Reef teeming with life in artificial reef trial in the Wadden Sea
Since November 2021, 48 artificial reefs have been installed along the Lauwersmeer Sea Dyke in Groningen to enhance the underwater ecosystem of the Wadden Sea. Researchers have brought the reefs along the Lauwersmeer Sea Dyke to the surface for the first time to examine the life on and around them. Britas Klemens Eriksson, Professor of Marine Ecology at the University of Groningen, is positive about the initial results: “What we’re seeing is that the artificial reefs along the sea dyke . We’ve discovered a lot of biodiversity on the reefs, such as fish and sessile organisms. That’s really good news.” Research into what lives on and around the reefs will continue through 2024. After that, a decision will be made on how and which artificial reefs will be permanently installed along the sea dyke.
Preliminary results
The footage clearly shows that there is plenty of marine life visible. And this is just above the water; there is much more life beneath the surface. Research coordinator and PhD researcher Jorien Rippen of Van Hall Larenstein and the University of Groningen: “We see a reef teeming with life. For instance, we observed many eels emerging from the reef. So they like to hide in these spots.” In addition to serving as a hiding place for eels, it also appears 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 like 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 of the University of Groningen explains the fish research: “We monitor the fish in two ways. We first monitored the fish before the reefs were deployed. After the reefs were deployed, we placed traps on the reefs to determine which species are present around them. 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 establish themselves permanently there.” The measurements will be repeated again next year and will provide the researchers with insight into the effects and effectiveness of the reef elements and tidal pools in the Wadden Sea.
About the trial
This unique, large-scale experiment on underwater nature provides new insights into how to soften the edges of the mudflats and thereby improve water quality and the natural environment. The results of the study will be used to create a final design for a reef near the dyke. In addition, the study provides scientific insight into the effects of the various elements in the Wadden Sea. The experiment will determine the best way realised increase habitats on and around the dyke realised connexion the mudflats and the land. As a result, the dyke will dyke to achieving the nature conservation goals for the Wadden Sea region and will make the ecosystem more robust and diverse.
Collaboration
The pilot project is part of the Lauwersmeerdijk-Vierhuizergat dyke reinforcement project, in which we are creating many additional features for nature. The underwater ecosystem at the foot of the dyke one example of this. The trial is also part of the Waddentools Swimway project. This project investigates how fish species currently use the Wadden Sea. This knowledge is translated into recommendations to improve fish stocks.
The project partners are Noorderzijlvest Water Authority, Het Groninger Landschap, Rijkswaterstaat Northern Netherlands, council 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 components are ECOncrete Tech, Reefsystems, and Moreef. Van Hall Larenstein and the University of Groningen are monitoring and researching the ecological development.
Want to learn more about the trial? Click here for more information.