Cadmium Uptake by Corbicula fluminea and Dreissena polymorpha: Effects of pH and Temperature
B. Fraysse, J.P. Baudin, J. Garnier-Laplace, A. Boudou, F. Ribeyre, C. Adam
Bull. of Environ. Contamination and Toxicology, 2000, 65(5), 638-645
Cadmium is a well-known environmental contaminant that affects aquatic environments. To monitor this pollutant and its bioavailability in freshwater ecosystems, the use of bioindicators, such as bivalves, is particularly well suited. However, prior experimental studies are required in order to determine the charactedstics (transfer kinetics and level) of the contamination to the .organisms. Two species were selected, the Asiatic clam (Corbicula fluminea) and the zebra mussel (Dreissena polymorpha). By reason of theirs ecological and physiological features (particularly a high filtration rate), these two species are very suitable as heavy. metal bioindicators as shown by ecotoxicological studies (Graney et al 1983; Kraak et al 1991; Merch, 1993; Claudi and Mackie 1994; Inza 1996). In addition, for monitoring the aquatic environment these two species are complementary, since they differ in habitat requirements. C. fluminea is a benthic infaunal species, whereas D. polymorpha is an epilithic species. The species also differ in optimal temperature for growth and reproduction, 14-22°C for C. flumlnea and 8-16°C for D. polymorpha (Claudi and Mackie 1994). One of the particularity of C. fluminea is to feed off by the suspended mater presents in the watbr column, as D. polymorpha, and also by the sediment particles by pedal feeding (Way and Hombach 1990).
The aim of the present study was to determine the effects of pH and temperature on the accumulation and distribution of cadmium in the soft tissues of the two molluscs.