Red Sea brine pools reveal clues to early life energy sources

A study published in the journal AGU Advances examines the “death pools” of the Red Sea—extreme, oxygen-free, and highly saline brine pools located on the ocean floor. While these environments appear inhospitable, researchers have discovered that they host various bacteria and archaea.

By analyzing sediments and organic matter from an active brine pool at a depth of 1,770 meters, as well as areas containing extinct pools, the team found significant concentrations of metals such as manganese, iron, molybdenum, and copper. In some locations, metal levels were more than 100 times higher than in surrounding areas.

The findings suggest that microbial manganese oxidation may have served as an energy source for primitive life forms billions of years ago, prior to the Great Oxidation Event. These geochemical signatures left in the sediment provide clues into how early organisms obtained energy before oxygen became abundant in Earth's atmosphere.