Navigation Invasive quagga mussel infesting Lakes Alpnach and Zug

The invasive alien quagga mussel has infested Lakes Alpnach and Zug. It is still unclear whether Lake Aegeri is also affected.

Despite preventive measures, divers discovered the quagga mussel in Lake Zug at the beginning of July, as the canton of Zug announced on Tuesday. The mussel was also found in Lake Alpnach at almost the same time. As samples from Lake Aegeri yielded unclear results, there is currently hope that it is not infested. The situation will continue to be monitored.

DNA traces taken from Lakes Zug and Alpnach indicate an infestation of the lakes for the first time, it was reported. The aquatic research institute Eawag commissioned a systematic search for the quagga mussel using sediment samples. However, the divers discovered the mussel before the investigations could begin.

In summer 2023, the canton of Zug introduced mandatory boat cleaning as a preventive measure. In April 2024, the government imposed a one-year ban on the launching of boats not registered in the canton in Zug waters. The canton of Schwyz followed suit at the end of May.

The Obwalden government is now following suit and banning the launching of boats from outside the canton on Lake Sarnen, Lake Lungern and Lake Melch, as announced by the Lake Lucerne Supervisory Commission on Tuesday. In addition, from August, all cantons in Central Switzerland will be required to report and clean ships.

Quagga mussels can have a major negative impact on the aquatic ecosystem, fisheries and infrastructure facilities, according to the statement. They impoverish habitats and clog up lake water intakes. The mussel originally comes from the Black Sea region, but is spreading rapidly due to so-called "migratory boats".

The quagga mussel has already been detected in Lake Geneva and Lake Constance. Accumulations of up to 25,000 mussels per square meter have been found there.

SDA