Sökning: "Marinbiologi"
Visar resultat 21 - 25 av 42 avhandlingar innehållade ordet Marinbiologi.
21. Allochthonous and autochthonous carbon sources of lake bacterioplankton
Sammanfattning : 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. LÄS MER
22. Waterfowl in temperate eutrophic lakes - Interactions with macroinvertebrates, submerged vegetation and fish
Sammanfattning : The aim of this thesis was to explore some of the important links between waterfowl and the biota in shallow eutrophic lakes in temperate areas. Waterfowl depend on macroinvertebrates as sources of protein and calcium, which are essential for egg production and growth. Macroinvertebrates in turn depend on submerged vegetation for food and shelter. LÄS MER
23. The Cyanophyte Arthrospira Fusiformis in African Waters - Eco-Physiology and Potential Use in Tropical Aquaculture
Sammanfattning : The cyanoprokaryote (blue-green algae) genus Arthrospira occurs in saline, alkaline tropical waters of Africa, Asia, and Central America. Traditionally Arthrospira has been used as a food supplement by the Kanembu tribe of Lake Chad and Aztecs living in the valley of Mexico City. LÄS MER
24. The effects of crayfish on interactions in freshwater benthic communities
Sammanfattning : This thesis examines how freshwater crayfish affect community interactions in benthic food webs. I have mainly studied the influence of the introduced signal crayfish (Pacifastacus leniusculus) on littoral communities, but also the influence of the native noble crayfish (Astacus astacus). LÄS MER
25. Consumption patterns and excretion in aquatic food websenrichment
Sammanfattning : 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. LÄS MER