Trophic interactions and behaviour: Studies relevant to a Baltic Sea biomanipulation
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
The main theme of this thesis is the interactions of animals with the environment and each other. The thesis was written within the framework of a biomanipulation project “Pikeperch in Himmerfjärden”. With the aim to investigate possible trophic pit-falls, give the manipulation the best possible start, and find ways to monitor the progression of the manipulation. In Paper I the diet of the invader cladoceran Cercopagis pengoi is analysed with stable isotopes; conducted prior to stocking. C.pengoi has a preference for large copepods, indicating possible competition with fish. Paper II investigates the behavioural differences between pikeperch fingerlings reared in different environments (pond vs. tank). Results suggest that fish reared in semi-natural ponds are more likely to survive directly after stocking. In Paper III and IV, the diel vertical migrations (DVM) of copepods are in focus. In Paper III the migrations of two copepod species: Acartia spp. and Eurytemora affinis are studied over season and life stage. The amplitude of migration was found to increase with ontogeny for both species, indicating evasion of visual predators. Paper IV examines the varying migratory patterns of adult female E. affinis finding that these animals migrate more actively when feeding conditions deteriorate and growth decreases. The overall conclusions of the thesis are that behavioural, not only direct trophic interactions are key when studying ecosystems.
Place, publisher, year, edition, pages
Stockholm: Department of Systems Ecology, Stockholm University , 2012. , 31 p.
zooplankton, non-indigenous species, selectivity; food web, rearing environment, fish stocking, Sander lucioperca, diel vertical migration, ontogeny, ovigerous
Research subject Marine Ecology
IdentifiersURN: urn:nbn:se:su:diva-79075ISBN: 978-91-7447-567-8OAI: oai:DiVA.org:su-79075DiVA: diva2:546978
2012-10-05, Nordenskiöldsalen, Geovetenskapens hus, Svante Arrhenius väg 12, Stockholm, 13:00 (English)
Tiselius, Peter, Professor
Hansson, Sture, ProfessorGorokhova, Elena, Professor
At the time of the doctoraldefense, the following papers were unpublished and had a status asfollows: Paper2: In press. Paper 4: Manuscript.2012-09-132012-08-262012-08-27Bibliographically approved
List of papers