Dino Weeks at AquaZoo

AquaZoo has started rearing young sea trout for the Fish for Connection project. This project aims to improve fish stocks in the Wadden Sea and surrounding waters, which also has a positive effect on local biodiversity.

The sea trout is a fish species that lives in both fresh and salt water. To reproduce, trout need to be able to swim from the sea to rivers and streams to lay eggs. However, these routes are often blocked by human infrastructure, such as dykes and locks. As a result, the fish are then unable to swim further, reducing their chances of reproduction. With the Fish for Connection project, several organisations, including the Waddenvereniging, Staatsbosbeheer and Sportvisserij Nederland, are working to reconnect waters and improve fish stocks.

AquaZoo joins this project by starting to raise sea trout. In the Wadden area at AquaZoo, four water tanks have been installed in which fish swim, sorted by size. These fish come from farms in northern Germany; they are offspring of wild sea trout. They will be cared for here for the next year, after which they will be released into the wild. William Kreijkes, head of animal care, explains: ‘Thousands of young sea trout are raised in special nurseries, such as now at AquaZoo. When they are a year old, we release them into the streams and they swim to sea on their own, we hope. Once these sea trout have lived at sea for several years, they will try to return to the streams where they were released, to reproduce.’

Preserving local nature
In addition to raising and releasing fish, AquaZoo is also committed to education. Klaas-Jan Leinenga, head of education, explains: ‘In our Wadden area, visitors learn all about the enormous biodiversity of the Wadden area. This project makes an important contribution to the entire ecosystem in the area. Indeed, not only sea trout benefit from the project. Other migratory fish such as river lamprey, sticklebacks and eels will also be able to swim from fresh to salt water and vice versa thanks to the modifications on the route. And the presence of fish, in turn, is important for many bird species and seals, for example. How the Fish for Connection project works, we will explain to visitors to AquaZoo with interactive education boards.’

The trout project fits well within AquaZoo's vision. Kreijkes: ‘We see this as part of a broader picture in which nature and species conservation play an increasingly important role. With European management programmes and nature conservation projects around the world, we have been doing this for years for the animals living in AquaZoo. By additionally collaborating on local projects like this, we also actively contribute to the restoration and conservation of native Dutch nature.’

Journey of the fish
After the fish are released, AquaZoo expects to raise a second batch of trout and the project will continue, again with partners such as the Waddenvereniging and Sportvisserij Nederland. Kreijkes: ‘It is possible that some of the fish will be zapped before the release and we can thus monitor whether they actually managed to swim back to sea.’ These insights will be used for further research.