Dark Oxygen Production at the Abyssal Seafloor: Implications for the Origin of Life on Earth and Astrobiology

The discovery of “dark oxygen” production at the abyssal seafloor represents a paradigm shift in our understanding of oxygen generation on Earth—and potentially throughout the universe. Traditional models have long maintained that oxygen production requires photosynthetic organisms and sunlight. However, recent research conducted in the Clarion-Clipperton Zone of the Pacific Ocean has revealed that polymetallic nodules can generate oxygen through seawater electrolysis in complete darkness, approximately 4,000 meters below the ocean surface. This phenomenon, termed dark oxygen production (DOP), challenges fundamental assumptions about the origin of aerobic life on Earth and expands the potential habitability of ocean worlds in our solar system, such as Europa and Enceladus. This paper reviews the mechanisms underlying dark oxygen production, its implications for evolutionary biology, and its significance for astrobiology and the search for extraterrestrial life.