Copper and Cadmium Accumulation in Populations of Littorina saxatilis from the Isle of Man Having Differential Tolerance to Zinc and Lead

The accumulation of Cu and Cd from solution was studied in Littorina saxatilis from five sites around the Isle of Man with different degrees of metal contamination. The winkles were exposed to increasing concentrations of each metal (0, 0.01, 0.1, 0.5 and 1.0 mg added Cu and added Cd) after acclimation to laboratory conditions. The experimentation was conducted in triplicate runs and after the exposure period, tissue metal concentrations were determined by atomic absorption spectrophotometry. Different accumulation profiles were observed for Cu and Cd. Cd accumulation was monotonic over the range of exposure concentrations, giving linear regressions with high coefficients of determination. Cu accumulation on the other hand was linear up to 0.5 mg but polynomial (quadratic) fits described the accumulation patterns better when all concentrations are included. Tissue Zn concentrations showed a significant relationship with Cd accumulation. No significant interpopulation differences in Cu accumulation were shown by Analysis of Covariance. Significant differences in Cd accumulation were found between populations although not reflective of the tolerance profile.