Dynamics of organochlorine compounds in different trophic levels os Los Padres pond in Argentina

GONZALEZ SAGRARIO, M. A., J. E. AIZPÚN DE MORENO, V. J. MORENO AND A. H. ESCALANTE.

Environmental Sciences

Scientific Publishing Division of MYU

Lugar: Tokyo; Año: 1998 vol. 6 p. 153 - 169

Total tissue of two macrophytes (Schoenoplectus californicus and Ludwigia sp.) one shrimp (Palaemonetes argentinus), and mesenteric fat, gonadal, hepatic and muscle tissues of two fishes (Rhamdia sapo and Oligosarcus jenynsii) from Los Padres pond in Argentina were analyzed for a variety of pesticides (1,1,1-Trichloro-2,2-bis[p-chlorophenyl]ethane, (DDT); hexachlorocyclohexanes, (HCHs); cyclodienes and mirex. Pesticides with higher water solubility, such as HCHs, were accumulated preferentially by macrophytes and shrimp. These organisms appear to be able to efficiently take up these compounds from water. Fish more efficientely accumulated compounds with higher lipophilicity, such as DDTs and heptachlor epoxide. According to our results, macrophytes are a pollutant sink in Los Padres pond. O. jenynssi accumulated pesticides mainly in the ovaries and to a lesser extent in the liver an muscle tissues. Mesenteric fat was found in both sexes of R. sapo with a low gonadal index, becoming a sink of organochlorine compounds. The greatest extent of DDE and heptachlor epoxide were accumulated in this tissue. The effect of the release of high levels of pesticides, when mesenteric fat is metabolized, is discussed. High levels of organochlorines in fish muscle could reflect chronic pollutant exposure and in R. sapo, a bottom feeder, its association with bottom sediment. In general, the is a good correlation between lipid content and organochlorine  concentration.