Avancerad sökning

Hittade 3 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Non-indigenous zooplankton : the role of predatory cladocerans and of copepods in trophic dynamics

    Författare :Marc Andersen Borg; Fredrik Wulff; Markku Viitasalo; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acartia tonsa; Bythotrephes longimanus; Cercopagis pengoi; egg production; fitness; food web changes; ingestion rates; invasive species; metabolic balance; mortality; non-indigenous zooplankton; predation impact; salinity tolerance; stable isotopes; Marine ecology; Marin ekologi; marin ekologi; Marine Ecology;

    Sammanfattning : Human-mediated introductions of non-indigenous species now threaten to homogenize the biota of the Globe, causing huge economic and ecological damage. This thesis studies the ecological role of 3 invasive planktonic crustaceans, the omnivorous copepod Acartia tonsa (western Atlantic and Indo-Pacific) and the predatory cladocerans, Cercopagis pengoi (Ponto-Caspian) and Bythotrephes longimanus (Eurasian). LÄS MER

  3. 2. Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem : Bottom-up effects in an aquatic food web

    Författare :Norbert Häubner; Pauli Snoeijs; Jon Ågren; Rhena Schumann; Markku Viitasalo; Uppsala universitet; []
    Nyckelord :Baltic Sea; carotenoids; astaxanthin; tocopherols; Vitamin E; thiamine; Vitamin B1; pelagic food web; eutrophication; M74; phytoplankton; zooplankton; sprat; Sprattus sprattus balticus; herring; Clupea harengus; salmon; Salmo salar; cod; Gadus morhua; High Performance Liquid Chromatography HPLC ; electrochemical detection ECD ;

    Sammanfattning : The thesis combines laboratory experiments and field expeditions to study production, transfer and consumption of non-enzymatic antioxidants and thiamine in an aquatic food web. In particular, I (1) documented spatial and seasonal variation of tocopherols and carotenoids in the Baltic Sea pelagic food web, and (2) examined the effects of abiotic and biotic factors on tocopherol, carotenoid and thiamine concentrations in phytoplankton, zooplankton and fish. LÄS MER

  4. 3. Influence of cyanobacterial blooms on coastal fish recruitment

    Författare :Karl-Johan Persson; Catherine Legrand; Markku Viitasalo; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cyanobacteria; coastal fish recruitment; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : Cyanobacteria are the oldest oxygen-producing organisms on Earth and can be found in almost every terrestrial and aquatic habitat. Their long evolutionary history has enabled them to develop diverse adaptations in order to increase their survival in environments subjected to natural and anthropogenic changes. LÄS MER