Environment Central Switzerland: No new evidence of invasive quagga mussels
There have been no new detections of invasive quagga mussels in the lakes of Central Switzerland. As already known, quagga mussels are found in Lake Zug and Lake Lucerne. They were not detected in the other lakes surveyed.
17.10.2024, 08:00
SDA
The mussels were first detected in Lake Zug, Lake Alpnach and Lake Zurich in the summer of 2024, as the environmental offices of the cantons of Obwalden, Schwyz, Uri and Zug announced on Thursday. In order to clarify the situation in the other lakes in Central Switzerland, they took so-called environmental DNA samples using water samples.
These DNA samples allow the species present in a lake to be identified. The method is particularly suitable for invasive species. The advantage is the simple and environmentally friendly collection.
However, environmental DNA samples only allow conclusions to be drawn about the size and age of the organisms present, not their abundance, as the cantons working together in the Central Switzerland Environment Organization wrote. Another disadvantage is that the method does not provide clear evidence of the absence of a species.
Smaller lakes in Central Switzerland free of quagga
The water samples were analyzed by the Zurich water supply laboratory. There was no evidence of quagga mussels in Lakes Aegeri, Sempach, Baldegg, Rot, Lauerz, Sihl, Wägital, Hirschlen, Lungerer and Sarnen. However, the presence of mussels in Lakes Zug and Lucerne was confirmed.
For the cantons of Central Switzerland, the findings show the importance of suitable measures to protect the lakes that are still free of quagga mussels from the invaders.
Since August and September, the cantons of Bern, Lucerne, Zug, Schwyz, Uri, Obwalden and Nidwalden have made it compulsory to report and clean ships. Watercraft may only enter a new body of water if they have been professionally cleaned by an authorized company.
The quagga mussel originally comes from the Black Sea. Since it was first recorded in Switzerland in 2014, it has settled in Lakes Geneva, Neuchâtel, Biel and Constance. The mussel greatly alters the species composition and severely damages the aquatic ecosystem.
It also severely damages infrastructure such as drinking water supplies, heating systems and pipes. Their microscopic larvae get into pipes, settle there and clog them up over time.
