This study uses shotgun metagenomics of marine sedimentary ancient DNA from the Western Bering Sea to analyze ecosystem responses to sea-ice loss over the last ~20,000 years. The results show a shift from a sea-ice adapted late-glacial ecosystem (diatoms, copepods, codfish) to an ice-free Holocene ecosystem (cyanobacteria, salmon, herring). Ancient DNA is identified as a valuable tool for assessing long-term ecosystem responses to climate change, informing ocean and cryosphere risk assessments. Continuing sea-ice decline is predicted to impact carbon export and benthic food supply, potentially leading to northward species expansion.

Heike H. Zimmermann, Kathleen R. Stoof-Leichsenring, Viktor Dinkel, Lars Harms, Luise Schulte, Marc-Thorsten Hütt, Dirk Nürnberg, Ralf Tiedemann, Ulrike Herzschuh