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  • 1
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    Springer
    In:  Berlin, Springer, vol. 20, no. Publ. No. 12, pp. 23-40, (ISBN 1-4020-3326-5, VIII + 343 pp.)
    Publication Date: 1998
    Keywords: Global ; Change ; development ; fuzzy ; decision ; making ; ecology ; climate ; TBMeteorology ; agriculture ; emission ; wealth ; politics ; greenhouse ; ozone ; Modelling ; carbon ; dioxide ; CO2
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  • 2
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    In:  New York, Springer, vol. 8, no. Publ. No. 12, pp. 95-104, (ISBN 0-7868-6844-9)
    Publication Date: 1991
    Keywords: Dislocation ; Dynamic ; Rheology ; Inelastic ; Textbook of geophysics ; Textbook of physics ; Textbook of mineralogy
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  • 3
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    In:  Berlin, Springer, vol. 4, no. ALEX(01)-FR-77-01, AFTAC Contract F08606-76-C-0025, pp. 329, (ISBN 0-89871-507-5)
    Publication Date: 1991
    Description: Abschnitt 2.6 Bohrlochgeophysik, 10 S.
    Keywords: Engineering geophys. ; Textbook of geophysics ; Geoelectrics ; Seismics (controlled source seismology) ; Gravimetry, Gravitation ; RADAR ; Borehole geophys.
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  • 4
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    In:  Polar Biology, 11 (4). pp. 253-258.
    Publication Date: 2018-08-10
    Description: The moult fast in emperor penguin (Aptenodytes forsteri) chicks was studied during January 1990 at Drescher Inlet, eastern Weddell Sea. In early January feeding of the chicks had stopped and about 4,000–5,000 chicks were in the inlet. The number of starving chicks decreased rapidly until 26 January when all chicks had either left the inlet or died. Mean body mass loss of starving chicks was 257 g/day and the evaluated specific daily mass loss was 25 g/kg body mass. The critical body mass, i.e. the mass below which chicks die, during moulting starvation was estimated to be 4 kg. Mean body mass was higher and mass loss lower in chicks at more advanced moult stages. Chicks left the inlet before moult was completed, although the sea-ice was still stable.
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  • 5
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    In:  Marine Geophysical Researches, 20 (3). pp. 239-247.
    Publication Date: 2018-02-08
    Description: Bottom shots have been used for a number of years in seismic studies on the ocean floor. Most experiments utilized explosives as the energy source, though researchers have recognized the usefulness of collapsing water voids to produce seismoacoustic signals. Implosive sources, however, suffered generally from a lack of control of source depth. We present a new experimental tool, called SEEBOSEIS, to carry out seismic experiments on the seafloor utilizing hollow glass spheres as controlled implosive sources. The source is a 10-inch BENTHOS float with penetrator. Inside the sphere we place a small explosive charge (two detonators) to destabilize the glass wall. The time of detonation is controlled by an external shooting device. Test measurements on the Ninetyeast Ridge, Indian Ocean, show that the implosive sources can be used in seismic refraction experiments to image the subbottom P- wave velocity structure in detail beyond that possible with traditional marine seismic techniques. Additionally, the implosions permit the efficient generation of dispersed Scholte waves, revealing upper crustal S-wave velocities. The frequency band of seismic energy ranges from less than 1 Hz for Scholte modes up to 1000 Hz for diving P-waves. Therefore, broadband recording units with sampling rates 〉2000 Hz are recommended to sample the entire wave field radiated by implosive sources.
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  • 6
    Publication Date: 2020-07-30
    Description: The areas of marine pollen deposition are related to the pollen source areas by aeolian and fluvial transport regimes, whereas wind transport is much more important than river transport. Pollen distribution patterns ofPinus, Artemisia, Chenopodiaceae-Amaranthaceae, and Asteraceae Tubuliflorae trace atmospheric transport by the northeast trades. Pollen transport by the African Easterly Jet is reflected in the pollen distribution patterns of Chenopodiaceae-Amaranthaceae, Asteraceae Tubuliflorae, andMitracarpus. Grass pollen distribution registers the latitudinal extension of Sahel, savannas and dry open forests. Marine pollen distribution patterns of Combretaceae-Melastomataceae,Alchornea, andElaeis reflect the extension of wooded grasslands and transitional forests. Pollen from the Guinean-Congolian/Zambezian forest and from the Sudanian/Guinean vegetation zones mark the northernmost extension of the tropical rain forest.Rhizophora pollen in marine sediments traces the distribution of mangrove swamps. Only near the continent, pollen ofRhizophora, Mitracarpus, Chenopodiaceae-Amaranthaceae, and pollen from the Sudanian and Guinean vegetation zones are transported by the Upwelling Under Current and the Equatorial Under Current, where those currents act as bottom currents. The distribution of pollen in marine sediments, reflecting the position of major climatic zones (desert, dry tropics, humid tropics), can be used in tracing climatic changes in the past.
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  • 7
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    In:  Deutsche Hydrographische Zeitschrift, 44 (5-6). pp. 321-327.
    Publication Date: 2018-03-05
    Description: In den 1980er Jahren wurden umfangreiche Bestandsaufnahmen zur Formenvielfalt der Fischkrankheiten sowie der saisonalen und regionalen Fluktuation ihrer Befallsraten in deutschen Küstengewässern angestellt. Sowohl Formenvielfalt als auch viele der Befallsraten scheinen im Wattenmeer und insbesondere in den dortigen Flußmündungen größer zu sein als in Vergleichsgewässern. Drei “neue” Krankheitsformen werden vorgestellt: die nahrungsinduzierte Maulgranulomatose des Stints, die vermutlich durch Flexibacter-Bakterien verursachte Gelbe Pest des Kabeljaus und eine Fibrom des Steinpickers, in dem lentivirusähnliche Partikel nachgewiesen wurden. Das Schwergewicht der bisherigen Forschungsvorhaben lag auf dem Sammeln von Felddaten. Mangels experimenteller Arbeitsansätze müssen viele wichtige Fragen zur Bedeutung dieser Krankheiten daher heute noch unbeantwortet bleiben. So bleibt die Vermutung unbewiesen, daß ein Reihe von parasitenbedingten Krankheiten einen entscheidenden Beitrag zur natürlichen Sterblichkeit vor allem von jungen Nutzfischen im Wattenmeer liefert. Auch das komplizierte Wirkungsgefüge anthropogener und natürlicher Faktoren bei der Entstehung von Fischkrankheiten im Gebiet wird ohne gezielte experimentelle Arbeiten nicht aufzudecken sein. Das Auftreten von Gelber Pest, Ichthyophonus-Krankheit und lentivirusähnlichen Partikeln in Fischtumoren stellt ein beträchtliches Gefährungspotential für die deutsche Fischwirtschaft dar. Allgemein ist festzustellen, daß in Deutschland eine große Empfänglichkeit gegenüber Umweltproblemen auf dem Gebiet der Marinen Pathologie besteht. Die nationalen Forschungskapazitäten sind aufgrund anderer, meist kurzfristig angelegter Arbeitsschwerpunkte jedoch nicht ausreichend darauf vorbereitet, diese Probleme auch erfolgreich zu analysieren und zu bewerten. Als Konsequenz wird gefordert, der bislang vernachlässigten Grundlagenforschung auf dem Gebiet der Marinen Pathologie neben der reinen Datenerhebung auf See künftig eine größere Bedeutung zuzumessen. Das gilt insbesondere für experimentelle und für biochemisch- und mikroskopisch-diagnostische Arbeiten. Künftig auftretende Probleme werden nur dann rechzeitig zu bewerten und zu lösen sein, wenn sich ein ausreichend breit angelegtes und fundiertes Wissenspotential kontinuierlich weiterentwickeln kann.
