Stanford researchers found that diatoms beneath Arctic ice remain active even at -15°C, the coldest recorded movement for eukaryotic cells. This challenges previous beliefs and highlights their vital role in the Arctic ecosystem amid climate crisis.
If you take a core sample of ice from the far edges of the Arctic, you might notice a faint line of dirt-like material inside. These are called diatoms- tiny, single-celled algae that have shells made of glass. It has been previously known that diatoms can be found in ice before, but because they seemed stuck and inactive, not many scientists studied them closely.
Research from Stanford
New research from Stanford University has discovered that diatoms aren’t just trapped or dormant, they’re actually active and moving under the ice, even in extremely cold temperatures. The study was published in the journal Proceedings of the National Academy of Sciences.
Manu Prakash, a bioengineering professor at Stanford and the lead author of the paper, explained how surprising this is.
He said, “This is not 1980s-movie cryobiology. The diatoms are as active as we can imagine until temperatures drop all the way down to -15 C, which is super surprising.”
This is the coldest temperature anyone has ever recorded for movement in a eukaryotic cell—a type of cell found in plants, animals, fungi, and many microorganisms that have a nucleus inside. The team found that the movement depends on a mix of mucus-like material and tiny molecular motors inside the cells.
Skating Through the Arctic Ice
The diatoms in this study came from samples collected during a 45-day expedition in the Arctic’s Chukchi Sea. The Stanford team, including the Prakash Lab and scientists from the Earth system department, collected ice cores from 12 locations in the summer of 2023.
Back in the lab, the researchers recreated the Arctic’s icy conditions in petri dishes, using layers of frozen fresh water and very cold salty water. When sea ice forms, it pushes out salt and leaves behind tiny channels of fresh water inside the ice. Even when temperatures were lowered well below freezing, the diatoms moved easily through these tiny channels.
What amazed the team was that the diatoms didn’t move by shaking or waving parts of their bodies. Instead, they slid smoothly over surfaces. This type of movement called “gliding” which many diatoms use. How these tiny motors keep working in such cold temperatures is now a big question the team wants to answer.
Why It Matters
The discovery that diatoms are active under the ice changes how we think about the Arctic ecosystem. If diatoms are moving and alive, they might be helping to transport nutrients and energy through the food web, supporting other life forms. The researchers even wondered if the mucus trails left by the diatoms could help form new ice crystals, similar to how pearls grow around tiny grains of sand.
Prakash highlighted the urgency of this work. Many scientists warn that within 25 to 30 years, the Arctic as we know it might disappear because of climate change. More funding is needed to continue this research to discover and understand these fragile systems.