Search for dissertations about: "FOOD-WEB"
Showing result 6 - 10 of 144 swedish dissertations containing the word FOOD-WEB.
-
6. Baltic Sea food web dynamics and response to environmental change
Abstract : The Baltic Sea ecosystem is subject to a combination of external pressures such as fishery, changing climate and land-based nutrient inputs. In combination with internal food web mechanisms these external forces can lead to changes in the food web structure and function. READ MORE
-
7. Thiamin (vitamin B1) in the aquatic food web
Abstract : Thiamin (vitamin B1) is required for several life-sustaining processes in most organisms and cells, e.g. in the conversion of food to energy. It also serves as an antioxidant and is important for proper nerve signaling. READ MORE
-
8. Mysid growth, stable isotope fractionation, and energetics : implications for food web studies
Abstract : Field data, stable isotope analyses of the Baltic Sea food web structure,and experimental studies of the functional response indicate that theomnivorous crustacean Mysis mixta (Crustacea, Mysidacea) has no distinct trophic position, but can potentially affect plankton communitystructure and compete with herring and sprat for the zooplankton. Toevaluate field data on mysid body constituents, abundance and populationstructure, and that of their potentialprey, basic knowledge of feeding behaviour, growth mechanisms, andreproductive capabilities are required. READ MORE
-
9. Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem : Bottom-up effects in an aquatic food web
Abstract : The thesis combines laboratory experiments and field expeditions to study production, transfer and consumption of non-enzymatic antioxidants and thiamine in an aquatic food web. In particular, I (1) documented spatial and seasonal variation of tocopherols and carotenoids in the Baltic Sea pelagic food web, and (2) examined the effects of abiotic and biotic factors on tocopherol, carotenoid and thiamine concentrations in phytoplankton, zooplankton and fish. READ MORE
-
10. Mechanisms structuring the pelagic microbial food web : Importance of resource and predation
Abstract : Temporal and spatial variations of pelagic microorganisms in the northern Baltic Sea were studied, as well as factors influencing their abundance and growth rates. Three main questions were asked 1) How does increased productivity influence the structure of the microbial food web? 2) Does predation limitation vary between trophic levels? 3) What is the relative importance of resource and predation limitation at different trophic levels?A field study in the northern Baltic Sea showed that dominating protozoa, flagellates and ciliates, increased with increasing primary productivity from north to south. READ MORE