Influence of labelled food type on the accumulation and retention of 60Co by a freshwater fish,Cyprinus carpio L.

The study was carried out on 3 groups of 10 fish, each fed on a different natural labelled food. The preys selected were a crustacean (Gammarus pulex), a midge larvae (Chironomus sp.) and the soft tissues from a snail (Lymnaea stagnalis), which are usually consumed by carp in the natural environment. The contaminated food consumption by the fish resulted in a ⁶⁰Co maximum transfer factor ranging from 1.2 × 10^?2 to 5.1 × 10^?2 depending on the food type. These values, and the contamination kinetics indicate that the biomagnification of the radionuclides cannot occur, even over the long term. ⁶⁰Co depuration from fish was also influenced by the contaminated food type, previously ingested. The lower elimination rate correspond to the higher value of the transfer factor (Gammarus pulex) and inversely (Lymnaea stagnalis).