Toxicity and bioaccumulation of cadmium in marine protozoa communities

The behavior of cadmium in a protozoan community was analyzed in order to obtain new data concerning the toxicity and bioaccumulation of this heavy metal. For this purpose, microcosms with different concentrations of the pollutant (without cadmium, 500 microg Cd.l-1 and 1000 microg Cd.l-1) were used. Protozoans bioaccumulated 8. 74-283 microg Cd.g-1 dry weight, representing an accumulation capacity of 15.53-69.59 times more than that of bacteria. The addition of cadmium caused a significant reduction in protozoan density, whereas bacterial abundance was not affected.