Biology Researchers bring 7000-year-old algae back to life
Researchers have brought an algae that is several thousand years old back to life. The diatom Skeletonema marinoi sank to the bottom of the Baltic Sea almost 7,000 years ago and survived there without light and oxygen in the sediment.
28.03.2025, 10:54
SDA
According to the Leibniz Institute for Baltic Sea Research (IOW) in Rostock-Warnemünde, Germany, the cells of this diatom are among the oldest organisms to have been successfully revived from an inactive, so-called dauer stage.
Many creatures are able to enter a kind of sleep mode in order to survive under unfavorable conditions, the researchers explained. "In doing so, they switch to a state of reduced metabolic activity and often form special permanent stages with stable protective shells and stored energy reserves." This also applies to the diatom Skeletonema marinoi. "Its permanent stages sink to the bottom of bodies of water, where they are covered by sediment over time and preserved in the absence of air."
Ancient algae surprisingly fit
In their project, in which scientists from the Universities of Rostock and Constance were also involved, the IOW researchers examined sediment cores that were obtained from 240 meters of water during an expedition with the research vessel "Elisabeth Mann Borgese" east of the island of Gotland in 2021. From nine samples, viable algae were awakened from the permanent stage in the laboratory under favorable nutrient and light conditions and individual strains were isolated.
The diatom species Skeletonema marinoi was reportedly the only phytoplankton species to awaken from all samples. The oldest sample with viable cells was dated to an age of 6871 ± 140 years. "It is astonishing that the reawakened algae not only survived "just so", but have apparently not lost their "fitness", i.e. their biological capacity: They grow, divide and photosynthesize like their modern descendants," it said. Skeletonema marinoi is reportedly still widespread in the Baltic Sea today.
