Sven Ramdohr
Alfred Wegener Institute for Polar and Marine Research
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Featured researches published by Sven Ramdohr.
Antarctic Science | 2000
Horst Bornemann; Martin Kreyscher; Sven Ramdohr; Torge Martin; Alejandro R Carlini; Lutz Sellmann; Joachim Plötz
Weaned pups and post-moult female elephant seals (Mirounga leonina) were fitted with satellite transmitters at King George Island (South Shetland Islands) between December 1996 and February 1997. Of the nine adult females tracked for more than two months, three stayed in a localized area between the South Shetland Islands and the South Orkney Islands. The other six females travelled south-west along the coast of the Antarctic Peninsula up to the Bellingshausen Sea. Two of them then moved north-east and hauled out on South Georgia in October. One female was last located north of the South Shetland Islands in March 1998. In total, eight females were again sighted on King George Island and six of the transmitters removed. The tracks of the weaners contrasted with those of the adults. In January, five juveniles left King George Island for the Pacific sector spending about four weeks in the open sea west of the De Gerlache Seamounts. Three of them returned to the tip of the Antarctic Peninsula in June, of which one was last located on the Patagonian Shelf in November 1997. The juveniles avoided sea ice while the adults did not. The latter displayed behavioural differences in using the pack ice habitat during winter. Some females adjusted their movement patterns to the pulsating sea ice fringe in distant foraging areas while others ranged in closed pack ice of up to 100%. The feeding grounds of adult female elephant seals are more closely associated with the pack ice zone than previously assumed. The significance of the midwater fish Pleuragramma antarcticum as a potential food resource is discussed.
Antarctic Science | 2009
Cheryl Ann Tosh; Horst Bornemann; Sven Ramdohr; Michelle L. Schroder; Torge Martin; Alejandro R Carlini; Joachim Plötz; Marthan Nieuwoudt Bester
Abstract Adult male southern elephant seals instrumented in 2000 on King George Island (n = 13), travelled both to the north (n = 2) and to the east (n = 6) of the Antarctic Peninsula. Five males remained within 500 km of the island focusing movements in the Bransfield Strait and around the Antarctic Peninsula. Sea surface temperatures encountered by these animals showed little variation. While animal trajectories appeared unaffected by sea ice cover, areas of shallow depths were frequented. Three males moved as far as 75°S to the east of the Peninsula with maximum distances of more than 1500 km from King George Island. They travelled into the Weddell Sea along the western continental shelf break until they reached the region of the Filchner Trough outflow. Here the sea floor consists of canyons and ridges that support intensive mixing between the warm saline waters of the Weddell Gyre, the very cold outflow waters and ice shelf water at the Antarctic Slope Front. The need for re-instrumentation of adult males from King George Island is highlighted to investigate whether males continue to travel to similar areas and to obtain higher resolution data.
Physiological and Biochemical Zoology | 2001
Alejandro R Carlini; M. E. I. Márquez; Sven Ramdohr; Horst Bornemann; H. Panarello; Gustavo Adolfo Daneri
Weaning mass in southern elephant seals is highly variable, the heaviest pups being three times as heavy as the lightest ones. After weaning, pups undergo an extensive postweaning period in which they draw on their reserves. To quantify the energy expenditure during the postweaning period, changes in mass, body composition, and postweaning duration were measured in southern elephant seals at King George Island, South Shetland Islands, Antarctica. Overall, mean pup weaning mass was \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape
Marine Pollution Bulletin | 2004
Helmut Goerke; Kurt Weber; Horst Bornemann; Sven Ramdohr; Joachim Plötz
Marine Ecology Progress Series | 2005
Regina Eisert; Olav T. Oftedal; Michael Lever; Sven Ramdohr; Bernhard H. Breier; Graham K. Barrell
154\pm 26
Journal of Morphology | 2001
Ulrich Welsch; Sven Ramdohr; Bernd Riedelsheimer; Rudolf Hebel; Regina Eisert; Joachim Plötz
Polar Biology | 2005
Alejandro R Carlini; G. A. Daneri; M. E. I. Márquez; Horst Bornemann; H. Panarello; Ricardo Casaux; Sven Ramdohr; Joachim Plötz
\end{document} kg ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape
Polar Biology | 2004
Alejandro R Carlini; M. E. I. Márquez; H. Panarello; Sven Ramdohr; G. A. Daneri; Horst Bornemann; Joachim Plötz
EPIC3In: Wiencke, C., Ferreyra, G., Arntz, W., Rinaldi, C. (eds), Reports on Polar Research, Alfred Wegener Institute for Polar and Marine Research, 299, pp. 243-248, ISBN: 0176-5027 | 1998
Sven Ramdohr; Joachim Plötz; Horst Bornemann; C. Engelschalk; J. Thiery; Regina Eisert
n=117
EPIC3In: Miller, H. (ed), Koordiniertes Programm Antarktisforschung, Berichtskolloquium im Rahmen des Koordinierten Programms Antarktisforschung mit vergleichenden Untersuchungen in arktischen Eisgebieten , Reports on Polar Research, Alfred Wegener Institut f, 277, pp. 15-16, ISSN: 0176-5027 | 1998
Horst Bornemann; Joachim Plötz; Sven Ramdohr; Lutz Sellmann