How are oxygen budgets influenced by dissolved iron and growth of oxygenic phototrophs in an iron-rich spring system? Initial results from the Espan Spring in Fürth, Germany

Köhler, Inga; Martinez, Raul E.; Piatka, David; Herrmann, Achim J.; Gallo, Arianna; Gehringer, Michelle M.; Barth, Johannes A. C.

doi:https://doi.org/10.5194/bg-18-4535-2021

Articles | Volume 18, issue 15

Biogeosciences, 18, 4535–4548, 2021

https://doi.org/10.5194/bg-18-4535-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Biogeosciences, 18, 4535–4548, 2021

https://doi.org/10.5194/bg-18-4535-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 18, issue 15

Research article 04 Aug 2021

Research article | 04 Aug 2021

How are oxygen budgets influenced by dissolved iron and growth of oxygenic phototrophs in an iron-rich spring system? Initial results from the Espan Spring in Fürth, Germany

Inga Köhler et al.

Supplement

https://doi.org/10.5194/bg-18-4535-2021-supplement

Model code and software

Code PHREEQC D. L. Parkhurst and C. A. J. Appelo https://www.usgs.gov/software/phreeqc-version-3

Short summary

We investigated how high Fe(II) levels influence the O₂ budget of a circum-neutral Fe(II)-rich spring and if a combined study of dissolved O (DO) and its isotopic composition can help assess this effect. We showed that dissolved Fe(II) can exert strong effects on the δ¹⁸O_DO even though a constant supply of atmospheric O₂ occurs. In the presence of photosynthesis, direct effects of Fe oxidation become masked. Critical Fe(II) concentrations indirectly control the DO by enhancing photosynthesis.