Search for dissertations about: "Perca fluviatilis"

Showing result 21 - 25 of 44 swedish dissertations containing the words Perca fluviatilis.

  2. 21. Development of GC-HRMS procedures for determination of naturally occuring polar compounds in various environmental applications

    Author : Bodil Widell; Dag Broman; Caroline Leck; Joan Grimalt; Stockholms universitet; []
    Keywords : GC-HRMS; steroid hormones; amino acids; perch; size-resolved aerosol; Arctic; NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

    Abstract : The overall objectives of this dissertation were to gain further understanding of the two following environmentally significant issues: (i) Determination of natural steroid hormones in blood plasma from perch (Perca fluviatilis) during a reproductive cycle and to evaluate the possibility of using the steroid composition as a biomarker for early signs of endocrine disruptive effects. (ii) Determination of dissolved free amino acids in size resolved airborne particles collected over the Arctic pack ice area (>80°N) in summer and to study their overall relationship with the ocean surface microlayer as a potential source. READ MORE

  4. 22. Ecology across Boundaries : Food web coupling among and within ecosystems

    Author : Pia Bartels; Peter Eklöv; Lars J. Tranvik; Daniel E. Schindler; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cross-ecosystem; food web; habitat coupling; terrestrial-aquatic linkages; subsidy; allochthonous; lake ecosystem; population divergence; trait variation; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; Freshwater ecology; Limnisk ekologi; Biology; Biologi; Biologi med inriktning mot limnologi; Biology with specialization in Limnology;

    Abstract : Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. READ MORE

  5. 23. Habitat use in fish communities : size- and environment-dependent mechanisms affecting biotic interactions and population regulation

    Author : Ulrika Beier; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Through the influence of abiotic factors, the habitat use of organisms affects their metabolism as well as other species- and size-dependent individual-based rates. The habitat-specific performances of individuals interacting in different habitats thereby affect biotic interactions. READ MORE

  6. 24. Influence of cyanobacterial blooms on coastal fish recruitment

    Author : Karl-Johan Persson; Catherine Legrand; Markku Viitasalo; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Cyanobacteria; coastal fish recruitment; Akvatisk ekologi; Aquatic Ecology;

    Abstract : Cyanobacteria are the oldest oxygen-producing organisms on Earth and can be found in almost every terrestrial and aquatic habitat. Their long evolutionary history has enabled them to develop diverse adaptations in order to increase their survival in environments subjected to natural and anthropogenic changes. READ MORE

  7. 25. Spatial Modelling of Coastal Fish – Methods and Applications

    Author : Göran Sundblad; Ulf Bergström; Alfred Sandström; Peter Eklöv; Christian Möllmann; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; habitat; niche; species distribution modelling; juvenile; fish; larvae; spawning; Marine ecology; Marin ekologi; NATURAL SCIENCES; NATURVETENSKAP; Freshwater ecology; Limnisk ekologi; Biology; Biologi; Biology with specialization in Limnology; Biologi med inriktning mot limnologi; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology; Limnologi; Limnology;

    Abstract : Environmental factors influence species and habitats on multiple scales creating a mosaic of distribution patterns. Studying factors shaping these patterns are central to our understanding of population dynamics and ultimately ecosystem functioning. READ MORE