Germanium incorporation into sponge spicultes: Development of a proxy for reconstructing inorganic germanium and silicon concentrations in seawater

Michael Ellwood, Michelle Kelly, Bill Maher, Patrick De Deckker

    Research output: Contribution to journalArticle

    19 Citations (Scopus)

    Abstract

    Measurements of germanium (Ge) in deep-sea sponge skeletons are presented for sponges collected by dredge and for spicules isolated from a range of deep-sea sediment cores. Germanium to silicon (Si) ratios (Ge / Sisp) for sponge silica ranged between 0.075 and 0.380 μmol/mol, which are much lower than the present-day seawater Ge / Si ratio of 0.7 μmol/mol. A plot of Ge / Sisp versus estimated seawater Ge (and Si) concentration produced a linear relationship with the Ge content of spicules increasing with seawater Ge concentration. Plots of Ge / Sisp versus depth for both dredged sponges and sediment-bound spicules produced oceanic profiles similar to those of dissolved Ge (and Si) concentration. To explain the fractionation seen in the sponge Ge / Sisp data two models are presented. The first model used to interpret the data assumes that sponges only respond to the Ge content of the ambient seawater, implying that, Ge incorporation into sponge silica is independent of the seawater Ge / Si ratio up to a Si concentration of about 100 μmol/L. This model is consistent with the 68Ge uptake results of Davie et al. [E.I. Davie, T.L. Simpson, R. Garonne, Experimental germanium incorporation into siliceous sponge spicules, Biol. Cell 48 (1983) 191–202] for cultured spicules. Their results showed that the incorporation of Ge in sponge silica is only dependent on the Ge concentration of the water in which a sponge is growing. The second model used to explain the data assumes that Ge / Sisp fractionation results from subtle differences in the uptake kinetics of Ge and Si. While the assumptions used by each model to describe the data are different, it is possible to use sponge Ge / Sisp data to reconstruct palaeo-Ge concentrations using model I, and to reconstruct palaeo-Si concentrations using both models. Palaeo-Si concentrations estimated using both models are in good agreement
    Original languageEnglish
    Pages (from-to)749-759
    Number of pages11
    JournalEarth and Planetary Science Letters
    Volume243
    Issue number3-4
    DOIs
    Publication statusPublished - 30 Mar 2006

    Fingerprint

    Germanium
    germanium
    Silicon
    Seawater
    sponge
    silicon
    seawater
    spicules
    spicule
    incorporation
    Silicon Dioxide
    silica
    Fractionation
    silicon dioxide
    fractionation
    Sediments
    sediments
    plots

    Cite this

    @article{e9504912c247486db6ab1ebd1507cd9f,
    title = "Germanium incorporation into sponge spicultes: Development of a proxy for reconstructing inorganic germanium and silicon concentrations in seawater",
    abstract = "Measurements of germanium (Ge) in deep-sea sponge skeletons are presented for sponges collected by dredge and for spicules isolated from a range of deep-sea sediment cores. Germanium to silicon (Si) ratios (Ge / Sisp) for sponge silica ranged between 0.075 and 0.380 μmol/mol, which are much lower than the present-day seawater Ge / Si ratio of 0.7 μmol/mol. A plot of Ge / Sisp versus estimated seawater Ge (and Si) concentration produced a linear relationship with the Ge content of spicules increasing with seawater Ge concentration. Plots of Ge / Sisp versus depth for both dredged sponges and sediment-bound spicules produced oceanic profiles similar to those of dissolved Ge (and Si) concentration. To explain the fractionation seen in the sponge Ge / Sisp data two models are presented. The first model used to interpret the data assumes that sponges only respond to the Ge content of the ambient seawater, implying that, Ge incorporation into sponge silica is independent of the seawater Ge / Si ratio up to a Si concentration of about 100 μmol/L. This model is consistent with the 68Ge uptake results of Davie et al. [E.I. Davie, T.L. Simpson, R. Garonne, Experimental germanium incorporation into siliceous sponge spicules, Biol. Cell 48 (1983) 191–202] for cultured spicules. Their results showed that the incorporation of Ge in sponge silica is only dependent on the Ge concentration of the water in which a sponge is growing. The second model used to explain the data assumes that Ge / Sisp fractionation results from subtle differences in the uptake kinetics of Ge and Si. While the assumptions used by each model to describe the data are different, it is possible to use sponge Ge / Sisp data to reconstruct palaeo-Ge concentrations using model I, and to reconstruct palaeo-Si concentrations using both models. Palaeo-Si concentrations estimated using both models are in good agreement",
    author = "Michael Ellwood and Michelle Kelly and Bill Maher and {De Deckker}, Patrick",
    year = "2006",
    month = "3",
    day = "30",
    doi = "10.1016/j.epsl.2006.01.016",
    language = "English",
    volume = "243",
    pages = "749--759",
    journal = "Earth and Planetary Science Letters",
    issn = "0012-821X",
    publisher = "Elsevier",
    number = "3-4",

    }

    Germanium incorporation into sponge spicultes: Development of a proxy for reconstructing inorganic germanium and silicon concentrations in seawater. / Ellwood, Michael; Kelly, Michelle; Maher, Bill; De Deckker, Patrick.

