When hydrothermal iron fertilizes the surface ocean in the Western Tropical South Pacific Ocean

For the first time, iron measurements in the Western Tropical South Pacific reveal that shallow hydrothermal inputs from the Tonga Arc region fertilize the euphotic waters of this vast region. These results shed new light on the functioning of pelagic ecosystems in this region.  Indeed, blooms in this area are dominated by N2-fixing organisms (or diazotrophs), with iron requirements higher than those of non-diazotrophic organisms. The measurements of trace elements along a 4000 km ~ 19 ° S transect during the OUTPACE campaign together with Argo Float data and  circulation modeling, allowed Guieu and co-authors to establish that the important mesoscale activity of the region makes it possible to transport, disperse and maintain high iron concentrations several hundred kilometers from the source.

 18 Guieu
Figure: Surface Chlorophyll-a concentration (mg m−3) during the 45-day transect of the OUTPACE cruise (A) (The ocean color satellite products are produced by CLS. Figure courtesy of A. De Verneil). (B) Cross-section of dissolved Fe nM (0–500 m). Click here to view the figure larger.

Reference:

Guieu, C., Bonnet, S., Petrenko, A., Menkes, C., Chavagnac, V., Desboeufs, K. Maes, C., Moutin, T. (2018). Iron from a submarine source impacts the productive layer of the Western Tropical South Pacific (WTSP). Scientific Reports, 8(1), 9075. http://doi.org/10.1038/s41598-018-27407-z

Latest highlights

Science Highlights

Quantifying the weathered fluxes to the ocean is far from over: the overlooked role of rock coast erosion

This study reveals that cliff derived sediment supply is only three times less than the solid discharge of rivers for Europe.

21.01.2022

Science Highlights

Contrasting distributions of dissolved manganese, nickel, cadmium and zinc in the Mediterranean Sea

Extensive trace metal clean sampling during the Dutch GEOTRACES cruise in the Mediterranean Sea allowed Middag and his colleagues to establish the basin scale distribution of these trace metals.

19.01.2022

Science Highlights

Specific features characterize the dissolved iron distribution in the North Western Indian Ocean

Venkatesh Chinni and Sunil Kumar Singh propose dissolved iron profiles along two meridional transects realized during spring and fall seasons between the Arabian Sea and the sub-tropical western Indian Ocean…

07.01.2022

Science Highlights

Anthropogenic aerosol has become a dominant source of zinc in the deep water of the Northern South China Sea

Liao and colleagues determined zinc concentrations and isotope compositions in sinking particles collected in the Northern South China Sea…

24.11.2021

Rechercher