Search for dissertations about: "aquatic ecology"

Showing result 16 - 20 of 198 swedish dissertations containing the words aquatic ecology.

  2. 16. Ecotoxicological assessment by microcosm tests on plankton communities

    Author : Pardis Pirzadeh; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; aquatic ecology; limnology; Ecology; Ekologi; Hydrobiology; marine biology; musk substances; brominated flame retardants; structural effects; akvatisk ekologi; Environmental chemistry; Miljökemi; mesocosm;

    Abstract : The aim of this thesis is to present a short-term plankton community toxicity test in laboratory microcosms, with which the effect of the test substance on species abundance and composition of the community is evaluated. This laboratory microcosm is an intermediate between single-species tests and outdoor mesocosm tests. READ MORE

  4. 17. The role of young-of-the-year fish in lake ecosystems

    Author : Pia Romare; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; Rutilus rutilus; Perca fluviatilis; diet-dependent growth; density dependent growth; behavioural cascade; 0 fish behaviour; horizontal echo sounding; biomanipulation; trophic cascade; predation pressure; young-of-the-year fish; trophic interactions; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

    Abstract : Food chain theory is based on consumption; that is, presupposing that the only important interaction between organisms is that they actually meet in an unstructured environment and that one of them is consumed. Recently, studies, including biomanipulation projects, have indicated that trophic interactions are more complex than predicted by food chain theory. READ MORE

  5. 18. Waterfowl herbivory on submerged macrophytes in eutrophic lakes

    Author : Håkan Sandsten; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; limnology; Marinbiologi; limnologi; Hydrobiology; Växtekologi; Plant ecology; akvatisk ekologi; Djurekologi; Animal ecology; Anas; Fulica atra; Cygnus; alternative stable states; water depth; distribution; plant species composition; hydrophytes; propagule size; Herbivory; tuber; Potamogeton; marine biology; aquatic ecology;

    Abstract : Submerged macrophytes are thought to stabilize clear-water states of shallow lakes. The aim of this thesis was to elucidate how waterfowl herbivory can affect abundance, distribution and species composition of submerged macrophytes in eutrophic lakes. READ MORE

  6. 19. Predator-prey interactions in freshwater systems: The importance of chemical communication

    Author : Kajsa Åbjörnsson; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi; Hydrobiology; trophic cascades; non-lethal effects; benefits; costs; heredity; predator experience; alarmsubstances; dietary cues; amphibian larvae; invertebrates; visibility; fish; behaviour; Predator-prey; chemical cues;

    Abstract : Predator released chemical cues provide a valuable source of information to prey organisms that can be used to alter their behaviour in order to reduce predation risk. In this thesis, I have examined under what circumstances chemical cues may be used by prey, and if prey discriminate between different cues. READ MORE

  7. 20. The aquatic microbial food web and occurence of predation-resistant and potentially pathogenic bacteria, such as Francisella tularensis

    Author : Johanna Thelaus; Agneta Andersson; Mats Forsman; Farooq Azam; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; bacteria; protozoa; ecology; predation; nutrient-availability; microbial food web; model; predation-resistance; Francisella; reservoir; biofilm formation; Freshwater ecology; Limnisk ekologi;

    Abstract : All natural aquatic systems harbour a vast variety of microorganisms. In the aquatic microbial food web, the larger microorganisms (i.e. protozoa) feed on the smaller microorganisms (i. READ MORE