Palaeogene volcanics with plant-bearing sediment intercalations crop out extensively on King George Island in the South Shetland Islands, West Antarctica. The plant fossil assemblages are the most complete Palaeogene terrestrial foliar record in Antarctica. Compositional variations in the flora have previously been used to construct climate change models for the Tertiary. King George Island is part of the late Triassic to Recent, Andean - West Antarctic subducting margin. Eastwards subduction oceanic crust beneath the Antarctic Peninsula resulted in mountain building and crustal melting at depth that in turn led to large stratovolcanoes and active pyroclastic volcanism (Leat et al., 1995). Consequently the flora is preserved in a range of primary and reworked volcaniclastic sediments, that were deposited in lacustrine and ephemeral lacustrine basins developed on the volcanic surface. The King George Island flora consists of impressions and carbonised compressions of leaves of angiosperms, ...
The Notothenioidei dominates the fish fauna of the Antarctic in both biomass and diversity. This clade exhibits adaptations related to metabolic function and freezing avoidance in the subzero Antarctic waters, and is characterized by a high degree of morphological and ecological diversity. Investigating the macroevolutionary processes that may have contributed to the radiation of notothenioid fishes requires a well-resolved phylogenetic hypothesis. To date published molecular and morphological hypotheses of notothenioids are largely congruent, however, there are some areas of significant disagreement regarding higher-level relationships. Also, there are critical areas of the notothenioid phylogeny that are unresolved in both molecular and morphological phylogenetic analyses. Previous molecular phylogenetic analyses of notothenioids using partial mtDNA 12S and 16S rRNA sequence data have resulted in limited phylogenetic resolution and relatively low node support. One particularly controversial result
Mitochondrial membranes in cardiac muscle from Antarctic notothenioid fishes vary in phospholipid composition and membrane fluidity ...
This study was conducted to describe the cardiovascular responses to intra-arterial injections of serotonin in the Antarctic fish Pagothenia borchgrevinki and to elucidate the underlying mechanisms. Immunohistochemistry was used to localise serotonin-containing cells within the gills. Simultaneous and continuous recordings of ventral and dorsal aortic blood pressure, heart rate and ventral aortic blood flow (cardiac output) were made using standard cannulation procedures in combination with Doppler flow measurement. An extracorporeal loop with an in-line oxygen electrode allowed continuous measurements of arterial oxygen pressure PaO2. Pre-branchial injection of serotonin (5-hydroxytryptamine, 5-HT) or the 5-HT2 receptor agonist alpha-methylserotonin increased the branchial vascular resistance and ventral aortic pressure, while the 5-HT1 receptor agonist piperazine was without effect. The branchial vasoconstriction produced by serotonin injection was completely blocked by the 5-HT1/5-HT2 ...
The ocellated icefish (Chionodraco rastrospinosus) is a fish of the family Channichthyidae. It lives in the cold waters off Antarctica and is known for having transparent haemoglobin-free blood. C. rastrospinosus live in the Southern Ocean up to a depth of 1 km. They grow up to 52 centimetres (20 in) and average 30 centimetres (12 in). The adults feed on krill and other fish. Larvae are 17 mm long when they hatch, and grow by about 2 mm a week. The larval stage lasts for up to 18 months during which they feed mainly on krill. They become sexually mature at four years, and normally live up to about eight years, but sometimes as long as twelve. In the Antarctic autumn, adult C. rastrospinosus migrate to shallow waters to spawn at a depth of 200-300 m. The eggs are scattered and hatch six months later around April. Haemoglobin gives oxygenated blood its red colour. Unlike other vertebrates, fish of the Antarctic icefish family (Channichthyidae) do not use haemoglobin to transport oxygen around ...
The Antarctic icefishes (family Channichthyidae, suborder Notothenioidei) constitute the only vertebrate taxon that fails to produce red blood cells. These fishes can be paired with closely related, but erythrocyte-producing, notothenioids to discover erythropoietic genes via representational difference analysis. Using a B30.2-domain-encoding DNA probe so derived from the hematopoietic kidney (pronephros) of a red-blooded Antarctic rockcod, Notothenia coriiceps, we discovered a related, novel gene, bloodthirsty (bty), that encoded a 547-residue protein that contains sequential RING finger, B Box, coiled-coil, and B30.2 domains. bty mRNA was expressed by the pronephric kidney of N. coriiceps at a steady-state level 10-fold greater than that found in the kidney of the icefish Chaenocephalus aceratus. To test the function of bty, we cloned the orthologous zebrafish gene from a kidney cDNA library. Whole-mount in situ hybridization of zebrafish embryos showed that bty mRNA was present throughout ...
The purpose of this study was to extend our investigation into the regulation of the HSR in the Antarctic notothenioid fish Trematomus bernacchii, a species that appears to lack heat-inducible Hsp expression (Hofmann et al., 2000). The fishes endemic to the Southern Ocean display a range of biochemical and molecular processes that allow them to tolerate their extreme environment and, in some cases, have lost attributes common to other fish (Somero et al., 1998). These changes include the production of anti-freeze proteins (DeVries, 1988), the loss of hemoglobin and/or myoglobin in some species (Cocca et al., 1997; Sidell et al., 1997; Somero et al., 1998) and the storage of extra lipid reserves for energy (Sidell et al., 1995), buoyancy (Eastman, 1988) and for aiding in oxygen delivery to tissues (Londraville and Sidell, 1990). To address the possibility that such a cold-adapted species could lose an otherwise highly conserved cellular response to heat stress, we examined the expression of hsp ...
Hoffman, J., Peck, L., Linse, K., & Clarke, A. C. (2011). Strong population genetic structure in a broadcast-spawning Antarctic marine invertebrate. Journal of Heredity, 102(1), 55-66. doi:10.1093/jhered/ ...
The Antarctic marine fauna has been isolated in the cold (-2°C), stable, and oxygen-rich Southern Ocean for 25 million years, and consequently these animals are extremely cold-adapted. One family within the Antarctic notothenioid fishes, the icefish, has lost the capacity to produce erythrocytes and the oxygen transport protein hemoglobin. Their profound anemia makes them an evolutionary mutant model of human anemias. Using a comparative-genomic approach, we have isolated 10 novel genes that are differentially expressed by the red-blooded species Notothenia coriiceps and the white-blooded icefish, Chaenocephalus aceratus, and may be novel genes involved in erythropoiesis. We have identified one of these genes (hemogen - hemgn) as a putative ortholog of mammalian EDAG and RP59. In mammals, these genes are involved in the proliferation of blood and bone cells, however, whether the putative ortholog hemgn functions similarly in fishes has not be reported. In the current study, we use a ...