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  • 8
    Publication Date: 2020-07-14
    Description: The present study demonstrates that a distinct land-associated community of mesopelagic micronekton exists around the Hawaiian Islands. This “mesopelagic-boundary community” replaces the oceanic mesopelagic community over bottom depths of approx 400 to 700 m and includes about 14 species of fishes, 5 of shrimps and 4 of squids. Similar species of the mesopelagic micronekton have been reported in association with other landmasses at the boundary between the oceanic mesopelagic realm and upper continental or island slopes. These species may form a cosmopolitan “mesopelagic-boundary community” which shows regional differences in taxonomic composition, abundance and diversity. Boundary communities, with populations which are both tightly constrained geographically and relatively accessible to shore-based research programs, offer unique opportunities for studying biological processes of the mesopelagic realm and the interactions between neritic and oceanic populations. Data is presented from three midwater and two neuston sampling projects undertaken around the main Hawaiian Islands between 1987 and 1989; additional evidence from the literature is also discussed.
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  • 9
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    In:  Polar Biology, 11 (5). pp. 305-309.
    Publication Date: 2020-06-10
    Description: A seabird and mammal census was carried out in the north-eastern Weddell Sea during the austral winter of 1986. The German research icebreaker Polarstern operated in heavy pack ice along the Greenwich Meridian between the northern sea ice boundary and the Antarctic coast. Crabeater seals (Lobodon carcinophagus), minke whales (Balaenoptera acutorostrata), Adélie penguins (Pygoscelis adeliae), Antarctic petrels (Thalassoica antarctica) and snow petrels (Pagodroma nivea) were found to be more abundant in the vicinity of the submarine Maud Rise, about 700 km north of the continental margin, than in other areas of substantial ice cover traversed during that cruise. The aggregations of birds and mammals are expected to reflect aggregations of their principal food, krill (Euphausia superba) wintering underneath the ice cover. The distribution pattern of krill predators coincides with the course of a warm water belt upwelling near Maud Rise. This upwelling could induce local ice melting which in turn may result in an increased release of sea ice algae.
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  • 10
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    In:  In: The biology of Latimeria chalumnae and evolution of coelacanths. Developments in environmental biology of fishes, 12 . Springer, Dordrecht, pp. 287-300.
    Publication Date: 2017-08-03
    Description: In 1987 and 1989 coelacanths were observed for the first time in their natural habitat with the help of submersibles. Coelacanths were found between 150–253 m depth, their preferential depth seems to be around 200 m; the water temperature ranged between 16.5–22.8° C. During the day coelacanths aggregate in small non-aggressive groups in sheltered lava-caves. Caves might be a limiting factor for distribution. At night they leave the caves for hunting by drifting singly along the steep lava slopes. They migrate between different caves located within a large home range covering more than 8 km coastline. Coelacanths are site-attached, some for a period of at least 2 years. Our own observations and earlier catch records show that only the west coast of Grand Comoro is a suitable coelacanth habitat with more structural complexity and prey fish abundance than other coastlines of the island. From our survey we estimated a total coelacanth population off Grand Comoro to be 150–210 individuals; a saturated population would be 370–510 individuals. This small relict population seems to be stable. International protection of coelacanths against commercial interests is needed.
    Type: Book chapter , NonPeerReviewed
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  • 11
    Publication Date: 2017-08-03
    Description: We report first observations on social behavior ofLatimeria chalumnae in its natural environment at around 200 m depth in the Comoro Archipelago, Western Indian Ocean. Coelacanths aggregate in small nonaggressive groups in sheltered lava-caves. They live in open site-attached social systems with individuals occupying large overlapping home ranges of more than 8 km coastline, some for a period of at least 2 years.
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  • 12
    Publication Date: 2019-09-23
    Description: This paper describes (i) the Recent distribution pattern of various types of carbonate sediments in Troms county (northern Norway), and (ii) the onset of carbonate sedimentation after the final deglaciation of the Fennoscandian ice-shield. The distribution of major facies belts is strongly dependent on hydrographic and topographic constraints. The main bulk of carbonate deposits is derived from maerl-producing coralline algal biotopes that are restricted to the photic zone of waveprotected areas and influenced by tidal currents. Furthermore, extended mollusc and echinoderm-rich arenites are present in the area investigated. In deeper subtidal areas, terrigenous sediments of Late Weichselian to Early Holocene age are preserved. However, these are strongly influenced by later winnowing processes, generating a coquina lag deposit that serves as a secondary hardground for a diverse fouling community. The Holocene facies successions can be seen in several raised outcrops, containing the transition from glacigenic to Recent non-glacigenic depositional conditions. Autochthonous radiocarbon dated rhodolith banks, which mark the onset of carbonate sedimentation, yielded surprisingly young ages of 5,500 YBP. Around 5,500 YBP, present-day oceanographic and climatic conditions had already been firmly established. This time-lag can be explained with the behaviour of postglacial sea level fluctuations in the area. From 10,000 their cooperation in this project. We address our sincere thanks specifically to Prof. T.O. Vorren, Dr. M. Hald, Dr. B. Gulliksen, Dr. J. Hansen, Dr. J.J. Møller, Dr. E. Thomsen, and Dr. G. Corner for their dedicate help in organizing our field trips in Troms and for extensive scientific discussions. Special thanks to capitain K. Bendiksen for his patience and professional skill while operating the vessel ‘OTTAR’ in the skerry area even under bad weather conditions. S. Rasmussen and G. Ellingsen assisted during the cruises and very kindly introduced us to the Norwegian way of life. Special thanks to the two reviewers (Prof. Dr. W.-Ch. Dullo and anonymus) for their critical but constructive remarks. J. Welling and Dr. M. Kaminski improved the language of the final version of the manuscript. This project is part of the German Science Foundation’s main research program ‘Globale und regionale Steuerungsprozesse biogener Sedimentation”. Financial support was kindly provided by the Deutsche Forschungs-gemeinschaft (He 1671/1-1, 2).
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  • 13
    Publication Date: 2018-03-21
    Description: In the Atlantic sector of the Southern Ocean, data from vertebrate predators and commercial fisheries suggests that the distribution of the ommast rephid squid Martialia hyadesi is related to the Antarctic Polar Frontal Zone, but it spreads further to the north in some years (Rodhouse, in press). A mass stranding of M. hyadesi occurred on Macquarie Island in 1971 (O'Sullivan et al. 1983) suggesting that its distribution is c ircumpolar (Rodhouse and Yeatman 1990). However, apart from a single beak collected from the s tomach of a wandering albatross at Mar ion Island (Imber and Berruti 1981) its presence has not, until now, been confirmed in the Indian Ocean sector and in particular it is not included in the list of cephalopods from the Kerguelenian Province (Lu and Mangold 1978). M. hyadesi is a major prey item of the grey-headed albatross, Diomedea chrysostoma, and the southern elephant seal, Mirounoa leonina, at South Georgia (Rodhouse et al. 1990; Rodhouse et al., unpublished data) and is present in the diet o f several other predators in the Scotia Sea area including the wandering albatross, Diomedea exulans (Rodhouse et al. 1987) and the giant petrels, Macronectes halli and M. gioanteus (Hunter 1983). It occasionally occurs as a significant by-catch in the lllex argentinus fishery on the Pa tagonian Shelf and has been taken during commercial squid jigging trials in the Scotia Sea at the Antarctic Polar Frontal Zone (Rodhouse, in press). It appears to have potential for commercial exploitation in the sub-Antarctic waters of the Atlantic sector of the Southern Ocean (Rodhouse 1990). In view of the ecological importance of M. hyadesi to Antarctic predators, and the likelihood that it will be commercially exploited in the future, it is important to thoroughly establish its geographical range, and in particular to confirm its circumpolar distribution.
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  • 14
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    In:  Naturwissenschaften, 78 . pp. 383-384.
    Publication Date: 2018-01-25
    Description: Seit jeher will der Geologe wissen, aus welchem Material die Erde besteht, wie ihre Struktur aussieht und welche physikalischen, chemischen und biologischen Vorgänge dabei im Laufe der Erdgeschichte zusammengewirkt haben. Indessen muß er sich, wie alle Historiker, auch heute noch weitgehend damit bescheiden zu ermitteln, wie und wann etwas geschehen ist, und nicht, warum. Daran ist vor allem die Komplexität der Fragen schuld und die Schwierigkeit, einschlägig zu experimentieren.
