Experts challenge deep-sea 'dark oxygen' claim, call for retracting 2024 study

A 2024 study claimed that deep-sea polymetallic nodules could generate oxygen in total darkness via seawater electrolysis, but a December 2025 opinion article from marine scientists and electrochemists argues the results are flawed and likely artifacts, citing improper chamber ventilation, absence of negative controls, missing hydrogen data, and a thermodynamics violation; the authors defend their work and plan a spring CCZ expedition to test the phenomenon, but many experts say the study should be retracted unless the evidence is revised.