Sökning: "Benthic Flux"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Benthic Flux.

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. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

   Författare :Anders Tengberg; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

   Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER

4. 3. Contaminated sediments: Methods to assess release and toxicity of organic chemical mixtures

   Författare :Lukas Mustajärvi; Anna Sobek; Jarkko Akkanen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sediment; Hydrophobic organic contaminants; Flux; Bioturbation; Passive sampling; Passive dosing; Mixture toxicity; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : Bottom sediments around the world store large amounts of legacy hydrophobic organic contaminants (HOCs), forming mixtures of unknown chemical composition. Primary emissions to the environment of many HOCs have been reduced as a consequence of regulation. LÄS MER

5. 4. 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

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