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  • 15
    Publication Date: 2016-01-13
    Description: We provide evidence that the symbiosis of fungal endophyte and plant host should only be defined in the broad sense as originally used by De Bary to mean the living together of organisms of different species. Using endophytic fungi that were isolated from healthy plant tissue,- we tested for the potential pathogenicity of the fungal isolates and did physiological experiments to understand the endophyte-host association. Due to the variability of the interaction with respect to the role of the endophyte and with respect to the physiological Status of both partners, only a definition of symbiosis that does not specify the advantages and disadvantages for the individual partners can accurately describe this interaction.
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  • 16
    Publication Date: 2018-05-29
    Description: Analogue experiments in part I led to the conclusion that pyroclastic flows depositing very high-grade ignimbrite move as dilute suspension currents. In the thermo–fluid–dynamical model developed, the degree of cooling of expanded turbulent pyroclastic flows dynamically evolves in response to entrainment of air and mass loss to sedimentation. Initial conditions of the currents are derived from column-collapse modeling for magmas with an initial H2O content of 1–3 wt.% erupting through circular vents and caldera ring-fissures. The flows spread either longitudinally or radially from source up to a runout distance that increases with higher mass flux but decreases with higher gas content, temperature, bottom slope and coarser initial grain size. Progressive dilution by entrainment and sedimentation causes pyroclastic currents to transform into buoyant ash plumes at the runout distance. The ash plumes reach stratospheric heights and distribute 30–80% of the erupted material as widespread co-ignimbrite ash. Pyroclastic suspension currents with initial mass fluxes of 107-1012 kg/s can spread for tens of kilometers with only limited cooling, although they move as supercritical, strongly entraining currents for the eruption conditions considered here. With increasing eruption mass flux, cooling during passage through the fountain diminishes while cooling during flow transport increases. The net effect is that eruption temperature exerts the prime control on emplacement temperature. Pyroclastic suspension currents can form welded ignimbrite across their entire extent if eruption temperature is To〉1.3.Tmw, the minimum welding temperature. High eruption rates, a large fraction of fine ash, and a ring-fissure vent favor the formation of extensive high-grade ignimbrite. For very hot eruptions producing sticky, partially molten pyroclasts, analysis of particle aggregation systematics shows that factors favoring longer runout also favor more efficient aggregation, which reduces runout. As a result, very high-grade ignimbrites cannot spread more than a few tens of kilometers from their source. In cooler pyroclastic currents, particles do not aggregate, and the sedimentation process may involve re-entrainment of particles, which potentially leads to more extensive cooling and longer runout; such effects, however, are only significant when net erosion of substrate occurs. Model results can be employed to estimate mass flux and duration of ignimbrite eruptions from measured ignimbrite masses and aspect ratios. The model also provides an alternative explanation of the observed decrease in H/Lratios with ignimbrite mass.
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  • 17
    Publication Date: 2016-11-14
    Description: Factors influencing the fate of ice algae released from melting sea ice were studied during a R V Polarstern cruise (EPOS Leg 2) to the northwestern Weddell Sea. The large-scale phytoplankton distribution patterns across the receding ice edge and small-scale profiling of the water column adjacent to melting ice floes indicated marked patchiness on both scales. The contribution of typical ice algae to the phytoplankton was not significant. In experiments simulating the conditions during sea ice melting, ice algae revealed a strong propensity to form aggregates. Differences in the aggregation potential were found for algal assemblages collected from the ice interior and the infiltration layer. Although all algal species collected from the ice were also found in aggregates, the species composition of dispersed and aggregated algae differed significantly. Aggregates were of a characteristic structure consisting of monospecific microaggregates which are likely to have formed in the minute brine pockets and channels within the ice. Sinking rates of aggregates were three orders of magnitude higher than those of dispersed ice algae. These observations, combined with the negligible seeding effect of ice algae found during this study, suggest that ice algae released from the melting sea ice are subject to rapid sedimentation. High grazing pressure at the ice edge of the investigation area is another factor eliminating ice algae released during melting. Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation
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  • 18
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    In:  Marine Biology, 111 . pp. 227-235.
    Publication Date: 2018-06-06
    Description: Zooplankton was sampled by a Rectangular Midwater Trawl (RMT 1 + 8) in Weddell Sea surface waters (0 to 300 m) between 66 and 78°S during austral summer (February – March 1983). Sixty-nine taxa including different developmental stages were considered and divided into 16 size classes between 〈1 and 〉39.5 mm length. Biomass was determined by taxon and size class for three different meso- and macroplankton communities in the oceanic region, on the northeastern shelf and on the southern shelf of the Weddell Sea. The highest biomass of 11.2 mg DW m−3 (3.4 g DW m−2) was found in the northeastern shelf community (70 to 74°S), where juvenile and adultEuphausia crystallorophias accounted for 3.7 mg DW m−3 (1.1 g DW m−2). Although not quantitatively sampled, early copepodite stages (CI to CIII) ofCalanoides acutus andCalanus propinquus ranked second with 2.7 mg DW m−3 (0.8 g DW m−2). Biomass in the northeastern shelf community was concentrated in the size ranges 1 to 4 mm and 19.5 to 39.5 mm. The oceanic community of the central Weddell Sea was dominated by copepods smaller than 5 mm, which made up half of the total oceanic biomass. The tunicateSalpa thompsoni (7.0 to 8.5 mm) was the dominant single species with 1.6 mg DW m−3 (0.5 g DW m−2). Euphausiids, mainly juvenile and adult krillEuphausia superba, comprised 1.2 mg DW m−3 (0.4 g DW m−2). Total standing stock in the oceanic community was 9.4 mg DWm−3 (2.8 g DW m−2). Lowest biomass values were found in the southern shelf community (south of 75°S) with 4.0 mg DW m−3 (1.2 g DW m−2), concentrated in the 1 to 4 mm and 14.5 to 34.5 mm size classes. Abundant species were the pteropodLimacina helicina (1 to 2 mm; 0.7 mg DW m−3; 0.2 g DW m−2) andE. crystallorophias (24.5 to 39.5 mm; 0.9 mg DW m−3; 0.3 g DW m−2). The data reveal that it is essential to distinguish among subsystems in the Southern Ocean. This leads to a better understanding of the structure and function of those pelagic food webs which represent alternatives to the paradigmatic krill-centered system.
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  • 19
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    In:  Springer, Berlin [u.a.], 475 pp. ISBN 3-540-63512-2
    Publication Date: 2012-01-27
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  • 20
    Publication Date: 2016-05-17
    Description: In the sediments of both of the investigated lakes, the tephra from the Mercato-Ottaviano eruption (Vesuvius, southern Italy) (ca. 7900 B.P.) could be identified. The palynological investigations show that from ca. 9000-7200 B.P. (8000-6000 cal B.C.) deciduous oak forests predominated, with only a few representatives of Mediterranean vegetation. At the transition to the central European Atlantic Period those forests changed to an open vegetation type, dominated byJuniperus andPhillyrea. At about 5500 B.P. (4400 cal B.C.), theJuniperus-Phillyrea vegetation was replaced byQuercus ilex woodland that still occurs on the island of Mljet today and is considered to be the natural vegetation of the Dalmatian coastland. The associated vegetation of theQ. ilex forests changed several times. At the beginning of theQ. ilex period,Juniperus values were still high, but soon they decreased andErica spread. In more recent times theQ. ilex forests were partially replaced by plantations ofPinus halcpensis. Indicators of human impact are sparse throughout the pollen record. Clear evidence for human influence exists only from ca. 3100 B.P. (1300 cal B.C.) whenJuglans andPinus halepensis were introduced to the area. Later,Olea andSecale cultivation can be suggested and further spreading ofJuniperus indicates use of the land as pasture.
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  • 21
    Publication Date: 2018-03-02
    Description: The dependence of results from coarse-resolution models of the North Atlantic circulation on the numerical advection algorithm is studied. In particular, the sensitivity of parameters relevant for climate simulations as e.g., meridional transport of mass and heat and main thermocline thickness is investigated. Three algorithms were considered: (a) a central difference scheme with constant values for horizontal and vertical diffusion, (b) an upstream scheme with no explicit diffusion, and (c) a flux-corrected transport (FCT) scheme with constant and strictly isopycnal diffusion. The temporal evolution of the three models on time scales of centuries is markedly different, the upstream scheme resulting in much shorter adjustment time whereas the central difference scheme is slower and controlled by vertical diffusion rather than advection. In the steady state, the main thermocline structure is much less diffusive in the FCT calculation which also has much lower heat transport. Both horizontal circulation and overturning in the meridional-vertical plane are strongest in the upstream-model. The results are discussed in terms of the effective vertical (diapycnal) mixing in the different models. A significant increase in vertical resolution would be required to eliminate the high sensitivity due to the numerical algorithms, and allow physically motivated mixing formulations to become effective.
