During the year, Boskalis executed a climate adaptive project in Dorset’s Hengistbury Head nature reserve in southern England which encompasses a unique combination of coastal defense and nature enhancement. The project, on behalf of the local council, involved the renewal of a 150-meter-long groyne at the foot of the headland and the installation of various rock and reef units under Boskalis’ Artificial Reefs Program.
Hengistbury Head represents a significant milestone for the practical application of artificial reefs. It is the first time that a client has included artificial reefs as an integral part of a broader project scope. Successful pilots have shown that the reefs enhance levels of biodiversity, even in a temperate environment. The stability of the reefs had also been validated through physical scale-model testing.
“The combination of these tests meant we could show our client the reefs would remain stable in the dynamic environment around the groyne and could result in enormous improvements in the ecology,
which is required as per local legislation,” said Boskalis Environmental Engineer Renske Free.
A total of 98 reef and rock units were placed along the length of the renewed groyne to connect the deeper marine habitat to the shoreline. The structures provide substrate and areas of shelter – in the form of holes and tunnels in the reefs – for fish, while tidal pools and custom-made rock pools create habitats for other species at low tide. Several rocks from the old groyne were re-deployed to also kickstart marine life within the structure itself.
The seven-ton reefs were designed by our partners Reefsystems and ARC Marine and installed using a combination of excavators and barges. “This project is a great example of what can be achieved
through detailed collaboration between the operational team on site and engineers in the office. Through this combined effort, we managed to integrate the extensive and challenging environmental plans within the overall project scope,” said Renske.
Over the next two years, a comprehensive monitoring scope will be executed to compare the ecological benefits of the different environmental enhancement units to that of conventional rock. “This is
important for both our clients and Boskalis as it can provide further evidence of the extent to which artificial reefs increase biodiversity and enhance marine life, and also which structures are best suited for
specific local conditions,” said Renske.
In recent years, Boskalis’ Artificial Reefs Program has piloted and installed numerous reef designs. Please visit the Artificial Reefs Program website for further details www.boskalis.com/artificialreefs.
