Hydrobiological Journal

Radionuclides in Some Components of the Southern Bug River Ecosystem

SINOPSIS

The comparative data are reported concerning the radioactivity of abiotic and biotic components of ecosystems of the Southern Bug River, its tributaries, along with the Tashlyk and Ladyzhyn reservoirs in 1988-1992 (the first of them serves as cooling water body for the South Ukrainian Nuclear Power Plant, SUNPP). Radionuclides of Chernobyl origin exerted a significant influence on the radioactive background in these areas. The contents of ⁹⁰Sr and ¹³⁷Cs in the Southern Bug waters were substantially higher in 1988 than before the Chernobyl accident (1986); accumulation of radionuclides in bottom sediments and fish was the highest. In 1992, the contamination level of bottom grounds in the upper reaches of the Southern Bug almost approached the pre-accident level as to ⁹⁰Sr, whereas ^l37Cs content remained 5.4 times higher than in 1978-1984. The SUNPP is influencing to some degree the radioactivity level in the Tashlyk reservoir, and therefore this source is considered as one of constant factors forming the radioecological situation in the Southern Bug basin.