Kociolek, J.P.; Blanco, S.; Coste, M.; Ector, L.; Liu, Y.; Karthick, B.; Kulikovskiy, M.; Lundholm, N.; Ludwig, T.; Potapova, M.; Rimet, F.; Sabbe, K.; Sala, S.; Sar, E.; Taylor, J.; Van de Vijver, B.; Wetzel, C.E.; Williams, D.M.; Witkowski, A.; Witkowski, J. (2020). DiatomBase. Pinnularia C.G. Ehrenberg, 1843. Accessed through: RAS (Eds.) (2020) Register of Antarctic Species at: http://ras.biodiversity.aq/aphia.php?p=taxdetails&id=149208 on 2020-10-28 ...
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The major ions, sodium (Na+), calcium (Ca2+), and chloride (Cl−), deposited in central Antarctica and preserved in ice cores originate from both marine and continental sources. They provide important proxy records, helping to reconstruct past climatic processes. However, it is difficult to clearly separate the individual contributions from the two sources, particularly the continental one during glacial periods. On the basis of Na+ and Ca2+ records at an unprecedented resolution from the European Project for Ice Coring in Antarctica (EPICA) Dome C ice core back to the penultimate glacial period, mean ion mass ratios were deduced for the continental and the sea-salt aerosol body over East Antarctica. The sea-salt ion mass ratios are in the range predicted for both wind-induced bubble bursting of breaking waves on the open ocean and sea ice brine-derived aerosols, respectively, thus allowing no clear decision on the contribution of sea ice to the central Antarctic sea-salt aerosol. The ...
The Census of Antarctic Marine Life (CAML) and its polar counterpart, Arctic Ocean Diversity, have pioneered new understandings of the evolution and diversity of life.. Led by the Australian Antarctic Division, CAML coordinated 18 major research voyages to Antarctica and the Southern Ocean during the IPY. Australian scientists participated in three CAML voyages focusing on waters adjacent to East Antarctica - known as the Collaborative East Antarctic Marine Census (CEAMARC). These voyages, aboard Japans Umitaka Maru, Frances LAstrolabe and Australias Aurora Australis, studied sea-bed communities and the deep pelagic (open ocean) zone of the region adjacent to Terre Adélie and George V Land.. Altogether, CAML revealed that Antarctica is a single bioregion united by the Circumpolar Current - the largest current in the world. Previously thought to be low in species diversity, the Antarctic is now known to have an unexpected richness of life. In addition, molecular techniques show Antarctica to ...
The Antarctic Ecosystem Research Division ( AERD) conducts research to fulfill NOAAs mandate of providing scientific advice that supports United States (U.S.) interests related to resource management by the Commission for the Conservation of Antarctic Marine Living Resources ( CCAMLR), of which the U.S. is a Member. NOAA Fisheries Antarctic research is mandated by the U.S. Antarctic Marine Living Resources (AMLR) Convention Act of 1984, thus the program of work undertaken and managed by the AERD is widely known as the U.S. AMLR Program. The U.S. AMLR Program is internationally recognized for its ongoing contributions to ecosystem-based management of fisheries that impact krill, finfishes, krill-dependent predators, and other components of the Antarctic ecosystem. The AERD manages the US AMLR Program under the direction of George Watters. ...
The Antarctic Ecosystem Research Division ( AERD) conducts research to fulfill NOAAs mandate of providing scientific advice that supports United States (U.S.) interests related to resource management by the Commission for the Conservation of Antarctic Marine Living Resources ( CCAMLR), of which the U.S. is a Member. NOAA Fisheries Antarctic research is mandated by the U.S. Antarctic Marine Living Resources (AMLR) Convention Act of 1984, thus the program of work undertaken and managed by the AERD is widely known as the U.S. AMLR Program. The U.S. AMLR Program is internationally recognized for its ongoing contributions to ecosystem-based management of fisheries that impact krill, finfishes, krill-dependent predators, and other components of the Antarctic ecosystem. The AERD manages the US AMLR Program under the direction of George Watters. ...
We review the scientific literature, especially from the past decade, on the impacts of human activities on the Antarctic environment. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived. Contemporary sewage management practices at many coastal stations are insufficient to prevent local contamination but no introduction of non-indigenous organisms through this route has yet been demonstrated. Human activities, particularly construction and transport, have led to disturbances of flora and fauna. A small number of non-indigenous plant and animal species has become established, mostly on the northern Antarctic Peninsula and southern archipelagos of the Scotia Arc. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity on bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its ...
Relative sea level rise at Kerguelen Island over the last 55 years has been investigated using a combination of historical and recent tide gauge data.
The Grunehogna Craton (GC, East Antarctica) is interpreted as part of the Archaean Kaapvaal Craton of southern Africa prior to Gondwana breakup. The basement of the GC is exposed only within a small area comprising the dominantly leucocratic Annandagstoppane (ADT) S-type granite. The granite (and hence the craton) has been dated previously only by Rb-Sr and Pb-Pb mica and whole-rock methods. Here, the crystallization age of the granite is determined to be 3067 ± 8 Ma by U-Pb dating of zircon. This age is coeval with that of granitoids and volcanic rocks in the Swaziland and Witwatersrand blocks of the Kaapvaal Craton. Inherited grains in the ADT granite have ages of up to 3433 ± 7 Ma, and are the first evidence of Palaeoarchaean basement in Dronning Maud Land. The age spectrum of the inherited grains reflects well-known tectono-magmatic events in the Kaapvaal Craton and forms important evidence for the connection of the GC to the Kaapvaal Craton for at least 2·5 billion years and probably ...
Antarctic sea ice is constantly on the move as powerful winds blow it away from the coast and out toward the open ocean. A new study shows how that ice migration may be more important for the global ocean circulation than anyone realized.
Lemke, P. (1980): Linear stochastic dynamic model of Arctic and Antarctic sea ice variability , Workshop on Stochastic Dynamic Forecasting, October 1979, ECMWF, Reading, England ...
Plankton sampling by the training vessel Umitaka-maru in the Indian sector of the Southern Ocean in the austral summer of 2010/2011Plankton sampling by the training vessel Umitaka-maru in the Indian sector of the Southern Ocean in the austral summer of 2010/2011AA12026903 ...
