Recherches écotoxicologiques sur la contamination des peuplements de poissons de la réserve naturelle nationale de Camargue par les polluants organiques persistants

Abstract

Our study was carried out in order to assess the overall contamination by the persistent organic pollutants of eels from a protected coastal wetland, the French National Nature Reserve of Camargue and its effects on the exposed populations. Levels of organochlorine compounds (OC), pesticide residues, polycyclic aromatic hydrocarbons (PAH) and polychlorobiphenyls (PCB) were analyzed in organs of eels, collected from the Vaccarès Lagoon. The PAH and OC contamination proved to be widespread but fluctuating. They showed in the average, especially for PCB, a very high level. The tissular distribution of PAH displayed a shift during the 4 years. The overall biological load has decreased in the liver and the gall from 1998 to 2000. The naphtalene was the most abundant in 1998 but after 1999 its average content in fishes decreases and the most frequent PAH are of molecules with 3 to 5 benzene cycles. The lindane load, which peaked prior to 1998 when its use was banned in France, has decreased in 1999, though it leveled at rates similar to the one’s of pp’-DDE and remains presently still significant. At the opposite, liver and muscle concentrations of dieldrin and HCB have unexpectedly showed a trend to the increase since 1999. By the way of a multivariate analysis, it may be concluded that three hepatic activities involved in the protection against oxyradicals : catalase seem to be most sensitive biomarkers. The muscle and gill ATPases as well as the muscle and brain AChE must be considered as more significant biomarkers than the biotransformation enzymes.