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  • 22
    Publication Date: 2020-06-30
    Description: Two strains of budding purple bacteria. Rhodobium sp. KR-36m and KR-54m, were isolated from freshwater sulfur-rich hot springs (Kunashire Island, the Kurils) and found to belong to facultative halophiles with a salinity optimum of 1-3%. By most of phenotypic criteria, these bacteria were close to the seawater species Rbi. marinum. They oxidized sulfide to sulfur in the course of photosynthesis, and were in this respect similar to Rbi. marinum: although Rbi. marinum had been described as oxidizing sulfide to sulfur and thiosulfate, the type strain Rbi. marinum DSM 2698 used in this work was found to oxidize sulfide only to sulfur. Based on phenotypic features and data on DNA-DNA homology, strains KR-36m and KR-54m were assigned to the species Rbi. marinum. Accordingly, the diagnosis of this species should be revised as follows: (I) Rbi. marinum oxidizes sulfide to sulfur in the process of photosynthesis, (2) requires thiamine and p-aminobenzoate, (3) and can inhabit freshwater environments, specifically, freshwater sulfur-rich hot springs.
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  • 23
    Publication Date: 2016-05-12
    Description: In 1992, the Ford gold deposit was rediscovered during field work in the Kwekwe district near the Indarama mine, approximately 200 km southwest of Harare, Zimbabwe. Based on diamond drilling and open pit operations, estimated ore reserves are at least 3 Mt with an average gold content of 2.5 g/t. The gold deposit is located within a porphyritic granite dike with a thickness of 20–50 m, striking 800 m NNW-SSE. It dips 60–70° to the NE and intrudes a volcano-sedimentary sequence of tholeiitic basalts, acid volcanics, and banded iron formations of the Bulawayan Group (2900–2700 Ma). The intrusion of the dike occurred at 2541 ± 17 Ma (Pb/Pb step leaching technique) within a second order structure and is related to displacement along transcrustal deformation zones such as the Sherwood- and Taba-Mali deformation zones. Gold mineralization is confined to the s-shaped part of the dike intrusion. At the present stage of mining, the deposit is characterized by the absence of major veins, the occurrence of disseminated pyrite throughout the orebody, and a distinct alteration pattern comparable to that of porphyry copper deposits. The central zone of the dike shows a typical K-feldspar-albite-sericite-pyrite (±biotite?) alteration, followed by a narrow external propylitic zone. Native gold with an average Ag content of 5 wt.% and a grain size of 5–100 μm is rare and occurs within pyrite and secondary K-feldspar. Sulphide mineral separates of pyrite and minor arsenopyrite probably contain invisible gold (up to 120 ppm) amenable to cyanidation. Anomalously high gold values of ∼7 ppm have been found in the transition between the K-feldspar-albite-sericite-pyrite alteration and the propylitic zone, indicating that the mineralizing fluids have experienced major physico-chemical changes in the transition zone. The regional tectonic position of the orebody suggests that the emplacement of the granite and the gold mineralization are structurally controlled. The Pb isotope composition of several leachates of pyrite indicate isotope disequilibrium with magmatic minerals and point to a contamination of the mineralizing fluid by Pb from older (sedimentary?) sources. Stable isotope geochemistry of sulphides and carbonates as well as the metallogeny of the deposit compare to shear-zone hosted gold mineralization in the Kwekwe district, for which a deep crustal origin has been discussed. Although this study documents contrasting evidence for a porphyry-gold versus a shear-zone type of mineralization, it is suggested that gold-bearing fluids were syntectonically introduced into a ductile shear zone within the granite dike either during cooling of the intrusion or later in Archaean or early Proterozoic times.
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  • 24
    facet.materialart.
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    In:  Naturwissenschaften, 78 . pp. 158-166.
    Publication Date: 2016-10-07
    Description: Planktonic foraminifera first appeared in the Early Jurassic, approx. 200 million years ago. They occurred in great abundance in the oceans only after an important marker Ievel of 130 million years (Early Cretaceous). Since that time, planktonic foraminifera are the most important first ranking Stratigraphie markers and indicators forachanging world's ocean. Knowledge of the ecological demands of living planktonic foraminifera help one to understand their environment in the past because of their high sensitivity to environmental changes; thus, they can be used to reconstruct the oceanic paleoclimate by means of their morphology, faunal assemblage and chemical composition.
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  • 25
    Publication Date: 2016-11-14
    Description: Fifty specimens of Notothenia coriiceps caught in Potter Cove, King George Island, were examined for ecto- and endoparasites. Of the 22 parasite species found, 18 were helminths, 2 were hirudineans and 2 were crustaceans. The isopod Aega antarctica and an unidentified hirudinean are reported for the first time from this fish host. Dominant parasites were the adults of Aspersentis megarhynchus, the invasive stage of Corynosoma spp. (cystacanth) and the adults of Macvicaria pennelli, with respective prevalences of infestation of 94, 76 and 74%. The preferred sites of infestation were the pylorus and intestine, where five different larval (nematodes and cestodes) and eight adult (digeneans and acanthocephalans) parasite species were found. No adult nematodes and cestodes were found and no parasites could be isolated from the musculature. The results of the present study are related to previous findings on the parasite fauna of N. coriiceps. The comparison implies a high parasite diversity in this benthic Antarctic fish species. Most parasites found appear to have a wide range of distribution within Antarctic waters together with a low host specificity. Besides its role as final host for several species of trematodes and acanthocephalans, N. coriiceps serves as transmitter of parasite larvae to piscivorous birds and seals. It is concluded that the parasite fauna in Antarctic fish species provides important insights into the different habitat use and trophic relationship of their fish hosts.
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  • 26
    Publication Date: 2016-05-12
    Description: The sulfur isotopic composition of sulfides and barite from hydrothermal deposits at the Valu Fa Ridge back-arc spreading center in the southern Lau Basin has been investigated. Sulfide samples from the White Church area at the northern Valu Fa Ridge have δ34S values averaging +3.8‰ (n= 10) for bulk sphalerite-chalcopyrite mineralization and +4.8‰ for pyrite (n= 10). Barite associated with the massive sulfides exhibits an average of +20.7‰ (n= 10). Massive sulfides from the active Vai Lili hydrothermal field at the central Valu Fa Ridge have much higher δ34S ratios averaging +8.0‰ for bulk sphalerite-chalcopyrite mineralization (n= 5), +9.3‰ for pyrite samples (n= 5), and +8.0‰ and +10.9‰ for a chalcopyrite and a sphalerite separate, respectively. The isotopic composition of barite from the Vai Lili field is similar to that of barite from the White Church area and averages +21.0‰ (n= 8). Sulfide and barite samples from the Hine Hina area at the southern Valu Fa Ridge have δ34S values that are considerably lighter than those observed for samples from the other areas and average −4.9‰ for pyrite (n= 9), −4.0 and −5.7‰ for two samples of sphalerite-chalcopyrite intergrowth, and −3.4‰ for a single chalcopyrite separate. The total spread in the isotopic composition of sulfides from Vai Lili and Hine Hina is more than 20‰ over a distance of less than 30 km. The δ34S values of sulfides at Hine Hina are the lowest values so far reported for volcanic-hosted polymetallic massive sulfides from the modern seafloor. Barite from the Hine Hina field also has unusually light sulfur with δ34S values of +16.1 to +16.7‰ (n= 5). Isotopic compositions of the sulfides at Hine Hina indicate a dramatic decrease in δ34S from ordinary magmatic values and, in the absence of biogenic sulfur and/or boiling, imply a unique 34S-depleted source of probable magmatic origin. Sulfide-barite mineralization in the Hine Hina area is associated with a distinctive alteration assemblage consisting of cristobalite, pyrophyllite, kaolinite, opal-CT, talc, pyrite, native sulfur, and alunite. Similar styles of alteration are typically known from high-sulfidation epithermal systems on land. Alunite-bearing, advanced argillic alteration in the Hine Hina field confirms the role of acidic, volatile-rich fluids, and a δ34S value of +10.4‰ for the sulfur in the alunite is consistent with established kinetic isotope effects which accompany the disproportionation of magmatic SO2 into H2S and H2SO4. The Hine Hina field occurs near the propagating tip of the Valu Fa back-arc spreading center (i.e., dominated by dike injections and seafloor eruptions) and therefore may have experienced the largest contribution of magmatic volatiles of the three fields. The sulfur isotopic ratios of the hydrothermal precipitates and the presence of a distinctive epithermal-like argillic alteration in the Hine Hina field suggest a direct contribution of magmatic vapor to the hydrothermal system and support the concept that magmatic volatiles may be an important component of some volcanogenic massive sulfide-forming hydrothermal systems.
