OBSERVATIONS ON THE GEOCHEMISTRY OF SOLUBLE COPPER, IRON, NICKEL, AND ZINC IN THE SAN-FRANCISCO BAY ESTUARY

At discharges of 300-400 m3/s, surface waters of the San Francisco Bay estuary contain dissolved Cu and Ni at levels of 1 to 4 ppb. This is approximately an order of magnitude higher than waters outside the Bay. Zn concentrations are 2-6 ppb within the estuary and generally less than 1 ppb outside. Cd concentrations are 0.08 to 0.2 ppb within the estuary and 0.05 to 0.11 ppb outside. The behavior of all these elements is probably dominated by physical processes during most seasons, although Cu shows evidence for removal during summer months when river flow is low. Cu, Ni, and Zn show an excess of about 1 ppb relative to conservative mixing in the more saline portion of the estuary. This excess is attributed to municipal and industrial discharges. © 1979, American Chemical Society. All rights reserved.