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Author Thomas, D.N.; Gleitz, M. url  openurl
  Title Allocation of photoassimilated carbon into major algal metabolite fractions: Variation between two diatom species isolated from the Weddell Sea (Antarctica) Type Journal Article
  Year 1993 Publication Polar Biology Abbreviated Journal Polar Biol  
  Volume 13 Issue 4 Pages 281-286  
  Keywords carbon fixation; metabolites; biomass; Nitzschia curta; Chaetoceros; Psw; Weddell Sea  
  Abstract Distribution of photoassimilated carbon into major metabolite classes differed between two Antarctic diatom species, Nitzschia curta and a small unicellular Chaetoceros sp.. Time course uptake studies (over 54 h) revealed that¹?C allocation appeared to be equilibrated after approximately 8 h at light saturated photosynthesis. During short term dark periods (6 h), polysaccharides as well as low-molecular-weight compounds were catabolised to sustain protein synthesis in the dark, whilst lipid reserves were not mobilised for this process. Experiments with these two species were conducted at 0 and -1.5 degree C, although no difference in the distribution of radiolabel was measured between the two temperatures. It is hypothesised that under near-optimal conditions fast growing species are characterised by a high carbon turnover associated with a rapid flow of newly assimilated carbon into polymeric compound classes. On the other hand, slower growing species (such as N. curta) may store a significant amount of surplus carbon in the low-molecular-weight metabolite fraction. Species specific preferences were observed when comparing the accumulation of radiolabel into the lipid pools.  
  Address  
  Corporate Author Thesis  
  Publisher Springer-Verlag Place of Publication (up) Heidelberg Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0722-4060 ISBN Medium  
  Area Expedition Conference  
  Notes Bibliogr.: 48 ref.; Marine Approved no  
  Call Number refbase @ admin @ Thomas+Gleitz1993 Serial 760  
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Author Thomas, D.N.; Kennedy, H.; Kattner, G.; Gerdes, D.; Gough, C.; Dieckmann, G.S. url  openurl
  Title Biogeochemistry of platelet ice: its influence on particle flux under fast ice in the Weddell Sea, Antarctica Type Journal Article
  Year 2001 Publication Polar Biology Abbreviated Journal Polar Biol  
  Volume 24 Issue 7 Pages 486-496  
  Keywords  
  Abstract An array of four sediment traps and one current meter was deployed under a well-developed platelet layer for 15 days in the Drescher Inlet in the Riiser Larsen ice shelf, in February 1998. Traps were deployed at 10 m (just under the platelet layer), 112 m (above the thermocline), 230 m (below thermocline) and 360 m (close to sea floor). There was a substantial flux of particulate organic material out of the platelet layer, although higher amounts were collected in the traps either side of the thermocline. Material collected was predominantly composed of faecal pellets containing diatom species growing within the platelet layer. The size classes of these pellets suggest they derive from protists grazing rather than from larger metazoans. Sediment trap material was analysed for particulate organic carbon/nitrogen/phosphorus (POC/PON/POP) and ?¹³CPOC (carbon isotopic composition of POC). These were compared with organic matter in the overlying platelet layer and the water column. In turn, the biogeochemistry of the platelet layer and water column was investigated and the organic matter characteristics related to inorganic nutrients (nitrate, nitrite, ammonium, silicate, phosphate), dissolved organic carbon/nitrogen (DOC/DON), pH, dissolved inorganic carbon (DIC), oxygen and ?¹³CDIC (carbon isotopic composition dissolved inorganic carbon).  
  Address  
  Corporate Author Thesis  
  Publisher Springer-Verlag Place of Publication (up) Heidelberg Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0722-4060 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Thomas++2001_2 Serial 762  
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Author Thomas, D.N.; Lara, R.J.; Eicken, H.; Kattner, G.; Skoog, A. url  openurl
  Title Dissolved organic matter in Arctic multi-year sea ice during winter: major components and relationship to ice characteristics Type Journal Article
  Year 1995 Publication Polar Biology Abbreviated Journal Polar Biol  
  Volume 15 Issue 6 Pages 447-483  
  Keywords sea ice; Arctic; Dom  
  Abstract Ice cores were collected between 10.03.93 and 15.03.93 along a 200 m profile on a large ice floe in Fram Strait. The ice was typical of Arctic multi-year ice, having a mean thickness along the profile of 2.56 ±0.53 m. It consisted mostly of columnar ice (83%) grown through congelation of seawater at the ice bottom, and the salinity profiles were characterized by a linear increase from 0 psu at the top to values ranging between 3 and 5 psu at depth. Distributions of dissolved organic carbon (DOC) and nitrogen (DON) and major nutrients were compared with ice texture, salinity and chlorophyll a. DOC, DON, dissolved inorganic nitrogen (DIN), NH?? and NO?? were present in concentrations in excess of that predicted by dilution curves derived from Arctic surface water values. Only NO?? was depleted, although not exhausted. High DOC and DON values in conjunction with high NH?? levels indicated that a significant proportion of the dissolved organic matter (DOM) was a result of decomposition/grazing of ice algae and/or detritus. The combination of high NH?? and NO?? points to regeneration of nitrogen compounds. There was no significant correlation between DOC and Chl a in contrast to DON, which had a positively significant correlation with both salinity and Chl a, and the distribution of DOM in the cores might best be described as a combination of both physical and biological processes. There was no correlation between DOC and DON suggesting an uncoupling of DOC and DON dynamics in multi year ice.  
