Reef teeming with life in artificial reef trial in the Wadden Sea

Preliminary results 

The images clearly show that there is plenty of marine life visible. And this is only above water; there is much more living underwater. Research coordinator and PhD researcher Jorien Rippen from Van Hall Larenstein University of Applied Sciences and the University of Groningen: "We see a reef teeming with life. We saw lots of eels emerging from the reef. They like to hide in these places." In addition to being a hiding place for eels, it also seems to be a nursery. Young eels have been discovered there. But the reef elements are also a great place for shellfish, echinoderms, and algae to attach themselves. "The holes are attractive for crabs and shrimp to hide in. You also see sessile organisms such as oysters, barnacles, sea anemones, and sea squirts."

How are the reefs studied?

The University of Groningen and Van Hall Larenstein University of Applied Sciences are monitoring progress in a scientific study using various methods. On the one hand, manual measurements are being taken of underwater plants, animals, and fish. PhD researcher Maryann Watson from the University of Groningen explains the fish research: "We are monitoring the fish in two ways. We first monitored the fish before the reefs were deployed. After the reefs were deployed, we placed fish traps on the reefs to find out which species occur around the reefs. And now that the reefs have been brought on board, we collect all the fish that fall off and measure them in the same way." In addition to manual monitoring of the reef, the research team also uses a 3D scanner. Jorien Rippen: "Because we do this every year, we can see how the reef develops over time, for example in terms of size, but also whether the species actually settle there permanently." The measurements will be repeated again next year and will give the researchers insight into the effects and effectiveness of the reef elements and tidal pools in the Wadden Sea. 

About the trial

This unique large-scale trial for underwater nature provides new insights into softening the edges of the Wadden Sea, thereby improving water quality and nature. The results of the research will soon be used to create a final design for a reef near the dike. In addition, the research provides scientific insight into the effects of the elements in the Wadden Sea. The trial will reveal the best way to increase habitats on and around the dike and the connection between the mudflats and the land. As a result, the dike will contribute to achieving the nature conservation goals for the Wadden Sea region and make the ecosystem more robust and diverse.

Collaboration

The trial is part of the Lauwersmeer-Vierhuizergat dyke reinforcement project, which involves creating many additional benefits for nature. The underwater nature at the foot (toe) of the dike is one example of this. The trial is also part of the Waddentools Swimway project. This project is investigating the existing use of the Wadden Sea by fish species. This knowledge is being translated into recommendations for improving fish stocks.

Partners in the project are the Noorderzijlvest Water Authority, Het Groninger Landschap, Rijkswaterstaat Noord-Nederland, the municipality of Het Hogeland, the province of Groningen, engineering firm Arcadis, and the Waddenkwartier consortium (Heijmans and GMB). The project is co-financed by the Wadden Fund and the Programmatic Approach to Large Water Bodies. The suppliers of the elements are ECOncrete Tech, Reefsystems, and Moreef. Van Hall Larenstein University of Applied Sciences and the University of Groningen are monitoring and researching the ecological development.

Want to know more about the trial? Click here for more information.