Sökning: "grey seal"

Visar resultat 1 - 5 av 14 uppsatser innehållade orden grey seal.

  1. 1. Säl och valjakt ur ett långtidsperspektiv

    Master-uppsats, Uppsala universitet/Institutionen för arkeologi och antik historia

    Författare :Hanna Sjöberg; [2020]
    Nyckelord :Sälar; valar; jakt; Gotland; Östersjön;

    Sammanfattning : Hunting for marine mammals, mainly the seal species found in the Baltic Sea has long been on Gotland. Much research has been done on how and when seals have been hunted, mainly in the cave Stora Förvar on Stora Karlsö off the west coast of Gotland and on Ajvide. LÄS MER

  2. 2. Trapping efficiency and retention ability of four pontoon trap entrance types for use in coastal cod fishing, a fishing gear development field trial in the Baltic sea

    Kandidat-uppsats, SLU/Dept. Of Aquatic Resources

    Författare :Nils Nyquist; [2019]
    Nyckelord :cod; pontoon trap; entrance type; coastal fisheries; video analysis; BORIS;

    Sammanfattning : As the Baltic Sea cod gets smaller both in number and size, and the grey seal population continues to increase, the need for alternative fishing methods in coastal fisheries increases. In this project one commercially used and three experimental pontoon trap entrances are tested with the objective to investigate if there are differences in trapping efficiency and retention ability when fishing for cod. LÄS MER

  3. 3. Seal Predation Costs on the Vendace Fishery in the Bothnian Bay : A partial bioeconomic analysis of the economic costs inflicted upon the vendace fishery by seal predation

    Magister-uppsats, Umeå universitet/Nationalekonomi

    Författare :Simon Lindgren; [2019]
    Nyckelord :;

    Sammanfattning : This study examines the costs in terms of lost revenues inflicted upon the vendace fishing industry by increased seal predation in the Bothnian Bay between the years of 2008 and 2017. A partial bioeconomic model is used to estimate the costs of predation, where a constant stock management type is assumed. LÄS MER

  4. 4. Can tourism Seal the deal? : an explorative study on Seal tourism in Sweden

    Uppsats för yrkesexamina på avancerad nivå, SLU/Dept. of Economics

    Författare :Ebba Alteg; [2019]
    Nyckelord :benefits; seals; survey; wildlife tourism; wildlife management;

    Sammanfattning : The increased seal populations in the Swedish coastal areas have resulted in increased damages for fishing companies with associated costs. The negative aspect of seals has been quantified (costs for small-scale fishers) but both negative and positive aspects of natural resources must be considered for politicians to make efficient policy decisions. LÄS MER

  5. 5. Impact of Great cormorant (Phalacrocorax carbo sinensis) on post-smolt survival of hatchery reared salmon (Salmo salar) and sea trout (Salmo trutta)

    Master-uppsats, SLU/Dept. of Wildlife, Fish and Environmental Studies

    Författare :Carolina Gavell; [2018]
    Nyckelord :great cormorant; salmon; sea trout; sea trout; grey seal; post-smolt survival;

    Sammanfattning : To compensate for the losses due to altered stream habitat large amounts of hatchery-reared Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) are released into the Baltic Sea each year. During the last decades there have been an overall declining trend in the post-smolt survival of both hatchery reared and wild salmon in the Baltic Sea. LÄS MER