Cadmium contamination, accumulation and some effects of this metal in mussels from a polluted marine environment

Abstract

Results are presented for the effect of two variables on cadmium uptake in the common blue mussel, namely shore height and distance from the point of source of cadmium contamination. A significant increase in cadmium concentration with distance downshore was demonstrated. A cadmium pollution gradient was detected over short horizontal distances away from the source of contamination. Calculation of flesh condition factors for the populations sampled suggested that condition was not affected by the high cadmium levels detected. Investigations to determine the rate of uptake of cadmium in transplanted mussels indicated: (i) that young animals should be used in accumulation experiments because they grow more quickly and, therefore, respond more rapidly to their environment; and (ii) transplanted animals should be given a minimum of 30 days to regain condition and resume growth following the stress effects due to relocation. Attempts to correlate shell thickness with cadmium concentration were inconclusive. The study confirmed that Mytilus edulis is an excellent bioindicator of local pollution be cadmium.