Press release

August 19, 2026, No. 127

Quagga Mussel: Curbing Its Spread and Protecting Waterways

County Office Provides Information on Invasive Mussel Species and Asks Citizens for Their Help

Bad Tölz-Wolfratshausen District. The quagga mussel is increasingly spreading throughout European waters. Local waters are also affected by this spread: the invasive mussel species has already been detected in Lake Starnberg. The Bad Tölz-Wolfratshausen District Office has therefore published a fact sheet about the quagga mussel, its effects, and how each individual can help prevent it from establishing itself in other bodies of water.

The quagga zebra mussel (Dreissena rostriformis bugensis) is native to the Danube River estuary where it flows into the Black Sea. It can spread rapidly in new bodies of water and reach high population densities there. It spreads primarily through planktonic larvae that enter the water. Boats, water sports equipment, and swimwear—which may carry mussels or larvae—play a significant role in its spread.

The impact on the affected bodies of water can be significant. As a filter feeder, the quagga mussel removes suspended food particles from the water and can thereby significantly disrupt food chains within the ecosystem. Native species, particularly other mussels, may be displaced. In addition, large numbers of these mussels can, for example, clog water pipes or block the engine cooling systems of boats.

Everyone can help contain the spread

The best way to prevent further spread is to avoid transporting the mussel and its larvae between different bodies of water.

Anyone who uses boats, water sports equipment, trailers, or other gear in different bodies of water should therefore inspect them carefully, completely remove any residual water, clean the equipment, and then allow it to dry thoroughly. If cleaning and drying are not possible, disinfection may be necessary.

The District Office therefore asks all water sports enthusiasts, as well as owners of boats and other watercraft, to consistently follow the appropriate safety precautions.

The County Administrative Office provides further information and specific guidance on the proper procedure in its fact sheet on the quagga mussel .

Background:
The quagga mussel (Dreissena rostriformis bugensis) is an invasive alien species. Once it has colonized a body of water, it is generally very difficult to reverse its spread. This makes preventive measures and the avoidance of unintentional transport between bodies of water all the more important.

Sabine Schmid
Press spokeswoman
Bad Tölz-Wolfratshausen District Office