Sökning: "grayling"

Hittade 5 avhandlingar innehållade ordet grayling.

  1. 1. Salmonid behaviour under winter conditions

    Författare :Johan Watz; Larry Greenberg; Eva Bergman; John Piccolo; Richard Cunjak; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; drift; energy budget; foraging; grayling; ice cover; lotic; metabolic rate; predation; salmon; stream; stress; temperature; trout; Biology; Biologi;

    Sammanfattning : Winter conditions are believed to play an important role in the population dynamics of northern temperate stream fish, challenging the ability of fish to physiologically and behaviourally adapt. Climate change is predicted to increase both mean temperature and temperature fluctuations, especially during winter, leading to dynamic environmental conditions in terms of river ice production and flow. LÄS MER

  2. 2. Conservation of landlocked Atlantic salmon in a regulated river : Behaviour of migratory spawners and juveniles

    Författare :Anna Hagelin; Eva Bergman; Fleming Ian; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atlantic salmon; conservation; migration; spawning; hydropower; competition; juveniles; brown trout; hatchery reared; fallback; delay; Biology; Biologi;

    Sammanfattning : Hydropower dams represent one of the major threats to river ecosystems today. The dams block migratory routes in many rivers, which is problematic for migratory fish species. Trap-and-transport may be an alternative to fish passage solutions, as a strategy to compensate for lost river connectivity. LÄS MER

  3. 3. Winter behaviour of stream salmonids: effects of temperature, light, and ice cover

    Författare :Johan Watz; Larry Greenberg; Eva Bergman; John Piccolo; Svein Jakob Saltveit; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stream salmonids; winter behaviour; efftect of temperatur; light; ice cover; environment; fish populations; Biology; Biologi;

    Sammanfattning : In boreal streams, stream salmonids typically face low water temperatures and variable ice conditions during winter, and thus stream salmonids are expected to use different behavioural strategies to cope with these environmental conditions. The studies presented in this thesis explore how temperature, light intensity, and surface ice affect salmonid behaviour, with focus on drift-feeding and ventilation rates. LÄS MER

  4. 4. Hidden Diversity Revealed : Genomic, Transcriptomic and Functional Studies of Diplomonads

    Författare :Jon Jerlström-Hultqvist; Staffan Svärd; Adrian Hehl; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Giardia intestinalis; Spironucleus salmonicida; Spironucleus barkhanus; intestinal parasite; hydrogenosome; mitosome; lateral gene transfer; horizontal gene transfer; diplomonad; metamonad; sexual recombination; transfection; protein complex purification; Biology with specialization in Evolutionary Organismal Biology; Biologi med inriktning mot evolutionär organismbiologi; Biologi med inriktning mot mikrobiologi; Biology with specialization in Microbiology; Biology with specialization in Molecular Biology; Biologi med inriktning mot molekylärbiologi; Biologi med inriktning mot molekylär evolution; Biology with specialization in Molecular Evolution;

    Sammanfattning : The diplomonads are a diverse group of eukaryotic microbes found in oxygen limited environments such as the intestine of animals were they may cause severe disease. Among them, the prominent human parasite Giardia intestinalis non-invasively colonizes the small intestine of humans and animals where it induces the gastrointestinal disease giardiasis. LÄS MER

  5. 5. Environmental-flow assessments for current and future run-off in a large river system regulated for hydropower production

    Författare :Åsa Widén; Roland Jansson; Birgitta Malm-Renöfält; Michael McClain; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental flows; eco-hydrology; hydropower; river ecosystem; environmental benefits; climate change; collaboration; resource management; Ekologisk reglering; vattenkraft; produktionsoptimering; hydrologi; hydraulik; akvatiskt ekosystem; miljönytta; klimatförändringar; samverkan; vattenresurs management;

    Sammanfattning : In 2019, Sweden implemented legislative changes to renegotiate hydropower permits to both consider environmental rehabilitation and to ensure national supply of hydropower. This means that efforts for environmental rehabilitation of the 2,000 hydropower plants in Sweden need to be considered. LÄS MER