Search for dissertations about: "HALICHOERUS-GRYPUS"

Showing result 1 - 5 of 8 swedish dissertations containing the word HALICHOERUS-GRYPUS.

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

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

    Abstract : 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. READ MORE

  4. 2. Salmonids and grey seals (Halichoerus grypus) : mitigation in pontoon traps

    Author : Linda Calamnius; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : In the 1970’s, the seal populations of the Baltic Sea Area were at historically low levels. They have recovered and increased since then. The increase of the seal populations is a success for the management of the Baltic Sea Area environment. It has also meant an increase in number of interactions with coastal fisheries. READ MORE

  5. 3. Complexity and Change in a Simple Food Web : Studies in the Baltic Sea (FAO Area 27.IIId)

    Author : Henrik Österblom; Sture Hansson; Robert W Furness; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Avian cholera; Bottom-up; Bycatch; Clupea harengus; Ecosystem; Food web; Gadus morhua; Halichoerus grypus; Regime shift; Sprattus sprattus; Top-down; Trophic cascade; Uria aalge; Marine ecology; Marin ekologi;

    Abstract : An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. READ MORE

  6. 4. 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

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

    Abstract : 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. READ MORE

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

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

    Abstract : 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. READ MORE