Sökning: "Zooplankton"

Visar resultat 26 - 30 av 98 avhandlingar innehållade ordet Zooplankton.

  1. 26. Climate change impacts on aquatic consumer communities

    Författare :Shuntaro Koizumi; Pär Byström; Ryan Sponseller; Jonathan Shurin; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Climate change; warming; browning; aquatic consumers; zooplankton; benthic insects; fish; ecosystem experiment; environmental science; miljövetenskap;

    Sammanfattning : Climate change represents a serious threat to aquatic ecosystems, with an increase in lake temperatures already observed that is expected to continue in the near future. Aside from the direct effects of warming, climate change is also partially responsible for the browning of lakes. LÄS MER

  3. 27. Morphological antipredator adaptations in water fleas

    Författare :Hans Lord; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Body drag; Daphnia cristata; Reynolds number; viscosity; zooplankton; Bosmina; swimming velocity; cyclomorphosis; sexual dimorphism; head area; helmet angle; trophic condition; allometry; invertebrate predator; fish;

    Sammanfattning : Some Bosmina and Daphnia species have the ability to develop extreme morphological antipredator defences, such as long antennules, high carapaces and helmets. The relative sizes of these plastic traits may differ substantially between populations, and also between individuals within a population, between sexes and during ontogeny. LÄS MER

  4. 28. Experimental Studies on the Regulation of Pigment Dynamics in Phytoplankton and Copepods by Dissolved Inorganic Nutrients

    Författare :Lies Van Nieuwerburgh; Pauli Snoeijs; Ulf Båmstedt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Astaxanthin; Baltic Sea; carotenoids; diatoms; eutrophication; food web; mesocosms; microalgae; M74 syndrome; oxidative stress; phytoplankton blooms; zooplankton; Biologi; Biology; Biologi;

    Sammanfattning : This thesis examines the role of dissolved inorganic nutrients in generating changes in phytoplankton community and pigment composition and if such changes can affect the production of the antioxidant astaxanthin in the ecosystem via pelagic copepods. The background of my studies is the possible relationship between eutrophication and a reproductive disturbance in Baltic populations of Atlantic salmon (M74), which is associated with astaxanthin and thiamine deficiencies and oxidative stress. LÄS MER

  5. 29. Phenotypic responses of zooplankton to variable conditions

    Författare :Marcus Lee; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Multiple threats; Plasticity; Risk-Spreading; sexual conflict; ultraviolet radiation; Daphnia; Copepods;

    Sammanfattning : Organisms are continually challenged by multiple threats in the environment, and such threats are seldom constant in either time or space. Therefore, organisms must maintain physiological, behavioural, morphological and life- history adaptations across environments to prevent reductions in fitness. LÄS MER

  7. 30. Zooplankton responses to threats from UV and predation

    Författare :Samuel Hylander; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Ultraviolet radiation (UV) has been present longer than any biological life, and during the development of life the radiation intensities were initially high. Eventually a vital ozone layer developed, but despite that this layer screens out most of the high energy wavelengths, some still enter the biosphere and is potentially harmful to life on earth. LÄS MER