Sökning: "toothed whales"

Hittade 3 uppsatser innehållade orden toothed whales.

  1. 1. Making nets more acoustically visible : Floats as passive mitigation measures to reduce bycatch of harbour porpoise (Phocoena phocoena) in gillnets

    Master-uppsats, SLU/Dept. Of Aquatic Resources

    Författare :Frida Rosshagen; [2023]
    Nyckelord :toothed whales; harbour porpoise; Phocoena phocoena; incidental capture; bycatch; fisheries; fishing gear; ; gillnet; mitigation; reduction; low-cost; passive acoustic reflector; float;

    Sammanfattning : Incidental capture in fishing gear is today affecting at least 112 marine mammal species worldwide and for many smaller toothed whale species (Odontocete), gillnets are considered to be the largest problem. Although some effective mitigation measures exists, these are often context specific and many might be hard to implement due to reasons such as high costs and maintenance. LÄS MER

  3. 2. Evolutionary Theories of Menopause

    Kandidat-uppsats, Linköpings universitet/Institutionen för fysik, kemi och biologi

    Författare :Fanny Hägg; [2020]
    Nyckelord :Menopause; Post-reproduction; The grandmother hypothesis; The reproductive conflict hypothesis; Inclusive fitness; Kin selection; Odontoceti; Orcinus orca;

    Sammanfattning : Menopause, the cessation of female reproduction well before death, is a puzzling phenomenon, because evolutionary theory suggests there should be no selection for survival when reproduction has ended. Nevertheless, menopause does exist in a limited number of species, and besides humans it has predominately evolved among toothed whales (Odontoceti). LÄS MER

  4. 3. Hur plast påverkar valar

    Kandidat-uppsats, SLU/Dept. of Animal Environment and Health

    Författare :Rebecka Clern; [2019]
    Nyckelord :makroplast; fiskeutrustning; fiskenät; spöknät; intrassling; förtäring;

    Sammanfattning : Plastproduktionen har ökat avsevärt sedan 1950-talet, och dessvärre hamnar allt för stor del av plasten i naturen. På grund av plasters egenskaper kan det ta flera sekel innan de bryts ned, och idag befarar forskarna att det kan komma att finnas mer plast i haven än vad det kommer finnas fisk – redan år 2050. LÄS MER