Quagga mussels are causing problems for waterworks on Lake Constance. The mussel was introduced from the Black Sea region around ten years ago.
They have also already arrived at Lake Geneva and Lake Biel. Lake Zurich, on the other hand, is still free of the mussel. It is not possible to prevent the animals from spreading further in areas that are already infested. This could lead to major changes in the ecosystem. For some fish species, the food supply is increasing because they eat the mussels. Other stocks have declined due to the lack of plankton.