University of Southern Denmark: New project to restore polluted lakes

With DKK 22.1 million ($3.4 million) in funding from Innovation Fund Denmark, Kasper Reitzel from the University of Southern Denmark’s Department of Biology will lead the development of a new restoration technology designed for use in Danish lakes.

Lakes are among the most heavily impacted ecosystems in Denmark and across Europe. Although nutrient inputs to many lakes have been reduced, phosphorus-rich sediments continue to release nutrients into the water. The result is murky water, algal blooms, biodiversity loss, and greenhouse gas emissions.

A new project, RESTORE, will now demonstrate a sustainable and circular solution that can restore the ecological condition of lakes, reduce their greenhouse gas emissions, and recycle valuable resources for agriculture.

RESTORE will develop a sediment removal system known as the Lakebot (in Danish søbot), designed to remove nutrient-rich surface sediments more gently and efficiently than existing solutions.

The lakebot will build on a prototype tested in Lake Ormstrup in 2024 by Kasper Reitzel and colleagues.

As part of the project, sediment will be removed at full scale from three Danish lakes. Researchers will monitor the lakes before, during, and after the restoration work to document the effects on water quality, biodiversity, and greenhouse gas emissions.