Imperial College London
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Professor Mark Rehkämper

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Isotope Geochemistry
 
 
 
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Contact

 

markrehk Website

 
 
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Location

 

451Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{de:2017:10.1016/j.marchem.2017.06.010,
author = {de, Baar HJW and van, Heuven SMAC and Abouchami, W and Xue, ZICHEN and Galer, SJG and Rehkamper, M and Middag, R and van, Ooijen J},
doi = {10.1016/j.marchem.2017.06.010},
journal = {Marine Chemistry},
pages = {105--121},
title = {Interactions of dissolved CO2 with Cadmium Isotopes in the Southern Ocean},
url = {http://dx.doi.org/10.1016/j.marchem.2017.06.010},
volume = {195},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Here we report the first ever observations of a strong correlation in ocean surface waters of the dissolved δ114Cd with dissolved CO2. This is observed in the Southern Ocean along the 0°W meridian in both the Antarctic Circumpolar Current and the Weddell Gyre, as well as in the Weddell Sea proper, near the Antarctic Peninsula and in Drake Passage. This uniform trend in several surface water masses hints at a uniform biochemical mechanism within the Southern Ocean. One hypothesis for the underlying mechanism would be a role of Cd in the carbonic anhydrase function for conversion of bicarbonate ion [HCO3−] into CO2, the latter being required by RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) that only accepts CO2. At low ambient [CO2] the algae maintain growth by also operating a Carbon Concentrating Mechanism (CCM) for utilization of [HCO3−] and its conversion to CO2. For this the algae need more enzyme carbonic anhydrase that normally has Zn as its co-factor, but Cd may substitute for Zn and there also are Cd-specific carbonic anhydrases known for some phytoplankton species. Indeed in incubations of the local plankton communities it is shown that the phytoplankton have a very strong preferential uptake of CO2, such that the uptake ratio {[CO2]/[HCO3−]} is much higher than the dissolved ratio {[CO2]/[HCO3−]} in ambient seawater. Therefore the here reported observations in the Southern Ocean are also expressed for δ114Cd as function of the ratio {[CO2]/[HCO3−]} in ambient seawater. Future research of local phytoplankton in unperturbed natural waters of the Southern Ocean is recommended to be able to verify the hypothesis of a function of Cd in carbonic anhydrase in Antarctic phytoplankton.
AU  - de,Baar HJW
AU  - van,Heuven SMAC
AU  - Abouchami,W
AU  - Xue,ZICHEN
AU  - Galer,SJG
AU  - Rehkamper,M
AU  - Middag,R
AU  - van,Ooijen J
DO  - 10.1016/j.marchem.2017.06.010
EP  - 121
PY  - 2017///
SN  - 1872-7581
SP  - 105
TI  - Interactions of dissolved CO2 with Cadmium Isotopes in the Southern Ocean
T2  - Marine Chemistry
UR  - http://dx.doi.org/10.1016/j.marchem.2017.06.010
UR  - http://hdl.handle.net/10044/1/49686
VL  - 195
ER  -
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