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

North-South section of bioactive cadmium, nickel, zinc, copper and iron along GEOTRACES transect GP19 in the Pacific Ocean

Zheng and his colleagues propose the first full sections of the simultaneous dissolved distributions of five nutrient-type trace metals in the western South Pacific Ocean.

MOTES: a new facility designed for trace element sampling in seawater

Zhang and a group of engineers and researchers from Shanghai and Qingdao are presenting a modular trace element sampling facility.

A thorough estimate of the hydrothermal plumes on neodymium concentration and isotope oceanic cycles

Basak and co-workers investigated the influence of particulate matter on neodymium distributions in the Southern East Pacific Rise Hydrothermal Plume.

What are the drivers of the distributions of cadmium, nickel, zinc, copper and cobalt, manganese and aluminium in the Atlantic Ocean? Two papers are tackling this issue

Chen and co-authors reveal that the distributions of dissolved tracers at depth in the South Atlantic are predominantly controlled by the mixing of North Atlantic Deep Water and waters of Antarctic origin…

Rechercher