The aim of this international project is to measure and model arctic UV-radiation and assess the effects on freshwater planktonic organisms and foodwebs. The fieldwork and experiments are conducted at Ny-Alesund, Spitsbergen. The specific aim of our participation is to study the food web effects of UV-B stress by means of in-situ enclosure studies. In the laboratory we found that UV-B stressed algal cells may increase in volume and form a thicker cell wall. These changes in the algal cells may reduce their digestibility by zooplankton. Further the role of photopigments (like melanin and carotenoids), present in some zooplankters, will be studied in relation to the survival of these animals at high UV-B exposure. Research activities Grazing experiments with Daphnia pulex (melanic and hyaline) are performed in in-situ enclosures (under different UV exposures) in the Brandal Lagune during July. The green alga Chlamydomonas will be incubated in-situ under different UV exposures to assess the potential use of this alga as a biodosimeter for UV-B. Further the survival of melanic and hyaline daphnids will be tested in-situ.
Laboratory and in-situ UV exposure experiments Sampling frequency: only in July
- University of Oslo (prof.dr. D.O. Hesssen) - Norwegian Institute of Water Research (dr. B.A. Faafeng and Dr. A. Hobaek) - Uppsala University (Sweden)