Radioecological Study of the Marsh Frog Pelophylax ridibundus as a Component of the Aquatic Ecosystem of Lake Kozhakul (Southern Urals)
摘要
The accumulation of anthropogenic radionuclides 90Sr and 137Cs by the marsh frog Pelophylax ridibundus in Lake Kozhakul, adjacent to the southeastern boundary of the East Ural radioactive trace, has been studied. Concentrations of 90Sr in adult amphibians at the sampling site vary ~100 times and those of 137Cs vary 4 times. All concentrations of 90Sr and 137Cs in the components of Lake Kozhakul (adult frogs, Cladophora, perch, and silty sediments) are significantly higher than similar average values in water bodies of the Middle Urals that have not been subjected to strong radioactive impacts and accidental contamination. It is found that 60% of adult frogs are contaminated with 90Sr above the permissible standard established for fish, and fingerlings of frogs approach this standard. It is concluded that the studied amphibian species can be a good bioindicator of contamination of aquatic ecosystems with this radionuclide in sites of radioactive contamination.