Restoring vibrant marine life at Køge Bay

In response to years of deteriorating ecosystems and loss of biodiversity in Køge Bay, WSP is helping to build a series of stone reefs of great importance to the marine environment. 

Since 1900, approximately 8 million m³ of stones have been removed from Danish waters in connection with harbour construction, coastal defences, and other land construction projects. Over the years, those activities have left a barren seabed in their wake, which has diminished the number of species and the occurrence of marine life. 

Stone reefs are of great importance to the marine environment and biodiversity, serving several different functions for fish and plants. Multiple fish species use stone reefs to complete their life cycle, while others use them to find shelter from predators. Furthermore, reefs with kelp forests are one of the marine habitats that holds the greatest biomass and species diversity and are therefore of vital importance in respect to attracting and preserving abundant marine life in Køge Bay.

Addressing the challenges

Through the Køge Bay Marine Park project, WSP will help prepare a holistic and ecosystem-based solution that gives back to nature by enhancing the quality of the marine environment and ensuring a healthy ecosystem for its future. This goal will be accomplished by building stone reefs, concrete reefs, educational reefs, fish hotels, and biohuts. Additionally, biogenic reefs inhabited by blue mussels will increase microalgae filtration, thus ensuring clearer water and more abundant light for seaweed and other aquatic plants, including eelgrass. 

The reefs will form part of the Køge Bay Marine Park project, which has received a grant of approximately DKK 10 million from the Velux Foundation. Funds received from the grant will be used to establish a total of seven stone reefs. 

A powerful collaboration

Behind the stone reefs is the Køge Bugt Stenrev voluntary association, and the project is being carried out in collaboration with WSP Denmark, the Technical University of Denmark (DTU Aqua and DTU Sustain), the Natural History Museum of Denmark at the University of Copenhagen, Den Blå Planet, and the municipalities of Stevns, Køge, Greve, Solrød, and Ishøj. 

WSP involvement:

• WSP has an advisory role, leveraging extensive experience in marine restoration to help improve the quality of the marine environment and restore the biodiversity of Køge Bay.
• WSP is also in charge of the geophysical investigations and mapping of the seabed in the area as well as designing the reefs to increase the positive effect on biodiversity.
• WSP’s expertise will also contribute to the development of public dissemination campaigns to promote greater awareness of the issues that threaten the marine environment.