Sökning: "brackish water sediment"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden brackish water sediment.

  1. 1. Benthic metabolism and sediment nitrogen cycling in Baltic sea coastal areas : the role of eutrophication, hypoxia and bioturbation

    Författare :Stefano Bonaglia; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eutrophication; Sediment; Benthic Flux; Nitrogen Cycle; Denitrification; Baltic Sea; Biogeochemistry; biogeokemi; marin- och brackvattensekologi; Marine and Brackish Water Ecology; Marine Ecology; marin ekologi; geokemi; Geochemistry;

    Sammanfattning : Eutrophication is one of the greatest threats for the Baltic Sea, and one of its more critical consequences is bottom water hypoxia. Nutrient enrichment and oxygen-depletion affect both the deep central basins and a number of coastal areas, even though strategies for nutrient reduction have lately been implemented. LÄS MER

  3. 2. Phosphorus recycling in brackish and marine environments - Sediment investigations in situ in the Baltic Sea and the By Fjord

    Författare :Lena Viktorsson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phosphorus; sediment; anoxia; Baltic Sea; By Fjord; benthic flux;

    Sammanfattning : The phosphorus load to the oceans from land started to increase since around 1950 when man started to mine phosphorus-mineral from phosphorus-rich soils and bedrock. The increased use of phosphorus fertilizers in agriculture together with the growth of coastal cities increased the load of phosphorus to the coastal ocean where plankton production flourished. LÄS MER

  4. 3. Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments

    Författare :Maria Söderström; Åke Bergman; Bert van Bavel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PCB; DDT; HCB; trichloroguaiacol; transformation products; dimerisation; bromination; environmental pollutants; eutrophication; lakes; fresh water; baltic sea; monitoring; sediments; fish; phytoplankton; PCB; DDT; HCB; triklorguajakol; omvandlingsprodukter; dimerisering; bromering; miljöföroreningar; eutrofiering; sjöar; sötvatten; östersjön; miljöövervakning; sediment; fisk; fytoplankton; miljökemi; Environmental Chemistry;

    Sammanfattning : This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. LÄS MER

  5. 4. Aquatic vegetation in coastal ecosystems : The role of biotic interactions and environmental change for ecosystem functions and resilience in the Baltic Sea

    Författare :Åsa Austin; Johan S. Eklöf; Joakim P. Hansen; Serena Donadi; Matthew E. S. Bracken; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biodiversity; ecosystem functions; ecosystem multifunctionality; water clarity; fish recruitment; functional traits; feedbacks; biotic interactions; competition; facilitation; foundation species; seagrass; macrophytes; lagoons; brackish water; Baltic Sea; marin ekologi; Marine Ecology;

    Sammanfattning : Coastal ecosystems are among the most productive on Earth but subjected to many human pressures. In shallow coastal areas, aquatic vegetation constitutes foundation species that sustain secondary production and act as a nutrient filter, which may buffer human impacts. LÄS MER

  7. 5. Benthic fluxes of biogenic elements in the Baltic Sea : Influence of oxygen and macrofauna

    Författare :Nils Ekeroth; Sven Blomqvist; Per OJ Hall; Bjørn Sundby; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sediment biogeochemistry; Bioturbation; Benthic nutrient fluxes; Bottom water oxygenation; Box corer; Sediment sampling; Marine Ecology; marin ekologi;

    Sammanfattning : This thesis investigates how benthic fluxes of phosphorus (P), nitrogen (N), and silicon (Si) change upon oxygenation of anoxic soft bottoms in the brackish, eutrophicated Baltic Sea. Direct measurements in situ by benthic landers demonstrated that fluxes of dissolved inorganic P (DIP) from anoxic bottom sediments in the Eastern Gotland Basin are higher than previously thought (Paper I). LÄS MER