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Impact of benthic processes on biogeochemical organic carbon cycling and organic proxy records in marine sediments
Program coordinator(s): Prof. dr. ir. S. Schouten
Theme(s): 1 , 2
Funding date: 5-jul-06

Abstract
Organic matter (OM) processing in surface marine sediments results not only in extensive degradation of OM but also in major compositional changes in the small fraction of OM that is eventually recorded in the sedimentary archive. As these archived compounds are used by organic geochemists for paleoreconstructions, it is of great importance to understand the molecular consequences of this sedimentary OM processing and, in particular, the fate and production of biomarkers. OM processing is due to bacteria, archaea and eukaryotes, but we lack understanding of their relative importance and their impact on the composition of sediment OM. In this Darwin program we will examine the impact of the sedimentary processes which affect organic proxy records and the sedimentary carbon cycle by (1) investigating the key benthic organisms in processing OM and their impact on organic proxies, (2) establishing proxies for past benthic processes and (3) study the impact of re-oxygenation events on OM degradation, transformation and composition. It is foreseen that this program will lead to significant advances in the recognition of potential biases in organic proxy records and lead to major progress in our understanding of the relative roles of bacteria, archaea and eukaryotes in sediment OM processing.

This program contains the following projects:
1081: Prokaryotic and metazoan processing of organic matter in sediments
1082: Impact of post-depositional processes on organic proxies

Publications
Lara Pozzato (2012). Prokariotic, protozoan and metazoan processing of organic matter in the sediments: a tracer approach.
Darwin Center authors: Pozzato L.

Lengger, S.K., Hopmans, E.C., Sinninghe Damsté, J.S., Schouten, S. (2012). Comparison of extraction and work up techniques for analysis of core and intact polar tetraether lipids from sedimentary environments. Organic Geochemistry47: 34-40.
Darwin Center authors: Hopmans E. C., Lengger S., Schouten S., Sinninghe Damsté J. S.

Lengger, S.K., Hopmans, E.C., Reichart, G.-J., Sinninghe Damsté, J.S., Schouten, S. (2012). Intact polar and core glycerol dibiphytanyl glycerol tetraether lipids in the Arabian Sea Water Oxygen Minimum Zone: II. Selective preservation and degradation in sediments and consequences for the TEX86.. Geochimica.et Cosmochimica Acta98: 244-258.
Darwin Center authors: Hopmans E. C., Lengger S., Reichart G. J., Schouten S., Sinninghe Damsté J. S.

Lara Pozzato, Dick van Oevelen, Leon Moodley, Karline Soetaert, Jack J. Middelburg (2013). Carbon processing at the deep-sea floor of the Arabian Sea oxygen minimum zone: A tracer approach. Journal of Sea Research78: 45-58.
Darwin Center authors: Middelburg J.J., Pozzato L., Soetaert K. E. R.

S. K. Lengger (2013). Production and preservation of archaeal glycerol dibiphytanyl glycerol tetraethers as intact polar lipids in marine sediments: Implications for their use in microbial ecology and TEX86 paleothermometry.
Darwin Center authors: Lengger S.

Lengger, S.K. Hopmans, E.C. Sinninghe Damsté, J.S. Schouten, S (2014). Fossilization and degradation of archaeal intact polar tetraether lipids in deeply buried marine sediments ( Peru Margin). Geobiology12: 212-220.
Darwin Center authors: Hopmans E. C., Lengger S., Schouten S., Sinninghe Damsté J. S.

Lengger, S.K. Hopmans, E.C. Sinninghe Damsté, J.S. LneSchouten, S (2014). Impact of sedimentary degradation and deep water column production on GDGT abundance and distribution in surface sediments in the Arabian Sea: Implications for the TEX86 paleothermometer. Geochimica et Cosmochimica Acta142: 386-399.
Darwin Center authors: Hopmans E. C., Lengger S., Schouten S., Sinninghe Damsté J. S.

Lengger, S.K., Lipsewers, Y.A., de Haas, H., Sinninghe Damsté, J.S., Schouten, S. (2014). Lack of 13C-label incorporation suggests low turnover rates of thaumarchaeal intact polar tetraether lipids in sediments from the Iceland shelf. Biogeosciences11(2): 201-216.
Darwin Center authors: Lengger S., Lipsewers A., Schouten S., Sinninghe Damsté J. S.