The vertebrate mitochondrial genomes generally present a typical gene order. Exceptions are uncommon and important to study the genetic mechanisms of gene order rearrangements and their consequences on phylogenetic output and mitochondrial function. Antarctic notothenioid fish carry some peculiar rearrangements of the mitochondrial gene order. In this first systematic study of 28 species, we analyzed known and undescribed mitochondrial genome rearrangements for a total of eight different gene orders within the notothenioid fish. Our reconstructions suggest that transpositions, duplications, and inversion of multiple genes are the most likely mechanisms of rearrangement in notothenioid mitochondrial genomes. In Trematominae, we documented an extremely rare inversion of a large genomic segment of 5,300 bp that partially affected the gene compositional bias but not the phylogenetic output. The genomic region delimited by nad5 and trnF, close to the area of the Control Region, was identified as the hot spot
April Flowers for redOrbit.com - Your Universe Online One of the fastest warming regions on the planet - and the fastest warming part of the Southern Hemisphere - is the western Antarctic Peninsula. This warming has been the subject of scientific debate, especially in light of recent instrumental records of both atmospheric and oceanic warming from the region. Holding an equivalent of 5 meters of global sea level rise locked in ice, the Antarctic ice sheet is becoming increasingly vulnerable to collapse as the atmosphere and oceans continue to warm.. A new study from Cardiff University, published in a recent issue of Nature Geoscience, has traced glacial ice entering the ocean along the western Antarctic Peninsula using a unique 12,000-year record of microscopic marine algae fossils. The findings reveal that in the late Holocene - approximately 3500 - 250 years ago - the atmosphere had a more significant impact on warming along the western Antarctic Peninsula than oceanic circulation did.. Prior ...
Roberts, Donna (1997) Reconstruction of lake-water salinity from fossil diatom assemblages in saline lakes of the Vestfold Hills, Antarctica. PhD thesis, University of Tasmania. ...
Half of all vertebrate species share a series of chromosome fusions that preceded the teleost genome duplication (TGD), but we do not understand the causative evolutionary mechanisms. The Robertsonian-translocation hypothesis suggests a regular fusion of each ancestral acro- or telocentric chromosome to just one other by centromere fusions, thus halving the karyotype. An alternative genome-stirring hypothesis posits haphazard and repeated fusions, inversions, and reciprocal and nonreciprocal translocations. To study large-scale karyotype reduction, we investigated the decrease of chromosome numbers in Antarctic notothenioid fish. Most notothenioids have 24 haploid chromosomes, but bullhead notothen (Notothenia coriiceps) has 1. To understand mechanisms, we made a RAD-tag meiotic map with approximate to 10,000 polymorphic markers. Comparative genomics aligned about a thousand orthologs of platyfish and stickleback genes along bullhead chromosomes. Results revealed that 9 of 11 bullhead chromosomes arose
Early ecological research in McMurdo Sound revealed local spatial gradients in community structure associated with variations in anchor ice disturbance, fast ice and snow cover, and the effects of predators. Research contrasting the east and west sides of McMurdo Sound has shown major differences in benthic communities, which have been attributed to oceanographic influences on the advection of water-column productivity and the frequency of fast ice break-out. Despite these regional and local differences, coastal benthic communities in McMurdo Sound show a high level of stability, and contain a variety of large and potentially very long-lived species. In Terra Nova Bay, about half way along the Victoria Land Coast of the western Ross Sea, the coastal benthic communities provide some insightful contrasts with those in McMurdo Sound. For example, the abundance and depth distribution of dominant species such as Sterechinus neumayeri and Adamussium colbecki are markedly different from McMurdo Sound. ...
The waters around South Georgia are among the most productive in the Southern Ocean, with zooplankton populations close to the island, in particular Antarctic krill, supporting vast colonies of higher predators. However, our understanding of the processes governing variability in the supply of these food resources is limited by the poor spatial and temporal resolution of available data. Here, we use a numerical modeling approach to examine the underlying physical processes driving the recruitment and retention of zooplankton to the South Georgia shelf. Variability in the magnitude and spatial distribution of recruitment was dominated by the proximity and orientation of the southern Antarctic Circumpolar Current front to the shelf edge. Shelf retention was highest for source sites on the southwest shelf, with the main transport routes off the shelf to the north and northwest. Retention was lowest in the austral summer and winter; in summer increased glacial melt drives stronger off-shelf ...
The microbial communities that inhabit lithic niches inside sandstone in the Antarctic McMurdo Dry Valleys of life’s limits on Earth. The cryptoendolithic communities survive in these ice-free areas that have the lowest temperatures on Earth coupled with strong thermal fluctuations, extreme aridity, oligotrophy and high levels of solar and UV radiation. In this study, based on DNA metabarcoding, targeting the fungal Internal Transcribed Spacer region 1 (ITS1) and multivariate statistical analyses, we supply the first comprehensive overview onto the fungal diversity and composition of these communities sampled over a broad geographic area of the Antarctic hyper-arid cold desert. Six locations with surfaces that experience variable sun exposure were sampled to compare communities from a common area across a gradient of environmental pressure. The Operational Taxonomic Units (OTUs) identified were primarily members of the Ascomycota phylum, comprised mostly of the Lecanoromycetes and Dothideomycetes
Thehemolysateofthe AntarcticteleostGobionotothen gibberifrons(family Nototheniidae) contains two hemoglo-bins (Hb 1 andHb 2). The concentration of Hb 2 (15-20% of the total hemoglobin content) is higher than that found in most cold-adapted Notothenioidei. Unlike the other Antarctic species so far examined having two hemoglobins, Hb 1 and Hb 2 do not have globin chains in common. Therefore this hemoglobin system is made of four globins (two a-and twob-chains). The complete amino-acid sequence of the two hemoglobins (Hb 1,a 1 2b 1 2 ;Hb 2,a 2 b 2 2 ) has been established. ... ...
An important part of the McMurdo Long Term Ecological Research (LTER) project is identifying patterns and movements of nutrients in perennial ice-covered lakes. This data set addresses this core area of research and quantifies macronutrient concentrations found at specific depths in McMurdo Dry Valley lakes.. ...
An important part of the McMurdo Long Term Ecological Research (LTER) project is identifying patterns and movements of nutrients in perennial ice-covered lakes. This data set addresses this core area of research and quantifies macronutrient concentrations found at specific depths in McMurdo Dry Valley lakes.. ...
As expected, the population and allele patterns found within the Kerguelen Archipelago allow some general conclusions on the fate of populations after initial colonization. First of all, we note that these mice have retained a certain amount of genetic diversity. The heterozygosity values, as well as the average number of alleles, are comparable to the sample that we caught within a single deme in Europe (Paris). Since the mice that came with the first ship would likely represent the deme from the harbor where the ship started, we can assume that the mice entering these ships had a similarly reduced diversity (when compared to the diversity across demes in the French and German populations). Hence, there may have been only little additional loss of genetic diversity during the ship passage and after colonization. In population genetic terms this means that the mouse population would have quickly expanded after arrival on the Kerguelen Archipelago, which would have prevented further loss of ...
In a study spanning two decades, a team of researchers led by Colorado State University found declining numbers of soil fauna, nematodes and other animal species in the McMurdo Dry Valleys, one of the worlds driest and coldest ...