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  • 27
    facet.materialart.
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    In:  Hydrobiologia, 216-217 (1). pp. 335-342.
    Publication Date: 2019-03-15
    Description: Predation among pelagic cnidarians and ctenophores is reviewed. The diets of semaeostome scyphomedusae and hydromedusae commonly include other gelatinous zooplanktivores. However, few species of siphonophores and ctenophores are known to consume other gelatinous species. Most of these species can be said to exhibit intraguild predation, since they consume species that potentially compete with them for food. In addition, some hydromedusan and ctenophore species may consume other gelatinous zooplanktivores exclusively. Characteristics of cnidarians and ctenophores as predators and as prey of other gelatinous species are discussed.
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  • 28
    facet.materialart.
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    In:  In: Cycles and Events in Stratigraphy. , ed. by Einsele, G. Springer, Berlin, pp. 751-772.
    Publication Date: 2019-05-14
    Type: Book chapter , NonPeerReviewed
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  • 29
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    In:  Applied Microbiology and Biotechnology, 35 . pp. 128-133.
    Publication Date: 2019-10-17
    Description: Using bacteria that tolerate fairly high sodium sulphate concentrations and reduce sulphate and a coarse clay with buffering properties as solid electrolytes, biological fuel cells have been developed for providing electrical energy discontinuously. The biological active anodes, which accumulate fuel, contained a metal hydroxide catalyst that was converted during the biological process into a metal sulphide catalyst and functioned in a solidified aqueous electrolyte that contained sodium sulphate. The active carbon or titanium cathodes employed were activated with cobalt oxide spinels, molybdenum/vanadium compounds or metal chelates. When employed in continuous service for discontinuous energy consumption, fuel cells were capable of being operated with humus constituents or sugar waste as fuel over a period of 5 years without malfunction and maintenance. Positive results were achieved in the purification of waste-water with a modified type of fuel cell in which the production of energy was not dominant.
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  • 30
    facet.materialart.
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    In:  Journal of Applied Electrochemistry, 28 (10). 1073 -1081.
    Publication Date: 2019-10-22
    Description: A thermoelectrochemical process which allows reduction of sulfate to sulfide with current efficiency of 80% using graphitic carbon as an electrode is presented. The mechanism which requires undissociated sulfide (6.5m H2SO4) and works at temperatures close to 120°C, proceeds at low overpotential and in the absence of hydrogen evolution. A molecular model describing the interaction of H2SO4 with the carbon lattice of graphite leading to the liberation of H2S is discussed on the basis of electrochemical and photoelectron spectroscopic data. Applications of this process in energy and environmental technology (sulfide as energy source for CO2 reducing chemoautotrophic bacteria) and for elimination of sulfuric acid waste are discussed.
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  • 31
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    In:  Oceanology, 31 (1). pp. 110-112.
    Publication Date: 2020-11-19
    Description: A large-scale trawl survey in August 1989 and data from other surveys indicate that the mesopelagic zone (depth 200-500m) of the Sea of Okhotsk is most densely populated with squids, wit maximum catches of more than 500kg/h. The greatest concentrations occur above the continental slope, particularly in the northern TINRO basin and off the southwestern coast of Kamchatka, adjoining the most productive regions of the sea. Five squid associations are distinguished in terms of the makeup of the catches.
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  • 32
    Publication Date: 2021-04-22
    Description: A scientific research fishing expedition targeting the oceanic/slope ommastrephid squid Martialia hyadesi was undertaken by a Korean-registered squid jigger in CCAMLR area 48.3, near South Georgia, in June 1996, providing the first opportunity to collect data on the fishery biology of this species during the austral winter. Fishing took place over a period of 8 days; a series of eight drifts was undertaken along an approximately east/west transect of about 200 nautical miles to the north and west of South Georgia, over depths ranging from 1,700 to 2,713 m. All fishing was to the south of the Antarctic Polar Front. Data were collected on sea surface temperature, catch per unit of effort, size, sex, maturity status and stomach contents of the catch and a sample of squid was aged by counting putative, daily microgrowth increments in the sectioned statolith. All squid were caught by jigs operating at depths from 80 to 100 m to the surface. Catch per unit of effort per drift varied between 1.0 and 21.9 kg min−1 and there was no by-catch. Greatest numbers of squid were caught at dusk and dawn. Mantle length fell in the range 220–350 mm (males) and 212–370 mm (females). Most males were sexually mature (Lipinski's stages IV–V) and most females were immature (stage II). The absence of mature females suggests that no spawning takes place in this area during the austral winter. The squid were up to 1␣year of age and had hatched during the previous winter. They were apparently from the same cohort as had been sampled at the Antarctic Polar Front in February 1996. Myctophids were the major prey in the stomach contents and the squid Gonatus antarcticus was also important; crustaceans were relatively unimportant. The results suggest that concentrations of Martialia hyadesi are present in the vicinity of South Georgia, south of the Antarctic Polar Front, during the austral winter. The squid are actively feeding during the austral winter and are susceptible to jigging gear.
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  • 33
    facet.materialart.
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    In:  Marine Biology, 130 (3). pp. 335-344.
    Publication Date: 2021-04-19
    Description: The diet of the emperor penguin Aptenodytes forsteri in the western Ross Sea during spring was investigated by analysis of stomach contents sampled at three different localities. At Cape Washington, emperor penguins feeding chicks consistently preyed on fishes (89 to 95% by mass) and crustaceans (5 to 11%) over the four spring seasons examined. By far the commonest prey was the Antarctic silverfish Pleuragramma antarcticum (89% of the fish prey); the remainder of fish prey were mainly unidentified juveniles of different species of channichthyid fishes. Three species dominated the crustacean part of the diet, i.e. the gammarid amphipods Abyssorchomene rossi/plebs (30% of the crustacean prey) and Eusirus microps (22%), together with the euphausiid Euphausia crystallorophias (24%). At Coulman Island and Cape Roget, fishes, mainly P. antarcticum, formed the bulk of the food (88 and 93% by mass, respectively), crustaceans were minor prey (2.5 and 0.4%), and the squid Psychroteuthis glacialis accounted for a small but significant part of the food (3.5 and 0.8%). This study emphasizes the importance of the small, shoaling pelagic fish Pleuragramma antarcticum as a key link between zooplankton and top predators, including seabirds, in the food web and marine ecosystem of the Ross Sea.
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  • 34
    Publication Date: 2021-04-21
    Description: Concentrations of cadmium, copper and zinc were measured in 34 octopuses over a large range of size and weight, caught in the Kerguelen shelf waters. Compared with levels normally encountered in European cephalopods, Cd concentrations in both species were very high: 30.7–47.1 and 27.3–54.4 μg/g dry weight in Graneledone sp. and Benthoctopus thielei, respectively; Cu concentrations were generally low while Zn concentrations exhibited similar levels. Distribution of Cd in tissues showed that the high levels of Cd in Kerguelen octopuses resulted from very high levels of the metal in the digestive gland (369 and 215 μg/g dry wt in Graneledone sp. and Benthoctopus thielei, respectively). The digestive gland accumulated about 90% of the total Cd in the whole animal. Due to the very high concentrations of Cd in the Kerguelen octopuses, we hypothesize that these species play an important role in the process of Cd transfer throughout the food chain to top vertebrate predators in this area.
