Charlotte Kleint

Charlotte Kleint

Dr. Charlotte Kleint

GEO Room 5320
Klagenfurter Straße 2-4
28359 Bremen, Germany

Phone: +49 421 218 65405


currently on maternity leave

  • Go to page: Forschung
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  • Geochemical fluid composition of shallow and deep hydrothermal systems.
  • Stabilization and transport of hydrothermal metals in the water column
  • Elemental cycling in the ocean
  • Organic and inorganic complexation of trace metals
  • Analytics for trace metal determination in seawater
  • Marine mineral resources
  • Science coordination
A columnar, chimney-like rock formation in the deep sea from which black smoke rises.
7 m high black smoker at Tonga island arc

Hydrothermal vents at mid-ocean ridges or island arcs contribute large amounts of various trace metals to the ocean. Due to the shallower water depth of island arcs, their hydrothermal plumes can reach the photic zone - the area with the highest primary productivity - and directly supply important micronutrients or potential toxins such as iron, copper, zinc and arsenic. Ongoing research has shown that dissolved hydrothermal iron, for example, is transported thousands of kilometers from its original source into the oceans, contributing to the global oceanic metal budget.


This is due to both inorganic (e.g., in the form of sulfide nanoparticles) and organic complexation by small chelating molecules (called organic ligands), which is very important because this mechanism prevents precipitation of metals and allows their transport to the open ocean. A similar importance of organic complexation has been demonstrated for copper and can be inferred for other hydrothermal trace elements.

However, the impact of shallower submarine volcanic arcs on ocean biogeochemistry in the photic zone, as well as below, has not been well studied. With my research I would like to show that especially the role of these hydrothermal vents in the biogeochemical cycle of metals in the ocean as well as the bioavailability of the metals may have been underestimated so far.

Curriculum vitae

Scientific career

2024-2025Parental leave (1 year)
since 2021Senior Scientist (tenured), MARUM, Bremen Uni­versity
2021-2022Parental leave (1 year)
2016-2021PostDoc, Jac­obs Uni­versity Bre­men and MARUM, Bremen Uni­versity
2014Research Stay, Uni­versity of Ot­ago, New Zea­l­and (3 months)
2013-2016PhD student, Jacobs University Bremen
2012Trainee, Jacobs University Bremen
2009-2011MSc. Marine Geosciences at Bremen Uni­ver­si­ty
2006-2009BSc. Geosciences at Leibniz University of Hanover


  • Split image with a white smoker in the deep sea at the Tonga Arc on the left and the logo of the SO263 expedition showing the ship and a diving robot on the right.

    2018: SO263 - TONGARIFT (Tonga Arc)

    Suva (Fiji) - Suva (Fiji) / 01.06.2018 - 27.06.2018

  • Split image showing a black smoker in the deep sea at the Kermadec Arc on the left and the research vessel Sonne in the sunlit and palm-fringed harbor of Noumea in New Caledonia.

    2016: SO253 - HYDROTHERMADEC (Kermadec Arc, Southwest Pacific)

    Nouméa (New Caledonia) - Auckland (New Zealand) / 22.12.2016 - 21.01.2017

  • Split image showing a manganese nodule field in the deep sea on the right and scientists sitting at a table aboard the ship with semi-plastic tubes containing sediment cores being sampled.

    2015: SO240 - FLUM (Equatorial East Pacific)

    Manzanillo (Mexico) - Manzanillo (Mexico) / 03.05.2015 - 16.06.2015

  • Split image with the view of the foredeck of the research vessel Sonne, waves crashing on deck on the left side and a black smoker in the deep sea on the right side.

    2013: SO229 - COVOLVE (New Hebrides Island Arc)