The Lake Vida meteorological station was added to the McMurdo Dry Valley network in the 1995-1996 field season. It was established on the shore of Lake Vida in Victoria Valley, one of the largest lakes in the dry valleys, recently discovered to have a 19 m ice cover over a hypersaline brine of undetermined depth. The station was set up to sample sensors every 30 seconds and send summary statistics (for example, averages and maximums) to solid-state storage modules every 15 minutes. This has resulted in approximately 20 values being recorded for final storage in every output interval.. Sampling and Averaging Intervals For Sampling frequency and Data Logger output and averaging intervals please visit:http://mcmlter.lternet.edu/data/meteorology/methods/Interval_Dates.pdf. Seasonal Task Summary To view the data post-processing steps for each season please visit: http://mcmlter.org/meteorological-task-lists. ...
THE KERGUELEN ISLANDS are the exposed part of the Kerguelen oceanic plateau, a Large Igneous Province in the Antarctic plate domain. Its birth is related to both the spreading of the South East Indian Ridge (SEIR) overprinted by the long-lived Kerguelen plume. It provides a unique opportunity to study plume-ridge interactions and their implications for the composition of the oceanic mantle. Mantle xenoliths from the Kerguelen Islands are common in dykes or pipes of young alkaline lavas. The major and lithophile trace elements have been well-characterised over the last decade. The platinum group elements (PGE; Os, Ir, Ru, Rh, Pd, Pt) and chalcophile elements (S, Se, Cu) provide different information on the geological processes that operate in the lithosphere. This is because they are almost exclusively partitioned into a sulfide-rich melt, whereas major and lithophile trace elements have a greater affinity for silicate melts.. The PGE, S, Se and Cu were analysed in representative mantle xenoliths ...
ePIC (electronic Publication Information Center) is the official repository for publications and presentations of Alfred Wegener Institute for Polar and Marine Research (AWI)
Chen, Z.Z., Cheng ,C.H.C., Zhang, J.F., Cao, L.X., Chen, L., Zhou, L.H., Jin, Y.D., Ye, H., Deng, C., Dai, Z.H., Xu, Q.H., Hu, P., Sun, S.H., Shen, Y. and Chen, L.B.(2008) Transcrintomic and genomic evolution under constant cold in Antarctic notothenioid fish. Proceedings of the National Academy of Sciences of the United States of America 105:12944-12949. The sub-zero temperatures of the Southern Oceans require special adaptation to these extreme conditions, and the unique fish fauna of this region has provided textbook examples of molecular adaptation and molecular evolution in the context of thermal physiology. Previous studies have typically investigated single loci, but, in an exciting new survey, Chen et al. (2008) take a novel approach to characterize the genome-wide changes in gene transcription and relate these to adaptation to the cold Antarctic waters. A particular strength of this research is its tripartite strategy ...
Pinguine eignen sich wie kaum ein anderes Lebewesen als Nachweis für Veränderungen in den Ökosystemen der Antarktis. Ändert sich das Klima und damit beispielsweise auch die Nahrungsverfügbarkeit, hat das auch Auswirkungen auf die dort lebenden Pinguinarten. Ergebnisse aus einer Langzeituntersuchung im Auftrag des UBA verdeutlichen den Einfluss des Klimawandels auf Pinguine und andere Seevögel in der Antarktis: Steigende Temperaturen und höhere Niederschläge führen dazu, dass sich Arten, die stark an Eis gebunden sind, weiter nach Süden zurückziehen und Arten aus wärmeren Gebieten dafür ihren Platz einnehmen.. ...
Background Sooty (Puffinus griseus) and short-tailed (P. tenuirostris) shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Methodology/Principal Findings Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140°E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of
In Antarctica, the environmental conditions and the restrictions imposed by the Antarctic Treaty prevent inoculation with foreign bacteria. Therefore, our aim was to investigate native bacterial consortia which might serve to design bacterial formulas suitable for soil bioremediation processes at cold temperatures. Two bacterial consortia, M10 and J13, were isolated from diesel contaminated Antarctic soils. Their ability to use hydrocarbons was evaluated in vitro and by the detection of three catabolic genes (alkB, nahAc, xylE). Both consortia showed similar 16S rRNA gene profiles, suggesting the presence of the same phylotypes. Total 16S rDNA was cloned from M10 grown on diesel. Sixty clones were screened, grouped by restriction profiles of PCR-amplified inserts and sequenced. T-RFLP (Terminal-Restriction-Fragment-Length-Polymorphism) of clones showed that all phylotypes from the entire consortia were recovered. A culture-dependent approach was used to isolate M10 components able to utilise ...
Lichens are predominant and important flora in the terrestrial ecosystem of Antarctica. However, relatively few phylogenetic researches on Antarctic lichens have been accomplished. Phylogenetic researches using molecular techniques and advanced analysis algorithms are needed for a comprehensive guide to the identification and classification of Antarctic lichen-forming fungi, and to understand evolutionary relationships among lichen species with various geographical distributions. The floristic surveys were made in King George Island, Antarctica and fresh lichens were collected from January to February in 2006. A total of 225 lichen collections were obtained and identified to the species through the observation of macroscopic and microscopic characteristics. To provide information for phylogenetic relationships, nuclear large subunit (nLSU) rDNAs of 89 specimens were sequenced and compared with 201 sequences of lichen-forming fungi retrieved from the GenBank. Most of the Antarctic species were ...
Chapter 2 appears to be the equivalent of a post-print version of an article published as: Lake S., Burton H., van den Hoff J., 2003. Regional, temporal and fine-scale spatial variation in Weddell seal diet at four coastal locations in east Antarctica, Marine ecology progress series 254, 293- 305, Copyright © 2003 Inter-Research. Chapter 3 appears to be the equivalent of the peer-reviewed version of the following article: Lake, S., Wotherspoon, S., Burton, H. R., 2005. Spatial utilisation of fast-ice by Weddell seals Leptonychotes weddelli during winter. Ecography, 28(3), 295-306 which has been published in final form at http://dx.doi.org/10.1111/j.0906-7590.2005.03949.x This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.. Chapter 4 appears to beadult femal the equivalent of a post-print version of an article published as: Lake, S., Burton, H., Wotherspoon, S., 2006. Movements of Weddell seals during the winter months. Polar ...
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Instantly recognisable by the large, inflatable proboscis, the male southern elephant seal is the biggest seal in its family. Males can weigh eight to ten times as much as females, making them the most sexually dimorphic of all mammals (2). Females do not have a proboscis, but rather a short nose and a muzzle (4). Both sexes have robust bodies, thick necks and broad heads, and each digit of the fore flippers bears a large, black nail (4). The coat is light to dark silvery-grey or brown in adults and juveniles, whilst newborns have black coats, which turns into a short silvery-grey coat at around three weeks of age (5). Males develop a chest shield of thickened, creased and heavily scarred skin as they age, and also become paler across the face, proboscis and head (4). During the breeding season, southern elephant seals become stained rusty orange and brown from lying in their own excrement ...
