High variability in dissolved iron concentrations in the vicinity of the Kerguelen Islands (Southern Ocean) ...

• Main Authors: Quéroué, F, Sarthou, G, Planquette, H. F., Bucciarelli, E, Chever, F, Van Der Merwe, P, Lannuzel, D, Townsend, A. T., Cheize, M., Blain, S, D'Ovidio, F, Bowie, A. R.
• Format: Dataset
• Language: unknown
• Published: SEANOE 2015
• Subjects: Kerguelen Islands; Southern Ocean
• Online Access: https://dx.doi.org/10.17882/40729; https://www.seanoe.org/data/00296/40729/

Dissolved Fe (dFe) concentrations were measured in the upper 1300 m of the water column in the vicinity of the Kerguelen Islands as part of the second KErguelen Ocean Plateau compared Study (KEOPS2). Concentrations ranged from 0.06 nmol L-1 in offshore, Southern Ocean waters to 3.82 nmol L-1 within Hillsborough Bay, on the north-eastern coast of the Kerguelen Islands. Direct island runoff, glacial melting and resuspended sediments were identified as important inputs of dFe that could potentially fertilise the northern part of the plateau. A significant deep dFe enrichment was observed over the plateau with dFe concentrations increasing up to 1.30 nmol L-1 close to the seafloor, probably due to sediment resuspension and pore water release. Biological uptake was shown to induce a significant decrease in dFe concentrations between two visits (28 days apart) at a station above the plateau. Our work also considered other processes and sources, such as lateral advection of enriched seawater, remineralisation ...