Sökning: "Baltic Sea measurements"

Visar resultat 21 - 25 av 65 avhandlingar innehållade orden Baltic Sea measurements.

  1. 21. 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

  3. 22. Trophic complexity of zooplankton–cyanobacteria interactions in the Baltic Sea : Insights from molecular diet analysis

    Författare :Nisha H. Motwani; Elena Gorokhova; Jakob Walve; Catherine Legrand; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; bloom-forming filamentous cyanobacteria; diazotrophs; picocyanobacteria; zooplankton; grazing; molecular diet analysis; stable isotopes; biochemical indices; Marine Ecology; marin ekologi;

    Sammanfattning : Blooms of nitrogen fixing cyanobacteria (NFC) occur in many freshwater and marine systems, including the Baltic Sea. By fixing dissolved nitrogen, they circumvent general summer nitrogen limitation, while also generating a supply of novel bioavailable nitrogen for non-diazotrophic primary producers and ultimately supporting secondary production. LÄS MER

  4. 23. Meso-scale atmospheric flow modifications in the Baltic Sea area

    Författare :Birgitta Källstrand; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Meteorology; meteorologi;

    Sammanfattning : The wind climate in coastal areas often shows large local variations. For example sea-breeze circulations, internal boundary layers (IBL) and low level jets (LLJ) may contribute to more complex wind conditions than otherwise would be expected over the sea. LÄS MER

  5. 24. Tracing and apportioning sources of dioxins using multivariate pattern recognition techniques

    Författare :Anteneh Assefa; Mats Professor; Karin Professor; Paul Professor; Patrik Andersson; Shigeki Masunaga; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polychlorinated dibenzo-p-dioxin; polychlorinated dibenzofuran; positive matrix fac- torization; PMF; principal component analysis; PCA; Baltic Sea; sediment core; PCDD F; sources; marine; fish; environmental half-live; peak year; peak level; temporal trend; spatial variation; coastal; offshore; chemical fingerprint; Environmental Science; miljövetenskap;

    Sammanfattning : High levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in edible fish in the Baltic Sea have raised health concerns in the Baltic region and the rest of Europe. Thus, there are urgent needs to characterize sources in order to formulate effective mitigation strategies. LÄS MER

  7. 25. Mechanisms structuring the pelagic microbial food web : Importance of resource and predation

    Författare :Kristina Samuelsson; Agneta Andersson; Christiane Lancelot; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; pelagic microbial food web; bacteria; flagellates; ciliates; phytoplankton; mixotrophy; nutrient status; predation limitation; resource limitation; Baltic Sea; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : Temporal and spatial variations of pelagic microorganisms in the northern Baltic Sea were studied, as well as factors influencing their abundance and growth rates. Three main questions were asked 1) How does increased productivity influence the structure of the microbial food web? 2) Does predation limitation vary between trophic levels? 3) What is the relative importance of resource and predation limitation at different trophic levels?A field study in the northern Baltic Sea showed that dominating protozoa, flagellates and ciliates, increased with increasing primary productivity from north to south. LÄS MER