At the Bienen Old Rhine, there are plans for initial planting at former reed locations to regenerate the reed population. Mainly narrowleaf cattails (Typha angustifolia) are being planted because this species is particularly affected by the decline. A natural regeneration of the remaining plants would only be possible over a very long period of time. To ensure that the young plants are not destroyed by the coypu eating them, they are also protected by fences or cages. This method has already been successfully tested by the Nature Conservation Centre in the last three years before the start of the project. Protective screens, 1 m x 1 m with a mesh size of 5 cm, are used to build cages closed on all sides within which the reeds are initially planted. The cages are then also closed at the top. This prevents to coypu from being able to get into the cages in floods or when water levels are high. The individual cages can then be connected like a fence to secure larger areas for reed development. The components can also be easily installed in the muddy, soft soils in the Old Rhine without causing serious damage.
In addition, larger fences made of conventional game fencing are erected. But these do not offer comparable protection against eating as the screens. On the one hand, they are less stable and on the other, in the event of a flood, the coypu can get to the plants. The use of these two methods ensures an optimum of costs, labour and chances of success. Although the protective cages made of screens offer 100 % protection against the plants being eaten, they cannot be used in large areas because of the high costs. The preliminary studies show that the reeds can spread naturally from the initial planting site if there is no pressure from them being eaten.