This investigation has provided limited evidence for the occurrence of spawning by King George whiting in Victorian waters. Of the approximately 1600 specimens examined we found complete gonad maturation in only one female and did not find any fully mature males. Although we found several females in a highly developed reproduction state there was no evidence that these fish had spawned prior to capture or were about to spawn. These results suggest that King George whiting are not spawning where recreational anglers target them along the Victorian coast, and importantly, they imply that spawning King George whiting are not exploited by Victorian anglers. Our observation supports the anecdotal information supplied by recreational anglers during the project that suggests King George whiting in roe are rarely captured.. Although spawning adults were largely absent from recreational catches, we cannot rule out the possibility that spawning may occur in areas not fished by recreational anglers. ...
Antarctic krill (Euphausia superba) might have specific peptides that chelate iron ions and are iron carriers. In this study, iron-binding peptides were isolated from Antarctic krill using enzymatic (trypsin) hydrolysis and immobilized metal affinity chromatography (IMAC); the binding mode and surface morphology of Antarctic krill peptides (AKP)-iron complexes as well as their iron delivery behavior in the gastrointestinal tract were investigated. Results showed that the AKP bound 79.3% of available iron from the enzymatic hydrolysis for 180 min. The contents of negatively-charged amino acids (Asp and Glu) on the AKP showed a positive correlation (r = 0.80) with iron-binding activities (the data includes Asn and Gln), while positively-charged amino acids showed a negative correlation (r = −0.83). Moreover, His, Ser and Thr on the AKP were also involved in the iron-binding activities. Iron-binding peptides from Antarctic krill hydrolysates, isolated using IMAC-Fe3+ and identified using ...
Heat stress proteins are implicated in stabilizing and refolding denatured proteins in vertebrates and invertebrates. Members of the Hsp70 gene family comprise the cognate heat shock protein (Hsc70) and inducible heat shock protein (Hsp70). However, the cDNA sequence and the expression of Hsp70 in the Antarctic sea urchin are unknown. We amplified and cloned a transcript sequence of 1991 bp from the Antarctic sea urchin Sterechinus neumayeri, experimentally exposed to heat stress (5 and 10 °C for 1, 24 and 48 h). RACE-PCR and qPCR were employed to determine Hsp70 gene expression, while western blot and ELISA methods were used to determine protein expression. The sequence obtained from S. neumayeri showed high identity with Hsp70 members. Several Hsp70 family features were identified in the deduced amino acid sequence and they indicate that the isolated Hsp70 is related to the cognate heat shock protein type. The corresponding 70 kDa protein, called Sn-Hsp70, was immune detected in the coelomocytes and
Many remote and local climate variabilities influence Antarctic sea ice at different time scales. The strongest sea ice teleconnection at the interannual time scale was found between El Nino-Southern Oscillation (ENSO) events and a high latitude climate mode named the Antarctic Dipole. The Antarctic Dipole is characterized by an out-of-phase relationship between sea ice and surface temperature anomalies in the South Pacific and South Atlantic, manifesting itself and persisting 3-4 seasons after being triggered by the ENSO forcing. This study examines the life cycles of ENSO warm and cold events in the tropics and associated evolution of the ADP in high latitudes of the Southern Hemisphere. In evaluating the mechanisms that form the ADP, the study suggests a synthesized scheme that links these high latitude processes with ENSO teleconnection in both the Pacific and Atlantic basins. The synthesized scheme suggests that the two main mechanisms responsible for the formation/maintenance of the ...
A temperate phage, Psymv2, was isolated from an Antarctic soil bacterium, Psychrobacter sp. MV2. The morphology of Psymv2 was typical of the Siphoviridae, with an isometric head and non-contractile tail. The Psymv2 genome was found to be 35,725 bp in length, had a G + C content of 44.5 %, with 49 protein-coding genes and one tRNA gene predicted. Integration of Psymv2 occurred at an ssrA gene, with the last 27 bases of this gene directly repeated at the prophage ends. The genome was organised in a modular fashion: integration, regulation, packaging, head assembly, tail assembly, host specificity and lysis. While the genome sequence had little similarity on a nucleotide level to previously reported phage sequences, the genome architecture resembled that of Siphoviridae of low G + C Gram-positive bacteria. The closest relatives to Psymv2 were uncharacterized putative prophages within the P. arcticus 273-4 and Acinetobacter baumannii 6013113 genomes. Global alignment of the Psymv2 genome and these ...
Brominated diphenyl ethers (BDE47, 99, 100, and 209) were measured in air, snow and sea ice throughout western Antarctica between 2001 and 2007. BDEs in Antarctic air were predominantly associated with aerosols and were low compared to those in remote regions of the northern hemisphere, except in Marguerite Bay following the fire at Rothera research station in Sept 2001, indicating that this event was a local source of BDE209 to the Antarctic environment. Aerosol BDE47/100 reflects a mixture of commercial pentaBDE products; however, BDE99/100 is suggestive of photodegradation of BDE99 during long-range atmospheric transport (LRAT) in the austral summer. BDEs in snow were lower than predicted based on snow scavenging of aerosols indicating that atmospheric deposition events may be episodic. BDE47, -99, and -100 significantly declined in Antarctic sea ice between 2001 and 2007; however, BDE209 did not decline in Antarctic sea ice over the same time period. Significant losses of BDE99 and -100 from ...
The fluoride content of whole animals and different tissues of the euphausiid species Euphausia superba and Meganyctiphanes norvegica was analyzed by two different and improved methods of isolation an
If you have a question about this talk, please contact Claire Waluda.. If external to BAS, please email the organiser in advance to gain access to the building. The production of Antarctic krill oil is a large industry and is predicted to grow in the coming decades. Understanding how Antarctic krill lipids (oils) change in time and space is therefore of critical importance to maintaining a sustainable krill fishery. This study examined how the lipid and fatty acid content of Antarctic krill varies seasonally and spatially. We used samples of krill harvested by krill fishing vessels collected daily over a 3-year time period. Krill were staged, sexed, weighed and measured before undergoing lipid analysis. Our results show an annual fine-scale seasonal cycle for lipid content and composition in Antarctic krill. Levels of the ecologically and commercially important and health-benefitting omega 3 polyunsaturated fatty acids varied between seasons, giving us an enhanced insight into variations in the ...
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Lake Fryxell should be allected more strongly by the DIC input from streams than Lake Hoare because it receives much higher loads of DIC (tables 1 and 2). Using the modified formula, normalizing the DIC input with the lake area and assuming a mixing of the incoming stream water with the uppermost meter of the lakes water column, Lake Fryxell annually received 3.8%, 0.7% and 2.1% (average = 2.2%) of the DIC pool in the uppermost meter. The values for Lake Hoare are 9.3%, 5.5% and 5.5% (average = 6.8%). The absolute influx into Lake Hoare is much smaller, but because the lake has sucha low concentration of DIC it plays a more important role than in Lake Fryxell.. Primary productivity rates (PPRs) from Priseu (1995) were used to compare the average annual uptake of carbon at various lake depths with the available DIC At 5-8m depth, the annual uptake accounts for 0.43% of the DIC in Lake Hoare, and for 0.76% of the DIC in Lake Fryxell. These ratios are very similar, given that the PPR in Lake ...
