EGU2020-10928
https://doi.org/10.5194/egusphere-egu2020-10928
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

A sedimentary ancient DNA approach to elucidate the Labrador Sea paleoceanography over the last ~130,000 years

Stijn De Schepper1, Jessica Louise Ray2, Lisa Griem3, Nicolas Van Nieuwenhove4, Danielle Magann Grant1, Kristine Steinsland1, Katrine Sandnes Skaar2, and Umer Zeeshan Ijaz5
Stijn De Schepper et al.
  • 1NORCE Climate, Norwegian Research Centre and Bjerknes Centre for Climate Research, Bergen, Norway (stde@norceresearch.no)
  • 2NORCE Environment, Norwegian Research Centre, Bergen, Norway
  • 3Department of Earth Science, University of Bergen and Bjerknes Center for Climate Research, Bergen, Norway
  • 4Department of Earth Sciences, University of New Brunswick, Fredericton, Canada
  • 5School of Engineering, University of Glasgow, Glasgow, United Kingdom

Long sedimentary ancient DNA (sedaDNA) records from the marine environment are at present a curiosity and their utility in paleoceanographic research is not yet fully explored. Nevertheless, a few studies indicate that this ecogenetic repository represents an untapped source of new information with which paleoclimatic and paleoceanographic variability can be more deeply explored. We have generated a sedaDNA record from a 19.6 m-long sediment core in the Labrador Sea (Eirik Drift, south of Greenland). The record extends from the early Holocene to Marine Isotope Stage 5 (ca. 130,000 years ago), and we characterized several important climatic transitions in this time interval using stable isotope stratigraphy, ice-rafted detritus counts, and dinoflagellate cyst census counts. The primary goal of this investigation was to query the sedaDNA record for a biological indication of the last and penultimate deglaciation, as well as Heinrich events identified between 65,000 and 25,000 years ago. Our metabarcoding strategy targeted a broad diversity of eukaryotic organisms through amplification of the V7 hypervariable region of the small subunit ribosomal RNA (SSU rRNA) gene. The preliminary sedaDNA results indicate that eukaryote ancient DNA is present in all samples investigated, including those dating back to Marine Isotope Stage 5. Furthermore, we identified abundance shifts in Protaspidae (cercozoa), diatoms, dinoflagellates, and marine stramenopiles (amongst others) that may be linked to changes in paleoceanography during the last two deglaciations as well as Heinrich events (HE3, HE4).

How to cite: De Schepper, S., Ray, J. L., Griem, L., Van Nieuwenhove, N., Grant, D. M., Steinsland, K., Sandnes Skaar, K., and Ijaz, U. Z.: A sedimentary ancient DNA approach to elucidate the Labrador Sea paleoceanography over the last ~130,000 years, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10928, https://doi.org/10.5194/egusphere-egu2020-10928, 2020

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