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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Physical control of phytoplankton growth in the Baltic Sea : a multitude of spatio-temporal scales

    Författare :Sulev Nõmmann; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fytoplankton;

    Sammanfattning : Shipboard systems have been used for concurrent quasi-continuous measurements ofparticle size distribution, Chi fluorescence, salt and temperature and meteorologicalparameters. A resolution from 100 m to basin-wide, supplemented with variousmeasurements at fixed stations made it possible to investigate biological- physical couplingsduring the vernal phytoplankton bloom of the two years 1985/86 and in a coastal area ofthe Baltic Sea. LÄS MER

  3. 2. 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

  4. 3. Chemical composition of summertime High Arctic aerosols

    Författare :Karolina Siegel; Claudia Mohr; Annica Ekman; Ilona Riipinen; Lise Lotte Sørensen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aerosol; chemical composition; Arctic climate; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : This thesis presents new insights into the chemical composition of semi-volatile compounds in aerosol samples collected in the central Arctic Ocean close to the North Pole in September 2018. The central Arctic Ocean is an inaccessible location due to the lack of land areas along with heavy pack ice conditions. LÄS MER

  5. 4. Determining Chlorophyll-a Concentrations in Aquatic Systems with New Statistical Methods and Models

    Författare :Peter Dimberg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chlorophyll-a; statistical models; aquatic systems; lakes;

    Sammanfattning : Chlorophyll-a (chl-a) concentration is an indicator of the trophic status and is extensively used as a measurement of the algal biomass which affects the level of eutrophication in aquatic systems. High concentration of chl-a may indicate high biomass of phytoplankton which can decrease the quality of water or eliminate important functional groups in the ecosystem. LÄS MER

  7. 5. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

    Författare :Jonas Johansson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

    Sammanfattning : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. LÄS MER