ICEPRINT · Sea ice microalgae DNA fingerprints as proxies in past climate studies
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-01-01 → 2023-05-02
- EU contribution
- €273,687
- Participants
- 2
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Sea ice microalgae DNA fingerprints as proxies in past climate studies
One of the most striking changes observed during the satellite era is the sharp decline in Arctic sea ice extent. According to the latest IPCC projections, the Arctic will transition into a seasonally sea ice free regime within decades. Paleoclimatology relies on proxies or indicators preserved in climate archives such as ice cores, marine and terrestrial sediments to trace past climate changes. Proxies for sea ice include protist microfossils such as diatoms and dinoflagellates and lipid biomarkers. But even though progress has been made, there is a significant gap in our understanding of sea ice variability on longer timescales and the identification of new reliable sea ice proxies is crucial. Although sea ice itself leaves no traces on marine sediments, the sea ice environment harbors an enormously diverse and highly specialized community of sea ice microalgae. Considering that only a fraction of microalgae leave a microfossil record in marine sediments, tracing these using DNA is a promising approach, but is still in its infancy. One of the limitations is that for many potential indicator species a molecular reference is lacking. The aim of this project is to develop and test proxies derived from DNA for sea ice, using three objectives: OBJ1: Community-level: Investigating transport and fate of microalgae from the surface waters to the seafloor and their eventual incorporation into marine sediment records. OBJ2: Species-level - identification of sea ice proxies. OBJ3: Application of the identified genetic proxies. Within the ICEPRINT we presented the potential of the use of digital droplet PCR for absolute quantification of ancient DNA from sea ice microalgae for sea-ice proxies. This new approach holds to promise to allow for a better understanding of the past evolution of Arctic sea ice, and improve future predictions, with implications for global climate change and society at large.
Data: CORDIS, © European Union
Project objective
Through this MSC action, I propose to design, test, and apply new genetic proxies for reconstruction of past sea ice extent. Satellite observations show an abrupt decrease in the extent of seasonal sea ice and state-of-the-art projections point to a seasonally ice-free Arctic Ocean by mid-century. Predicting the full range of climate change impacts on the Earth system requires an understanding of past variability. Past sea ice information is, however, limited by the fact that sea ice leaves no direct fingerprint in the geological record. The identification of new reliable proxies for sea ice is one of the most important challenges facing paleoclimatology today. DNA from sea ice microalgae offers an exciting possibility, as the sea ice environment harbours an enormously diverse and highly specialized community of protists, including diatoms and dinoflagellates. Because only a small fraction of sea ice microalgae leave a microfossil imprint in marine sediments and many species are only identifiable by advanced microscopy techniques, one limitation is that molecular references are lacking for many potential DNA gene markers. To identify the potential proxies I will apply classical taxonomy and DNA metabarcoding to study the vertical export of microalgae in the spring, after sea ice melt. The potential of the new sea ice proxies will be tested and selected markers will be applied by exploring sedimentary ancient DNA preserved in marine sediments records from the Arctic.
Original text from CORDIS.
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Data: CORDIS, © European Union