Europaschutzgebiet Waldaist und Naarn

This protected area is located in the valleys of the Waldaist and Naarn rivers in the Mühlviertel region and derives its international importance from the occurrence of the freshwater pearl mussel. Once found throughout Europe, this mussel species is now acutely threatened with extinction.

The areas of the European nature reserve are located along the rivers Waldaist and Naarn as well as the tributaries Schwarze Aist and Kleine Naarn. These watercourses and their valley areas are largely intact natural areas with species-rich mixed hillside forests and, in some cases, still existing riparian forests of alder and ash in the valley bottoms. Parts of this nature reserve also lie within the protected area of the Mühlviertel Nature Park. In addition to the eagle owl and black stork, otter and great crested newt, it is above all the river pearl mussel population that makes these river valleys worthy of protection. The mussel species, which was once common throughout Europe, needs clean, low-lime water and streambeds free of sand and mud as a habitat - conditions that have now become rare. The river pearl mussels are also dependent on the native brown trout as a host for their complex, long-lasting and extremely disturbance-prone reproductive cycle. These conditions are still met in the Waldaist and Naarn areas, which is why projects are also being carried out here to breed this endangered mussel species.