Search for dissertations about: "Sprattus sprattus"

Showing result 1 - 5 of 10 swedish dissertations containing the words Sprattus sprattus.

  2. 1. Complexity and Change in a Simple Food Web : Studies in the Baltic Sea (FAO Area 27.IIId)

    Author : Henrik Österblom; Sture Hansson; Robert W Furness; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Avian cholera; Bottom-up; Bycatch; Clupea harengus; Ecosystem; Food web; Gadus morhua; Halichoerus grypus; Regime shift; Sprattus sprattus; Top-down; Trophic cascade; Uria aalge; Marine ecology; Marin ekologi;

    Abstract : An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. READ MORE

  4. 2. Zooplankton growth and trophic linkages : Implications for fish feeding conditions in the Baltic Sea

    Author : Towe Holmborn; Elena Gorokhova; Sture Hansson; Ilppo Vuorinen; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; AARS activity; biochemical markers; Clupea harengus; copepod physiology; food web interactions; non-indigenous species; RNA-based indices; Sprattus sprattus; stable isotopes; Marine ecology; Marin ekologi; Marine Ecology; marin ekologi;

    Abstract : The aim of this Thesis was to improve our understanding and assessment of feeding conditions for zooplanktivorous fish in the Baltic Sea.We investigated (papers I, II) the usefulness of biochemical proxies for assessments of growth and metabolic rates in the dominant Baltic copepod Acartia bifilosa. READ MORE

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

    Author : Norbert Häubner; Pauli Snoeijs; Jon Ågren; Rhena Schumann; Markku Viitasalo; Uppsala universitet; []
    Keywords : 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 ;

    Abstract : 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. READ MORE

  6. 4. Seabirds as food for thought : An integrative study on seabird ecology and ecosystem services in changing marine systems

    Author : Martina Kadin; Thorsten Blenckner; Morten Frederiksen; Olof Olsson; Johan Elmberg; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; seabirds; ecosystem services; social-ecological systems; marine systems; fisheries; foraging ecology; provisioning behaviour; common murre; common guillemot; Uria aalge; Stora Karlsö; Baltic Sea; naturresurshushållning; Natural Resources Management;

    Abstract : The importance of the benefits that humans obtain from the oceans is increasingly recognized, along with the rapid decline in marine resources that threatens these benefits. Studying seabirds – top predators in marine ecosystems, can provide insights about multiple pressures and the state of the oceans. READ MORE

  7. 5. Man, murres and modern fisheries : A case study in the Baltic Sea

    Author : Martina Kadin; Henrik Österblom; Olof Olsson; Carl Folke; Morten Frederiksen; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Seabirds; ecosystem dynamics; fisheries; indicators; ecosystem services; Baltic Sea; common murre; common guillemot; Uria aalge; naturresurshushållning; Natural Resources Management;

    Abstract : Overfishing and climate change put increasing pressure on marine systems, with effects on commercially targeted fish and top predators dependent on these resources. To achieve sustainable resource use, governance mechanisms need to incorporate knowledge about ecosystem dynamics. READ MORE