Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Sara Harðardóttir(1,2,3), Connie Lovejoy (2), Sofia Ribeiro(3)
Starfsvettvangur / Affiliations: 1. Marine and Freshwater Research Institute. Hafnarfjörður, Iceland. 2. Laval University. Quebec, Canada. 3. The Geological Survey of Denmark and Greenland, Copenhagen, Denmark.
Kynnir / Presenter: Sara Harðardóttir
The polar regions are warming at a rate unprecedented in millennia and one of the most striking effects of climate change is the loss of Arctic sea ice. As we move towards “blue summer” Arctic Ocean, predicting the full range of effects of climate change on the marine arctic environment, remains a challenge. Past sea-ice conditions are poorly understood beyond the satellite era. Stressing the demand for developing sea-ice proxies that can project sea ice variability over historical and geological timescales. Sea ice harbours a vast biodiversity of sea-ice microalgae with fine-tuned evolutionary traits. Recent studies show that DNA can be preserved in marine sediments for up to one million years and tracing sea ice by DNA fingerprints might be a promising approach.
Here we will present the potential of ancient DNA from sympagic dinoflagellate Polarella glacialis (Pgla-DNA) as a new sea-ice proxy. Our observations confirm that this species is common in first-year sea ice and sinking particulate matter follows sea-ice melt. We quantified Pgla-DNA in Arctic marine and fjord surface sediments and a marine sediment core spanning the Holocene, by gene copy number using a digital droplet PCR. We show that its detection in the paleorecord is more efficient following a molecular approach than standard micropaleontological methods. Polarella glacialis occurs in both the Arctic and Antarctic regions and the proxy may be useful in both hemispheres.