ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Publication Date: 2018-02-15
    Repository Name: EPIC Alfred Wegener Institut
    Type: Miscellaneous , NonPeerReviewed
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2018-02-15
    Repository Name: EPIC Alfred Wegener Institut
    Type: Conference , NonPeerReviewed
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2018-09-04
    Description: Marine ecosystems are exposed to increasing human pressures and climatic change worldwide. It has therefore become essential to describe ecosystem statuses with respect to multinational protection schemes, often necessitating long-term monitoring programmes. Changes in the food-web structure, which can be monitored via stable isotope measurements, represent an important descriptor of the status of marine ecosystems. We investigated long-term changes (29 years) in isotopic values (δ13C and δ15N) in four indicative organisms at different trophic levels in the southern North and Baltic Seas: bladderwrack (Fucus vesiculosus), blue mussel (Mytilus ssp.), eelpout (Zoarces viviparus), and herring gull (Larus argentatus). Time series analyses using generalised additive models revealed largely consistent declines in δ13C and δ15N throughout all trophic levels of the coastal food web at all study sites, indicating a clear change in these coastal regions from 1988 to 2016. There were no clear long-term patterns in egg biometrics for herring gulls, except for a consistent increase in eggshell thickness. The declines in stable isotope values were in line with the results of previous long-term studies of single higher-trophic-level species, which suggested that the noted changes were mainly caused by altered foraging patterns of the studied species. The current results demonstrate that declines in δ13Cand δ15N have occurred throughout the whole food web, not just in particular species. We discuss the possible reasons for the decrease in stable isotope values, including decreasing eutrophication and an increase in terrestrial carbon sources
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2017-01-26
    Description: Human exploitation and use of marine and coastal areas are apparent and growing in many regions of the world. For instance, fishery, shipping, military, raw material exploitation, nature protection and the rapidly expanding offshore wind power technology are competing for limited resources and space. The development and implementation of Integrated Coastal Zone Management (ICZM) strategies could help to solve these problems. Therefore, suitable spatial assessment, modeling, planning and management tools are urgently needed. These tools have to deal with data that include complex information on different spatial and temporal scales. A systematic approach based on the development of future scenarios which are assessed by combining different simulationmodels, GIS methods and an integrating set of ecological integrity indicators, was applied in a case study in the German North Sea. Here, the installation of huge offshore wind parks within the near future is planned. The aim was to model environmental effects of altered sea-use patterns on marine biota. Indicators of ecological integrity were used to assess altering conditions and possible ecosystem shifts ranging from systems' degradations to the development of highly productive and diverse artificial reef systems. The results showed that some ecosystem processes and properties and related indicators are sensitive to changes generated by offshore wind park installations while others did not react as hypothesized.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    Forschungs- und Technologiezentrum Westküste (FTZ) der Christian-Albrechts-Universität zu Kiel / IFM-GEOMAR
    In:  Forschungs- und Technologiezentrum Westküste (FTZ) der Christian-Albrechts-Universität zu Kiel / IFM-GEOMAR, Büsum, Germany, 156 pp.
    Publication Date: 2014-06-04
    Type: Report , NonPeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    facet.materialart.
    Unknown
    Inter Research
    In:  Marine Ecology Progress Series, 106 . pp. 1-9.
    Publication Date: 2018-04-09
    Description: Prey availability is one of the factors determining the distribution of seabirds at sea. Northern fulmars Fulmarus glaclalis and black-legged kittiwakes Rissa tridactyla were the most regular and frequent ship-followers across the central and northern North Sea during 2 surveys with a fishery research vessel in May-June and July-August 1992. Sixteen other species occurred less often and/or in lower numbers. Birds consumed 84 % of experimentally discarded roundfish and 8 % of discarded flatfish. On average, northern gannets Morus bassanus took the largest individuals of most fish specles, black-legged kittywakes the smallest The average size choices of herring gulls Larus argentatus, lesser black-backed gulls Larus fuscus and northern fulmars lay between these 2 extremes. The choice of fish lengths by birds vaned with different fish species. Northern gannet was the most successful species in consuming discards. Northern fulmars success rates decreased with the presence of larger ship-followers but were never high. Black-headed gull Larus ridibundus and common gull Larus canus were less successful than the more frequent typical ship-following species.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    In:  (Doctoral thesis/PhD), Christian-Albrechts-Universität Kiel, Kiel, Germany, 156 pp
    Publication Date: 2018-08-06
    Description: Patterns in seabird distribution and abundance and their relationship to environmental parameters were described and analysed using data obtained by ship-based transect counts in the North Sea. Principal component analysis and other statistics showed that distance to colony, trawler abundance and hydrography strongly influenced the distribution of seabirds in the German Bight. Salinity, transparency and thermal stratification appeared to be the most important hydrographic features. Cluster analysis revealed a group of four offshore species and seven inshore species. Relationships between important abiotic parameters and seabird diet are discussed. Both fisheries and hydrography are discussed as determinants of seabird distribution with the Northern Fulmar (Fulmarns glacialis) as an example in detail. It is concluded that the occurrence of Northern Fulmars in the German Bight can be basically explained by hydrographic features, the birds preferentially frequenting Central North Sea Water Masses. The utilization of trawler discards (fish and other animals that are caught by fisheries but not landed for various reasons) and offal by scavenging seabirds is described and quantified. Based on a literature review, the total amount of fishery waste in the North Sea region is estimated at about 789,000 t per year. The numbers of seabirds potentially supported by that food is estimated to be roughly 5.9 million individuals in an average scavenger community. It is calculated on the basis of numerous discard experiments that the mass of discards and offal consumed annually by birds in the whole North Sea in 1993-1994 amounted to 55,000 t of offal, 206,000 t of roundfish, 38,000 t of flatfish, 2,000 t of elasmobranchs and 9,000 t of benthic invertebrates per year, with considerable seasonal and regional differences. There are inter-specific differences in discards types (fish species and lengths) taken by birds, which can be partly explained by bird body morphometrics. Scavenging seabirds exploit discards with different success and by different feeding techniques. Both body length and body mass of the birds can well explain species order in a kleptoparasitism index but not in a foraging success index. It is concluded that competition between species often occurs when feeding at trawlers. During specific experiments, gulls were found to exploit discards apparently equally well during the day and at night. It is shown that seabirds often exhibit clear relationships with biotic and abiotic parameters which can be successfully used to indicate conditions in the marine environment. Recommendations for further field studies and analyses are given.
