ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2020-11-06
    Description: The fur seal, Arctocephalus gazella, population at Mossman Peninsula (Laurie Island) was studied from 1985 to 1987. Weekly counts were carried out at a 4 km bachelor haul-out beach from December through June. Maxima of 2 240, 2 787 and 5 196 juvenile and adult males were counted during March of the respective years. Census data indicate an increase in the non-breeding population of 13.5% between 1985–1986 and 46.5% between 1986–1987.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    facet.materialart.
    Unknown
    Springer
    In:  AMBIO, 18 (1). pp. 55-59.
    Publication Date: 2020-09-18
    Description: In the Antarctic there are large unexploited stocks of cephalopods with high potential commercial value and there are two important fisheries for squid in the cool temperate waters of the Southern Ocean, adjacent to the Antarctic, in the Atlantic and Pacific sectors. Squid fisheries can develop very rapidly, and if this were to happen in the Antarctic before adequate management plans could be established, there would be serious consequences for the squid stocks, and also for the vertebrate predator populations which depend on them. It is especially important to increase our knowledge of the Antarctic cephalopod species, their distribution and role in the food chain, and to understand their life cycles
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2020-07-30
    Description: At ODP Site 661 from the continental margin of Northwest Africa, authigenic clinoptilolites were investigated in detail. Based on chemical data, crystal size and shape and their intergrowth with associated mineral phases, two types of clinoptilolite (type A and B) occur representing different diagenetic conditions under which the formation of zeolites took place. Clinoptilolite type A was found in a sediment section comprises numerous hiatuses and stratigraphically condensed sediments and could have been formed during early diagenesis. In contrast, clinoptilolite type B was precipitated in Campanian sediments during later diagenesis, after the transformation from opal-A to opal-CT had taken place. At Site 661, the silica source for the authigenesis of both clinoptilolite types is biogenic opal. Volcanic ash material occurs, but in low amounts and thus is not a prerequisite for the formation of clinoptilolite at Site 661.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    facet.materialart.
    Unknown
    Springer
    In:  Marine Biology, 103 (3). pp. 333-338.
    Publication Date: 2020-07-14
    Description: Respiration and nitrogen excretion rates of mature adult Loligo forbesi were investigated at the Roscoff Laboratory (North Brittany, France) during individual short-term incubation experiments in January 1986. The squids were in post-digestive condition and not actively swimming. Both oxygen uptake and nitrogen excretion are continuous processes. The metabolic rates of this active nektonic species (145 ml kg-1 h-1 oxygen uptake, 18.56 μg g-1 h-1 ammonia excretion) are distinctly higher than those of benthic cephalopods. Proteins constitute the main metabolic substrate for energetic needs. Besides ammonia, urea is also continuously released, in amounts ranging from 5 to 16% of ammonia-excretion values.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    Springer
    In:  Polar Biology, 9 (3). pp. 137-145.
    Publication Date: 2020-06-10
    Description: The diets of five breeding seabird species were investigated on Adélie Land in January–February 1982. Stomach contents of Adélie penguins, Pygoscelis adeliae, were sampled by a water off-loading method and of Procellariiformes by spontaneous regurgitation. Diet compositions by mass were: Adélie penguin (79% euphausiid, 18% fish, 3% squid); Cape pigeon, Daption capense, (64% euphausiid, 29% fish, 7% carrion); Antarctic fulmar, Fulmarus glacialoides, (64% euphausiid, 20% carrion, 16% fish); snow petrel, Pagodroma nivea, (95% fish, 2% euphausiid, 1% carrion) and Wilson's stormpetrel, Oceanites oceanicus, (39% fish, 37% euphausiid, 13% carrion, 12% various crustaceans). The present Adélie penguin diet is consistent with those reported in other studies, given our knowledge of geographical variation in food availability. Differences in the diets of fulmarine petrels appear to relate to differences in foraging areas. The snow petrel is a fish-eating bird associated with pack-ice. Cape pigeon and Antarctic fulmar are mainly krill-eaters and we infer segregation along a neritic/oceanic gradient because of the importance of the neritic Euphausia crystallorophias in the former and the oceanic E. superba in the latter.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2020-06-10
    Description: The foraging behaviour of fur seals and two species of surface feeding seabirds was observed over swarms of vertically migrating krill along the Antarctic Peninsula in July 1987. Fur Seal haul out patterns were correlated with krill in the upper 30 m of the water column. Krill moved to the surface at night; seals subsequently foraged from 1400-0700 hours before returning to floes. Foraging was continuous through the night. Dive duration decreased as krill moved up to the surface; shorter dives may have been more successful than longer ones. It is possible that very deep dives, which occur early in a foraging bout, represent more of an attempt to assess krill depth and distribution rather than being a genuine foraging effort. Seabirds responded to the presence of a surface krill swarm by circling over it and foraging; krill at depths greater than 30 m elicited directional flight and low frequencies of prey capture attempts. Both Snow Petrels and Antarctic Terns preyed on krill, but each species approached the swarms from different habitats. Snow Petrels primarily overflew areas covered by ice; terns preferred open water. This suggested that prey encounters are essentially opportunistic, although the search for prey is limited to rather specific marine habitats. This feature may be important to our understanding of the factors that determine the pelagic distribution of seabirds.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    Springer
    In:  Polar Biology, 9 (6). pp. 385-390.