Antarctica is an attractive target for human exploration and scientific investigation, however the negative effects of human activity on this continent are long lasting and can have serious consequences on the native ecosystem. Various areas of Antarctica have been contaminated with diesel fuel, which contains harmful compounds such as heavy metals and polycyclic aromatic hydrocarbons (PAH). Bioremediation of PAHs by the activity of microorganisms is an ecological, economical and safe decontamination approach. Since the introduction of foreign organisms into the Antarctica is prohibited, it is key to discover native bacteria that can be used for diesel bioremediation. By following the degradation of the PAH phenanthrene, we isolated 53 PAH metabolizing bacteria from diesel contaminated Antarctic soil samples, with three of these isolates exhibiting a high phenanthrene degrading capacity. In particular, the Sphingobium xenophagum D43FB isolate showed the highest phenanthrene degradation ability,
Mycosporine-like amino acids (MAAs) that absorb UV radiation (310-360 nm) were investigated in 34 species of benthic marine invertebrates (fourteen sponges, two cnidarians, one nemertean, four molluscs, one bryozoan, two arthropods, eight echinoderms and two tunicates), two species of benthic fish and two species of red algae collected during the spring of 1992 from McMurdo Sound. In addition, MAAs were measured in the ripe ovaries, testes and brooded juveniles of four species of echinoderms. While 90% of the: species had MAAs in their tissues, both quantitative and qualitative measurements reflected a general lack of UV protectants among these fauna. Eight MAAs were detected among the species examined, but only four of these (mycosporine-glycine, shinorine, porphyra-334 and palythine) occurred in any appreciable number: of the species. Palythinol only occurred in the sponge Isodictya erinacea and asterina-330 and palythene only occurred in the red alga Iridaea cordata. MAAs were detected in the ...
Mitochondrial biogenesis is induced by low temperature in many fish species. For example, cold acclimation of Gasterosteus aculeatus (threespine stickleback) increases mitochondrial densities in oxidative skeletal muscle. Oxidative muscles of Antarctic icefishes (suborder Notothenioidei) also have high mitochondrial densities characterized by higher densities of phospholipids compared to red-blooded notothenioids. Mitochondrial biogenesis has been well studied in mammals yet it is unknown how mitochondrial phospholipid synthesis is regulated. I hypothesized that both activity and mRNA levels of glycerol-3-phosphate acyltransferase (GPAT), the rate-limiting enzyme in glycerolipid biosynthesis, would increase in oxidative muscle of stickleback, where mitochondrial biogenesis occurs, but not in liver, in response to cold acclimation, and that GPAT1 and /or GPAT2 mRNA levels would be higher in hearts of icefishes compared to red-blooded species. To test these hypotheses, maximal activity of GPAT and ...
Osumex 100% Pure Antarctic Krill Oil capsules are produced entirely from Antarctic Krill harvested from deep in the Antarctic Ocean. The oils are sent to Japan for encapsulation in vegetable soft gel capsules.. Krill oil is rich in Omega-3 Fatty Acids and Astaxanthin, a powerful antioxidant attached to the Omega-3. Astaxanthin is recognized for its health promoting free radical suppression. No additives or preservatives are used in the production of the krill oil capsules.. The long-chain Omega-3 fatty acids in krill oil are a phospholipid which is soluble in blood compared to the Omega-3 in fish oil which is a triglyceride which is not soluble in blood. This enables the Omega-3 to be able to cross the blood-brain barrier and are more bio-available to the body. Omega-3 bound phospholipid are far less prone to oxidations than Omega-3 in traditional triglycerides form giving it a longer shelf-life.. ...
Healthy Origins® Krill Oil is extracted from the Euphausia superba species of Krill found in the Antarctic waters of the southern ocean. Euphausia superba, with a biomass of over 500,000,000 tons, is one of the most abundant life forms on the planet. Since the 19th century, krill has been harvested as a food source for
Healthy Origins® Krill Oil is extracted from the Euphausia superba species of Krill found in the Antarctic waters of the southern ocean. Euphausia superba, with a biomass of over 500,000,000 tons, is one of the most abundant life forms on the planet. Since the 19th century, krill has been harvested as a food source for
Krill oil has gained attention not only for its Omega-3 fatty acids but for its bioavailability and Astaxanthin content. Research suggests that the bioavailability of Krill oil may be high because much of the EPA and DHA are bound to phospholipids which aid in the efficient transfer of essential nutrients to the bodys cells.* The Omega-3 Phospholipids and Astaxanthin in Krill oil help to support healthy heart, brain, eyes and liver functions.*. California Gold Nutrition Antarctic Krill Oil features RIMFROST Krill Oil with naturally occurring (not fortified) Astaxanthin that is sourced responsibly from the pristine waters of the Southern Ocean. The Fish Gelatin Softgels are manufactured in California, USA and a natural Strawberry and Lemon flavor is added to help mask any unpleasant fishiness.. ♦️Natural Flavor Coating Added to Help Mask Natural Krill Oil Aroma.. RIMFROST Antarctic Krill / Sustainable + Traceable + Transparent + Gently Processed = Premium Quality Krill Oil You Can ...
Polar regions are particularly sensitive to climate change, with the potential for significant feedbacks between ocean circulation, sea ice, and the ocean carbon cycle. However, the difficulty in obtaining in situ data means that our ability to detect and interpret change is very limited, especially in the Southern Ocean, where the ocean beneath the sea ice remains almost entirely unobserved and the rate of sea-ice formation is poorly known. Here, we show that southern elephant seals (Mirounga leonina) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice zone, allowing the major fronts to be mapped south of 60°S and sea-ice formation rates to be inferred from changes in upper ocean salinity. Sea-ice production rates peaked in early winter (April-May) during the rapid northward expansion of ...
Modern tracking technology and international collaboration have given IMAS researchers and their colleagues from eight countries unprecedented new insights into the life, behaviour and distribution of southern elephant seals.
Krill oil is an extract prepared from a species of Antarctic krill, Euphausia superba. Two of the most important components in krill oil are omega-3 fatty acids similar to those in fish oil, and phospholipid-derived fatty acids (PLFA), mainly phosphatidylcholine (alternatively referred to as marine lecithin). Studies have shown toxic residues in Antarctic krill and fish; however, the United States Food and Drug Administration has accepted notices from krill oil manufacturers declaring that krill oil and products derived from it meet the standards for Generally Recognized as Safe (GRAS) status, although the FDA itself has not tested the products. While not an endangered species, Antarctic krill are a mainstay of the diets of many ocean-based species including whales and there is some environmental and scientific concern that their population has decreased dramatically both due to climate change and human harvesting. Krill oil and oceanic fish oil are rich in omega-3 fatty acids, mainly ...
