Acronym: CoFeMUG
Programs:
    Ocean Carbon & Biogeochemistry [OCB]
    U.S. GEOTRACES [U.S. GEOTRACES]
URL:  
Start date: 2005-03
End date: 2008-03
Geolocation: South Atlantic subtropical gyre and Benguela upwelling region
Description:

The geochemistries of dissolved cobalt (Co) and iron (Fe) in the oceanic water column share several characteristics such as extremely low concentrations, redox chemistry, low solubility,and utilization as micronutrients by marine microbes. Iron has been the subject of considerable research focus in recent years due to its role in limiting phytoplankton productivity in oceanic and coastal upwelling environments. Cobalt has been much less studied, but recent data show it may be important in influencing primary productivity or phytoplankton community composition in certain geographical areas.

State-of-the-art geochemical and molecular biological techniques were used to address biogeochemical questions in the South Atlantic, and focus especially on the two trace metals, cobalt and iron. The 27-day cruise in November and December 2007 to the South Atlantic was designed to study cobalt and iron biogeochemistry and focus on four major hypotheses.

1. Large fluxes of labile cobalt are associated with upwelling systems even in Aeolian dominated environments.
2. Cobalt and phosphate show correlations in (and only in) surface waters due to micronutrient utilization and rapid remineralization. The slope of the correlation is dependent on the chemical speciation of cobalt.
3. The absence of Trichodesmium populations in the subtropical and tropical South Atlantic is caused by iron limitation.
4. Based on work from the California and Peru Upwelling regimes, primary productivity in the Benguela upwelling regime off of South West Africa may be iron limited or iron-cobalt colimited.

   A combination of geochemical and biological/molecular analyses were made across an oligotrophic-upwelling transition to examine how changing metal regimes affect the physiology and growth of the important primary producers Trichodesmium and Synechococcus.

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More information about project Cobalt, Iron and Micro-organisms from the Upwelling zone to the Gyre
Funding
Datasets associated with Cobalt, Iron and Micro-organisms from the Upwelling zone to the Gyre
Platform deployments associated with Cobalt, Iron and Micro-organisms from the Upwelling zone to the Gyre
People associated with Cobalt, Iron and Micro-organisms from the Upwelling zone to the Gyre