    Townsville (Australia) - Nouméa (New Caledonia) / 01.07.2013 - 26.07.2013


  • Bohrmann G, Streuff K, Römer M, Knutsen S-M, Smrzka D, Kleint J, Röhler A, Pape T, Sandstå NR, Kleint C, Hansen C, dos Santos Ferreira C, Walter M, de Paula Santos GM, Bach W (2024): Discovery of the first hydrothermal field along the 500-km-long Knipovich Ridge offshore Svalbard (the Jøtul field). Scientific Reports14, 10168.
    doi:10.1038/s41598-024-60802-3 |
  • Janssen D, Gilliard D, Rickli J, Nasemann P, Koschinsky A, Hassler CS, Bowie AR, Ellwood MJ, Kleint C, Jaccard SL (2023): Chromium stable isotope distributions in the southwest Pacific Ocean and constraints on hydrothermal input from the Kermadec Arc. Geochimica et Cosmochimica Acta  342, 31-44.
    doi:10.1016/j.gca.2022.12.010 |
  • Hansen CT, Kleint C, Böhnke S, Klose L, Adam‐Beyer N, Sass K, Zitoun R, Sander SG, Indenbirken D, Dittmar T, Koschinsky A, Perner M (2022): Impact of high Fe‐concentrations on microbial community structure and dissolved organics in hydrothermal plumes: an experimental study. Scientific Reports  12:20723.
    doi:10.1038/s41598-022-25320-0 |
  • Klose L, Kleint C, Bach W, Diehl A, Wilckens F, Peters C, Strauss H, Haase K, Koschinsky A (2022): Hydrothermal activity and associated subsurface processes at Niuatahi rear-arc volcano, North East Lau Basin, SW Pacific: Implications from trace elements and stable isotope systematics in vent fluids. Geochimica et Cosmochimica Acta  332, 103-123.
    doi:10.1016/j.gca.2022.06.023 |
  • Kleint C, Zitoun R, Neuholz R, Walter M, Schnetger B, Klose L, Chiswell SM, Middag R, Laan P, Sander SG, Koschinsky A (2022): Tra­ce me­tal dy­na­mics in shal­low hydro­ther­mal plu­mes at the Ker­ma­dec arc. Frontiers in Marine Science  8, 782734.
    doi:10.3389/fmars.2021.782734 |
  • Dede B, Hansen CT, Neuholz R, Schnetger B, Kleint C, Walke S, Bach W, Amann R, Meyerdierks A (2022): Niche differentiation of sulfur-oxidizing bacteria (SUP05) in submarine hydrothermal plumes. The ISME Journal.
  • doi:10.1038/s41396-022-01195-x |
  • Klose L, Keith M, Hafermaas D, Kleint C, Bach W, Diehl A, Wilckens F, Peters C, Strauss H, Klemd R, van Geldern R, Haase KM, Koschinsky A (2021): Trace element and isotope systematics in vent fluids and sulphides from Maka Volcano, north eastern Lau Spreading Centre: Insights into three-component fluid mixing. Frontiers in Earth Science  9:776925.
    doi:10.3389/feart.2021.776925 |
  • Peters C, Strauss H, Haase K, Bach W, de Ronde CEJ, Kleint C, Stucker V (2021): SO2 disproportionation impacting hydrothermal sulfur cycling: Insights from multiple sulfur isotopes for hydrothermal fluids from the Tonga-Kermadec intraoceanic arc and the NE Lau Basin. Chemical Geology  586, 120586.