ABSTRACT The diploid chromosome number 2n = 24 has been established in the harpacticoid copepod Tigriopus sp. coming from Kerguelen Island, while the population of Tigriopus inhabiting Crozet Island possesses the diploid number 2n = 22. The two populations differ also in homogeneity of the karyotype, thereby further supporting the hypothesis that these two populations belong to different species.
Sustainably Harvested Antarctic Krill: Antarctic krill oil is considered the purest krill oil in the world and an eco-friendly alternative to fish omega fatty acids. NordVida consistently utilizes sustainably harvested krill in the pristine waters of Antarctica yielding highly concentrated omega-3s EPA and DHA your body cant produce on its own. Every 1000 mg serving is rich in naturally occurring phospholipids and esterified astaxanthin for added antioxidant and overall benefits.*Phospholipid-Bound Omega-3S for Joint Heart & Brain*: Not all Omega-3s are created equal. NordVida Krill Oil taking the form of phospholipids can be more easily transported to and absorbed into our cells to boost our omega-3 index.* Increased omega levels in the body have been scientifically linked to optimal heart, brain, joint, eye and skin health, and they contribute to reducing inflammation in the body.*No Fish Burps & Fishy Aftertaste: Yes, you can reap all the benefits from your inflammation-fighting omega-3s without
The distribution of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) was examined in lead water in pack ice of the Weddell Sea. Samples were taken by pulling water into a syringe from a series of depths from 0,002 m to 4 m and deeper. Concentrations ofDMS, DMSP and DMSO remained low throughout the water column relative to surface water, which was highly enriched. Concentrations of the major sulfur compounds increased by over an order of magnitude during periods with smooth surface water conditions. This increase coincided with a profound stratification of the water column, caused by a decrease in salinity of near surface water. We estimate that the DMS emission from leads and open water in Antarctic sea ice could contribute significantly to the yearly DMS flux from the Southern Ocean.. ...
Phospholipids are one of the major bioactive ingredients of Antarctic krill Euphausea superba. A feasible and effective extraction method of Antarctic krill oil was investigated and modified by orthogonal test which the ratio of solid to liquid was 1:2.5, extraction time was 5 min, ratio of ethyl acetate (EA) and n-butanol (BuOH) was 1:1. With this method, the extract of krill oil has a higher phospholipids content of 27.7% - 42.3%, together with total oil yields of 4.15% - 6.18%.
Weddell seals in McMurdo Sound pup on the sea ice from the middle of October to early November. They weigh about 65 Ib. at birth (Bertram, 1940), double their weight in 10 days, and are page 135 weaned in six to eight weeks. From this point until they return to breed as three year olds, little is known of their habits. It has been postulated they go into the pack ice or along the northern inaccessible coast (Smith, 1966a) although it is not indicated whether this means the Victoria Land Coast, the periphery of the continent, or both. However, this postulation is based on the negative evidence that young seals have never been seen in large numbers anywhere.. Females first become pregnant at three years of age and have one pup a year thereafter. One female was found pupping in her third year, thus having bred in its second year, but this is exceptional (Smith, 1966a). Twinning is virtually non-existent. Weddell seals may live to 15 or 16 years of age but the average age in McMurdo Sound is about ...
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Emperor penguins have shown to be not as attached to their nesting locations as previously thought, meaning that they could adapt much easier to their chan
Very little is known about the mechanism of antifreeze action of antifreeze glycoproteins (AFGPs) present in Antarctic teleost fish. Recent NMR and CD studies assisted with total synthesis of synthetic AFGP variants have provided insight into the structure of short AFGP glycopeptides, though the observations did not yield information on the antifreeze mechanism of action. In this study, we use Hamiltonian replica exchange (HREX) molecular dynamics simulations to probe the structure and surrounding aqueous environments of both the natural (AFGP8) and synthetic (s-AFGP4) AFGPs. AFGPs can adopt both amphiphilic and pseudoamphiphilic conformations, the preference of which is related to the proline content of the peptide. The arrangement of carbohydrates allows the hydroxyl groups on terminal galactose units to form stable water bridges which in turn influence the hydrogen-bond network, structure, and dynamics of the surrounding solvent. Interestingly, these local effects lead to the perturbation of ...
New U-Pb SHRIMP ages from East Antarctica point to the existence of a laterally continuous orogenic belt that bisects the East Antarctic craton. This orogenic belt juxtaposes Archean crust to the south and east against Neoproterozoic metamorphic rocks to the north and west. It defines the margin of a separate lithospheric block that consists of a large section of East Antarctica and India that did not form part of east Gondwana or Rodinia as they are currently reconstructed. Instead, this Indo-Antarctic continent accreted with west Gondwana along the Mozambique suture shortly before collision and suturing along a second Pan-African suture now cropping out in the southern Prince Charles Mountains and Prydz Bay regions of Antarctica. This scenario is consistent with (1) the abrupt termination of ca. 990-900 Ma tectonism recognized in the northern Prince Charles Mountains-Rayner Complex-Eastern Ghats against Paleozoic orogenic belts, (2) the lack of terranes of equivalent age found elsewhere in ...
The chilly waters of the Southern Ocean are home to many different animals including eight types of whales, six types of seals, many types of fish, and Antarctic krill, a small shrimp-like animal. There are 17 types of penguins in Antarctica. Penguins are considered to be marine animals even though they live on land because they depend on the ocean for food. The Southern Ocean food chain begins like most marine food chains, with primary producers called phytoplankton. Through photosynthesis, phytoplankton convert the Sun s energy into food. Animals like Antarctic krill eat the phytoplankton and then larger animals such as penguins eat the krill ...
The Antarctic Ice Sheet stores water equivalent to 58 m in global sea-level rise. 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 giga-metric tonnes of carbon (GtC), Antarctica is projected to become almost ice-free with an average contribution to sea-level rise exceeding 3 m 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.. ...
AFGPs have evolved convergently in unrelated fishes from both Antarctic and Arctic seas to prevent freezing in these cold ice-laden environments. Previous studies have shown that AFGPs of Antarctic notothenioids are encoded by a family of polyprotein genes, with each gene encoding a large precursor containing multiple AFGP molecules linked in tandem by cleavable small spacers (Chen et al., 1997a). High concentrations of AFGPs circulate in the serum of several northern cods either through the whole year or during winter. The size and compositional heterogeneity has been reported for several species of northern cods, but only three AFGP genes from a partial genomic library of polar cod have been characterized. Four more polar cod B. saida AFGP gene sequences, their structures, and organization in the genome are reported here. Genomic Southern analysis indicates that a large AFGP gene family exists in its genome. A high percentage of the AFGP member genes appear to be arranged in tandem and ...