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  • 35
    Publication Date: 2021-04-21
    Description: The diet of adult and juvenile Weddell seals (Leptonychotes weddellii) in McMurdo Sound, Antarctica, was determined from both scat and stable isotope analyses, to ascertain if foraging behavior varied with age, season, or diving pattern. Scats were collected over 6 years and recovered hard parts identified. Stable carbon and nitrogen isotope values were determined for seal blood samples and potential prey items and used to identify primary prey species and assess trophic interactions. Pleuragramma antarcticum remains were recovered from between 70 and 100% of the scats, and there was little evidence for inter-annual or age-specific variation in foraging behavior. However, stable isotope and dive data analyses indicated that while most seals foraged predominantly on pelagic fish and squid, some juveniles concentrated on shallow benthic Trematomus spp. Combining these three methods permitted firm conclusions about diet and foraging behavior to be drawn.
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  • 36
    Publication Date: 2021-04-30
    Description: Strontium to calcium ratios were observed along longitudinal sections of statoliths of nine neon flying squid, Ommastrephes bartrami (LeSueur, 1821), including three mature females (422 to 454 mm mantle length, ML; 207 to 306 d old) obtained from the North Pacific (27–35°N; 144–150°E) during winter and six immature males and females (187 to 226 mm ML; 126 to 164 d old) collected from 39°N; 145°E and 39°N; 169°W during summer. The distances between the nucleus (core) and the edge of the dorsal dome were approximately 660 to 690 μm in mature females and 450 to 510 μm in the immature squid. Sr/Ca ratios were determined at intervals of 30 μm between the nucleus and edge of the dorsal dome. Sr/Ca ratios were higher in areas near the nuclei and peripheral portions of the dorsal dome than in the middle portions of the statoliths (270 to 420 μm from the nuclei, corresponding to ages of 60 to 90 d) in mature females; thus a U-shaped pattern was evident. Sr/Ca ratios in the six immature squid decreased from nucleus to the dorsal dome; in three squid the ratios slightly increased toward the dorsal dome edge. The observed Sr/Ca ratios in immature squid were considered to represent younger portions of the U-shaped pattern. In the present study we discuss this pattern in relation to environmental and biological conditions of O. bartrami, which undertakes seasonal migrations between spawning grounds in the Subtropical Domain and feeding grounds in the Subarctic Domain and Transitional Zone in the North Pacific Ocean. Although Sr/Ca ratios are potentially affected by ambient water temperature and ontogenetic conditions, including somatic growth and statolith growth, it was impossible to evaluate each environmental and biological effect separately, as variations in these factors are complicated and effects could be interdependent.
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  • 37
    facet.materialart.
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    In:  Marine Biology, 131 (3). pp. 559-566.
    Publication Date: 2021-04-22
    Description: The analysis of scats collected between 1989 and 1995 from the two fur seal species resident on subantarctic Marion Island, Arctocephalus gazella and A. tropicalis, showed that they fed predominantly on fish of the family Myctophidae (lanternfishes). Scat composition (prey species, abundance) was very similar for the two species. The seven species of myctophids that formed numerically 90 and 86% of the scat composition for A. gazella and A. tropicalis, respectively, all showed seasonal fluctuations in their contribution to seal diets. Electrona carlsbergi, E. subaspera, Metelectrona ventralis and Gymnoscopelus fraseri increased in winter in both species of fur seals, whereas Gymnoscopelus piabilis, Protomyctophum choriodon and P. tenisoni showed the opposite trend. Seal diets overlapped substantially with those of the king penguins (Aptenodytes patagonicus) resident on Marion Island, but no evidence for competitive exclusion could be found between these two major warmblooded consumers of marine resources at the Prince Edward Islands.
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  • 38
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    In:  Journal of Comparative Physiology B, 161 (3). pp. 285-291.
    Publication Date: 2021-05-11
    Description: The energy consumption of Adélie penguins while at rest in water (8.4 W·kg-1 at 4°C) or swimming below the surface was determined using a 21 m long canal fitted with respiration chambers at each end. Penguins chose to swim 86% of the time at speeds recorded in nature. Cost of transport was lowest (7.9 J·kg-1·m-1) at 1.7–2.3 m·s-1, corresponding to a power input of 15.8 W·kg-1, and only 50% as high as previously reported. Assuming a muscle efficiency of 0.25, propulsion efficiency is 0.4 and overall efficiency is 0.1. Calculated food requirements vary between 1060 g krill per adult and foraging trip at the beginning of the breeding season and 2500 g at the period of highest demand, prior to crèching of the chicks.
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  • 39
    Publication Date: 2021-06-15
    Description: We investigated the diet and aspects of foraging effort among Adélie penguins (Pygoscelis adeliae) breeding at three colonies on Ross Island, in the southwestern Ross Sea – Capes Royds, Bird and Crozier – during the chick-provisioning period of three austral summers, 1994–1995, 1995–1996 and 1996–1997. During the study period, pack-ice cover differed in waters offshore of these colonies, by colony, seasons and year. Diet differed among colonies only slightly. The fish Pleuragramma antarcticum was the most important prey, especially during years or periods within years when little pack ice was present. With respect to krill, which composed the remainder of diet, juvenile Euphausia crystallorophias were consumed predominantly in a year of heavy pack-ice cover; more adult krill were consumed in 2 years when pack ice was sparse. Foraging trip duration differed by colony, season and year and was related directly to distance from the colony to the nearest pack ice. The amount of food brought to chicks increased as trip duration increased, to a point (2 days), but then decreased as duration increased further (up to 4 days). On the basis of data on mass of parents and of meal sizes to chicks, it appeared that on the longest trips more of the food gathered by parents was used for self maintenance; on the longest trips, parents lost body mass. Successful foraging during chick rearing, the period when adult foraging is most intense, appears to depend on the proximity of pack ice to nesting colonies for this penguin species.
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  • 40
    Publication Date: 2021-06-15
    Description: The diet composition of king penguins (Aptenodytes patagonicus) at Heard Island (53°05′S; 73°30′E) was determined from stomach contents of 98 adults captured as they returned to the island throughout 1992. During the two growth seasons, the diet was dominated by the myctophid fish Krefftichthys anderssoni (94% by number, 48% by mass). The paralepidid fish Magnisudis prionosa contributed 〈1% by numbers but 17% by mass. Mackerel icefish (Champsocephalus gunnari) accounted for 17% by mass of chick diet in late winter, when chicks were malnourished and prone to starvation, although its annual contribution to the penguins' diet was only 3%. Squid was consumed only between April and August; Martialia hyadesi was the commonest squid taken, comprising 40–48% of the winter diet. The remainder of the diet consisted of the squid Moroteuthis ingens and fish other than K. anderssoni. The energy content of the diet mix fed to the chicks varied seasonally being highest during the growth seasons (7.83 ± 0.25 kJ g−1) and lowest in winter (6.58 ± 0.19 kJ g−1). From energetic experiments we estimated that an adult penguin consumed 300 kg of food each, of which its chick received 55 kg during the 1992 season. The chicks received large meals at the beginning of winter (1.2 ± 0.3 kg) and during the middle of the second growth season (1.2 ± 0.3 kg), and their smallest meals in late winter (0.4 ± 0.1 kg). The gross energy required to rear a king penguin chick was estimated to be 724 MJ. The potential impact of commercial fisheries on the breeding activities of king penguins is discussed.
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  • 41
    Publication Date: 2021-04-22
    Description: The diet of the Antarctic petrel Thalassoica antarctica was studied during two seasons at Svarthamaren, an inland colony in Dronning Maud Land, Antarctica, and in the pack ice off the coast of Svarthamaren. The most important food (wet mass) at Svarthamaren was crustaceans (67%), fish (29%) and squid (5%); however, individuals collected in the pack ice took mostly fish (87%). The prey composition and lengths of prey are comparable to what has been documented in other studies on this species. Estimates of food consumption by birds breeding at Svarthamaren (ca. 250,000 pairs) suggest that approximately 6500 tonnes of crustaceans, 2800 tonnes of fish and 435 tonnes of squid are consumed during the breeding season. The annual consumptions of these birds are estimated to be 34,100 tonnes of crustaceans, 14,700 tonnes of fish, and 2300 tonnes of squid. Satellite telemetry data indicate that Antarctic petrels from Svarthamaren may fly more than 3000 km during one foraging trip, and thus may cover a huge ocean area to obtain their prey.
