SEASONAL VARIATIONS OF CADMIUM, COPPER, MANGANESE, LEAD, AND ZINC IN WATER AND PHYTOPLANKTON IN MONTEREY BAY, CALIFORNIA1

Abstract

Surface water and mixed phytoplankton samples, collected over 1 year in Monterey Bay, California, were analyzed for Cd, Cu, Mn, Pb, and Zn. The phytoplankton appeared to have little effect on the concentrations of these elements in water with the exception of Cd, which decreased during peak periods of productivity. Generally, metal levels in nearshore surface waters appeared to be more dependent on hydrographical fluctuations than on biological factors. Surface water collected on a transect between Hawaii and Monterey was analyzed for these same trace metals, for inshore‐offshore comparisons. Levels of Cu, Mn, and Zn were usually higher inshore than offshore especially during periods of strong upwelling. Concentrations of Cd and Pb were almost always an order of magnitude higher inshore.