Evolution of radiocaesium contamination in fishes after the Chernobyl accident

The dynamics of radionuclide accumulation by fishes in different aquatic ec osystems was studied following the Chernobyl accident. Predatory and non pr edatory fishes in the Chernobyl NPP cooling pond, Kiev reservoir (Ukraine), Kojanovskoye lake (Russia) and Svyatoe lake (Belarus) were studied during the period 1986-1997. Concentration of radionuclides in fishes muscles decr eased significantly during the period 1986-1997. Speed of purification of f ishes depends on amount of radionuclides transferred in ponds and on hydrol ogical and hydrochemical features of the aquatic ecosystems.