CADMIUM, COPPER AND NICKEL DISTRIBUTIONS AT 4 STATIONS IN THE EASTERNCENTRAL AND SOUTH-ATLANTIC

Distributions of cadmium, copper and nickel at four stations in the ea stern part of the Atlantic Ocean from 30 degrees S to 34 degrees N are described based on analytical results from three laboratories. The Cd and Ni profiles show nutrient-like distributions with concentrations in the deep waters increasing from north to south. Copper profiles all show gradual increases from surface to bottom with the highest concen trations occurring near bottom on the most northerly station. Variatio ns in the deep-water Cd and Ni concentrations can be understood in ter ms of mixing of southern source waters with high concentrations with l ower concentration northern source waters. The deep-water Cu distribut ions indicate a significant near-bottom source to the northern end of the section. Cadmium vs. phosphate relationships show features that re sult from both regeneration and mixing. Higher Cd:PO4 ratios are seen in the southern source waters than in the northern waters, thus discou nting the suggestion that the inflection in the global Cd:PO4 relation ship at PO4 approximate to 1.3 mu M originates in the southern ocean. Differential regeneration of Cd and PO4 is seen through the equatorial oxygen minimum.