    doi:10.1016/j.chemgeo.2021.120586 |
  • Neuholz R, Kleint C, Schnetger B, Koschinsky A, Laan P, Middag R, Sander SG, Thal J, Türke A, Walter M, Zitoun R, Brumsack H-J (2020): Submarine Hydrothermal Discharge and Fluxes of Dissolved Fe and Mn, and He Isotopes at Brothers Volcano Based on Radium Isotopes. Minerals  10(11), 969 - Special Issue: Advances in Integrated Mineralogical, Geochemical, Isotopic and Numerical Modeling Study of Magmatic-Hydrothermal Systems.
    doi: 10.3390/min101109694 |
  • Neuholz R, Schnetger B, Kleint C, Koschinsky A, Lettmann K, Sander SG, Türke A, Walter M, Zitoun R, Brumsack H-J (2020): Near-field hydrothermal plume dynamics at Brothers Volcano (Kermadec Arc): A short-lived radium isotope study. Chemical Geology  533.
    doi: 10.1016/j.chemgeo.2019.119379 |
  • Kleint C, Bach W, Diehl A, Fröhberg N, Garbe-Schönberg D, Hartmann JF, de Ronde CEJ, Sander SG, Strauss H, Stucker V, Thal J, Zitoun R, Koschinsky A (2019): Geochemical characterization of highly diverse hydrothermal fluids from volcanic vent systems of the Kermadec intraoceanic arc. Chemical Geology  528.
    doi: 10.1016/j.chemgeo.2019.119289 |
  • Böhnke S, Sass K, Gonnella G, Diehl A, Kleint C, Bach W, Zitoun R, Koschinsky A, Indenbirken D, Sander SG, Kurtz S, Perner M (2019): Parameters governing the community structure and element turnover in Kermadec volcanic ash and hydrothermal fluids as monitored by inorganic electron donor consumption, autotrophic CO2 fixation and 16S tags of the transcriptome in incubation experiments. Frontiers in Microbiology  10:2296.
    doi: 10.3389/fmicb.2019.02296 |
  • Kleint C, Pichler T, Koschinsky A (2017): Geochemical characteristics, speciation and size-fractionation of iron (Fe) in two marine shallow-water hydrothermal systems, Dominica, Lesser Antilles. Chemical Geology  454, 44-53.
    doi: 10.1016/j.chemgeo.2017.02.02 |
  • Kleint C, Hawkes JA, Sander SG, Koschinsky A (2016): Voltammetric Investigation of Hydrothermal Iron Speciation. Frontiers in Marine Science (Marine Biogeochemistry)  3:75.
    doi: 10.3389/fmars.2016.00075 |
  • Kleint C, Kuzmanovski S, Powell Z, Bühring SI, Sander SG, Koschinsky A (2015): Organic Cu-complexation at the shallow marine hydrothermal vent fields off the coast of Milos (Greece), Dominica (Lesser Antilles) and the Bay of Plenty (New Zealand). Marine Chemistry  173, 244-252.
    doi: 10.1016/j.marchem.2014.10.012 |
  • Mohwinkel D, Kleint C, Koschinsky A (2014): Phase associations and potential selective extraction methods for selected high-tech metals from ferromanganese nodules and crusts with siderophores. Applied Geochemistry  43, 13-21.
    doi: 10.1016/j.apgeochem.2014.01.010 |

