Dwellers In The Deep: Biological Consequences Of Dark Oxygen
The striking recent putative detection of “dark oxygen” (dark O2) sources on the abyssal ocean floor in the Pacific at ∼4 km depth raises the intriguing scenario that complex (i.e., animal-like) life could exist in underwater environments sans oxygenic photosynthesis.
In this work, we thus explore the possible (astro)biological implications of this discovery. From the available data, we roughly estimate the concentration of dissolved O2 and the corresponding O2 partial pressure, as well as the flux of O2 production, associated with dark oxygen sources.
Based on these values, we infer that organisms limited by internal diffusion may reach maximal sizes of ∼0.1−1 mm in habitats with dark O2, while those with circulatory systems might achieve sizes of ∼0.1−10 cm. Optimistically, the estimated dark oxygen flux can potentially support biomass densities up to ∼3−30 g m−2, perhaps surpassing typical reported densities at similar depths in global deep-sea surveys.
Finally, we outline how oceanic settings with dark O2 may facilitate the origin(s) of life via the emergence of electrotrophy. Our findings indicate that complex life fueled by dark oxygen is plausibly capable of inhabiting submarine environments devoid of photosynthesis on Earth, conceivably extending likewise to extraterrestrial locations such as icy worlds with subsurface oceans (e.g., Enceladus and Europa), which are likely common throughout the Universe.
Manasvi Lingam, Amedeo Balbi, Madhur Tiwari
Comments: 32 pages; 0 figures
Subjects: Biological Physics (physics.bio-ph); Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph); Populations and Evolution (q-bio.PE)
Cite as: arXiv:2408.06841 [physics.bio-ph] (or arXiv:2408.06841v1 [physics.bio-ph] for this version)
https://doi.org/10.48550/arXiv.2408.06841
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Submission history
From: Manasvi Lingam
[v1] Tue, 13 Aug 2024 12:04:00 UTC (41 KB)
https://arxiv.org/abs/2408.06841
Astrobiology,
