Reoxygenating oceans: Startups lead the way in Baltic Sea

Ocean deoxygenation is one of the issues on the agenda at the UN COP summit on biodiversity, opening on October 21 in Columbia.

Researchers from Stockholm University in Sweden, the French industrial company Lhyfe, and a Finnish startup Flexens are working on a pilot experiment to reoxygenate the Baltic Sea by producing hydrogen at sea.

The BOxHy project is seeking an overall solution to the asphyxiation that threatens a sea bordering nine northern European countries.

The oxygen dissolved in the oceans is essential to sustaining as underwater organisms have no chance of surviving without it, scientists say.

"But for more than 50 years, its concentrations have been decreasing," said Christophe Rabouille, a scientist at France's CNRS scientific research center.

The loss of oxygen has two main causes, according to the International Union for Conservation of Nature.

The warming of oceans due to is one—warmer oceans contain less oxygen, while organisms require more oxygen in hotter waters.

The other is eutrophication, the process in which fertilizer runoff, sewage, animal waste, aqua culture and the deposits of nitrogen from burning fossil fuels creates excessive algae blooms.

The Baltic Sea borders nine northern European countries including Sweden, Finland and Poland.

An overabundance of seaweed in the Baltic Sea has contributed to the depletion of oxygen.

A wind turbine farm in the Baltic Sea, north-east of Rugen Island in Germany.