European scientists have joined forces with startups to tackle the pressing issue of ocean deoxygenation, particularly concerning the Baltic Sea. The BOxHy project, involving researchers from Stockholm University, the French company Lhyfe, and the Finnish startup Flexens, aims to address the decreasing oxygen levels in the Baltic Sea by producing hydrogen at sea. This depletion of oxygen in the ocean is primarily attributed to climate change and eutrophication, posing a significant threat to marine life and biodiversity. The project, supported by the UN as part of a decade-long initiative on sustainable ocean development, intends to explore the possibility of injecting gaseous oxygen at depth in the Baltic Sea. If successful, this innovative approach could have beneficial effects on the Baltic Sea ecosystem, potentially creating new habitats and fostering breeding grounds for marine species like cod. Flexens, the Finnish startup involved, has identified three potential zones for oxygen reinjection, with the French company Lhyfe specializing in producing oxygen and hydrogen from water using an electric current. While Lhyfe has previously released oxygen into the atmosphere, the project now envisions injecting it directly into the Baltic Sea to counter the deoxygenation crisis. The project is still in the planning phase, with the upcoming pilot project set to commence in 2025. This phase will focus on refining the oxygen injection method, assessing its environmental impact, and studying the effects on marine flora and fauna. Estimates suggest that up to 30 offshore platforms could be required to fully reoxygenate the Baltic Sea, highlighting the long-term and complex nature of this ambitious environmental endeavor.