Baltic Sea Oxygenation and Super-Green H2

Baltic Sea Oxygenation and Super-Green H2

Baltic Sea Oxygenation and Super-Green H2 1920 1080 Ocean Decade

Lead institution:

Flexens Oy Ab Finland

This project aims to tackle the problem of “anoxia”, which is the complete lack of oxygen in the marine environment, in the Baltic Sea by injecting oxygen into the sea via adapted, existing technology. To do so, the project is preparing a pilot scale demonstration in the Baltic Sea and the exploration of scientific and technical questions required prior to conceptualisation at a large scale.

Internal phosphorus loading in the Baltic Sea Proper and the Gulf of Finland is caused by strong anoxia below the halocline. External nutrient loading has decreased and is now surpassed by internal loading caused by a legacy of past nutrient loads. As green hydrogen production increases, deep injection of the electrolysis by-product oxygen below the halocline as a sea-based measure can become feasible to manage internal nutrient reserves in the Baltic Sea Proper. It can eliminate anoxia and suppress internal phosphorus loading with three principal environmental impacts: the restoration of aerobic benthic habitat, the sharp reduction of the phosphorus transport from deep to surface water driving algae blooms, and the suppression of the internal phosphorus loading and algae growth cycle causing persistent anoxia.

Start date: 01/10/2023
End date: 31/10/2024

Lead Contact: Szilvia Haide (

challenges: 1- Understand and beat marine pollution, 2- Protect and restore ecosystems and biodiversity, 4- Sustainable Ocean Economy
ocean_basins: Baltic Sea
type_of_action: Project


The Science We Need for the Ocean We Want





Join #OceanDecade

Privacy Preferences

When you visit our website, it may store information through your browser from specific services, usually in the form of cookies. Here you can change your Privacy preferences. It is worth noting that blocking some types of cookies may impact your experience on our website and the services we are able to offer.

For performance and security reasons we use Cloudflare

Enable/disable Google Analytics tracking code in browser

Enable / disable the use of Google fonts in the browser

Enable/disable embed videos in browser

Privacy policy

Our website uses cookies, mainly from 3rd party services. Define your Privacy Preferences and/or agree to our use of cookies.