TY - JOUR AU - Wold , Anette AU - Norrbin , Fredrika PY - 2004/06/01 Y2 - 2024/03/28 TI - Vertical migration as a response to UVR stress in Calanus finmarchicus females and nauplii JF - Polar Research JA - POLAR VL - 23 IS - 1 SE - Thematic cluster. Selected papers from the session Effect of Climate Variability on the Arctic Seas Ecosystems DO - 10.3402/polar.v23i1.6263 UR - https://polarresearch.net/index.php/polar/article/view/2070 SP - 27-34 AB - We conducted laboratory experiments to study the behavioural responses of Calanus finmarchicus females and nauplii exposed to artificial ultraviolet radiation (UVR) and photosynthetically active radiation (PAR). Both nauplii and females migrated downwards when exposed to UVR. Nauplii reacted mainly to UV-B radiation, while females responded also to UV-A. Nauplii were also collected in the field to check if vertical distributions supported the experimental findings. Light measurements in Vestfjorden showed that plankton were exposed to quite low doses of UVR most of the time. However, on days with a thin ozone layer, clear sky and low turbidity UV-B doses in the surface waters might be harmful. Strong turbulence in the surface layer prevents nauplii from adjusting their position, exposing them to fluctuating levels of UVR due to vertical mixing. Under calm conditions, however, copepods could migrate sufficiently to avoid harmful UVR doses. ER -