Freshwater and Alpine ecosystem response to Chernobyl fallout in Norway

Environmental and agricultural research programmes were initiated in Norway in June 1986 following the Chernobyl accident. The main fallout in Norway occurred on 28 and 29 April and had an extremely patchy distribution between 60 and 66 deg. C N. In Lake Hoeysjoeen in the county of North Troendelag, high radioactivity was found in the sediment and in all levels of the food chains from vegetation to fish, including phytoplankton, zooplankton, bottom animals, brown trout and Arctic char. Food chains for both wild and domestic animals are studied in the Alpine areas of central Norway. High seasonal variation has been found in the radiocaesium load of reindeer. Such a variation is a result of the high radioactivity (up to more than 100 kBq/kg dry weight) in lichens, the only winter food for reindeer. Also there are indications of increased calf mortality and chromosomal aberrations in the blood cells of the reindeer in nutrient poor areas with heavy fallout. In mountain pastures where sheep and goats graze, a sharp increase in meat and goat milk radiocaesium occurred during the late pasture season in 1988. This was caused by the large number of mushrooms with high levels of radioactivity. Present research in Norway will have to be continued in order to develop further national and international co-operation among scientists and institutions with whom biologists had little or no contact previously. (author). 11 refs, 3 figs