Millennial-scale variations in Arctic sea ice are recorded in sedimentary ancient DNA of the microalga Polarella glacialis

Sara Harðardóttir, James S. Haile, Jessica Louise Ray, Audrey Limoges, Nicolas Van Nieuwenhove, Catherine Lalande, Pierre-Luc Grondin, Rebecca Jackson, Katrine Sandnes Skaar, Maija Heikkilä, Jørgen Berge, Nina Lundholm, Guillaume Massé, Søren Rysgaard, Marit-Solveig Seidenkrantz, Stijn De Schepper, Eline D. Lorenzen, Connie Lovejoy, Sofia Ribeiro

Research output: Contribution to journalArticleResearchpeer-review


Sea ice is a critical component of the Earth’s Climate System and a unique habitat. Sea-ice changes prior to the satellite era are poorly documented, and proxy methods are needed to constrain its past variability. Here, we demonstrate the potential of sedimentary DNA from Polarella glacialis, a sea-ice microalga, for tracing past sea-ice conditions. We quantified P. glacialis DNA (targeting the nuclear ribosomal ITS1 region) in Arctic marine and fjord surface sediments and a sediment core from northern Baffin Bay spanning 12,000 years. Sea ice and sediment trap samples confirmed that cysts of P. glacialis are common in first-year sea ice and sinking particulate matter following sea-ice melt. Its detection is more efficient with our molecular approach than standard micropaleontological methods. Given that the species inhabits coastal and marine environments in the Arctic and Antarctic, P. glacialis DNA has the potential to become a useful tool for circum-polar sea-ice reconstructions.

Original languageEnglish
Article number25
Number of pages13
JournalCommunications Earth and Environment
Issue number1
Publication statusPublished - 9 Jan 2024

Programme Area

  • Programme Area 5: Nature and Climate


Dive into the research topics of 'Millennial-scale variations in Arctic sea ice are recorded in sedimentary ancient DNA of the microalga Polarella glacialis'. Together they form a unique fingerprint.

Cite this