Understanding winter patterns of zooplankton diel vertical migration (DVM) in a high Arctic fjord (Kongsfjorden, Svalbard)
Recent Arctic studies contradict the long-held paradigm of winter quiescence and document activity levels in the marine food web even during the darkest months of winter. A phenomenon that has attained considerable attention is patterns of Diel Vertical Migration (DVM) of zooplankton during the polar night.
Why do organisms migrate in a seemingly constant dark environment? This PhD thesis is aimed at examining the general patterns on DVM during the polar night in Svalbard waters, with a main aim of identifying which species are in fact migrating and why they conduct these energetically costly migrations. The results show that polar night DVM is a complex phenomenon, and involves several migration patterns. Zooplankton net sampling, in parallel with acoustics, revealed that krill were dominant species behind migratory patterns. Molecular and electrophysiological experiments showed that ambient light levels rather than endogenous genetic control governed winter migration patterns.
Kommisjonen
Veiledere:
- Professor Jørgen Berge, AMB
- Professor Tove Gabrielsen, UNIS
- Professor Paul Renaud, Akvaplan Niva
- Dr Finlo Cottier, Scottish Association for Marine Science
Bedømmelseskomité:
- Førsteamanuensis Kasia Blachowiak-Samolyk, Institute of Oceanology, Polen (1. opponent)
- Professor emeritus Friedrich Buchholz, Univ. i Hamburg, Tyskland (2. opponent)
- Førsteamanuensis Fredrika Norrbin, AMB (internt medlem og leder av komiteen)
Disputasen ble avholdt på engelsk og ble ledet av dekan Edel O. Elvevoll ved Fakultet for biovitenskap, fiskeri og økonomi.