  Address  
  Corporate Author Thesis  
  Publisher Springer-Verlag Place of Publication (up) Heidelberg Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0722-4060 ISBN Medium  
  Area Expedition Conference  
  Notes D Approved no  
  Call Number refbase @ admin @ Thomas++1995 Serial 763  
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Author Thomas, D.N. url  isbn
openurl 
  Title Frozen Oceans – The floating world of pack ice Type Book Whole
  Year 2004 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract Pack ice is a layer of frozen seawater on the top of the polar oceans, varying in thickness from a few centimetres to tens of metres. It is an ephemeral feature, not just of polar regions but also of seas such as the Baltic, Caspian and Sea of Okhotsk. At its maximum extent it covers 13% of the Earth's surface area, making it one of the major biomes on the planet.For many years seen as an obstacle to trade and a threat to human life, the ice itself is now perceived to be vulnerable as we come to realize the dangers posed by global warming. Sea ice not only dominates polar regions but is also central to global ocean circulation as well as global climate patterns. Every year the formation, consolidation and subsequent melt of millions of square kilometres of ice influence the whole of the ocean's ecosystems.This is the first book to offer the general reader access to a remote frozen habitat which has for so long fascinated explorers, writers and scientists. During the harsh polar winter the surface of the ocean freezes up, forming a temporary ice layer called pack ice, or sea ice. This gives rise to a spectacular floating world which for a number of months each year becomes home to a wealth of plant and animal life. The wonderful colour photographs of life on, in and under the ice help draw the reader into this superb account of an extreme environment. Guaranteed to capture the imagination.The author is a veteran of six expeditions to the Arctic and Antarctic, and this book is packed with photographs taken in the course of his journeys. His lively and readable text conveys his excitement at the dangers and possibilities of life on the ice. He provides an in-depth background to the whole ecosystem of sea ice, its living communities and the structure of the ice itself. The level of accurate scientific detail will satisfy anyone looking for a reliable, up-to-date overview of this topic.  
  Address  
  Corporate Author Thesis  
  Publisher Natural History Museum Place of Publication (up) London Editor Coyne, C.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 0-565-09188-3 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Thomas2004 Serial 756  
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Author Thomas, D.N.; Dieckmann, G.S. openurl 
  Title Biogeochemistry of Antarctic sea ice Type Journal Article
  Year 2002 Publication Oceanography and Marine Biology: An Annual Review Abbreviated Journal Oceanogr Mar Biol Annu Rev  
  Volume 40 Issue Pages 143-169  
  Keywords Sea ice; Biogeochemistry; Nutrients (mineral); Dissolved gases; Dissolved organic matter; Ps; Antarctic Ocean  
  Abstract Antarctic sea ice at its maximum extent in winter covers 40% of the Southern Ocean in a frozen layer, on average, 1 m thick. Sea ice is not solid, rather it is an ice crystal matrix permeated by a labyrinth of brine filled channels and pores in which life thrives. Organisms are constrained by a set of physicochemical factors quite unlike anything they encounter in the plankton from where they are recruited. Because sea ice is increasingly viewed as a suitable proxy for life in previous periods of the Earth's history, and even for astrobiology, it is pertinent that the physicochemical constraints acting upon sea-ice biology are better understood. The, largely microbial, network that develops in the ice itself imparts a unique chemistry that influences the nature and chemical composition of biogenic material released from the ice. This chemistry can result in the export of material to the sediments with distinctive chemical signatures that are useful tools for reconstructing past sea-ice cover of the oceans. This review synthesises information on inorganic nutrient, dissolved organic matter and dissolved gases from a variety of Antarctic ice habitats.  
  Address  
  Corporate Author Thesis  
  Publisher Taylor & Francis Place of Publication (up) London Editor Gibson, R.N.; Barnes, M.; Atkinson, R.J.A.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0415254620 ISBN Medium  
  Area Expedition Conference  
  Notes Review; Marine Approved no  
  Call Number refbase @ admin @ Thomas+Dieckmann2002 Serial 758  
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