a 1.5-km interval on a polar stereographic projection using the minimum curvature technique. Given the ubiquitous polar cover of snow, ice and sea water, the magnetic anomaly compilation offers important constraints on the global tectonic processes and crustal properties of the Antarctic. It also links widely separated areas of outcrop to help unify disparate geologic studies, and provides insights on the lithospheric transition between Antarctica and adjacent oceans, as well as the geodynamic evolution of the Antarctic lithosphere in the assembly and break-up of the Gondwana, Rodinia, and Columbia supercontinents and key piercing points for reconstructing linkages between the protocontinents. The magnetic data together with ice-probing radar and gravity information greatly facilitate understanding the evolution of fundamental large-scale geological processes such as continental rifting, intraplate mountain building, subduction and terrane accretion processes, and intraplate basin formation.
Edaphic fauna in a vegetation gradient in the Sete Cidades National Park.

Science.gov (United States)

Nunes, L A P L; Araújo, A S F; Pessoa, M M C; Sousa, R S; Silva, J D C; Matos-Filho, C H A

2018-04-09

The vegetation physionomy and cover can show patterns of diversity and composition of the edaphic community, depending on the quantity and quality of litter in a specific habitat. The objective of this study was to evaluate the effect of the vegetation gradient formed by Graminoid Field (GRF), Cerrado Sensu Stricto (CSS), Cerradão (CRD) and Semideciduous Seasonal Forest (SSF) on density, diversity and composition of the edaphic fauna community in two seasons of the year, in the Sete Cidades National Park (Piauí state). For fauna sampling, a total of eight pitfall traps, distanced 10 m, were placed in each area in the central part of each system, where they remained for seven days. In the wet period, there was a tendency to increase the number of individuals as a function of the complexity of the vegetation formation, with the inverse occurring in the dry period. It was verified an environmental variation of the climatic factors temperature and humidity according to the vegetal formation, contributing to a heterogeneous distribution of the fauna. The GRF formation presented a significantly lower value of average richness only in the dry period. Regarding the variables of diversity and uniformity, they did not show drastic variations in relation to the vegetation gradient studied. The dominant groups in the vegetation gradient were Formicidae, Coleoptera, Aranae, Acari and Collembola, with reduction of the number of Coleoptera in the dry season. Principal component analysis (PCA) revealed greater differences in the composition of the communities between the vegetation formations for the rainy season. At this time, the formations SSF and CRD were associated to a greater diversity of invertebrates than CSS and GRF, demonstrating the influence of the vegetation complexity on the soil fauna community.
Edaphic fauna in a vegetation gradient in the Sete Cidades National Park

Directory of Open Access Journals (Sweden)

L. A. P. L. Nunes

2018-04-01

Full Text Available Abstract The vegetation physionomy and cover can show patterns of diversity and composition of the edaphic community, depending on the quantity and quality of litter in a specific habitat. The objective of this study was to evaluate the effect of the vegetation gradient formed by Graminoid Field (GRF, Cerrado Sensu Stricto (CSS, Cerradão (CRD and Semideciduous Seasonal Forest (SSF on density, diversity and composition of the edaphic fauna community in two seasons of the year, in the Sete Cidades National Park (Piauí state. For fauna sampling, a total of eight pitfall traps, distanced 10 m, were placed in each area in the central part of each system, where they remained for seven days. In the wet period, there was a tendency to increase the number of individuals as a function of the complexity of the vegetation formation, with the inverse occurring in the dry period. It was verified an environmental variation of the climatic factors temperature and humidity according to the vegetal formation, contributing to a heterogeneous distribution of the fauna. The GRF formation presented a significantly lower value of average richness only in the dry period. Regarding the variables of diversity and uniformity, they did not show drastic variations in relation to the vegetation gradient studied. The dominant groups in the vegetation gradient were Formicidae, Coleoptera, Aranae, Acari and Collembola, with reduction of the number of Coleoptera in the dry season. Principal component analysis (PCA revealed greater differences in the composition of the communities between the vegetation formations for the rainy season. At this time, the formations SSF and CRD were associated to a greater diversity of invertebrates than CSS and GRF, demonstrating the influence of the vegetation complexity on the soil fauna community.
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...
Towards a tipping point? Exploring the capacity to self-regulate Antarctic tourism using agent-based modelling

NARCIS (Netherlands)

Student, J.R.; Amelung, B.; Lamers, M.A.J.

2016-01-01

Antarctica attracts tourists who want to explore its unique nature and landscapes. Antarctic tourism has rapidly grown since 1991 and is currently picking up again after the recent global economic downturn. Tourism activities are subject to the rules of the Antarctic Treaty System (ATS) and the
Depth distributions of DNA damage in Antarctic marine phyto- and bacterioplankton exposed to summertime UV radiation

NARCIS (Netherlands)

Buma, A.G.J.; de Boer, M.K.; Boelen, P.

