Elsevier, Marine Chemistry, (177), p. 110-123, 2015
DOI: 10.1016/j.marchem.2015.06.011
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The correlation between dissolved cadmium (Cd) and phosphate (PO4) in the modern ocean has been extensively studied. However, factors that cause the non-linearity in this global correlation are still largely debated and poorly constrained. In this study, we present vertical and meridional distributions of Cd concentrations along the GEOTRACES GA02 Leg 3 transect (53°S to 0°S) in the western South Atlantic. The vertical profiles of dissolved Cd show typical nutrient-like distributions, matching those of the macronutrient PO4. In the surface ocean, low Cd concentrations of 0.34–45 pmol kg− 1 are measured at all stations sampled. Below the fluorescence maxima, Cd concentrations increase with depth, reaching maxima at the depths of, or slightly below, the oxygen minimum. Similarly, surface waters have very low dissolved Cd/PO4 ratios, followed by a sudden decrease at depths corresponding to the fluorescence maxima, below which the Cd/PO4 ratios increase with depth.