Mytilus californianus as a bioindicator of trace metal pollution: Variability and statistical considerations

Trace metal variability was evaluated in two populations of Mytilus californianus through the analysis of individual specimens. Samples were collected from two areas in the Southern California Bight and analysed for their Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn content.Analysis of the data revealed that population variability was not the same between the two sites, indicating that variability may need to be evaluated for each population (site) studied. In general, the analysis of 10 to 30 individuals was necessary to yield maximum resolution in terms of trace metal concentrations between population means while maintaining cost effectiveness.