On 28 May 1932, the last gap in the Afsluitdijk was filled in. But now, almost 90 years later, a new gap is being created. With the construction of the ‘coupure’ through the Afsluitdijk, work has officially begun on the fish migration channel at Kornwerderzand. Over the next four years, a unique fish passage will be built right across the Afsluitdijk, allowing fish to swim freely between the Wadden Sea and the IJsselmeer. As a result, many species of fish will be able to reach their breeding grounds and other habitats, in some cases as far away as Germany and Switzerland.
Migratory fish need both salt and fresh water to grow and reproduce. Unfortunately, barriers such as the Afsluitdijk have made life difficult for these species over the past few decades. Millions of fish wait in the Wadden Sea for the sluices to open. When they sense the fresh water, they instinctively feel the urge to swim upstream. Fish-friendly sluice management at the Afsluitdijk allows fish to swim through at certain times, but with the construction of the fish migration channels many more fish, both big and small, and both strong and weak swimmers, will be able to move back and forth between salt and fresh water.
First contours of the fish migration channel already visible
More than a fish passage The fish migration channel will not only serve as a connection between the Wadden Sea and the IJsselmeer, but will also feature areas of brackish water on both sides of the Afsluitdijk, which will ebb and flow naturally with the tides. For migratory fish such as salmon, sea trout, smelt, herring, mullet and eel, the fish migration channel is literally a matter of life and death. But territorial fish, such as perch and zander, will also benefit from the improved food supply. The new connection between the Wadden Sea and the IJsselmeer is not only good for the fish; it will also serve as a powerful tool for nature restoration by providing more food for birds and sea mammals like porpoises and seals.
Artist’s impression of the fish migration channel.
International example The project is an initiative by the Waddenvereniging, Sportvisserij Nederland (Royal Dutch Angling Association), it Fryske Gea, the Blauwe Hart Natuurlijk and NetVISwerk. The National Postcode Lottery was one of the first financiers, and serves as a flywheel to build momentum from the concept to construction. The fish migration channel will be built by De Nieuwe Afsluitdijk, a partnership of the provinces of North Holland and Friesland and the municipalities Hollands Kroon and Súdwest-Fryslân. The partnership has commissioned building consortium Levvel to excavate the cut through the Afsluitdijk. The realisation of the fish migration channel through the Afsluitdijk will be followed with great interest internationally. The impact of climate change on densely populated delta regions is increasing around the world. In this iconic location, the Netherlands will show that there are solutions that combine safety, preservation of fresh water and nature restoration.