GUNDACKER , C. & K. J. WITTMANN, 1997: Bioakkumulation von Schwermetallen in Mollusken urbaner Gewässer. Abstractband des Symposium "Ökologie und Taxonomie von Süßwassermollusken", Salzburg 1997. 1p.
Heavy metal accumulation by molluscs in urban waters.
In waters of the city of Vienna, bivalves belonging to the genera Dreissena, Anodonta, and Unio, and gastropods belonging to Radix and Viviparus, accumulated essential trace metals (Cu, Zn) in higher concentrations as compared to potentially toxic (Pb, Cd) ones. Mollusc shells showed generally lower heavy metal contents as compared to body tissue. Especially, the body tissue of gastropods showed high concentration factors. For bivalves, detailed analysis of tissue-specific accumulation provided informations about storage organs, possible regulation and possible mechanisms of decontamination.
High contamination was found in certain waters with high anthropogenic impact. The examined indicator organisms rarely reflected local heavy metal loads in a direct way, as observed accumulation rates were rather an outcome of a number of abiotic and organismic factors. Correlations between accumulation rate and mode of feeding was only partly observed. Benthic molluscs accumulated heavy metals mainly from the sediment, in part also via gills or dermis.
Generally speaking, the waters of Vienna showed only a moderate heavy metal impact. An acute endangerment of the mollusc-hiocenoses by heavy metals may be excluded. The most sensible heavy metal indicators are proposed to be used for routine monitoring of urban waters. Organs with highest accumulation rates, such as bival%e gills (also serving as marsupial, may be particularly suitable. An essential prerequisite for such a biomonitoring would be standardization of methods.
Danube; bioindicators; freshwater; ecotoxicology; bioaccumulation of heavy metals
Dreissena; Anodonta; Unio; Radix; Viviparus