Influence of food availability on the accumulation of137Cs by fishes of the cooling pond of the Chernobyl NPS

In 1986-1988 the content of 137Cs in the fishes kept in breeding cages in the cooling pond of the Chernobyl NFS in the absence of artificial food was compared with that in free-living fishes characterized by different types of nutrition. The body mass of polybenthophagous fishes kept in cages and the content of 137Cs in them were several times lower than those registered in free-living fishes. It has been found that the content of 137Cs in Ictalurus punctatus depended inversely on its dimensions. As a result of the absence of artificial food, by summer 1988 the death rate of I. punctatus and Cyprinus carpio belonging to polybenthophagous species of fishes accounted for almost 100%. The content of 137Cs and biological characteristics in free-living planktophagous species of fishes (Hypophthalmichthys molitrix and Aristichthys nobilis) were closely similar to those kept in cages, which was conditioned by the same food availability. © 2005 Begell House, Inc.