Sökning: "Grey seals"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden Grey seals.

  1. 1. The conflict between Grey seals (Halichoerus grypus) and the Baltic coastal fisheries : new methods for the assessment and reduction of catch losses and gear damage

    Författare :Arne Fjälling; Mats Amundin; Sverre Sjölander; Anders Fernö; Linköpings universitet; []
    Nyckelord :Ecology; Grey seals; Baltic coastal fisheries; Ekologi; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : There is a problematic interaction going on between grey seals and the small scale coastal fisheries in the Baltic. A large number of seals are by-caught and drowned each year, and the viability of the fishery is threatened by catch losses caused by the seals. LÄS MER

  2. 2. Ancient genomics of Baltic seals : Insights on the past Baltic grey seal and harp seal populations

    Författare :Maiken Hemme Bro-Jørgensen; Kerstin Lidén; Morten Tange Olsen; Aikaterini Glykou; Olle Karlsson; Stockholms universitet; []
    Nyckelord :HUMANITIES; HUMANIORA; Ancient DNA; Baltic Sea; DNA preservation; extinction; mitogenome; seal hunting; sex identification; arkeologi med inriktning mot laborativ arkeologi; Scientific Archaeology;

    Sammanfattning : This thesis aims to study and describe the ancient populations of grey and harp seals in the Baltic Sea, and to present new methodological approaches for general use in ancient DNA studies.The dissertation is comprised of five studies: a review of the use of paleogenetics in studying ancient human-marine mammal interactions; a method paper investigating patterns of DNA preservation in ancient pinniped samples; a method paper presenting a genetic sex identification method for ancient pinnipeds; a population genomic study of the Baltic grey seal; and a population genomic study of the now extinct Baltic harp seal. LÄS MER

  3. 3. Seals and fisheries: a study of the conflict and some possible solutions

    Författare :Sara Königson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; seals and fisheries; grey seal; coastal fisheries; harbour seal; seal-safe fishing gear;

    Sammanfattning : Interaction between seals and fisheries along the Swedish coast has serious environmental and economic consequences. This thesis describes the conflict as it affects four different small-scale coastal fisheries; the eel fisheries on the west coast, the herring fisheries and salmon fisheries in the northern Baltic and the cod fisheries in the central Baltic. LÄS MER

  4. 4. Assessment and reduction of the conflicts between commercial fisheries and grey seals (Halichoerus grypus) in Swedish waters

    Författare :Arne Fjälling; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; conflict; fishery; grey seal; mitigate; predation; salmon; trap; konflikt; fiskeri; gråsäl; skadeförebyggande; predation; lax; fälla;

    Sammanfattning : Along with the recovery of the Baltic Sea grey seal population from very low figures in the late 1970 's, there were clear signs of a rapidly increasing conflict between grey seals and fisheries. The set trap fisheries for salmonids seemed to be suffering the worst, but such data as were available were bard to evaluate. LÄS MER

  5. 5. Assessment of dietary patterns and prey consumption of marine mammals: Grey seals (Halichoerus grypus) in the Baltic Sea

    Författare :Karl Lundström; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; grey seal; Halichoerus grypus; Baltic Sea; diet; predation; fish; consumption; fatty acid signature analysis; bioenergetics; foraging ecology;

    Sammanfattning : The Baltic Sea has been severely affected by pollution and resource overexploitation during the last centuries. The grey seal (Halichoerus grypus) is a good example of how a species can be affected by such changes. LÄS MER