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Full-Text Articles in Physical Sciences and Mathematics
Preferential Depletion Of Zinc Within Costa Rica Upwelling Dome Creates Conditions For Zinc Co-Limitation Of Primary Production, P. Dreux Chappell, Jagruti Vedmati, Karen E. Selph, Heather A. Cyr, Bethany D. Jenkins, Michael R. Landry, James W. Moffett
Preferential Depletion Of Zinc Within Costa Rica Upwelling Dome Creates Conditions For Zinc Co-Limitation Of Primary Production, P. Dreux Chappell, Jagruti Vedmati, Karen E. Selph, Heather A. Cyr, Bethany D. Jenkins, Michael R. Landry, James W. Moffett
OES Faculty Publications
The Costa Rica Dome (CRD) is a wind-driven feature characterized by high primary production and an unusual cyanobacterial bloom in surface waters. It is not clear whether this bloom arises from top-down or bottom-up processes. Several studies have argued that trace metal geochemistry within the CRD contributes to the composition of the phytoplankton assemblages, since cyanobacteria and eukaryotic phytoplankton have different transition metal requirements. Here, we report that total dissolved zinc (Zn) is significantly depleted relative to phosphate (P) and silicate (Si) within the upper water column of the CRD compared with other oceanic systems, and this may create conditions …
Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick
Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick
OES Faculty Publications
Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, …