Exploring preserved fossil dinoflagellate and haptophyte DNA signatures to infer ecological and environmental changes during deposition of sapropel S1 in the eastern Mediterranean
Boere, Arjan C.
Rijpstra, W. Irene C.
de Lange, Gert J.
Sinninghe Damste, Jaap S.
Coolen, Marco J. L.
MetadataShow full item record
In this study we used a comparative multiproxy survey (fossil DNA, calcareous nannofossils, and lipid biomarkers) to test whether preserved genetic signatures provide an accurate view of haptophyte and dinoflagellate populations during deposition of the eastern Mediterranean sapropel S1 and the organic carbon-depleted oxidized marls flanking the S1 and to see if we could identify important environmental indicator species that did not fossilize and escaped previous microscopic identification. The marls above and below the S1 contained low concentrations of lipid biomarkers diagnostic for dinoflagellates and haptophytes (i.e., dinosterol and long-chain alkenones), but 500 base pair long ribosomal DNA fragments of these protists were below the detection limit. In contrast, dinoflagellate and haptophyte DNA could be recovered from the organic carbon-rich S1, but the most abundant sequences did not represent species that were part of the nannofossil (this study) or previously described dinocyst composition. The oldest section of S1 (9.8 to ∼8 14C kyr B.P.) revealed a predominance of dinoflagellate phylotypes, which were previously only detected in anoxic Black Sea sediments. In the same section of the core, the most abundant haptophyte sequence showed highest similarity with uncultivated haptophytes that were previously shown to grow mixotrophically as predators of picocyanobacteria, an adaptation that promotes growth in oligotrophic marine waters. Sequences with highest similarities to clones found in marine surface waters predominated in the S1 after ∼8 14C kyr B.P. We discuss whether the shifts in haptophyte and dinoflagellate populations inferred from the preserved DNA reflect known environmental changes that occurred during the formation of sapropel S1.
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 26 (2011): PA2204, doi:10.1029/2010PA001948.
Suggested CitationPaleoceanography 26 (2011): PA2204
Showing items related by title, author, creator and subject.
217 000-year-old DNA sequences of green sulfur bacteria in Mediterranean sapropels and their implications for the reconstruction of the paleoenvironment Coolen, Marco J. L.; Overmann, Jorg (2006-08-08)Deep-sea sediments of the eastern Mediterranean harbor a series of dark, organic carbon-rich layers, so-called sapropels. Within these layers, the carotenoid isorenieratene was detected. Since it is specific for the ...
Sachs, Julian P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1997-02)The goals of this thesis were: (1) to establish methods for the determination of nitrogen and carbon isotope ratios in marine particulate and sedimentary chlorophyll derivatives; (2) to establish chlorophyll δ15N and ...
Hydrology in the Sea of Marmara during the last 23 ka : implications for timing of Black Sea connections and sapropel deposition Vidal, L.; Menot, Guillemette; Joly, C.; Bruneton, H.; Rostek, F.; Cagatay, M. Namik; Major, Candace O.; Bard, Edouard (American Geophysical Union, 2010-02-06)Sediments deposited under lacustrine and marine conditions in the Sea of Marmara hold a Late Quaternary record for water exchange between the Black Sea and the Mediterranean Sea. Here we report a multiproxy data set based ...