Levels of dose-forming radionuclides in the young perch (Perca fluviatilis) in the Zaporizke Reservoir

Abstract

It had been investigated the content levels and the coefficients of accumulation from water of the main dose-forming radionuclides (137Cs, 90Sr, 226Ra, 232Th, 40К) in different-age Perca fluviatilis from the Samara Bay and the lower part of the Zaporizke Reservoir. The three age groups of fish were used: one-summer old (0+), two summers old (1+), and three summers old (2+). The obtained data on consecutive reduction of radionuclide activity values in juvenile perch showed that maximal 137Cs content was found in individuals of age (0+), and the minimal one – in individuals aged (1+) from Samara Bay. The maximal accumulation of radioisotopes 90Sr was in individuals aged (0+) in the lower part of the Zaporizke Reservoir, and the minimal one in the perch of age (1+) in the Samara Bay. The highest levels of 226Ra and 40K were found in the (0+) fish from the Samara Bay, and the lowest contents were in individuals aged (2+) in the lower part of the reservoir. The value of the 232Th content level was maximal in the two-summer-olds from the lower part of the reservoir, and the minimal one – in (0+) fish from the Samara Bay. Artificial radionuclide 137Cs was accumulated in the largest amount by perch (0+) from the Samara Bay, and 90Sr – by fish from the lower part of the Zaporizke Reservoir. By values of accumulation coefficients, 232Th was in second place after 137Cs, indicating its significant contribution to the formation of the total dose of radiation. Majority of radioisotopes investigated were more intensively accumulated by the juvenile perch in the Samara Bay compared to the lower part of the Zaporizke Reservoir. The highest level of radionuclide accumulation at both studied sites of the Zaporizke Reservoir has been observed in (0+) fish.