In order to examine the feasibility of this approach, we have determined the distribution of Zn, Cu and Cd in the fractionated cytosol of sea urchins (Strongylocentrotus purpuratus) and collected from three stations along the southern California coast. Point Dume (Fig. 1) was designated a control station due to the lack of either trace metal or chlorinated hydrocarbon contamination in the sediment and the normality of the benthic population (Word & Mearns, 1979).