Aspects of the Surface Distributions of Copper, Nickel, Cadmium, and Lead in the North Atlantic and North Pacific

Abstract

The concentrations of copper, nickel, and cadmium have been determined on over 400 surface samples; 10 samples were also analyzed for lead. Nickel and cadmium are closely associated with nutrient distributions, being low (about 2 nmol kg⁻¹ for Ni and less than 20 pmol kg⁻¹ for Cd) in the central gyres and elevated to 3–3.5 nmol kg⁻¹ (Ni) and 40–80 pmol kg⁻¹ (Cd) in the equatorial eastern Pacific and in the cool eastern boundary currents. There are large regional variations in their element-nutrient correlations, however. Copper is slightly elevated in cool eastern boundary waters (1.3 nmol kg⁻¹) relative to North Pacific and South Atlantic central gyres, but the Sargasso Sea has higher copper concentrations (1.4 nmol kg⁻¹) than the other central gyres. Copper concentrations in coastal waters of the Gulf of Panama are elevated to 3–4 nmol kg⁻¹; this coastal water advects seaward and creates ‘events’ of high — Cu waters in the oceanic interior. Lead concentrations in the North Atlantic (100–250 pmol kg⁻¹) are higher than in the North Pacific.