    In: Earth and Planetary Science Letters, Vol. 243, No. 3-4, 30.03.2006, p. 749-759.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Germanium incorporation into sponge spicultes: Development of a proxy for reconstructing inorganic germanium and silicon concentrations in seawater

    AU - Ellwood, Michael

    AU - Kelly, Michelle

    AU - Maher, Bill

    AU - De Deckker, Patrick

    PY - 2006/3/30

    Y1 - 2006/3/30

    N2 - Measurements of germanium (Ge) in deep-sea sponge skeletons are presented for sponges collected by dredge and for spicules isolated from a range of deep-sea sediment cores. Germanium to silicon (Si) ratios (Ge / Sisp) for sponge silica ranged between 0.075 and 0.380 μmol/mol, which are much lower than the present-day seawater Ge / Si ratio of 0.7 μmol/mol. A plot of Ge / Sisp versus estimated seawater Ge (and Si) concentration produced a linear relationship with the Ge content of spicules increasing with seawater Ge concentration. Plots of Ge / Sisp versus depth for both dredged sponges and sediment-bound spicules produced oceanic profiles similar to those of dissolved Ge (and Si) concentration. To explain the fractionation seen in the sponge Ge / Sisp data two models are presented. The first model used to interpret the data assumes that sponges only respond to the Ge content of the ambient seawater, implying that, Ge incorporation into sponge silica is independent of the seawater Ge / Si ratio up to a Si concentration of about 100 μmol/L. This model is consistent with the 68Ge uptake results of Davie et al. [E.I. Davie, T.L. Simpson, R. Garonne, Experimental germanium incorporation into siliceous sponge spicules, Biol. Cell 48 (1983) 191–202] for cultured spicules. Their results showed that the incorporation of Ge in sponge silica is only dependent on the Ge concentration of the water in which a sponge is growing. The second model used to explain the data assumes that Ge / Sisp fractionation results from subtle differences in the uptake kinetics of Ge and Si. While the assumptions used by each model to describe the data are different, it is possible to use sponge Ge / Sisp data to reconstruct palaeo-Ge concentrations using model I, and to reconstruct palaeo-Si concentrations using both models. Palaeo-Si concentrations estimated using both models are in good agreement

    AB - Measurements of germanium (Ge) in deep-sea sponge skeletons are presented for sponges collected by dredge and for spicules isolated from a range of deep-sea sediment cores. Germanium to silicon (Si) ratios (Ge / Sisp) for sponge silica ranged between 0.075 and 0.380 μmol/mol, which are much lower than the present-day seawater Ge / Si ratio of 0.7 μmol/mol. A plot of Ge / Sisp versus estimated seawater Ge (and Si) concentration produced a linear relationship with the Ge content of spicules increasing with seawater Ge concentration. Plots of Ge / Sisp versus depth for both dredged sponges and sediment-bound spicules produced oceanic profiles similar to those of dissolved Ge (and Si) concentration. To explain the fractionation seen in the sponge Ge / Sisp data two models are presented. The first model used to interpret the data assumes that sponges only respond to the Ge content of the ambient seawater, implying that, Ge incorporation into sponge silica is independent of the seawater Ge / Si ratio up to a Si concentration of about 100 μmol/L. This model is consistent with the 68Ge uptake results of Davie et al. [E.I. Davie, T.L. Simpson, R. Garonne, Experimental germanium incorporation into siliceous sponge spicules, Biol. Cell 48 (1983) 191–202] for cultured spicules. Their results showed that the incorporation of Ge in sponge silica is only dependent on the Ge concentration of the water in which a sponge is growing. The second model used to explain the data assumes that Ge / Sisp fractionation results from subtle differences in the uptake kinetics of Ge and Si. While the assumptions used by each model to describe the data are different, it is possible to use sponge Ge / Sisp data to reconstruct palaeo-Ge concentrations using model I, and to reconstruct palaeo-Si concentrations using both models. Palaeo-Si concentrations estimated using both models are in good agreement

    U2 - 10.1016/j.epsl.2006.01.016

    DO - 10.1016/j.epsl.2006.01.016

    M3 - Article

    VL - 243

    SP - 749

    EP - 759

    JO - Earth and Planetary Science Letters

    JF - Earth and Planetary Science Letters

    SN - 0012-821X

    IS - 3-4

    ER -