Sökning: "Marine Ecology"

Visar resultat 26 - 30 av 342 avhandlingar innehållade orden Marine Ecology.

1. 26. Zooplankton growth and trophic linkages : Implications for fish feeding conditions in the Baltic Sea

   Författare :Towe Holmborn; Elena Gorokhova; Sture Hansson; Ilppo Vuorinen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AARS activity; biochemical markers; Clupea harengus; copepod physiology; food web interactions; non-indigenous species; RNA-based indices; Sprattus sprattus; stable isotopes; Marine ecology; Marin ekologi; Marine Ecology; marin ekologi;

   Sammanfattning : The aim of this Thesis was to improve our understanding and assessment of feeding conditions for zooplanktivorous fish in the Baltic Sea.We investigated (papers I, II) the usefulness of biochemical proxies for assessments of growth and metabolic rates in the dominant Baltic copepod Acartia bifilosa. LÄS MER

3. 27. Persistent organic pollutants in benthic foodwebs

   Författare :Niklas Holmqvist; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; Intraspecific interactions; streams; nutrients; lakes; crayfish; eels; Persistent organic pollutants; Benthic foodwebs; akvatisk ekologi; Environmental chemistry; Miljökemi;

   Sammanfattning : Concentrations of persistent organic pollutants (POPs) in aquatic biota are dependent on several factors both on individual and on system level. Bioaccumulation of POPs in pelagic biota in lakes as well as fish in streams has been shown to be dependent on nutrient regime of the system. LÄS MER

4. 28. Modelling spatial and temporal species distribution in the Baltic Sea phytobenthic zone

   Författare :Antonia Nyström Sandman; Hans Kautsky; Martin Isaeus; Georg Martin; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; species distribution modelling; niche; gradient; prediction; environmental factors; phytobenthos; scale; Marine ecology; Marin ekologi; Marine Ecology; marin ekologi;

   Sammanfattning : Statistical modelling is often used to relate the presence or abundance of species to environmental predictors, thereby providing a basis for predictive mapping of species or biodiversity. The variables included must thus be relevant and reflect actual changes in the environment. LÄS MER

5. 29. Ecotoxicological assessment by microcosm tests on plankton communities

   Författare :Pardis Pirzadeh; Biologiska institutionen; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

7. 30. The role of young-of-the-year fish in lake ecosystems

   Författare :Pia Romare; Biologiska institutionen; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER