Substantial intra-basin variation of the dissolved metal/phosphorus ratio in the different water masses of the Indian Ocean

The first simultaneous, full-depth, and basin-scale section-distribution of dissolved (D) aluminum (Al), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu),  zinc (Zn), cadmium (Cd), and lead (Pb) is reported in the Indian Ocean. In addition to widespread co-limitation for phytoplankton production by dissolved iron (DFe) and occurrence of redox-related processes, the authors observe an important variability of the dissolved metal/phosphorus ratio among the water masses within the Indian ocean (up to a factor of 300 between Arabian Surface waters and Lower Circumpolar Deep Water). The Cu/P, Zn/P, and Cd/P ratios are within the same order of magnitude for both phytoplankton and deep water, whereas the Mn/P, Fe/P, and Co/P ratios of phytoplankton can increase 100-fold or more compared to those in deep water. Such results are questioning the validity of using an “extended Redfield ratio” to trace metals. The consistent mechanism yielding these variations remains to be understood...

Meridional section distribution (~70°E) of the DMn/DAl ratio

Figure: Meridional section distribution (~70°E) of the DMn/DAl ratio.

Reference:

Thi Dieu Vu, H., Sohrin, Y. (2013) Diverse stoichiometry of dissolved trace metals in the Indian Ocean, Scientific Reports 3, DOI: 10.1038/srep01745

Latest highlights

Science Highlights

Volcanic emissions in the Southern Ocean: an efficient and unexpected source of iron for this remote area

This study suggests that volcanic emission can represent a significant source of bioavailable Fe to open ocean anaemic ecosystems.

20.09.2021

Science Highlights

Surprisingly heavy silicon isotopes in the surface and deep Arctic Ocean

Brzezinski and his colleagues report on a comprehensive study of the Arctic Ocean silicic acid concentrations and silicon isotopic composition…

14.09.2021

Science Highlights

Unique winter dataset of particulate and dissolved cadmium in the Indian sector of the Southern Ocean

Cloete and collaborators analysed particulate and dissolved cadmium at 7 stations in austral winter along a North South section off South Africa.

06.09.2021

Science Highlights

A new proxy for ocean iron bioavailability

The approach established and verified in this study, opens a new way for determining dissolved iron bioavailability in samples across the ocean.

23.07.2021

Rechercher