    Type: Thesis , NonPeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-02-13
    Description: The Wadden Sea is one of the most important stop-over sites for breeding and migrating birds. About 10–12 million birds per year use the area for foraging and consume about 25%–45% of the standing stock of macrozoobenthos. However, little is known about the influence of birds on the entire ecosystem. We conducted ecological network analysis (ENA) on an important bird breeding and resting site, the Norderaue tidal basin in the northern German Wadden Sea, to determine the influence of birds on the entire food web. The model was based on the yearly average biomass of system compartments empirically sampled every season at the study site. The analysis revealed a complex and well-connected food web (high flow diversity and effective link-density) dominated by short pathways but with a high throughput of energy. The system's energy had a high degree of freedom for its development. However, there is a strong dependency on external imports of phytoplankton due to the dominance of suspension feeders suggested by a low recycling and the detritivory to herbivory ratio. A large variety of bird species uses the area for foraging and induces a negative impact on their prey items revealed by the mixed trophic impact analysis. The food sources and also the competitors of the birds' prey items were positively influenced by the birds via indirect pathways in the network. Furthermore, there is a negative impact among the bird compartments probably due to competition between the bird species. A sensitivity analysis, conducted by changing the bird biomass in the model, revealed only small changes in the activity, complexity and connectivity of the system. The linkage to other system components could amplify these changes in the system functioning. It is therefore recommended to include birds in coastal food web studies which has rarely been done before. The use of holistic approaches such as ENA would facilitate decisions on management measures by providing a simplified representation of the entire ecosystem including all direct and indirect connections between the system components.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1439-0361
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Von April bis Juli 1993 wurden in der südöstlichen Nordsee von Schiffen aus auf 300 m breiten Transekten Seevögel kartiert. Dabei konnte für einige Arten der Bestand abseits des Wattenmeeres und der Küste hinlänglich genau geschätzt werden. Baßtölpel (800 Ind.), Eissturmvogel (8000 Ind.), Dreizehenmöwe (4200 Ind.) und Trottellumme (3100 Ind.) kamen fast ausschließlich in der Nähe des Brutplatzes Helgoland und weiter seewärts vor. Herings- (25 000 Ind.) und Silbermöwe (2100 Ind.) waren weit verbreitet; die Heringsmöwe konzentrierte sich weiter entfernt von der Küste als die Silbermöwe und trat in hohen Dichten vor allem in der Nähe von Fischkuttern auf. Mantelmöwen (1200 Ind.) wurden vor allem im Südosten des Untersuchungsgebietes regelmäßig, aber in stets geringer Anzahl festgestellt. Sturm- und Lachmöwe wurden fast nur im Wattenmeer in allerdings oftmals hoher Dichte registriert. Die Flußseeschwalbe war stark an die Kolonien nahe der Küste gebunden, während die Brandseeschwalbe auch weiter auf See beobachtet wurde.
    Notes: Abstract Seabirds were counted from ships on 300 m wide transects in the southeastern North Sea between April and July 1993. For some species the numbers off the coast and off the Waddensea area could be estimated. Gannet (Morus bassanus, 800 individuals), Fulmar (Fulmarus glacialis, 8000 ind.), Kittiwake (Rissa tridactyla, 4200 ind.) and Common Guillemot (Uria aalge, 3100 ind.) occurred with few exceptions only in the vicinity of the breeding site on Helgoland and further towards the open sea. Lesser Black-backed Gull (Larus fuscus, 25000 ind.) and Herring Gull (Larus argentatus, 2100 ind.) were widely distributed: Lesser Black-backed Gulls concentrated in larger distances from the coast than Herring Gulls did. They were found in high densities above all near trawlers. Great Black-backed Gulls (Larus marinus, 1200 ind.) were seen regularly but always in low numbers in the southeastern part of the study area. Common Gull (Larus canus) and Black-headed Gull (Larus ridibundus) were observed almost exclusively in the Wadden Sea but in sometimes remarkably high densities. Common Terns (Sterna hirundo) were more or less confined to the area of their breeding colonies whereas Sandwich Terns (Sterna sandvicensis) were also found further out to the sea.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    Geologisch-Paläontologisches Institut der Universität Kiel
    In:  Berichte aus dem Sonderforschungsbereich 313, Veränderungen der Umwelt - Der Nördliche Nordatlantik, 62 . Geologisch-Paläontologisches Institut der Universität Kiel, Kiel, Germany, 62 pp.
    Publication Date: 2019-02-08
    Type: Report , NonPeerReviewed
    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...