    Publication Date: 2020-06-10
    Description: The diet of the emperor penguin Aptenodytes forsteri in the eastern Weddell Sea, Antarctica was studied during October and November 1986 by stomach content analysis. Emperor penguins fed mainly on Antarctic krill Euphausia superba, Antarctic silverfish Pleuragramma antarcticum and squid Psychroteuthis glacialis. Benthic prey was not found. The prey composition suggests two different feeding strategies, shallow dives exploring the rugged underside of sea ice where krill is taken, and deep dives when mesopelagic fish and squid are consumed. Chicks were fed on average every 1.44 days.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    facet.materialart.
    Unknown
    Springer
    In:  In: Plankton ecology - success in plankton communities. , ed. by Sommer, U. Springer, Berlin, Germany, pp. 1-8.
    Publication Date: 2019-08-07
    Type: Book chapter , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    facet.materialart.
    Unknown
    Springer
    In:  Contributions to Mineralogy and Petrology, 102 (1). pp. 112-126.
    Publication Date: 2019-05-13
    Description: A global compositional dichotomy for N-MORB magma (N1/N2) is recognized on the basis of Na2O, TiO2, CaO, and Al2O3 contents, and their respective ratios. We have characterized the two magma sub-types by means of their trace element patterns, and attempted to explain the differences in major and trace element contents in terms of a partial melting model, using data from DSDP/IPOD Leg 82. Mass balance calculations for N-MORB glass and rock compositions indicate that differences between N1-and N2-MORB are consistent with simple differences (5%–10%) in the degree of partial melting of a plagioclase-(±spinel) lherzolite, at pressures 〈10 kbar, rather than their respective derivation from plagioclase- and spinel-lher-zolite sources. Based on published and calculated partition coefficients, and calculated source magmaphile trace element compositions, the calculations indicate that the overall range of N-MORB compositions may be derived by between approximately 8% and 20% partial melting of a fertile lherzolite source. Fluid dynamic and melt kinematic considerations will probably necessitate refinement of the model, but should also take account of its qualitative precepts.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-02-01
    Description: Manganese nodules from the Kane Gap (a deep sea channel connecting the Sierra Leone and Gambia Basins off West Africa) were investigated chemically and dated by10Be along cross-sections. Comparing the nodule structure with the stratigraphy of the related sediments, the following conclusions are drawn concerning the sedimentation processes during the last 4 to 6×106 years: The growth of the nodules started about 4 to 4.5 Ma before present during or near to the end of a period of erosion on a fossil-free, probably Miocene sediment. During the first phase of only a few hundred thousandyears, the nodules grew very quickly (7 to 〉18 mm/Ma). Fe-rich hydrogenetic material formed the internal sections of the nodules during this time. Slowing down of the bottom currents, resulting in deposition of thin sediment covers for short intervals, caused the character of the nodules to change to a more diagenetic composition. The growth rates were reduced to about 1 to 2 mm/Ma. The time of slowing is roughly 3 to 4 Ma BP. Probable uncertainties of the dating and growth rates resulting from supposed changes of the10Be supply to the nodules due to variations of the near bottom environment are discussed.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...