RELATIONSHIP BETWEEN BIOLOGICAL PARAMETERS AND BIOACCUMULATION OF SOME ORGANOCHLORINES (PESTICIDES, PCB) BY FISHES IN THE RIVER SEINE (FRANCE)

The accumulation of organochlorine compounds (alpha, beta and gamma HC H, HCB, pp'DDE pp'DDT and polychlorobiphenyls) by fishes of two differ ent species, the Roach (Rutilus rutilus) and the Perch (Perca fluviati lis), predator of the Roach, have been studied at two stations situate d on the catchment basin of the Seine. Only polychlorobiphenyls show h igh contents in these fishes. The polychlorobiphenyl compositions of t hese organisms correspond to those found in most environments. There i s no systematic relationship between the bioconcentration and the size of the fish. The reproductive cycle appears to have a significant imp act on the organochlorine contents. Moreover, the extent of PCB amplif ication with trophic level depends partly on the mode of expression of their contents, related either to body weight or to lipid weight. Thu s the PCB body contents in the Perch are slightly higher than in the R oach, whereas, regarding lipid weight, the contents are twice as high as in the predator species. In the Roach, body contents of micropollut ants are only two six times higher than in Molluscs (Anodonta cygnea, Vivipara vivipara). The Roach and the zebra mussel show important diff erences in the PCB composition, whereas there are none between the Per ch and the Roach; in the latter species, they do not seem to change wi th age.