Sökning: "nanoflagellates"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet nanoflagellates.

  1. 1. Pelagic microorganisms in the northern Baltic Sea : Ecology, diversity and food web dynamics

    Författare :Johnny Berglund; Agneta Andersson; Ramon Massana; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; resource limitation; predation limitation; microbial food web; heterotrophic microorganisms; nanoflagellates; ciliates; protists; resource heterogeneity; chrysomonads; chrysophytes; group-specific PCR-DGGE primers; Baltic Sea; Marine ecology; Marin ekologi;

    Sammanfattning : Heterotrophic microorganisms are important for the flow of carbon and nutrients in the sea. Bacteria, nanoflagellates and ciliates are relevant components of the pelagic food web. In order to be able to predict the outcome of e.g. LÄS MER

  3. 2. Flagellates in the marine microbial food web : the ecology of a mixotrophic nanoflagellate, Ochromonas sp

    Författare :Agneta Andersson-Nordström; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Microbial food web; flagellates; Ochromonas sp.; mixotrophy; size- selective grazing; remineralisation; excretion of DFAA;

    Sammanfattning : Nanoflagellates were found to be abundant in a coastal area of the northern Bothnian Sea. The maximum concentration of nanoflagellates, approximately 8000 cells ml-1, was observed in July, coinciding with a decrease in the abundance of cyanobacteria. LÄS MER

  4. 3. Distribution and fate of polychlorinated biphenyls within the pelagic microbial food web

    Författare :Petra Wallberg; Per Larsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Biologi; zoologi; Zoology;

    Sammanfattning : The composition and production of the plankton community in aquatic environments will in turn influence the food-web structure of larger predators, nutrient cycling, the sinking flux and, hence, the fate of hydrophobic organic contaminants. The aim of the research presented here was to study the distribution and fate of PCBs within the microbial food web, including bacteria, flagellates, ciliates, and phytoplankton. LÄS MER

  5. 4. Ecological effects of pesticides in freshwater model ecosystems

    Författare :Lina Wendt-Rasch; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; Hydrobiology; community; zooplankton; algae; herbicide; insecticide; pesticide mixture; macrophytes; cypermethrin; metsulfuron-methyl; risk assessment; pesticides; microcosms; limnologi; akvatisk ekologi;

    Sammanfattning : In this thesis I have investigated the effects of pesticide exposure on the ecosystem level using various types of experimental ecosystems, i.e. microcosms. The direct effect of exposure to cyperemthrin, a pyretroid insecticide, was a rapid decrease of crustancean zooplankton in enclosures in a lake. LÄS MER

  7. 5. The role of allelopathy in microbial food webs

    Författare :Astrid Weissbach; Catherine Legrand; Ellen Van Donk; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Microbial food web; Allelopathy; Alexandrium tamarense; Prymnesium parvum; Infochemicals; marine plankton community; Freshwater ecology; Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : Phytoplankton produce allelochemicals; excreted chemical substances that are affecting other microorganisms in their direct environment.In my thesis, I investigated strain specific variability in the expression of allelochemicals of the harmful flagellate Prymnesium parvum, that is euryhaline but mainly bloom forming in brackish water. LÄS MER