During a survey from January to March 1998, the occurrence of W-B radiation (UVBR)-induced DNA damage in Antarctic marine phytoplankton and bacterioplankton was investigated, Sampling was done in Ryder Bay, off the British base Rothera Station, 67 degreesS, 68 degreesW (British Antarctic Survey).
Iodine-129 in Snow and Seawater in the Antarctic: Level and Source

DEFF Research Database (Denmark)

Xing, Shan; Hou, Xiaolin; Aldahan, Ala

2015-01-01

Anthropogenic 129I has been released to the environment in different ways and chemical species by human nuclear activities since the 1940s. These sources provide ideal tools to trace the dispersion of volatile pollutants in the atmosphere. Snow and seawater samples collected in Bellingshausen...... sites in the Southern Hemisphere. This feature indicates that 129I in Antarctic snow mainly originates from atmospheric nuclear weapons testing from 1945 to 1980; resuspension and re-emission of the fallout 129I in the Southern Hemisphere maintains the 129I level in the Antarctic atmosphere. 129I...
Combustion of available fossil-fuel resources sufficient to eliminate the Antarctic Ice Sheet

Science.gov (United States)

Winkelmann, R.; Levermann, A.; Ridgwell, A.; Caldeira, K.

2015-12-01

The Antarctic Ice Sheet stores water equivalent to 58 meters in global sea-level rise. Here we show in simulations with the Parallel Ice Sheet Model that burning the currently attainable fossil-fuel resources is sufficient to eliminate the ice sheet. With cumulative fossil-fuel emissions of 10 000 GtC, Antarctica is projected to become almost ice-free with an average contribution to sea-level rise exceeding 3 meters per century during the first millennium. Consistent with recent observations and simulations, the West Antarctic Ice Sheet becomes unstable with 600 to 800 GtC of additional carbon emissions. Beyond this additional carbon release, the destabilization of ice basins in both West- and East Antarctica results in a threshold-increase in global sea level. Unabated carbon emissions thus threaten the Antarctic Ice Sheet in its entirety with associated sea-level rise that far exceeds that of all other possible sources.
Penguin eggshell membranes reflect homogeneity of mercury in the marine food web surrounding the Antarctic Peninsula

Energy Technology Data Exchange (ETDEWEB)

Brasso, Rebecka L., E-mail: rlb1196@uncw.edu [University of North Carolina Wilmington, Department of Biology and Marine Biology, 601 South College Road, Wilmington, NC 28403 (United States); Polito, Michael J. [University of North Carolina Wilmington, Department of Biology and Marine Biology, 601 South College Road, Wilmington, NC 28403 (United States); Lynch, Heather J. [Ecology and Evolution Department, 640 Life Sciences Bldg., Stony Brook University, Stony Brook, NY 11794 (United States); Naveen, R. [Oceanites Inc., PO Box 15259, Chevy Chase, MD 20825 (United States); Emslie, Steven D. [University of North Carolina Wilmington, Department of Biology and Marine Biology, 601 South College Road, Wilmington, NC 28403 (United States)

2012-11-15

Remote regions such as the Antarctic have become increasingly important for investigations into far-reaching anthropogenic impacts on the environment, most recently in regard to the global mercury cycle. Spatial patterns of mercury availability in four regions of the Antarctic Peninsula were investigated using three species of sympatrically breeding Pygoscelis penguins as biomonitors. Eggshells with intact membranes from Adelie, Gentoo, and Chinstrap penguins were collected at 24 breeding colonies in the South Orkney Islands, South Shetland Islands, eastern Antarctic Peninsula, and western Antarctic Peninsula during the 2006/2007 austral summer. In addition, we compared eggshell membrane mercury concentrations with eggshell stable isotope values ({delta}{sup 15}N and {delta}{sup 13}C) to determine if species-specific trophic or foraging habitat preferences influenced female mercury exposure prior to breeding. With few exceptions, mercury concentrations were found to be fairly homogeneous throughout the Antarctic Peninsula suggesting little spatial variation in the risk of exposure to dietary mercury in this food web. Mercury concentrations in Gentoo and Adelie penguins were similar while Chinstrap penguins tended to have higher eggshell membrane mercury concentrations than their congeners. However, inter and intra-specific differences in eggshell membrane mercury concentration were not related to eggshell {delta}{sup 15}N or {delta}{sup 13}C values, a likely result of all three species foraging at similar trophic positions. The lack of regional-scale differences in mercury availability in this marine ecosystem may be a reflection of generally uniform atmospheric deposition and upwelling of regionally homogeneous deep water rather than from geographically distinct point sources. -- Highlights: Black-Right-Pointing-Pointer We examined regional patterns of mercury availability in the Antarctic Peninsula. Black-Right-Pointing-Pointer Three species of Pygoscelis
Diversity of some fauna in National Chambal Sanctuary in Madhya Pradesh, India

Directory of Open Access Journals (Sweden)

PREMANAND KALKRISHANA MESHRAM

2010-10-01

Full Text Available Meshram PM (2010 Diversity of some fauna in National Chambal Sanctuary in Madhya Pradesh, India. Biodiversitas 11: 211-215. National Chambal Sanctuary (NCS gives very good account of avifauna. It over emphasizes significant and important birds species available which are of National and International importance. Crocodiles use sand banks for nesting and basking. Fauna in the NCS is very much influenced by various factors like habitat suitability and protection of their habitats. Their distribution is depending on availability of deep water pools. Another important factors on which distribution of animals depends long stretches of long sand banks. Sloppy to steep sand bank with loose soil were good habitats for nesting of crocodiles, turtles and birds. NCS areas were considerably altered and there were disturbance by the sand miners, poachers, fishermen and farmers. Consequently the poor survival is recommended to greater protection by management practices. Effective co-operations between the Forest Department of Madhya Pradesh and neighbouring states were needed as sand mining and poaching becomes an interstate problem. Thus, strategic location of this site in the migratory route of water birds enhances its importance as a significant water bird habitat. In the present study diversity of some fauna in NCS is discussed.

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