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  • 42
    Publication Date: 2021-06-11
    Description: We tested the usefulness of the fatty acid signature-method in investigating the diet of seabirds in conjunction with the conventional technique of stomach-content analysis. We compared the fatty acid composition of subcutaneous white adipose tissue (SWAT) of king penguin chicks (Aptenodytes patagonicus) during fattening periods to that of total lipids from their food. In both spring and autumn, the fatty acid composition of chick SWAT was identical to that of the dietary lipids. Because the diet of adult king penguins feeding for self-maintenance (i.e. not for their chicks) was essentially unknown, we subsequently analysed their SWAT fatty acid patterns after premolting and prebreeding foraging trips (during which they build up large energy reserves). The fatty acid composition of SWAT from adults was identical to that of chick adipose tissue and food. King penguin diet and SWAT were characterized by high levels of very long-chain mono-unsaturated fatty acids (20 to 24 carbon atoms, 16 to 23% by mass) and (n-3) poly-unsaturated fatty acids (19 to 27%); these consisted mainly of 20:1n-9 (5 to 8%) and 22:1n-11 (5 to 8%), and 22:6n-3 (10 to 13%) and 20:5n-3 (3 to 9%), respectively. Prey items identified from chick stomach contents indicated that the bulk of the food was oceanic myctophid fishes, mainly Electrona carlbergi, Krefftichthys anderssoni and Protomyctophum tenisoni. The fatty acid composition of four other species of myctophid fishes was similar to that of penguin diet and SWAT, but markedly different from that measured for a squid species and that reported for crustaceans. These findings indicate that adult king penguins prey on myctophid fish not only to feed their chicks but also for their own nutrition. The fatty acid signature-technique is therefore a reliable method to gain information on the food and feeding ecology of seabirds when more conventional techniques are of limited value. Such information is important to the understanding of trophic relationships between key species of the ecosystems, and also to provide insight into the nature of avian adaptations to the marine environment.
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  • 43
    Publication Date: 2021-06-15
    Description: The number of predators from Heard Island foraging in shelf waters, their prey requirements, and the proportion of their diet that was commercial and non-commercial fish were estimated. The calculated annual consumption of commercial fish species varied between 36,360 and 84,166 tonnes. The non-commercial Krefftichthys anderssoni was the preferred prey for most predators, and when its occurrence in diets was low it was replaced by crustaceans and commercial fish species. The estimated annual consumption of Champsocephalus gunnari was approximately 2 and 6 times the highest and lowest estimates respectively of the biomass of this species, obtained from three fisheries research cruises. For Dissostichus eleginoides, the maximum estimate was 28% of the highest estimate of biomass. The current fishery for D. eleginoides will most likely impact on southern elephant seals, whose population decreased by 50% between the 1950s and the 1980s, possibly as a result of overfishing around Iles Kerguelen.
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  • 44
    Publication Date: 2021-06-16
    Description: We investigated the diet and aspects of foraging effort among Adélie penguins (Pygoscelis adeliae) breeding at three colonies on Ross Island, in the southwestern Ross Sea – Capes Royds, Bird and Crozier – during the chick-provisioning period of three austral summers, 1994–1995, 1995–1996 and 1996–1997. During the study period, pack-ice cover differed in waters offshore of these colonies, by colony, seasons and year. Diet differed among colonies only slightly. The fish Pleuragramma antarcticum was the most important prey, especially during years or periods within years when little pack ice was present. With respect to krill, which composed the remainder of diet, juvenile Euphausia crystallorophias were consumed predominantly in a year of heavy pack-ice cover; more adult krill were consumed in 2 years when pack ice was sparse. Foraging trip duration differed by colony, season and year and was related directly to distance from the colony to the nearest pack ice. The amount of food brought to chicks increased as trip duration increased, to a point (2 days), but then decreased as duration increased further (up to 4 days). On the basis of data on mass of parents and of meal sizes to chicks, it appeared that on the longest trips more of the food gathered by parents was used for self maintenance; on the longest trips, parents lost body mass. Successful foraging during chick rearing, the period when adult foraging is most intense, appears to depend on the proximity of pack ice to nesting colonies for this penguin species.
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  • 45
    Publication Date: 2021-06-15
    Description: The diet of non-breeding male Antarctic fur seals (Arctocephalus gazella) was investigated at Harmony Point, Nelson Island, South Shetland Islands, by the analysis of 18 and 33 scats collected during February 1996 and 1997 respectively. Overall, fish were the most frequent prey (74.5%) and predominated by mass (54.4%), whereas krill predominated by number (94.2%). This coincides well with the pattern observed in 1997, but in 1996 krill was the most important prey by number and mass (50.2%). The importance of the remaining taxa represented in the samples (octopods, hyperiids and bivalves) was negligible. Among fish, myctophids represented 85.2% of the fish mass, with Gymnoscopelus nicholsi and Electrona antarctica being the main prey. These two species predominated in 1997, whereas the channichthyid Cryodraco antarcticus and the nototheniid Gobionotothen gibberifrons were dominant in 1996. The importance of the myctophids as prey of the Antarctic fur seal is discussed.
    Type: Article , PeerReviewed
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  • 46
    Publication Date: 2021-04-29
    Description: Prey species of the deepwater squid Moroteuthis ingens were examined for 37 large specimens captured in New Zealand waters. Caecum contents were predominantly less than 80% full and covered a range of digestion stages. The diet consisted of fish (at least seven species, of which four were myctophids) and squid. The most abundant prey was the myctophid Lampanyctodes hectoris, which was represented by 1323 otoliths from 22 caeca. The second most abundant prey was viperfish (Chauliodus sloani) and/or dragonfish (Stomias boa), represented by 537 otoliths from 17 caeca. Individual squid appeared to ingest surprisingly large numbers of fish (up to 100) during a single feeding period and could achieve feeding rates greater than 10% of their body weight per day. While some males appeared to ingest larger numbers of L. hectoris, females targeted significantly larger individuals of L. hectoris thereby ingesting a greater biomass of fish.
    Type: Article , PeerReviewed
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  • 47
    Publication Date: 2021-06-15
    Description: All of the fish identified in stomach contents and regurgitations of breeding and chick Cape petrels collected during January and February 1996 at Fildes Peninsula and Harmony Point, both in the South Shetland Islands and at Laurie Island, South Orkney Islands, were myctophids, a family never previously reported in the diet of breeding Cape petrels. Electrona antarctica was the most important fish prey, followed by Electrona carlsbergi at Fildes Peninsula, Krefftichthys anderssoni at Harmony Point and Gymnoscopelus braueri at Laurie Island. The absence of Pleuragramma antarcticum in the diet of this petrel, which is considered a P. antarcticum-feeder, is discussed.
    Type: Article , PeerReviewed
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  • 48
    Publication Date: 2021-05-05
    Description: The distribution and abundance of the onychoteuthid squid Moroteuthis ingens were assessed for the Patagonian Shelf in the Falkland Islands region. Catch records from the commercial fishery and a research cruise were recorded from 1988 to 1996. Sampling included benthic, pelagic and semi-pelagic trawls and jigging. Moroteuthis ingens was recorded from 1,414 stations out of a total of 9,060 stations with 79.9% of all positive stations being from benthic trawls. Catch size ranged up to approximately 3,000 kg. The length frequency analysis and maturity indices suggested a major recruitment onto the shelf in September with a movement off the shelf during winter. There appears to be a lack of mature females on the Patagonian Shelf, indicating that females migrate into deeper offshore water to spawn. Observations of predation on Moroteuthis ingens on the Patagonian Shelf, along with a literature review, revealed that at least 4 mammal, 17 bird and 13 fish species prey on this squid.
    Type: Article , PeerReviewed
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  • 49
    facet.materialart.
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    In:  Helgoländer Meeresuntersuchungen, 52 (1). pp. 29-40.
