Recent research has discovered that polymetallic nodules on the seabed may produce 'dark' oxygen, providing oxygen for life on the ocean floor. This revelation has posed a challenge to deep-sea mining negotiations by frustrating mining companies and raising concerns among environmentalists. The study's findings have fueled calls for a moratorium on deep-sea mining until a better understanding of its potential impacts is achieved. This development underscores the critical importance of thoroughly assessing the environmental impact of cobalt mining activities, especially those in deep-sea ecosystems.