Koschinsky A, Kleint C (2014): Manganknollen – Rohstoff für Zukunftstechnologien. Beitrag in Geowissenschaftliche Mitteilungen (GMIT)  57, 21-25.


  • Kleint C, Bach W, Sander SG, Zitoun R, Middag R, Laan P, Koschinsky A (2019): Hydrothermal fluxes of trace metals (such as Zn and Fe) into surface waters along the the Kermadec Intraoceanic Arc. Goldschmidt-Conference 2019, Barcelona, Spain (Talk).
  • Kleint C, Bach W, Diehl A, Fröhberg N, Garbe-Schönberg D, Hartmann JF, de Ronde C, Sander SG, Strauss H, Stucker V, Zitoun R, Koschinsky A (2018): Heterogeneous Geochemical Composition of Hydrothermal Fluids from the Kermadec Intraoceanic Arc with Potential Implications for Ocean Biogeochemistry. Gordon Research Conference on Ocean Biogeochemistry (GRC) 2018, Hong Kong, China (invited Talk and Poster).
  • Kleint C, Bach W, Diehl A, Fröhberg N, Garbe-Schönberg D, Hartmann JF, de Ronde C, Sander SG, Strauss H, Stucker V, Zitoun R, Koschinsky A: Heterogeneous Geochemical Composition of Hydrothermal Fluids from the Kermadec Intraoceanic Arc with Potential Implications for Ocean Biogeochemistry. Gordon Research Seminar on Ocean Biogeochemistry (GRS) 2018, Hong Kong, China (Talk and Poster).
  • Kleint C, Fröhberg N, Zitoun R, Sander SG, Strauss H, Koschinsky A (2017): Diversity of hydrothermal fluids from four vent sites at the Kermadec Island Arc and its relevance for elemental fluxesGoldschmidt-Conference 2017, Le Palais des Congrès de Paris, Paris, France (Talk).
  • Kleint C, Sander SG, Koschinsky A (2016): Dissolved Fe and Fe binding ligand concentrations at the hydrothermal vent fields in the Coriolis Troughs, New Hebrides Island Arc. Ocean Sciences Meeting (OSM) 2016, Ernest N. Morial Convention Center New Orleans, Louisiana, USA (Poster).
  • Sander SG, Powell Z, Koschinsky A, Kuzmanovski S, Kleint C (2014): Stabilization of dissolved trace metals at hydrothermal vent sites: Impact on their marine biogeochemical cycles. European Geosciences Union General Assembly 2014, Vienna, Austria.
  • Kleint C, Kraemer D, Koschinsky A (2014): Phase associations and selective extraction of high-technology metals from ferromanganese nodules and crusts with the siderophore Desferrioxamine BGeoFrankfurt 2014, Goethe-University Frankfurt, Frankfurt, Germany (Talk).
  • Kleint C, Koschinsky A (2014): Copper-ligand complexation at shallow water hydrothermal vents off the coast of Milos and Dominica. Ocean Sciences Meeting (OSM) 2014, Convention Center Honolulu, Hawaii, USA (Poster).
  • Kleint C, Koschinsky A, Powell Z (2013): Geo-Bio interactions in shallow water hydrothermal vents and their impact on trace metals. ASLO 2013 Aquatic Sciences Meeting, Ernest N. Morial Convention Center New Orleans, Louisiana, USA (Vortrag).
  • Kleint C, Koschinsky A (2012): High-tech metals in marine ferromanganese nodules and crusts: concentrations, phase associations and potential methods of selective extraction. GeoHannover 2012, Leibniz University Hanover, Hanover, Germany (Talk).
  • Kleint C, Koschinsky A, Mohwinkel D (2012): High-tech metals in marine ferromanganese nodules and crusts: contents and possibilities of selective extraction. European Mineralogical Conference (EMC) 2012, Goethe-University Frankfurt, Frankfurt; Germany (Talk).
  • Koschinsky A, Kleint C, Mohwinkel D, Halbach P, Kuhn T (2011): Extraction of valuable trace metals from ferromanganese nodules and crusts with different chemical leaching agents. Underwater Mining Institute (UMI) 2011, Hilo Hawaiian Hotel, Hawaii, USA.
  • GIF Young Scientists Meeting (German-Israeli Foundation for Scientific Research and Development) - "Going Down Into the Abyss: Ocean-Floor Processes, Deep Life, and Climate Archives", MARUM, Bremen, Germany, October 2019 (invited Talk).
  • „Initiative: future-orientated deep-sea mining”, Jacobs University and MARUM, Bremen, Germany, 2014, 2015 and 2016 (Coordination and Talk).
  • „Organic Ligands - A Key Control on Trace Metal Biogeochemistry in the Oceans” SCOR Working Group 139, Sibenik, Croatia, April 2015.
  • „Research in Shallow Marine and Fresh Water Systems” Bremen University, Germany, February 2013 (Talk).
  • „Voltammetry and Geotraces” COST Action Group ES801 „The Ocean Chemistry of Bioactive Trace Elements and Paleoclimate Proxies”, Sibenik, Croatia, October 2012 (Talk).


PhD Thesis

  • Kleint C (2016): The spe­cia­ti­on and or­ga­nic com­plexa­ti­on of iron (Fe) and cop­per (Cu) in dif­fe­rent ma­ri­ne hydro­ther­mal vent sys­tems. Doktorarbeit, Jacobs University Bremen

Master Thesis

  • Kleint C (2011): Pha­se as­so­cia­ti­ons of some rare va­luable me­tals (Pt, Zr, Hf, Nb, Ta, Mo, W, Th and REY) in fer­ro­man­ga­ne­se no­du­les and crusts and po­ten­ti­al me­thods for selec­tive extrac­tion. Master Thesis, Bremen University

Bachelor Thesis

  • Kleint C (2009): The Geo­che­mi­cal and Mi­ne­ra­lo­gi­cal Cha­rac­te­riza­t­i­on of Man­ga­ne­se No­du­les from the Ger­man Ex­plo­ra­ti­on Claim. Bachelor Thesis, Leibnitz University Hanover


Reviewer for

  • German Research Foundation (DFG)
  • Scientific Reports
  • Economic Geology
  • Marine Chemistry
  • Geochemistry, Geophysics, Geosystems
  • Environmental Chemistry
  • Geofluids


  • Marine Resources in Space and Time (MSc. Marine Geosciences, winter semester 2022/2023)
  • Exercises in General Chemistry for Geoscientists (in German, BSc. Geosciences, winter semester 2022/2023)
  • Applied Geochemistry, Environmental Geochemistry, Introduction into Earth and Environmental Sciences, Geochemistry of Aqueous Systems (BSc.  Earth and Environmental Sciences, Jacobs University, Bremen, 2019-2021)