    Publication Date: 2021-06-21
    Description: In semi-adultSepia officinalis L. (Cephalopoda) from the Bay of Arcachon (France) a congenital malformation of the systemic heart is described by macro-and microscopical methods. It concerns an atypical doubling of the site of insertion at the cephalic aorta at the apical ventricle. Its comparison with the paired anlagen of the systemic heart complex in normal embryogenesis and the central circulatory system ofNautilus gives rise to interpret it as a form of atavism. The possible causal role of mutagenic antifoulings is discussed.
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  • 50
    Publication Date: 2018-01-19
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  • 51
    Publication Date: 2019-09-23
    Description: Abundant cone sheets form one of the last magmatic stages in the Tertiary central complex on the Scottish peninsula of Ardnamurchan and can be grouped into a younger inner and an older outer suite relative to a gabbro intrusion. Most of the cone-sheets consist of tholeiitic to transitional basalt with MgO contents between 7.5% and 4%, although more evolved rocks also occur (to 0.5% MgO). The mafic samples are slightly enriched in the light rare earth elements (Chondrite-normalized La/Sm ∼1.1), the enrichment increases in the more evolved rocks. The compositional variation of the basaltic rocks is mainly due to crystal fractionation of olivine and clinopyroxene at depths of ∼10 km but trace elements show simultaneous assimilation of Archean Lewisian granulite crust. The andesitic to rhyolitic lavas formed by fractional crystallization from the contaminated basaltic magma coupled with assimilation of Proterozoic Moine metasediments at uppermost crustal levels. The occurrence of composite cone-sheets with basaltic and rhyolitic parts and mixtures between these magmas implies that the melts ascended successively but within a short period of time. The parental magmas of the Ardnamurchan cone-sheets must have formed at relatively shallow depths in the mantle and are comparable to the youngest tholeiitic lavas from the neighbouring island of Mull.
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  • 52
    Publication Date: 2016-12-01
    Description: Climatologists generally expect an anthropogenic global warming that could raise sea level 50-150 centimeters in the next century and more thereafter. One of the impacts would be the loss of coastal wetlands. Although the inundation of adjacent dry land would enable new wetlands to form, much of this land is or will soon be developed. If developed areas are protected, wetlands will be squeezed between an advancing sea and the land being protected, which has already happened in China and the Netherlands, where people have built dikes for centuries. Unlike those countries, the United States has enough land to accommodate the landward migration of wetlands; but governments lack the funds to purchase all the coastal lowlands that might be inundated and the legal authority to prohibit their development. We propose a third approach: allowing property owners to use coastal lowlands today as they choose, but setting up a legal mechanism to ensure that the land is abandoned if and when sea level rises enough to inundate it. Although compensation may be required, this approach would cost less than 1 percent as much as purchasing the land, and would be (1) economically efficient by enabling real estate markets to incorporate expectations of future sea level rise; (2) constitutional by compensating property owners; and (3) politically feasible by pleasing people who care about the long-term fate of the coastal environment without disturbing people who either are unconcerned about the distant future or do not believe sea level will rise. Because planning today would be more effective than reacting later, the U.S. government should develop a long- term strategy in the next three years.
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  • 53
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    In:  In: The mosaic cycle concept of ecosystems. , ed. by Remmert, H. Springer, Berlin, Germany, pp. 132-146. ISBN 3-540-52502-5
    Publication Date: 2012-03-28
    Type: Book chapter , NonPeerReviewed
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  • 54
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    In:  Oecologia, 87 (2). pp. 171-179.
    Publication Date: 2017-10-10
    Description: Different initial mixtures of phyto-and zooplankton from different lakes were grown under identical chemical and physical conditions in medium size (8-and 12–1) laboratory microcosm cultures until convergence of phytoplankton species composition was attained. Five such experiments with four (four experiments) or three (one experiment) microcosm cultures were run. Three experiments were performed with weak stirring which permitted sedimentary elimination of the diatoms. Two experiments were conducted with stronger stirring to prevent sedimentation. In the three ldquosedimentation intensiverdquo experiments, the final phytoplankton community was composed of the filamentous chlorophyte Mougeotia thylespora together with a smaller biomass of nanoplanktic algae. In the two ldquosedimentation freerdquo experiments the final phytoplankton community consisted of pennate diatoms. Both dissolved nutrient concentrations and the chemical composition of biomass suggested strong nutrient limitation of algal growth rates in the final phase of the experiments. The zooplankton communities at the end of the experiments were composed of species that were apparently unable to ingest the large, dominant algae and that presumably fed on the nanoplanktic ldquoundergrowthrdquo and the bacteria. There was a distinct sequence of events in all experiments: first, the large zooplankton species (Daphnia and Copepoda) were replaced by smaller ones (Chydorus, Bosmina, rotifers); second, all cultures within one experiment developed the same nutritional status (limitation by the same nutrient); and third, the taxonomic composition of phytoplankton of the different cultures within one experiment converged. The last took 7–9 weeks, with is about 2–3 times as long as the time needed in a phytoplankton competition experiment to reach the final outcome.
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  • 55
    Publication Date: 2019-05-14
    Description: The Jurassic carbonate series of the Lechtal and Allgäu Nappes in the central part of the Northern Calcareous Alps reflect formation of orogen-parallel structures with swells and basins. Regional facies patterns display the morphologies of the various depositional environments. During the Middle Jurassic, an elongated swell evolved parallel to the overall structural strike in the central part of Lechtal Nappe, while in the southern part a basin started to subside. This configuration reflects the initial stage of rotational block faulting on the southern continental margin of the Tethys. Similar structural and facies settings were also established in the northern part of the Lechtal Nappe and in the southern Allgäu Nappe. Synsedimentary tectonics induced a variety of downslope sediment mass movements and increased facies differentiation on the slopes. In the upper section of the middle Jurassic sequences red nodular limestones with frequent intercalations of intraformational breccias and conglomerates indicate downslope sediment movements. During the Oxfordian, the Tethyan-wide deposition of radiolarites also covered the basin in the southern Lechtal Nappe. Contemporaneous deposition of pelagic radiolarian-bearing limestones dominated on the slope of the surrounding northern swell, while its peak was covered by a shallow water carbonate facies, e.g. a specific pseudopeloid and oolithic facies, which was also injected downslope into the pelagic facies. The Oxfordian to Tithonian section reveals a characteristic pelagic carbonate facies succession, e.g. with Protoglobigerina facies at the base, followed by aSaccocoma facies and a calpionellids facies on top. In the northern Lechtal Nappe and in the Allgäu Nappe various similar radiolarite basins with intersected swells were discovered.
    Type: Article , PeerReviewed
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  • 56
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    Springer
    In:  Criteria for an equitable distribution of internationally tradeable emission certificates: a comment | Earth system analysis: integrating science for sustainability
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/bookPart
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  • 57
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    In:  Implementing carbon mitigation measures in the forestry sector a review | Carbon dioxide mitigation potentials of forests and wood industry
    Publication Date: 2022-03-21
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  • 58
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    In:  Simulated impacts of mean vs. intra-annual climate changes on forests | Simulated impacts of interannual vs. absolute climate changes on the functioning of forests
    Publication Date: 2022-03-21
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  • 59
    facet.materialart.
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    In:  Thermodynamic orientors: how to use thermodynamic concepts in ecology | Eco targets, goal functions, and orientors
    Publication Date: 2022-03-21
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  • 60
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    In:  Umweltforschung quergedacht. Perspektiven integrativer Umweltforschung und -lehre
    Publication Date: 2022-03-21
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  • 61
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    In:  Earth system analysis: Integrating science for sustainability | Earth system analysis: integrating science for sustainability
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/bookPart
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  • 62
    facet.materialart.
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    In:  Die globale Umwelt als Wille und Vorstellung. Zur transdisziplinären Erforschung des Globalen Wandels | Umweltforschung quergedacht. Perspektiven integrierter Umweltforschung und -lehre
    Publication Date: 2022-03-21
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  • 63
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    In:  Viscous vortical flows
    Publication Date: 2022-03-21
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  • 64
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    In:  On the inconsistency at the interface of climate impact studies and global climate simulations | Earth system analysis: integrating science for sustainability
    Publication Date: 2022-03-21
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  • 65
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    In:  Die Modellierung umweltbedingter Konflikte (Modeling Environmental Conflict) | Umwelt und Sicherheit. Herausforderungen für die internationale Politik (Environment and Security -
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/bookPart
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