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| Titel |
The effect of growth rate and light intensity on the hydrogen isotopic composition of long-chain alkenones produced by Emiliania huxleyi |
| VerfasserIn |
A. Benthien, M. T. J. van der Meer, S. Schouten, I. Zondervan, J. Bijma |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023724
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| Zusammenfassung |
| A potential new tool for paleo-salinity reconstructions uses the hydrogen isotopic
composition of long-chain alkenones produced mainly by the coccolithophorid species
Emiliania huxleyi and Gephyrocapsa oceanica. Using culture experiments, it has been shown
that the fractionation between D/H composition of the water and C37-alkenones is relatively
constant. However, more recent work on E. huxleyi and G. oceanica provided evidence that
δD of alkenones not only reflects the D/H ratio of ambient culture water at the time of
algal growth but that the amount of hydrogen isotopic fractionation seems to be
dependent on growth rate and salinity itself (Schouten et al., 2006, Biogeosciences 3,
113-119).
In this study we investigated the effect of light controlled growth rate variations on the δD
signal of alkenones produced by E. huxleyi. We show that the amount of isotopic
fractionation was not directly controlled by algal growth rate but strongly dependent on the
provided light intensity, which in turn controlled the growth rate. In our presentation we will
discuss the implications of this observation for (i) factors affecting hydrogen isotopic
fractionation during lipid biosynthesis and (ii) the applicability of the proposed alkenone δD
proxy for paleo-reconstructions. |
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