Abstract: In Antarctic waters, the superfamily Lysianassoidea is one of the most important amphipod groups both in terms of species number and abundance. Dominant members of this superfamily are species of the orchomenid complex, found throughout the Southern Ocean. This study presents the first molecular phylogenetic analysis based on a representative subset of the Antarctic species belonging to different ... orchomenid genera and hence provides a framework for a systematic revision of these taxa. The current classification of the orchomenid genera is mainly based on mouthpart morphology. The validity of these morphological characters was assessed by resolving phylogenetic relationships using nuclear 28S rRNA and mitochondrial cytochrome oxidase subunit I sequences. The molecular data rejected most of the previously proposed taxonomic subdivisions within this complex. The genera Abyssorchomene and Orchomenella as well as the subgenus Orchomenopsis appeared to be non-monophyletic ...
Glaciers are present on every continent and approximately fifty countries, excluding those (Australia, South Africa) that have glaciers only on distant subantarctic island territories. Extensive glaciers are found in Antarctica, Chile, Canada, Alaska, Greenland and Iceland. Mountain glaciers are widespread, especially in the Andes, the Himalayas, the Rocky Mountains, the Caucasus, Scandinavian mountains and the Alps. Mainland Australia currently contains no glaciers, although a small glacier on Mount Kosciuszko was present in the last glacial period.[33] In New Guinea, small, rapidly diminishing, glaciers are located on its highest summit massif of Puncak Jaya.[34] Africa has glaciers on Mount Kilimanjaro in Tanzania, on Mount Kenya and in the Rwenzori Mountains. Oceanic islands with glaciers include Iceland, several of the islands off the coast of Norway including Svalbard and Jan Mayen to the far North, New Zealand and the subantarctic islands of Marion, Heard, Grande Terre (Kerguelen) and ...
The Arctic trend is in fact more than three times faster than the Antarctic one. The net result is a statistically significant global decrease of more than a million km2.
The Arctic trend is in fact more than three times faster than the Antarctic one. The net result is a statistically significant global decrease of more than a million km2.
Eucarida is a superorder of the Malacostraca, a class of the crustacean subphylum, comprising the decapods, krill, Amphionides and Angustidontida. They are characterised by having the carapace fused to all thoracic segments, and by the possession of stalked eyes.. Eucarida is a diverse and abundant group, comprising the following four orders:. The members of the Euphausiacea are commonly called krill and are all marine shrimp-like species whose pleopods (abdominal appendages) function as swimmerets. They swarm and mostly feed on plankton. This group is composed of only 90 species, some of which are the most abundant species on the planet; in fact, it is estimated that the biomass of the Antarctic krill Euphausia superba is 500 million tons.. Decapoda is a group with 15,000 species which have 5 pairs of thoracopods and a well-developed carapace that covers the gills (which are exposed in krill). They include lobsters, crabs, shrimp and prawns. The decapods are further subdivided on the basis of ...
Abstract Aim, The aim here was to assess whether the present-day assemblage of subantarctic flowering plants is the result of a rapid post-Last Glacial Maximum (LGM) colonization or whether subantarctic flowering plants survived on the islands in glacial refugia throughout the LGM. Location, The circumpolar subantarctic region, comprising six remote islands and island groups between latitudes 46 and 55 S, including South Georgia in the South Atlantic Ocean, the Prince Edward Islands, les Crozet, les Kerguelen, the Heard Island group in the South Indian Ocean and Macquarie Island in the South Pacific Ocean. Methods, Floristic affinities between the subantarctic islands were assessed by cluster analysis applied to an up-to-date dataset of the phanerogamic flora in order to test for the existence of provincialism within the subantarctic. A review of the primary literature on the palaeobotany, geology and glacial history of the subantarctic islands was carried out and supplemented with additional ...
Clean Antarctic Krill features K·REAL® Antarctic krill oil, which provides the omega-3 fatty acids (EPA and DHA) attached to phospholipids as well as to triglycerides. Clinical testing suggests that this molecular composition absorbs into red blood cells, reduces the n-6:n-3 PUFA ratio, and increases the omega-3 index
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Metadata record for data from ASAC Project 2899 See the link below for public details on this project. We conducted a genomic analysis of Archaea and Bacteria collected from lakes in the Vestfold Hills, Antarctica. This provided a new level of understanding about the life forms inhabiting these cold lakes. Linked to knowledge of meteorological, geological, chemical and physical data that has been collected over years of previous research, the new genomic data will generate a complete understanding of how the microorganisms have evolved and how they have transformed and presently interact with the Antarctic environment. Deriving an integrated understanding of microbial ecology is essential for determining ways of preserving the health of the Worlds ecosystems. The data are available for download as an excel spreadsheet and a word document from the URL given below. The GPS coordinates where samples were collected from are as follows: (Note these are UTM (Universal Transverse Mercator) ...
Recent advances in biotechnology have allowed the study of new bacterial strains, which can produce enzymes that can be used in the bioremediation of heavy metals. Microbially induced carbonate precipitation (MICP) is a recent well-recognized process that has the potential to precipitate heavy metals, mainly those with a valency of +2 (Kumari et al., 2016). There are two enzymes, urease and carbonic anhydrase, that play an important role in the MICP process. The role of carbonic anydrase (EC 4.2.1.1) in MICP is generally underestimated and most of the studies in past mainly focus on urease-producing microorganisms (Li et al., 2013; Kumari et al., 2014; Li et al., 2014).In the present study, Psychrobacter sp. SHUES1 was isolated from frozen alkaline soil sample collected at Shanghai, China. This bacterium produced lipase and protease at 4°C in a plate assay. The ability of Psychrobacter sp. to show extracellular lipolytic activity at low temperatures is widely known (Xuezheng et al., 2010); however, the
Turning microplastics into nanoplastics through digestive fragmentation by Antarctic krill. Amanda L. Dawson, So Kawaguchi, Catherine K. King, Kathy A. Townsend, Robert King, Wilhelmina M. Huston & Susan M. Bengtson Nash. Microplastics (plastics ,5 mm diameter) are at the forefront of current environmental pollution research, however, little is known about the degradation of microplastics through ingestion. Here, by exposing Antarctic krill (Euphausia superba) to microplastics under acute static renewal conditions, we present evidence of physical size alteration of microplastics ingested by a planktonic crustacean. Ingested microplastics (31.5 µm) are fragmented into pieces less than 1 µm in diameter. Previous feeding studies have shown spherical microplastics either; pass unaffected through an organism and are excreted, or are sufficiently small for translocation to occur. We identify a new pathway; microplastics are fragmented into sizes small enough to cross physical barriers, or are ...