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Publication . Preprint . Other literature type . Article . 2009

Dissolved iron (II) in the Baltic Sea surface water and implications for cyanobacterial bloom development

Eike Breitbarth; Johan Gelting; Jakob Walve; Linn Hoffmann; David R. Turner; Martin Hassellöv; Johan Ingri;
Open Access
Published: 01 Jan 2009 Journal: Biogeosciences, volume 6, pages 2,397-2,420 (eissn: 1726-4189, Copyright policy )
Publisher: Copernicus GmbH

Abstract. Iron chemistry measurements were conducted during summer 2007 at two distinct locations in the Baltic Sea (Gotland Deep and Landsort Deep) to evaluate the role of iron for cyanobacterial bloom development in these estuarine waters. Depth profiles of Fe(II) were measured by chemiluminescent flow injection analysis (CL-FIA) and reveal several origins of Fe(II) to the water column. Photoreduction of Fe(III)-complexes and deposition by rain are main sources of Fe(II) (up to 0.9 nmol L−1) in light penetrated surface waters. Indication for organic Fe(II) complexation resulting in prolonged residence times in oxygenated water was observed. Surface dwelling heterocystous cyanobacteria where mainly responsible for Fe(II) consumption in comparison to other phytoplankton. The significant Fe(II) concentrations in surface waters apparently play a major role in cyanobacterial bloom development in the Baltic Sea and are a major contributor to the Fe requirements of diazotrophs. Second, Fe(II) concentrations up to 1.44 nmol L−1 were observed at water depths below the euphotic zone, but above the oxic anoxic interface. Finally, all Fe(III) is reduced to Fe(II) in anoxic deep water. However, only a fraction thereof is present as ferrous ions (up to 28 nmol L−1) and was detected by the CL-FIA method applied. Despite their high concentrations, it is unlikely that ferrous ions originating from sub-oxic waters could be a temporary source of bioavailable iron to the euphotic zone since mixed layer depths after strong wind events are not deep enough in summer time.

Subjects by Vocabulary

Microsoft Academic Graph classification: Algal bloom Mixed layer Plankton Oceanography Surface water Photic zone Bottom water Anoxic waters Environmental science Phytoplankton

Library of Congress Subject Headings: lcsh:Ecology lcsh:QH540-549.5 lcsh:Life lcsh:QH501-531 lcsh:Geology lcsh:QE1-996.5


Earth-Surface Processes, Ecology, Evolution, Behavior and Systematics, Geochemistry, Geokemi

123 references, page 1 of 13

Anderson, M. A. and Morel, F. M. M.: The Influence of Aqueous Iron Chemistry on the Uptake of Iron by the Coastal Diatom Thalassiosira weissflogii, Limnol. Oceanogr., 27, 789-813, 1982.

Barbeau, K., Moffett, J. W., Caron, D. A., Croot, P. L., and Erdner, D. L.: Role of protozoan grazing in relieving iron limitation of phytoplankton, Nature, 380, 61-64, 1996.

Barbeau, K., Rue, E. L., Bruland, K. W., and Butler, A.: Photochemical cycling of iron in the surface ocean mediated by microbial iron(III)-binding ligands, Nature, 413, 409-413, 2001.

Barbeau, K., Rue, E. L., Trick, C. G., Bruland, K. T., and Butler, A.: Photochemical reactivity of siderophores produced by marine heterotrophic bacteria and cyanobacteria based on characteristic Fe(III) binding groups, Limnol. Oceanogr., 48, 1069-1078, 2003.

Barbeau, K.: Photochemistry of organic iron(III) complexing ligands in oceanic systems, Photochem. Photobiol., 82, 1505-1516, doi:10.1562/2006-06-16-ir-935, 2006.

Bergstro¨m, S., Alexandersson, H., Carlsson, B., Josefsson, W., Karlsson, K.-G., and Westring, G.: Climate and hydrology of the Baltic Basin, in: Ecol. Stud.. A systems analysis of the Baltic Sea, Ecol. Stud., 148, 75-112, 2001.

Boyanapalli, R., Bullerjahn, G. S., Pohl, C., Croot, P. L., Boyd, P. W., and McKay, R. M. L.: Luminescent whole-cell cyanobacterial bioreporter for measuring Fe availability in diverse marine environments, Appl. Environ. Microbiol., 73, 1019-1024, doi:10.1128/aem.01670-06, 2007. [OpenAIRE]

Boyd, P. W., Jickells, T., Law, C. S., Blain, S., Boyle, E. A., Buesseler, K. O., Coale, K. H., Cullen, J. J., de Baar, H. J. W., Follows, M., Harvey, M., Lancelot, C., Levasseur, M., Owens, N. P. J., Pollard, R., Rivkin, R. B., Sarmiento, J., Schoemann, V., Smetacek, V., Takeda, S., Tsuda, A., Turner, S., and Watson, A. J.: Mesoscale Iron Enrichment Experiments 1993- 2005: Synthesis and Future Directions, Science, 315, 612-617, doi:10.1126/science.1131669, 2007.

Bru¨gmann, L., Bernard, P. C., and Vangrieken, R.: Geochemistry of Suspended Matter from the Baltic Sea 2 - Results of Bulk TraceMetal Analysis by AAS, Marine Chem., 38, 303-323, 1992.

Bru¨gmann, L., Hallberg, R., Larsson, C., and Loffler, A.: Trace metal speciation in sea and pore water of the Gotland Deep, Baltic Sea, 1994, Appl. Geochem., 13, 359-368, 1998.

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