Aarhus creates artificial reefs using excess construction materials

The Danish Municipality is recycling surplus concrete to form habitats for marine creatures

On 15 October, the Danish Municipality of Aarhus proudly shared that it is creating new habitats for small marine creatures by recycling construction materials. Currently, Lighthouse United and Per Aarsleff A/S are working together to build the tallest residential building in the municipality.

During the construction of ‘Lighthouse’, the two bodies came up with the idea of recycling excess concrete locally instead of driving it back to the factory. Thus, the idea to use blocks of concrete to construct artificial reefs where algae can grow, crabs can hide, and fish can breed, was born. 

Promoting biodiversity in Aarhus’ canals

Until now, there has been a lack of habitats for marine creatures in Aarhus’ canals. To change this and promote biodiversity, Aarhus Municipality collaborated with Lighthouse United and Per Aarsleff A/S to launch “Recycle Reef”.

This project was officially inaugurated on 14 October when a group of students from Samsøgade School helped the municipality pour 4 tonnes of mussels into the city’s canals. The organisers hope that the mussels will help convert the concrete blocks into artificial reefs that will attract more marine creatures to the area.

The brown dots illustrate where concrete reef will be established, the purple ones show the mussel reefs, and the blue-green ones depict where eelgrass is to be planted in the future
Source: Aarhus Municipality

Councillor for Technology and the Environment Bünyamin Simsek commented on the initiative, noting: “This is a wonderful project that puts both biodiversity and sustainability on the agenda. Life below the water surface gets a much-needed boost, and at the same time, it contributes to a more exciting urban environment for the people of Aarhus.”

Simsek’s statement was echoed by the Project Director at Per Aarsleff A/S, Kim Peters, who shared that the company wants to utilise residual construction materials in a way that benefits the local area. Furthermore, Peters highlighted the project’s potential to influence future developments: 

“It’s definitely an exciting way to think about recycling, and I think we’ll see more of this in the future.”