The speciation of dissolved zinc in the Atlantic sector of the Southern Ocean

A Review of the Stable Isotope Bio-geochemistry of the Global Silicon Cycle and Its Associated Trace Elements

“…Culture studies show that the Zn/Si content of diatom bSiO 2 relate to the concentration of free Zn 2+ ions in the ambient seawater (Ellwood and Hunter, 1999). However, more recent observations of Zn speciation in the Southern Ocean question this link, because the variability in free Zn 2+ ion concentrations are not captured by diatom bSiO 2 Zn/Si (Baars and Croot, 2011). Field studies support a link between diatom bSiO 2 Zn/Si and productivity and diatom bSiO 2 burial rates, although the mechanism behind this relationship is less clear and could relate to nutrient uptake vs. supply, growth rate or salinity (Hendry and Rickaby, 2008;Andersen et al, 2011).…”

Silicon and zinc biogeochemical cycles coupled through the Southern Ocean

“…Export of organic matter with such an elevated Zn:P ratio in the Southern Ocean could thus lead to a decoupling of the large-scale distributions of Zn and PO 4 in a similar manner to that proposed by Sarmiento et al (2004) (Baars and Croot, 2011). In our simulations, we assess the influence of such a Zn 2+ -dependence of Zn uptake on the large-scale distribution of Zn.…”

Dissolved cadmium in the Southern Ocean: Distribution, speciation, and relation to phosphate

“…This could cause high Cd uptake rates despite absolute lower concentrations of Cd compared to higher latitude stations. Due to upwelling, south of the APF, both Zn and Cd are high while Mn is low and Cd uptake is likely to occur via the Mn uptake system (Sunda and Huntsman 2000;Baars and Croot 2011). The Cd uptake rate V Cd via the Mn system has been previously described by Sunda and Huntsman (2000) as:…”