During the recent Southwest Delta Knowledge Day, researchers Jaco de Smit and Wietse van de Lageweg organized a session on 'Supplementation for Nature Management.'
Suppletions are interventions where artificial sediment is added, for example, to restore an eroding sandbar to its original height. This method is applied not only along sandy coastlines but is also essential in the Eastern Scheldt to maintain the intertidal area.
The construction of the Eastern Scheldt storm surge barrier has reduced the natural dynamics of tidal flows, leading to "sand hunger": the sand from the higher sandbars slowly shifts into deeper channels. This reduces food availability for birds and lessens protection against high waves. Lower sandbars are less effective at breaking waves, which increases the pressure on dikes.
A Promising Measure
Nature management suppletions are seen as a promising approach to address challenges like biodiversity loss and climate change. However, knowledge in this area is fragmented and spread across various parties, such as water and land managers, research institutions, and community organizations. The breakout session aimed to identify knowledge gaps and explore concrete action perspectives.
During the session, three speakers discussed various aspects of supplementation. Daan Rijks from Boskalis spoke about the Roggenplaat supplementation and the challenges of working in a tidal system. Jim van Belzen from Wageningen Marine Research provided an update on biodiversity and the recolonization of Roggenplaat three years after its establishment. Rutger Blok from Rijkswaterstaat highlighted the design of the upcoming Galgeplaat supplementation, including the technical, ecological, and legal considerations involved. Participants then prioritized key themes and mapped out opportunities for nature management suppletions in the short, medium, and long term.
Involvement in the Knowledge Community
Since 2023, the 'Building with Nature' research group has been involved with the Knowledge Community on Nature Management Supplementation. This community aims to consolidate relevant knowledge and experience for future nature-based supplementations, with the Eastern Scheldt serving as a showcase. This is achieved through monitoring, modeling, experimentation, practical collaboration, and developing conceptual frameworks. The focus is on fostering knowledge to mitigate the effects of sand hunger on nature.
The theme of Southwest Delta Knowledge Day 2024 was nature restoration. This annual day is organized by the Southwest Delta Knowledge Community, which includes Rijkswaterstaat, the Ministry of Agriculture, Nature, and Food Quality, the Zeeland Environmental Federation, and various research institutions and knowledge centers.
For more information on nature management suppletions and the Southwest Delta Knowledge Day, please visit this website.