A scientific discovery made in the Chukotka Sea, between Russia and Alaska, has altered the understanding of life in extreme environments. Researchers found microalgae capable of actively moving at temperatures as low as −15 °C within the sea ice, a biological record for eukaryotic organisms.
The study, published in an international scientific journal, revealed that these tiny life forms do not remain immobile during the polar winter, as previously believed. On the contrary, they continue to move and develop biological activity even in conditions where the water is almost completely frozen.
The discovery emerged after a scientific expedition collected ice cores in the Arctic. Once the samples were brought to the laboratory, researchers reproduced polar conditions and observed something unexpected under the microscope: small green organisms slowly moving within microscopic channels in the ice.
In addition to raising new questions about the adaptation of life to extreme temperatures, the discovery reinforces the ecological importance of ecosystems hidden beneath the frozen surface of the Arctic.
A living ecosystem hidden under the snow
The protagonists of this discovery are diatoms, microscopic microalgae protected by a silica structure similar to a tiny glass shell.
These organisms play essential roles in marine ecosystems, as they produce oxygen, capture carbon dioxide, and form the base of numerous oceanic food chains.
For years, the scientific community believed that diatoms became practically inactive under the ice during the coldest stages of the year. However, new observations show that they remain active even in extreme temperatures.
The detected behavior also suggests that these microalgae could actively participate in the redistribution of nutrients within the sea ice, creating small microecosystems invisible to the human eye.
How they manage to move in extreme temperatures
The movement mechanism of these diatoms surprised researchers with its biological complexity. The microalgae secrete a viscous substance called mucilage that allows them to slowly slide through the ice channels.
They then use molecular proteins similar to those found in human muscles, such as actin and myosin, to propel themselves and move across the icy surface.
The most striking aspect is that these Arctic species seem to move even faster than other diatoms from temperate regions, evidence of extreme evolutionary adaptation to polar conditions.
Scientists believe that this discovery completely changes the perception of sea ice, which ceases to be seen as an inert surface and becomes a dynamic and biologically active environment.
What are diatoms and why are they essential for the planet?
Diatoms are unicellular microalgae found in oceans, lakes, and humid environments around the planet. Although they are invisible to the naked eye, they play a fundamental role in the ecological balance globally.
These organisms generate a huge proportion of atmospheric oxygen through photosynthesis and help capture large amounts of CO₂, contributing to regulating the Earth’s climate.
Additionally, they form the nutritional base of numerous aquatic ecosystems, supporting fish, crustaceans, and other marine species essential for biodiversity.
Their ability to adapt to extreme conditions also sparks interest in fields like astrobiology, as they could offer clues about how life might survive on icy worlds beyond Earth, such as Europa or Enceladus.
As global warming accelerates the loss of ice in the Arctic, scientists warn that these microscopic ecosystems could disappear before being fully understood. The discovery of mobile diatoms thus becomes a signal of the extraordinary resilience of life and, at the same time, the fragility of polar environments in the face of climate change.
