Scientists investigating the frozen Enigma Lake in Antarctica have discovered an ecosystem full of strange microbial communities. Enigma Lake in Antarctica lives up to its name. The permanently ice-covered lake, named for the strange debris cone at its center, was until recently thought to be frozen. However, scientists have discovered a hidden freshwater layer beneath the ice-covered surface, and various microorganisms live in this layer.

During an expedition to Antarctica from November 2019 to January 2020, researchers probed the lake with ground-penetrating radar and found at least 40 feet (12 meters) of liquid water beneath the ice. The researchers then drilled through the ice and sent a camera to explore the depths of the lake.

The team first tested to determine where the water was coming from. This was important to determine because the area had little rainfall, strong winds, and intense solar evaporation; Therefore, the water in Enigma Lake should have dried up a long time ago. Based on the chemical composition of salts in the water, the researchers hypothesized that the water in the lake is constantly replenished through an unknown underground pathway by the nearby Amorphous Glacier.

An ecosystem hidden beneath Antarctic ice

Scientists have discovered that although Enigma Lake’s waters are isolated from the atmosphere, they are home to various types of microbial life that cover the lake floor in patches known as microbial mats. Most of these organisms are photosynthetic, providing high concentrations of dissolved oxygen to the lake.

Some mats formed thin, sharp layers on the lake bottom. Others “resembled a crumpled, thick carpet, sometimes forming large amorphous tree-like structures up to 40 cm high” [сантиметрів або 16 дюймів] and up to 50-60 cm in diameter [20–24 дюймів]”, researchers wrote in a study published Dec. 3 in the journal Communications Earth and Environment.

Microbial inhabitants included several species patessibacteria – Small single-celled organisms that attach to larger host cells to form a mutually beneficial or predatory relationship. These organisms have never before been found in ice-covered lakes and cannot normally thrive in high-oxygen conditions. patessibacteria They may have developed unique metabolic techniques to survive.

“This discovery reveals the complexity and diversity of food webs in permanently ice-covered Antarctic lakes, revealing the possibility of previously unrecognized symbiotic and predatory lifestyles,” the researchers wrote in the study.

On icy moons such as Europa or Enceladus, an environment similar to Lake Enigma exists. Co-author Stefano Urbini, a geophysicist at the National Institute of Geophysics and Volcanology in Italy, wrote in a translated statement that the lake’s extreme ecosystem could provide insight into conditions where microbial life might exist on other worlds.