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 HCH, HCB, pp'DDE pp'DDT and polychlorobiphenyls) by fishes of two different species, the Roach (Rutilus rutilus) and the Perch (Perca fluviatilis), predator of the Roach, have been studied at two stations situated on the catchment basin of the Seine. Only polychlorobiphenyls show high contents in these fishes. The polychlorobiphenyl compositions of these organisms correspond to those found in most environments. There is no systematic relationship between the bioconcentration and the size of the fish. The reproductive cycle appears to have a significant impact on the organochlorine contents. Moreover, the extent of PCB amplification with trophic level depends partly on the mode of expression of their contents, related either to body weight or to lipid weight. Thus the PCB body contents in the Perch are slightly higher than in the Roach, whereas, regarding lipid weight, the contents are twice as high as in the predator species. In the Roach, body contents of micropollutants are only two six times higher than in Molluscs (Anodonta cygnea, Vivipara vivipara). The Roach and the zebra mussel show important differences in the PCB composition, whereas there are none between the Perch and the Roach; in the latter species, they do not seem to change with age.