Cadmium isotopes, tracers of the cadmium sequestration as cadmium sulphide in oxygen minimum zone?

The linear relationship between the seawater cadmium and phosphate dissolved concentrations lead to use the cadmium/calcium (Cd/Ca) imprinted in calcareous archives to reconstruct the past phosphate (PO4) distributions. However, variations in the Cd/PO4 ratio between different water masses and within vertical oceanic profiles were recently identified. Among the processes that could explain these variations, sequestration […]

Jan / 07 / 2019

Cadmium to phosphorus ratio in euphotic zone particulates: why does it vary?

Bourne and co-workers examine the particulate cadmium to phosphorus ratio (Cd/P) variations of 3 particle fractions (<1µm, 1-51µm and >51µm) from 50 casts covering spatial and temporal scales never reached so far for these parameters. This impressive data set allows them to study the effects of an El Niño, upwelling, large-scale in situ Fe fertilization, low-oxygen conditions, […]

Nov / 01 / 2018

Contrasting fates of the cadmium-cadmium isotopes in the Kuroshio and Oyashio environmental systems

Yang et al. (2018, see reference below) studied the relative importance of physical and biogeochemical processes on controlling the isotopic composition of dissolved and particulate cadmium (Cd) in a GP18 transect, crossing over the relatively cold and eutrophic Oyashio Extension region and the relatively warm and oligotrophic Kuroshio Extension region. Particulate samples revealed preferential uptake […]

Jul / 18 / 2018

Impressive set of data reveal new features on the modern cadmium–phosphate relationship

Xie and co-authors (2015, see reference below) report vertical profiles of dissolved cadmium (Cd) in the western South Atlantic Ocean (GEOTRACES section GA02), which show nutrient-like distributions similar to those of the macronutrient phosphate (PO4). A close look at the data reveal: In the surface ocean, preferential uptake of Cd over PO4 by phytoplankton occurs […]

Jan / 25 / 2016

Changing the cadmium : phosphorus paradigm?

The well-established strong linear relationship linking dissolved cadmium (Cd) and phosphorus (P) concentrations in seawater is at the origin of the attraction of Cd as a proxy for PO4 in the paleocean. However, exploring the dissolved Cd and PO4 distributions in the ocean, Quay and co-workers (2015, see reference below) show that the Cd/P of […]

Sep / 21 / 2015

Undocumented cadmium, zinc and copper sink in oxygen minimum zones

Cadmium (Cd) is a micronutrient for marine algae and has a marine distribution similar to the macronutrients nitrate and phosphate. The use of sedimentary microfossil records of Cd, thus, allow reconstructions of past ocean nutrient distributions that facilitate the understanding of the role of the oceans in the carbon cycle and climate change. However, this […]

Jun / 11 / 2014

Recent and original results in the Southern Ocean on mercury speciation and cadmium isotopes

For the first time detailed mercury (Hg) speciation was determined along an Australia-Antarctic section (Cossa, et al., 2011) and cadmium (Cd) isotopes along a South Africa-Antarctic section (Abouchami W., et al., 2011). Both were acquired along two IPY-GEOTRACES sections: SR3 CASO-GEOTRACES (GIPY6) and ZERO&DRAKE (GIPY5) respectively. Hg species distribution suggests distinct features in the Southern […]

Apr / 11 / 2012