Search for dissertations about: "aquatic ecology"

Showing result 1 - 5 of 183 swedish dissertations containing the words aquatic ecology.

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

    University dissertation from Kajsa Åbjörnsson, Limnology, Ecology Building, S-223 62 Lund, Sweden

    Author : Kajsa Åbjörnsson; Lund University.; Lunds universitet.; [2002]
    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

  2. 2. Consumption patterns and excretion in aquatic food websenrichment

    University dissertation from Department of Ecology, Lund University

    Author : Anders Persson; Lund University.; Lunds universitet.; [1997]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; trophic interactions; translocation; biomanipulation; enrichment; phosphorus; model; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : This thesis links biogeochemical cycling to classical ecology. Predictions derived from food chain theory, based on Lotka-Volterra type of interactions, were tested in aquatic environments with the main hypothesis that consumers affect lower levels of organization by both predation and excretion of limiting nutrients. READ MORE

  3. 3. Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective

    University dissertation from Department of Biology, Lund University

    Author : Melanie Hedgespeth; Lund University.; Lunds universitet.; [2015]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ecotoxicology; aquatic; trophic level; pharmaceutical; SSRI; beta-blocker; sertraline; fluoxetine; propranolol; fish; daphnia; snail; predator; prey; behavior; life history; multiple stressor;

    Abstract : Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. READ MORE

  4. 4. Allochthonous and autochthonous carbon sources of lake bacterioplankton

    University dissertation from Department of Ecology, Lund University

    Author : Emma Kritzberg; Lund University.; Lunds universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnologi; akvatisk ekologi; aquatic ecology; marine biology; Hydrobiology; bacterial community composition; bacterial growth efficiency; bacterioplankton; carbon subsidy; dissolved organic carbon; limnology;

    Abstract : Organic substrates for pelagic bacteria are derived from dissolved organic carbon (DOC) in the water column that originates either from primary production from within the lake itself (autochthonous), or import of organic matter from the terrestrial watershed (allochthonous production). This thesis addresses the utilization of allochthonous versus autochthonous carbon (C) sources by lake bacterioplankton. READ MORE

  5. 5. The significance of sexuality and cyst formation in the life-cycles of four marine dinoflagellate species

    University dissertation from Lund University

    Author : Rosa Figueroa; Lund University.; Lunds universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; cyst; Hydrobiology; akvatisk ekologi; marine biology; aquatic ecology; limnology; sexuality.; meiosis; Lingulodinium polyedrum; life-cyle; limnologi; Marinbiologi; Gymnodinium nolleri; Gymnodinium catenatum; Alexandrium catenella; dinoflagellates;

    Abstract : Sexuality and cyst formation were studied in the marine dinoflagellate species Gymnodinium catenatum Graham, Gymnodinium nolleri Ellegaard ? Moestrup, Alexandrium catenella (Whedon et Kofoid) Balech, and Lingulodinium polyedrum (Stein) Dodge. The study included the morphological characterization of sexual stages and processes, the time and description of meiosis, the study of the length and regulation of the mandatory dormancy period of resting cysts, and the relationships among parental strains and cyst progeny at phenotypic and molecular levels. READ MORE