DNA-damage and pigmentation in alpine and arctic zooplankton as bioindicators of UV-radiation

Summary

Alpine and arctic zooplankton communities in shallow habitats may be good bioindicators of detrimental UV-stress. For several reasons, the wide-spread genus Daphnia is particularity well suited for studies of genetic and morphological effects. While carotenoid pigmentation in Daphnia as well may be related to nutritional status (lipid-content) as light, the presence of cuticular melanin is a unique property of the highly light-stressed populations, and increased relative success of melanized clones or populations should indicate increased UV-stress. Melanin may act both directly as a light screen and as a powerful antioxidant to UV-induced oxydants and free radicals. Laboratory and field studies of UV or near-UV induced single and double strand DNA-breaks associated with other forms of photoproducts may be used to predict harmful levels of irradiation.